Norma 223 very short life?

[JPB4BAMA]

Wondering if anyone else has seen this. I've just competed the fourth firing of a round of 223 Norma bought right before the shortage from Midsouth. First firing was fire forming to 223 AI, with 22gr RL15 under Sierra 90 gr Moly Coated SMK. Last three were 24.0 Gr Varget with Hornady 88 ELDM, Federal 205M. After the last firing upon inspection I see distinct signs of case separation on 4 of 75 pieces. All brass was annealed prior to F/L sizing with 0.002 bump in Redding Type S die. Never saw any signs of pressure, Quick Load gives me an expected pressure of 44.7 kpsi at the observed 2640 MV. So I know Norma is a very reputable brand, but just wondering if others have seen this, or is it possible that the bulk stuff was "seconds". It shot great, but at only four hits after Fire forming at this milder load I'm wondering about it. Same Load in Lapua is pushing 25 Loadings and still going strong. One reason I tried this was to keep my brass discrete for the two rifles chambered the same.

 

[Nowhere Man]

My buddy loads 223/90grn bergers into the lands with lapua brass and only gets 3-4 reloads before the primers fall out.

 

[JPB4BAMA]

Pockets were a bit looser than when new but still snug, so that was not too good either, but I figgures they would last about 8 or ten from that perspective, But head separation this early is what is bothering me,

 

[XTR]

Bolt gun or AR?

Are you certain of the shoulder bump? Case head separation in almost every instance I’ve seen has to do with either gas guns that are hard on brass or brass that is stretching in the chamber, either multiple chambers or it’s being pushed back too far.

 

[JPB4BAMA]

Its a custom bolt gun, and cut with the same reamer as my other one that I shoot Lapua in. And yes I am certain on the bump, 0.002 +/- the ).0005 precision on the caliper. And then just to make sure I check in the actual chamber with the bolt guts removed.
Now, what I don't know is on the initial fire forming if the std 223 case was such that it started the tensile stress failure???, But since firing #1 every case checked for headspace with a comparator cut from the same reamer as the chanber, thus my concern.

 

[6bra1k]

let me ask an out of left field question
did norma make the brass ?
(this is based on past history where known brass makers sub contracted brass that was thought to not be a "target" round. real crappy reviews from users. in the case of lapua 223 it really was trash. i know, i have some 223 rem and some MATCH..a big difference.
just because it has there name does not mean they made it or that it is MATCH standards)
and second question, why .002, why not .001 ??

 

[Bill K]

Make of brass will not matter, if you are showing signs of case separations, then you are having pressure issues or headspace issues. And when primer pockets start opening, as some mention, then that is a sign of high pressure. Anneal, FL size, trim to proper length and use a lower powder charge, for your rifle.

 

[6bra1k]

yes the maker and quality of the brass does matter...poor brass is just that poor brass.
to say it does not matter is showing a lack of clarity..nuff said

 

[JPB4BAMA]

let me ask an out of left field question
did norma make the brass ?
(this is based on past history where known brass makers sub contracted brass that was thought to not be a "target" round. real crappy reviews from users. in the case of lapua 223 it really was trash. i know, i have some 223 rem and some MATCH..a big difference.
just because it has there name does not mean they made it or that it is MATCH standards)
and second question, why .002, why not .001 ??

I really have no idea who the actual manufacturer is, just "relying" on the advertisement and headstamp. It was a shot in the dark. With that said I have had not so pleasant results with NORMA mfg brass in the past. To elaborate about 5 years ago when I was first starting to get back into shooting after a very long hiatus I was lulled into the 6.5 Creedmore craze. Wanting to have my cake and eat it too, I tried some PRIME ammo 6.5 that was loaded into NORMA brass, thinking I would practice with the factory loads and have good brass left over for about the price of decent virgin brass. Well, over 50% lost the primer pockets on the first (factory load) firing. Further investigation and discussion with a very high quality brass maker in PA, revealed that Norma was using a higher Cu content brass rather than the standard "cartridge" brass used by others. This was actually confirmed on those cases, first by the visually more red/copper colour of the case as compared to theirs. I also had a piece of the brass analyzed and it was in fact roughly 80/20 Cu/Zn with a few other trace elements. That said the current 223 brass does not have the same distinct colour difference and I no longer have the ability to have it analyzed so I assume it is standard cartridge brass.

