Some pierced primers with new Lapua 223 brass

[jlorenzo]

I bought my first box of Lapua to try. Read enough that you can just load them and shoot. Against my better judgment I did load them without doing anything to the brass. 24gr of Varget (I though was standard not crazy high pressure) which is at least a 4-5 years old out of an opened 8# jug. 77gr SMKs at 2.395 COAL 1.985 CBTO. CCI 400s.
Got either pierced primers or badly cratered. Will post pics soon.

I checked the brass before hand to see if it would chamber in my gun and every piece I tried did, maybe 10 pieces. They did have different case head to shoulder datum measurements but I didn't think it would matter as I just wanted them fireformed.

I'm realizing now I may have also been slightly into the lands. The 77s ogive doesn't allow for as long a COAL as something like an ELD, this combined with the dry Varget and an 80 degree day I think may have been my problem. Also the bullets didn't seat smoothly having not champfered the case mouths (I new I should've but wanted to see if I could just load the new brass). I think I may have had excess neck tension as well.

I have been shooting LC and Winchester exclusively in this gun without any issues, much hotter loads than this also. 24.5gr of 8208 XBR w/75gr ELDs is on the lower side of that node, 80.5gr Bergers with 25gr of N140 also shot well and was on the lower side of the node. I like to load on the lower side so I have some wiggle room on warmer days.

I pulled the bullets, sized and decapped, reprimed, loaded 23.5gr of Varget (I forgot how much this stuff sucks to work with), and loaded to 2.375 COAL or 1.966 CBTO to make sure I'm not in the lands.

I have tested 88gr ELDs with a new lot of Varget and got passed 24gr without seeing any pressure.

Any thoughts as to what might be going on? Ive never had a pierced primer ever before.
Some on another forum are telling me the CCI 400 is "too soft", which I doubt because I have shot 24gr of Varget behind 77s in a gas gun with CCI 400s at 2.25" COAL.

This is a Tikka T3x action, 26" Bartlein M24 profile, not sure of the chamber as I bought the gun used. It shoots amazingly well and this is the first problem Ive had with it, hundreds of rounds with LC or Winchester without any issue. My CBTO with 75gr ELD is 1.963 CBTO, that was .030" back from jam using my micrometer seating die. Finding the jam using the Erik Cortina method, which I'm finding myself still in the lands after backing of .020-030".

*I am using a Hornady custom FL sizing die and do not yet have a mandrel die, can't figure out which way to go on those. I bump the should .020-.025" in my bolt gun.

 

[jlorenzo]

No ejector spots either. A burr on the rims of a couple of them though. I thought I was being conservative with 24gr of Varget

 

[tommeboy]

CCI 400's are meant for 22 hornet and 30 carbine NOT 223. You just found out why.

 

[Jon D]

Sierras stated max for a bolt gun is 22.1 grs with the 77 and varget. Starting way above max isn't a good practice. I've had chambers where 24 gr's of varget was fine and some that it was not. The internet is full of half truths.

Pick up a reloading manual, start low and work up any new combination.

Try a 41, br4, 450, rem 7-1/2, or fed ar gold medal. These are tougher primers. Some of these primers will increase or decrease pressure more than others. Again, start low and use a chronograph if you have one.

 

[fkimble@charter.net]

Different brands of brass can have different powder capacity. Was this a new gun you'd never loaded for? If you change any component always drop the powder charge and work back up. Pierced and/or cratered primers is not usually a brass problem. Oversized firing pin hole will cause craters all day even with a mild load. Wrong primers will crater and or pierce easily. Not sure what you think brass prep would have done to help. Loading into lands will raise pressure every time. So wrong primer, bullets seated too long and no "start low and work up". All rookie loading errs. Some times you can get away with one or two but three is a stacked deck against you. All Lapua brass needs is a slight inside mouth chamfer and run a mandrell thru to open up a usually too tight inside diameter.