Concerning the 0.002 bump - well its sort of in the middle of the tolerance, but mostly I got that advice from several others that are a whole hell of a lot better shooters than I am, and in general I find that most really good guys (not the internet snipers) are very interested in helping and giving good advice to help the sport. I also saw that that number was also recommended by Eric Cortina, and he seems to be pretty straight up as well.

As for simply over pressuring, I can't see how running 10kpsi below the SAAMI spec could be the culprit. Absolutely No other signs on the brass or action indicate this. Maybe I'm off, but if so would really like to know where to go. So some might ask why so slow out of and Ackley - This gun has a good node at about 1.43ms and bumping it up to the next one is then really pushing it. It shoots better there than I do, and I thought it might be good for brass and barrel life not to temp fate.

Thanks

 

[Ned Ludd]

I've been running what I believe is the same Norma brass from MidSouth that you have. According to them, it is made for them by Norma. I also have fireformed all the pieces once with a reduced load, and have just begun to work up full-pressure loads with it, so mine is only 2X-fired at most. As yet, I have not observed any issues with it. However, I am using it in .223 Rem F-TR rifles, which are not AI chambers.

As XTR noted above, case-head separation is typically a totally different issue than simple over-pressure, which usually kills the primer pockets in 3-4 firings with the hot loads we use in F-TR (2800+ fps with 90 VLDs). As I understand it, case-head separation in a .223 is far more likely to result from over-working the brass (i.e. too much shoulder bump over 2-3 re-sizings will often cause case-head separation). Is it possible that could have occurred somehow during the AI fire-forming process?

Another possibility that occurs to me is that on the surface, a load with 24.0 gr Varget under 88s seems like it ought to be generating a lot greater velocity than 2640 fps/44.7K psi. However, I don't know your barrel length or freebore length, so that is merely an observation. Nonetheless, it's probably worth re-checking your QL file to make certain all the inputs are correct, and the QL pressure prediction is really matching up like you think it is. It won't cost much effort just to double-check and be sure.

Finally, you might also want to compare you shoulder measurements (i.e. how much the CBTS measurement grew after each firing). If the growth prior to re-size is excessive, it could be a over-sized chambering issue, which could certainly be associated with case-head separation under the right circumstances. Again, I can't tell how likely this would be, but it's something you can easily check with little effort on your part, which may at least allow you to rule out one possible cause. Sometimes when you experience issues such as this, examining each possible variable one at a time is the only way you can ultimately find the cause. It can sometimes be painful, but solving the issue makes it worth the effort.

 

[fkimble@charter.net]

If your not jamming the bullet or using a false shoulder for the fire-forming load, then depending on the shoulder length of the factory brass, you could be pushing the shoulder a good amount during the fire-forming . This initial stretch could start the head separations. What signs of head separation are you seeing? PS we love pics of problem brass etc.

Frank

 

[JPB4BAMA]

If your not jamming the bullet or using a false shoulder for the fire-forming load, then depending on the shoulder length of the factory brass, you could be pushing the shoulder a good amount during the fire-forming . This initial stretch could start the head separations. What signs of head separation are you seeing? PS we love pics of problem brass etc.

Frank

 

[JPB4BAMA]

The initial loads for Fire Forming were also barrel break in loads. Loaded 22.8 Gr RL-15, 90 SMK Moly, Seated 10 INTO the lands as determined via Hornady gauge (so this might be +/- a bit, but you could feel them engage on bolt closure). Now I did not measure or trim the virgin brass, just opened/rounded the neck with Lee Collet die and loaded. Indecently those shot lights out too. I do have about 100 virgin cases that have not been touched, so I might go back and see what they measure up like, just for giggles.

The signs are the bright ring at about 1 cm from the base of the case as in the attached photo. Sorry I crushed the necks without taking pictures of the inside, but there was clearly a corresponding tensile stress ring in the same place. I did not do the paperclip thing since I have the bore scope to actually see it.

Now let me add this tidbit as full disclosure. For some reason, probably the reamer/chamber, when I initially sized the brass from the first firing with the die set up per instructions, the headspace grew, even at full compression. So I had to have my shell holder milled by 10 thou to get enough of the case into the die to bump back enough that I could chamber the sized case. After this as I was doing the die adjustments, I know that a few cases overshot my aim of -0.002, but only to about 0.004 or 0.005 below the as fired datum line. That being about the tolerance, I really was not concerned, but I am open to the possibility that this might be the culprit, IF it remains limited to that small number that have already manifested the issue. I'll know this after the next outing as I already have 80 loaded for my next match that are currently on the third firing.