Frank

 

[Walt Krafft]

I have shot thousands of 77s with 24.3 Varget at mag length. It is the primer giving you problems. Stop using them now or you will soon need a new bolt and firing pin.

 

[Laurie]

Current Lapua 223 holds around 30.5gn water firefomed which is a bit less than R-P, LC, or Winchester and yes, this does raise pressures noticeably in such a small case cartridge. Seating the SMKs into the lands as you did probably had a significantly greater effect - this really does push pressures up.

When people say you can 'use Lapua brass straight out of the box', that's got to be qualified by the need to inside-chamfer case-mouths. The phrase means that Lapua consistency is such that weight batching, neck thickness measuring, flash-hole deburring and other tricks of 'accuracy' case preparation can be largely dispensed with for most applications. They also tend to have marginally undersize necks out of the box giving a lot of neck tension unless run over a lubed expander ball or mandrel.

The CCI-400 is a very weak-cup model. It and the Rem 6 1/2 should only be used in 223 with light loads. This pair have 20 thou' cup thickness while the CCI-450, Rem 7 1/2 and most others use 25 thou' and probably a harder brass grade with it. What then happens with the CCI-400 depends partly on maximum pressures, partly on the firing pin tip fit in the bolt-face. Slackness there sees cratering start earlier and progress faster leading to 'blanking' where the cup fails usually blowing a small disk back into the bolt body which can affect primer strike and gun operation / reliability.

 

[SKWERLZ]

In 223 i only run #400’s in light pew pew ammo.
They are pretty fragile compared to 450’s, 7 1/2 and few other primers.

 

[243winxb]

Drop to 21 grs

 

[Ned Ludd]

I have known a couple .223 Rem F-TR shooters using either a Savage or Remy 700-based action that started getting pierced primers. In both cases, the loads were not "hot". In both cases, having the firing pin hole bushed and the pin turned down was one option to help solve the issue (i.e. both of these rifles are known to have larger-than-necessary firing pin hole diameter, which is often associated with pierced primer issues). In talking with them, I found out both had been using CCI 400 primers. In their specific examples, making a switch to Fed 205 SRPs completely solved the issue. Switching to CCI 450s, or some other SRP with a harder/thicker cup would have likely also achieved the same goal.

I don't recall ever coming across statements to the effect that Tikka action firing pin diameters or firing pin holes are on the large side, but just because I haven't come across that info previously doesn't mean it couldn't be the case. IMO - pierced primers are really bad news. All sorts of things can happen inside an action when the super-hot gas comes spewing out through a pierced primer; most of them are not good. I mention this because the firing pin marks on the primers in your image look to be on the large side to me. However, it may just be an optical illusion from the image. The good news is that that trying a primer with a harder/thicker cup first is the easy road. If that solves the issue, all is good. If not, there are other approaches such as having the firing pin hole bushed that may do the trick.

With regard to prepping virgin Lapua brass, I have also loaded them straight out of the box. The results were less than satisfactory in my hands. Case neck measurements and seating force quickly enlightened me that neck tension (interference fit) within the various Lot #s of Lapua .223 Rem brass I have gone through is not as uniform as I would like it to be. In fact, neck diameter in certain Lot #s was all over the map. So I found that running virgin Lapua brass through a sizing die with the appropriate bushing diameter, usually a 0.246" or 0.247" bushing, followed by a final neck-sizing step with a 0.2225" mandrel gave much better results; achieving very close to .002" neck tension. So good in fact, I have used prepped virgin Lapua brass in quite a few F-TR matches. In my hands with the proper preparation, virgin brass can shoot almost as well as fire-formed. One critical difference is that running virgin cases through a bushing die will not bump the shoulder at all if the die has been properly set. In other words, the cartridge base-to-shoulder (CBTS) measurement of virgin brass remains the same after being prepped, while neck tension is markedly improved. This can leave sufficient case head clearance that promotes the occurrence of blown primers in virgin brass, even with loads that are not "hot". Once the cases have been expanded to fit the chamber and sized back down only ~.002" at the shoulder, this issue disappears. So I don't run "full pressure" loads in prepped virgin brass. In my hands, once you've popped a primer in .223 Rem brass, the primer pocket is done. So basically a blown primer means a trashed case. My .223 Rem brass seems to do a little better if I use a slightly reduced load for the first firing, never allowing the opportunity for the increased headspace to allow blown primers. I mention this because in the last sentence of your OP, you stated:

"*I am using a Hornady custom FL sizing die and do not yet have a mandrel die, can't figure out which way to go on those. I bump the should .020-.025" in my bolt gun."

I am hoping that is simply a misplaced decimal point and you meant you are bumping the shoulders about .002" to .0025". As I noted above, virgin Lapua brass at the shoulder is already short (CBTS) relative to my chambers as compared with some other brands of brass, which can increase the odds of blown primers on the first firing. There are different methods you can use in order to set the shoulder bump with a new die. I prefer to obtain a few cases fired with [safely] reduced loads and work with those. I typically use a reduced load and fire about 10 rounds to obtain an average velocity for use in "calibrating" QuickLoad, so that brass works well to satisfy both needs at the same time (i.e. for calibrating QL as well as setting up a new re-sizing die). Typically, such loads are predicted to be running somewhere in the 40-45K psi range, which is sufficient to expand the brass, but not so high as to possibly cause blown primers in virgin brass. If you decide to give the mandrel approach a try, these are what I use:

Expander Die Body

21stcenturyinnovation.com

Caliber Specific Expander Mandrel Kits

Our caliber specific expander mandrels are available in .0005” increments in calibers 22 to 338 and will range from .001” above bullet diameter to at least .003” below bullet diameter depending on caliber. This will allow the reloader to find proper neck tension to fine-tune their loads. The...

21stcenturyinnovation.com

In the grand scheme of things, a mandrel and die are relatively inexpensive tools that can be very useful, and additional diameter mandrels added over time as needed. Initially, I did all my brass sizing with a bushing die. Eventually, I discovered that using a mandrel as the final sizing step gave me a slightly better and more consistent neck diameter and neck tension than a bushing die alone, likely because I don't turn necks. The difference between the two isn't huge in my hands, but enough to tell that there is a slight difference. Again, the use of mandrels isn't absolutely essential, so you can decide over time whether you wish to go that route. The primary downside to using both a bushing die and a mandrel as sizing steps is that you're basically doing twice the amount work re-sizing the brass as with a bushing die alone. So it takes a bit longer, but I have been very pleased with the results after making the decision to do both steps.

 

[jlorenzo]

I have known a couple .223 Rem F-TR shooters using either a Savage or Remy 700-based action that started getting pierced primers. In both cases, the loads were not "hot". In both cases, having the firing pin hole bushed and the pin turned down was one option to help solve the issue (i.e. both of these rifles are known to have larger-than-necessary firing pin hole diameter, which is often associated with pierced primer issues). In talking with them, I found out both had been using CCI 400 primers. In their specific examples, making a switch to Fed 205 SRPs completely solved the issue. Switching to CCI 450s, or some other SRP with a harder/thicker cup would have likely also achieved the same goal.

I don't recall ever coming across statements to the effect that Tikka action firing pin diameters or firing pin holes are on the large side, but just because I haven't come across that info previously doesn't mean it couldn't be the case. IMO - pierced primers are really bad news. All sorts of things can happen inside an action when the super-hot gas comes spewing out through a pierced primer; most of them are not good. I mention this because the firing pin marks on the primers in your image look to be on the large side to me. However, it may just be an optical illusion from the image. The good news is that that trying a primer with a harder/thicker cup first is the easy road. If that solves the issue, all is good. If not, there are other approaches such as having the firing pin hole bushed that may do the trick.