 

[JPB4BAMA]

I've been running what I believe is the same Norma brass from MidSouth that you have. According to them, it is made for them by Norma. I also have fireformed all the pieces once with a reduced load, and have just begun to work up full-pressure loads with it, so mine is only 2X-fired at most. As yet, I have not observed any issues with it. However, I am using it in .223 Rem F-TR rifles, which are not AI chambers.

As XTR noted above, case-head separation is typically a totally different issue than simple over-pressure, which usually kills the primer pockets in 3-4 firings with the hot loads we use in F-TR (2800+ fps with 90 VLDs). As I understand it, case-head separation in a .223 is far more likely to result from over-working the brass (i.e. too much shoulder bump over 2-3 re-sizings will often cause case-head separation). Is it possible that could have occurred somehow during the AI fire-forming process?

Another possibility that occurs to me is that on the surface, a load with 24.0 gr Varget under 88s seems like it ought to be generating a lot greater velocity than 2640 fps/44.7K psi. However, I don't know your barrel length or freebore length, so that is merely an observation. Nonetheless, it's probably worth re-checking your QL file to make certain all the inputs are correct, and the QL pressure prediction is really matching up like you think it is. It won't cost much effort just to double-check and be sure.

Finally, you might also want to compare you shoulder measurements (i.e. how much the CBTS measurement grew after each firing). If the growth prior to re-size is excessive, it could be a over-sized chambering issue, which could certainly be associated with case-head separation under the right circumstances. Again, I can't tell how likely this would be, but it's something you can easily check with little effort on your part, which may at least allow you to rule out one possible cause. Sometimes when you experience issues such as this, examining each possible variable one at a time is the only way you can ultimately find the cause. It can sometimes be painful, but solving the issue makes it worth the effort.

Thanks Ned.
I was thinking the same thing concerning the velocity, but I'm pretty confident on this (MV). I had posted another issue relative to trying to get my MV SD's under control that you and others commented on, and in that endeavor I have measured multiple strings with both a Magnetospeed and LabRadar and the both corroborate each other within a few FPS. Then on top of that the actual bullet drop at range (600) is pretty much on as well, so I don't think there is a big issue here. Likewise in the other gun that is shooting BARE bullets, I'm at 23.8gr and getting about the same.

Now being rather new to the use of Quick Load, what I did to get the pressures was set all measurable parameters to actual (Case length, OAL, Friction Proofed, actual H20 capacity (32.0 gr for Norma, and 31.4 for Lapua)) and then adjust the Ba until the velocity matches (Ba= 0.57 vs 0.615 Default). So when that was done that was the resulting 44kpsi that I indicated. Now I am not overly comfortable with adjusting powder parameters, but since the instructions I read indicate that +/- 10% might be normal between different lots and cartridge application, I am working under the premise that this is OK ?????? The fact that sizing force (subjective measure) is very light adds confidence to a lower pressure load as well.

The Rifle in question with the NORMA brass is a new Kreiger 28" 4 groove. Actual BBL length as finished on the rifle is 28.25. The other Rifle (Lapua Brass only) is a 6 groove Shilen Match select on it's second run after being cut back and chambered with the same reamer, it is now 27.2 inches.

I really don't know the Freebore, but it was a standard PT&G 223 AI reamer and the print indicates a LEAD of 0.7869, so I guess that is probably close to the actual.

Thanks for all for the replies, really enjoy reading them and adding to my knowledge base.

 

[Ned Ludd]

FWIW - the barrel will likely speed up a bit as it is fired, typically within the first 150-200 rounds or so. In my hands that might be something around 20-30 fps, perhaps a bit more. It can happen gradually, or sometimes seemingly all at once. That might be sufficient to boost the velocity at that charge weight closer to the 2700 fps mark, but it still seems a bit slow to me.