With regard to prepping virgin Lapua brass, I have also loaded them straight out of the box. The results were less than satisfactory in my hands. Case neck measurements and seating force quickly enlightened me that neck tension (interference fit) within the various Lot #s of Lapua .223 Rem brass I have gone through is not as uniform as I would like it to be. In fact, neck diameter in certain Lot #s was all over the map. So I found that running virgin Lapua brass through a sizing die with the appropriate bushing diameter, usually a 0.246" or 0.247" bushing, followed by a final neck-sizing step with a 0.2225" mandrel gave much better results; achieving very close to .002" neck tension. So good in fact, I have used prepped virgin Lapua brass in quite a few F-TR matches. In my hands with the proper preparation, virgin brass can shoot almost as well as fire-formed. One critical difference is that running virgin cases through a bushing die will not bump the shoulder at all if the die has been properly set. In other words, the cartridge base-to-shoulder (CBTS) measurement of virgin brass remains the same after being prepped, while neck tension is markedly improved. This can leave sufficient case head clearance that promotes the occurrence of blown primers in virgin brass, even with loads that are not "hot". Once the cases have been expanded to fit the chamber and sized back down only ~.002" at the shoulder, this issue disappears. So I don't run "full pressure" loads in prepped virgin brass. In my hands, once you've popped a primer in .223 Rem brass, the primer pocket is done. So basically a blown primer means a trashed case. My .223 Rem brass seems to do a little better if I use a slightly reduced load for the first firing, never allowing the opportunity for the increased headspace to allow blown primers. I mention this because in the last sentence of your OP, you stated:

"*I am using a Hornady custom FL sizing die and do not yet have a mandrel die, can't figure out which way to go on those. I bump the should .020-.025" in my bolt gun."

I am hoping that is simply a misplaced decimal point and you meant you are bumping the shoulders about .002" to .0025". As I noted above, virgin Lapua brass at the shoulder is already short (CBTS) relative to my chambers as compared with some other brands of brass, which can increase the odds of blown primers on the first firing. There are different methods you can use in order to set the shoulder bump with a new die. I prefer to obtain a few cases fired with [safely] reduced loads and work with those. I typically use a reduced load and fire about 10 rounds to obtain an average velocity for use in "calibrating" QuickLoad, so that brass works well to satisfy both needs at the same time (i.e. for calibrating QL as well as setting up a new re-sizing die). Typically, such loads are predicted to be running somewhere in the 40-45K psi range, which is sufficient to expand the brass, but not so high as to possibly cause blown primers in virgin brass. If you decide to give the mandrel approach a try, these are what I use:

Expander Die Body

21stcenturyinnovation.com

Caliber Specific Expander Mandrel Kits

Our caliber specific expander mandrels are available in .0005” increments in calibers 22 to 338 and will range from .001” above bullet diameter to at least .003” below bullet diameter depending on caliber. This will allow the reloader to find proper neck tension to fine-tune their loads. The...

21stcenturyinnovation.com

In the grand scheme of things, a mandrel and die are relatively inexpensive tools that can be very useful, and additional diameter mandrels added over time as needed. Initially, I did all my brass sizing with a bushing die. Eventually, I discovered that using a mandrel as the final sizing step gave me a slightly better and more consistent neck diameter and neck tension than a bushing die alone, likely because I don't turn necks. The difference between the two isn't huge in my hands, but enough to tell that there is a slight difference. Again, the use of mandrels isn't absolutely essential, so you can decide over time whether you wish to go that route. The primary downside to using both a bushing die and a mandrel as sizing steps is that you're basically doing twice the amount work re-sizing the brass as with a bushing die alone. So it takes a bit longer, but I have been very pleased with the results after making the decision to do both steps.

Thanks for the post, yes my decimal point is in the wrong place.
Would you go with a FL sizing die with the decap and expander ball removed and a mandrel or just a bushing die if it came down to those? Trying to plan out my next move and far as dies and brass sizing.

I am thinking I could pull the decap pin and expander out of my Hornady FL die and then use a mandrel to set final neck tension? My FL die is sizing the neck down considerably I assume before the expander ball pulls back out?

 

[Ned Ludd]

I remove the decapping pins/expander balls on all my Redding Type S dies. It may not be the same with all the die expander ball setups available from various manufacturers, but with the ones I have there is a tendency of the expander ball to induce runout. I have not noticed runout to be any issue whatsoever when using a mandrel, presumably because there are differences between how the two work (i.e. pushing a mandrel down into the case neck rather than pulling an expander ball out through the case neck). Regardless, if you plan to use a mandrel as the final neck-sizing step, there is really no reason to use an expander ball that may or may not be the correct diameter for you intended application. Plus, that would also be working the brass a little more than necessary.

FWIW - I use a Harvey hand de-capping tool to remove spent primers. This is solely because I do not like to be tied to the reloading bench (i.e. using the press) when decapping brass. I can decap as many cases as I want with the Harvey tool while sitting on the couch watching TV. So removal of the decapping pin/expander ball from the dies has never been an issue for me with regard to decapping cases. If you wish to try a bushing die/mandrel-based procedure, you will want to remove the expander ball because it will likely interfere with the entire process. When using a mandrel when using a mandrel as the last sizing step, I typically use a bushing that is .001" to .002" smaller than I would use if the bushing die were to be the sole neck-sizing step. That way, I am sure the mandrel is actually doing some work on the necks and opening them up slightly to all the same diameter. If the selected bushing leaves the necks very close in diameter to what the mandrel will size them, I find the final neck diameter/neck tension variance is greater, as though the mandrel din't work as efficiently on all the cases.

When using a bushing die to size necks, spring-back of the brass when the case is withdrawn from the bushing die causes the neck to open up ever so slightly after being squeezed down by the bushing. When using a mandrel to open necks up from the inside, the spring-back works in the opposite direction. In other words, the necks will close up ever so slightly as the mandrel is withdrawn. For that reason, a mandrel that is .0015" under bullet diameter will typically give very close to .002" neck tension. Because all mandrels may not be made to the same tolerances (like bushings), having a range of sizes can be useful. However, even with only one you can simply take a few measurements to determine exactly to what diameter the mandrel is opening/sizing the necks, then choose a bushing you know will size the necks down to at least .001" below that value.

As an example, my .308 Win chambers are .342" (no-turn) in the neck dimension. Fired cases consistently have neck diameters of 0.3415" to 0.3420". When I first started reloading, I found that a 0.336" bushing routinely gave a final neck diameter of within about .0005" of the desired 0.336" diameter (bushings are not always equal in terms the final neck diameter, regardless of the bushing diameter printed on the package). After seating bullets, the neck diameter would be 0.338", leaving ~.002" clearance per side in a 0.342" neck chamber. When adding a mandrel step to the process, I found that I need to use a 0.335" or 0.334" bushing (rather than 0.336") so that the 0.3065" mandrel would open them all up with optimal uniformity, very close to 0.336" final OD. As with everything, this needs to be checked via measurements with the actual bushings/mandrels to be used as the manufacturer's tolerances are not zero. But it's pretty easy to figure out with a few measurements.

The use of mandrels is probably one of those things that fall into the category of "limited potential returns". As I mentioned previously, I believe from both measurements and seating force that the use of a mandrel as the final neck-sizing step has generated slightly better consistency than a bushing die alone in my hands. But it is not a HUGE improvement, only a small one. So the inherent precision to which the setup itself is capable, the shooter, and the shooter's personal precision needs/requirements would all certainly come into play when trying to decide whether adding a mandrel step to the reloading process would be of noticeable benefit, or provide dividends in terms of the added expense and effort it entails. I can't really answer those questions for someone else, only myself. However, the one thing I can state with reasonable certainty is that adding a mandrel sizing step should never cause the consistency of neck tension to become worse if it is done properly. So for anyone that decides to try out a mandrel sizing step, it primarily involves the cost of a die and mandrel, and the extra time to carry out the additional sizing step, which are fairly minor considerations, IMO.