You're using QL the same way I do. I input all measured data, then adjust Ba until predicted velocity exactly matches measured velocity. I generally do not mess with other user-changeable variables besides Ba, although you can. One question I would have is the case volumes you're using as inputs. Are those actual water volumes you measured using your fired brass? If not, they may not be all that accurate. Actual water volumes determined with my fired brass gives me about 30.8 gr and 31.5 gr case volumes with Lapua and Norma brass, respectively. Using larger case volumes might be a possible explanation of the lower pressure output (44.7K psi). Also - on your reamer print, the "lead" is the same as "freebore", in your case, it looks like .0618", although it was hard for me to read the number. The term freebore is just one that gets thrown around a lot in conversation.

If I ever encounter any issues or questions, my thinking is typically to do the simplest and most straightforward things that require as little effort on my part as possible, in order to potentially rule some things in/out. Hence my suggestions. It looks like you're getting there with load development. I would keep after it until you figure out the brass issue, watching carefully for pressure signs, etc. Best of luck with it!

 

[JPB4BAMA]

FWIW - the barrel will likely speed up a bit as it is fired, typically within the first 150-200 rounds or so. In my hands that might be something around 20-30 fps, perhaps a bit more. It can happen gradually, or sometimes seemingly all at once. That might be sufficient to boost the velocity at that charge weight closer to the 2700 fps mark, but it still seems a bit slow to me.

You're using QL the same way I do. I input all measured data, then adjust Ba until predicted velocity exactly matches measured velocity. I generally do not mess with other user-changeable variables besides Ba, although you can. One question I would have is the case volumes you're using as inputs. Are those actual water volumes you measured using your fired brass? If not, they may not be all that accurate. Actual water volumes determined with my fired brass gives me about 30.8 gr and 31.5 gr case volumes with Lapua and Norma brass, respectively. Using larger case volumes might be a possible explanation of the lower pressure output (44.7K psi). Also - on your reamer print, the "lead" is the same as "freebore", in your case, it looks like .0618", although it was hard for me to read the number. The term freebore is just one that gets thrown around a lot in conversation.

If I ever encounter any issues or questions, my thinking is typically to do the simplest and most straightforward things that require as little effort on my part as possible, in order to potentially rule some things in/out. Hence my suggestions. It looks like you're getting there with load development. I would keep after it until you figure out the brass issue, watching carefully for pressure signs, etc. Best of luck with it!

Yes, it is actual H2O volume as measured on Fired Cases, with an inverted spent primer. 20 random samples and all within +/- 0.1gr. Meniscus is flat at case capacity.

 

[fkimble@charter.net]

Ref the case pic: the"line" around the case is definitely in the general area where a case head separation might occur. but the case coloration also changes at that same spot. Could just be where the die actually starts sizing the case. I could not enlarge the pic for a better look. Would be interesting to split a couple of those cases to see what the inside looks like. Keep us posted

Frank

 

[JPB4BAMA]

Ref the case pic: the"line" around the case is definitely in the general area where a case head separation might occur. but the case coloration also changes at that same spot. Could just be where the die actually starts sizing the case. I could not enlarge the pic for a better look. Would be interesting to split a couple of those cases to see what the inside looks like. Keep us posted

Frank

I could split them, but as I mentioned, with the bore scope there was clear tensile stress thinning in that same ring. Should have took pictures of that, but I crushed them first to keep them out of service. If I can find a dremel tool maybe I will cut some and post for other reference.
Thanks
JPB

 

[JPB4BAMA]

I could split them, but as I mentioned, with the bore scope there was clear tensile stress thinning in that same ring. Should have took pictures of that, but I crushed them first to keep them out of service. If I can find a dremel tool maybe I will cut some and post for other reference.
Thanks
JPB

Well I found the Dremel. Clear initiation of tensile failure at the site. Sorry for the crappy photos, but all I have is a phone these days. First one is as cut, then on the second I cleaned up a bit of the carbon. And that surprised me how much carbon was in the bottom 1cm, and how hard it was to get off. above the mark came clean pretty quick but the crusty crab below is really thick. Sort of makes me wonder if I really should wet tumble on occasion, but I quit to preserve carbon in the neck and it is also a mess and if you don't really rinse well and kill the acid cleaning agent then you get corrosion, even if you "think" you rinsed well.

Enjoy the pics.

 

[JPB4BAMA]

Ref the case pic: the"line" around the case is definitely in the general area where a case head separation might occur. but the case coloration also changes at that same spot. Could just be where the die actually starts sizing the case. I could not enlarge the pic for a better look. Would be interesting to split a couple of those cases to see what the inside looks like. Keep us posted

Frank

pics posted