 

[Mike F H]

I am a bit late here,however there are two things causing the problem,soft primer cups as others have mentioned and headspace.Ned has nailed the matter of headspace with new Lapua cases and a milder first firing will sort it out.Checking new unfired cases with a headspace comparator will show that they are not all the same length and as a result some will have greater headspace before firing.

 

[ta6ppc]

I bought my first box of Lapua to try. Read enough that you can just load them and shoot. Against my better judgment I did load them without doing anything to the brass. 24gr of Varget (I though was standard not crazy high pressure) which is at least a 4-5 years old out of an opened 8# jug. 77gr SMKs at 2.395 COAL 1.985 CBTO. CCI 400s.
Got either pierced primers or badly cratered. Will post pics soon.

I checked the brass before hand to see if it would chamber in my gun and every piece I tried did, maybe 10 pieces. They did have different case head to shoulder datum measurements but I didn't think it would matter as I just wanted them fireformed.

I'm realizing now I may have also been slightly into the lands. The 77s ogive doesn't allow for as long a COAL as something like an ELD, this combined with the dry Varget and an 80 degree day I think may have been my problem. Also the bullets didn't seat smoothly having not champfered the case mouths (I new I should've but wanted to see if I could just load the new brass). I think I may have had excess neck tension as well.

I have been shooting LC and Winchester exclusively in this gun without any issues, much hotter loads than this also. 24.5gr of 8208 XBR w/75gr ELDs is on the lower side of that node, 80.5gr Bergers with 25gr of N140 also shot well and was on the lower side of the node. I like to load on the lower side so I have some wiggle room on warmer days.

I pulled the bullets, sized and decapped, reprimed, loaded 23.5gr of Varget (I forgot how much this stuff sucks to work with), and loaded to 2.375 COAL or 1.966 CBTO to make sure I'm not in the lands.

I have tested 88gr ELDs with a new lot of Varget and got passed 24gr without seeing any pressure.

Any thoughts as to what might be going on? Ive never had a pierced primer ever before.
Some on another forum are telling me the CCI 400 is "too soft", which I doubt because I have shot 24gr of Varget behind 77s in a gas gun with CCI 400s at 2.25" COAL.

This is a Tikka T3x action, 26" Bartlein M24 profile, not sure of the chamber as I bought the gun used. It shoots amazingly well and this is the first problem Ive had with it, hundreds of rounds with LC or Winchester without any issue. My CBTO with 75gr ELD is 1.963 CBTO, that was .030" back from jam using my micrometer seating die. Finding the jam using the Erik Cortina method, which I'm finding myself still in the lands after backing of .020-030".

*I am using a Hornady custom FL sizing die and do not yet have a mandrel die, can't figure out which way to go on those. I bump the should .020-.025" in my bolt gun.

I can’t get that much varget in the case with a 77 in Lapua brass in fact I kinda pegged out pressure wise at 24.3 varget with a 69 smk.

I have shot both cci 400 and 450’s and haven’t had a pierced primer yet.

I am shooting a 27” Bartlien on a defiance action 7 twist.

 

[Walt Krafft]

I can’t get that much varget in the case with a 77 in Lapua brass in fact I kinda pegged out pressure wise at 24.3 varget with a 69 smk.

I have shot both cci 400 and 450’s and haven’t had a pierced primer yet.

I am shooting a 27” Bartlien on a defiance action 7 twist.

There are a LOT of different 223 chambers. What chamber you have and what overall length your loads are can greatly effect pressure.

 

[ta6ppc]

There are a LOT of different 223 chambers. What chamber you have and what overall length your loads are can greatly effect pressure.

Standard sammi spec chamber im shooting the 77 and 69 smk mag length

 

[Laurie]

I can’t get that much varget in the case with a 77 in Lapua brass in fact I kinda pegged out pressure wise at 24.3 varget with a 69 smk.

Compressed loads are common with heavier bullets seated to the 2.26" SAAMI COAL. It's important to measure resulting COALs to ensure that heavy compression hasn't pushed the bullet back out a bit after seating, and sometimes to check again before use as such push-back may only affect COAL over subsequent hours / days. At best, over-length rounds cause problems with magazine fit / feed; at worst they can see the bullet pushed into the lands on the short-freebore SAAMI chamber producing a pressure-spike.

Answers? You have a choice of:

1) Get a funnel with a drop-tube. There is an MTM kit with a (IIRC) 4-inch tube and Forster does a neat if pricey universal calibre job with a small dia. 5.5-inch tube. I like the latter and it's often invaluable on 223. Use a slow trickle pour from the scale pan, angle the case / funnel slightly and pour from the side to get a 'swirl motion' like water going down a drain. The pour method and drop-tube improve powder settling so you get more into the same space. With some extruded powders, 223 charges can be increased by a grain in this cartridge.

2) Use roomier brass. Lapua is very well made and strong but has a lower capacity than many makes. Have a look at the weight / water capacity table here:

https://www.accurateshooter.com/cartridge-guides/223rem/

It's still useful, even though very old and a bit out of date. Note the government Lake City Arsenal case at the top, one of the reasons that this make is popular.

3) Change powder to a higher density product and/or faster burner that utilises smaller charges. eg replace VarGet with Alliant AR-Comp or a dense ball powder such as Ramshot TAC or Shooters World 'Match'.

4) Simply limit loads to what the case will comfortably hold even if it sees MVs down a bit. Does your present maximum shoot well? In any event at 24.3gn VarGet with a 77 in the SAAMI chamber, you're over book max charge. Hodgdon quotes 23.7gn maximum (compressed) for the 77gn SMK at 2.26" in Winchester brass. As Lapua cases are lower capacity than Win, this increases pressures for any charge weight, so you are even more over the powder manufacturer's maximum charge weight. I'm not surprised you're seeing pressure!

 

[SKWERLZ]

I have known a couple .223 Rem F-TR shooters using either a Savage or Remy 700-based action that started getting pierced primers. In both cases, the loads were not "hot". In both cases, having the firing pin hole bushed and the pin turned down was one option to help solve the issue (i.e. both of these rifles are known to have larger-than-necessary firing pin hole diameter, which is often associated with pierced primer issues). In talking with them, I found out both had been using CCI 400 primers. In their specific examples, making a switch to Fed 205 SRPs completely solved the issue. Switching to CCI 450s, or some other SRP with a harder/thicker cup would have likely also achieved the same goal.

I don't recall ever coming across statements to the effect that Tikka action firing pin diameters or firing pin holes are on the large side, but just because I haven't come across that info previously doesn't mean it couldn't be the case. IMO - pierced primers are really bad news. All sorts of things can happen inside an action when the super-hot gas comes spewing out through a pierced primer; most of them are not good. I mention this because the firing pin marks on the primers in your image look to be on the large side to me. However, it may just be an optical illusion from the image. The good news is that that trying a primer with a harder/thicker cup first is the easy road. If that solves the issue, all is good. If not, there are other approaches such as having the firing pin hole bushed that may do the trick.

With regard to prepping virgin Lapua brass, I have also loaded them straight out of the box. The results were less than satisfactory in my hands. Case neck measurements and seating force quickly enlightened me that neck tension (interference fit) within the various Lot #s of Lapua .223 Rem brass I have gone through is not as uniform as I would like it to be. In fact, neck diameter in certain Lot #s was all over the map. So I found that running virgin Lapua brass through a sizing die with the appropriate bushing diameter, usually a 0.246" or 0.247" bushing, followed by a final neck-sizing step with a 0.2225" mandrel gave much better results; achieving very close to .002" neck tension. So good in fact, I have used prepped virgin Lapua brass in quite a few F-TR matches. In my hands with the proper preparation, virgin brass can shoot almost as well as fire-formed. One critical difference is that running virgin cases through a bushing die will not bump the shoulder at all if the die has been properly set. In other words, the cartridge base-to-shoulder (CBTS) measurement of virgin brass remains the same after being prepped, while neck tension is markedly improved. This can leave sufficient case head clearance that promotes the occurrence of blown primers in virgin brass, even with loads that are not "hot". Once the cases have been expanded to fit the chamber and sized back down only ~.002" at the shoulder, this issue disappears. So I don't run "full pressure" loads in prepped virgin brass. In my hands, once you've popped a primer in .223 Rem brass, the primer pocket is done. So basically a blown primer means a trashed case. My .223 Rem brass seems to do a little better if I use a slightly reduced load for the first firing, never allowing the opportunity for the increased headspace to allow blown primers. I mention this because in the last sentence of your OP, you stated:

"*I am using a Hornady custom FL sizing die and do not yet have a mandrel die, can't figure out which way to go on those. I bump the should .020-.025" in my bolt gun."

I am hoping that is simply a misplaced decimal point and you meant you are bumping the shoulders about .002" to .0025". As I noted above, virgin Lapua brass at the shoulder is already short (CBTS) relative to my chambers as compared with some other brands of brass, which can increase the odds of blown primers on the first firing. There are different methods you can use in order to set the shoulder bump with a new die. I prefer to obtain a few cases fired with [safely] reduced loads and work with those. I typically use a reduced load and fire about 10 rounds to obtain an average velocity for use in "calibrating" QuickLoad, so that brass works well to satisfy both needs at the same time (i.e. for calibrating QL as well as setting up a new re-sizing die). Typically, such loads are predicted to be running somewhere in the 40-45K psi range, which is sufficient to expand the brass, but not so high as to possibly cause blown primers in virgin brass. If you decide to give the mandrel approach a try, these are what I use:

Expander Die Body

21stcenturyinnovation.com

Caliber Specific Expander Mandrel Kits

Our caliber specific expander mandrels are available in .0005” increments in calibers 22 to 338 and will range from .001” above bullet diameter to at least .003” below bullet diameter depending on caliber. This will allow the reloader to find proper neck tension to fine-tune their loads. The...

21stcenturyinnovation.com

In the grand scheme of things, a mandrel and die are relatively inexpensive tools that can be very useful, and additional diameter mandrels added over time as needed. Initially, I did all my brass sizing with a bushing die. Eventually, I discovered that using a mandrel as the final sizing step gave me a slightly better and more consistent neck diameter and neck tension than a bushing die alone, likely because I don't turn necks. The difference between the two isn't huge in my hands, but enough to tell that there is a slight difference. Again, the use of mandrels isn't absolutely essential, so you can decide over time whether you wish to go that route. The primary downside to using both a bushing die and a mandrel as sizing steps is that you're basically doing twice the amount work re-sizing the brass as with a bushing die alone. So it takes a bit longer, but I have been very pleased with the results after making the decision to do both steps.

Yea, you add thin cup to a sloppy boltface common to production rifles and your asking for it.

 

[searcher]

When you said you didn't do any brass prep - did that include not sizing the brass? Sizing it lengthens the brass and more or less brings the headspace to closer to where it should be - or at least close enough to not have the presence of "overly excessive" headspace. Could be you did have excessive headspace (unless you know better as having measured it) and the brass slamming back onto that firing pin with what are normally thought of as a thinner primers could certainly cause that, even if not a hot load. Lapua is not immune to quality control issues - but I'd bet against such issues in this situation.

 

[mgdietrich]

Lapua has way less capacity than LC brass. Drop your powder charge .5 grain or more.