CCI BR PRIMERS ---- MISFIRING...

[Mark Walker in TX]

Yep, CCIBR2s are horrible. You don't want to purchase any more. You want to leave them on the shelves for others. These are not the droids, err primers, you are looking for…

8) 8) 8)

 

[jonbearman]

What kind of speeds with the 20-250AI?

 

[daniel brothers]

What kind of speeds with the 20-250AI?

There lies my dilemma.... speed....vs... accuracy.... Hmm.... My hot rounds are around 3950 with 55 gr bergers, cci br primers.... but with fed mag primers, it averages 4000-4025 ... but they're on the hot side for sure... and accuracy is okay... probably 1/2" or so...but when shooting them around 3750... Man O Man...it smokes.

I came across this slow speed accidently as I was fireforming these few pieces of brass. I filled the case with Imr 4350... up to the neck and shot them in nearly the same hole with this punky-pink speed. I didn't build this rifle to shoot those pinky speeds, but it can work for now.

I was working up some loads at my friends house in Oklahoma, and my last two shots with this load in unformed brass were touching at 300 yd.

I was trying to sight it in at 300 yds with my 5 shots. The first one was 1 inch low with the magnospeed attached. I then took it off, and shot the second round, and it touched the first hole....fluke I thought... I adjusted the scope up, and it hit to the right of the 1" orange dot... I adjust scope again... 4th shot hit inside 6 oclock in orange dot... and the 5th shot hit the 4th hole... it looked closer to one hole than two holes.... so I quit right there and took off to Kansas for Fur-Dogs.... and here I am for a few weeks in my RV, chasing dogs and snapping caps.

Here's the Little Beast...

 

[amlevin]

I had a run of "Misfires" on BR-2 and BR-4 primers for a while. Two different rifles and calibers so I took a look at the "common denominator's", Me and the priming tool.

I had just changed priming tools from a Lee to a Hornady. I couldn't get the leverage with the Hornady and was seating the primers only until the anvil contacted the bottom of the primer pocket. When I went back to the Lee, and started seating the primers so the cup contacted the bottom of the pocket the problem went away. Several thousand primers later, all the same brand and type, and no misfires.

I proved the problem by carefully removing a "failed" primer or two. Even though there was a "dent" in the cup face, the anvil still protruded below the cup as it did fresh out of the tray.

Don't know if this is the problem here but it certainly was the cause for me.

 

[snakepit]

In the last few years I have fired several thousand CCI BR2 and BR4 primers and have not had a single misfire.

 

[dkhunt14]

There lies my dilemma.... speed....vs... accuracy.... Hmm.... My hot rounds are around 3950 with 55 gr bergers, cci br primers.... but with fed mag primers, it averages 4000-4025 ... but they're on the hot side for sure... and accuracy is okay... probably 1/2" or so...but when shooting them around 3750... Man O Man...it smokes.

A Federal Magnum primer is a hot primer and could cause the velocity's and pressure to rise. Matt

 

[daniel brothers]

The Federal Mag Primers did cause the pressure to increase, so I don't shoot them.... but my buddy was using them in his 20-250 AI... and they are hot for sure.

Amlevin, you might be correct on the primer tool, because I had just changed tools... I'll see what happens when I get my other one back out...thanks...Dan

 

[daniel brothers]

I may have fixed it. I had used my friends priming tool instead of mine because I was working up loads at his house, and when the problem started. I just removed the primers from the unfired rounds and re-installed new BR-2 primers with my tool, and they popped just fine. I reloaded them for testing tomorrow, but so far I think it was all in not seating them deep enough in the pockets.... we'll see.

thanks for your help...May Jesus Bless You ALL

Ps... I would try them today, but the PDogs are hiding from the cold and wind... maybe they'll stick their heads up tomorrow.

 

[jlow]

The lesson here is after you seat a primer (regardless of whether it is for a rifle or pistol), always do a finger swipe test on the primer. Any proud primer even to a very small degree will be obvious. Proud primers are always the most likely culprit when shooter find their primers not going off and light primer strikes.

 

[GrocMax]

I'm saying they are misfiring... but it's probably not the primers.... surely not... probably something else. I have been using cci 200 primers in my 20-250AI, without any problems, but I ran out of them, and bought some BR primers instead. I'm having 2-3 misfires out of every 10 shots... but the firing pin indent is very shallow on them, and even on the ones that do fire.

What else could my problem be...?

thanks...Dan

Ran into this exact same problem fireforming both 6TCU and 223AI. Got nothing to do with headspace or case sizing. Got everything to do with using thick cup primers. Pin strike is actually NECK SIZING in the chamber, shoving the whole case forward, 23 deg shoulder is not enough to stop the case from going .020" deeper. Problem gone when using normal cup primers, or bullet hard into the lands.
Experimented with setting pin protrusion to .080" then use a NEW properly sized empty case. Primer fired, extracted case the primer gas created enough pressure to 50% form the case, and shove the primer cup .020" out of the case head. That case went in with negative headspace, and came out with the primer hanging out, and a longer neck.

 

[Greyfox]

In the past ten years I've fired a minimum of 15,000 CCI BR-4s in benchrest competition. I have not had one single misfire. I am comfortable in stating that your problem is not the primer. Maybe the priming tool, possibly the headspace, but not likely the primer.

Rick

 

[GrocMax]

Its thick cup primers vs. AI fireforming from shallow shoulder angle 223 parent case. ZERO to do with headspace. ZERO to do with primer seating.

The reduced sensitivity/increased strength form the thick cup SR primers (7 1/2, 450, BR4, Tula) allows the pin strike to shove the entire cartridge forward without setting off the primer. Problem is 100% gone using normal cup thickness primers. NOT related to headspace, crush fit going in, neck is .020" longer coming out with an unfired primer.

 

[BoydAllen]

A friend had a rifle in the same caliber that yours is, and a couple of cases of factory ammo. With one brand he had a lot of misfires, with the other none. We measured the shoulder to head dimension of both brands, the problem rounds were shorter at the shoulder than the ones that worked. Gauges and numbers aside, for an AI you want some feel when you close the bolt. Your lite strikes lead me to believe that you have too much headspace. With an AI the only thing that gives you headspace control is line contact at the neck shoulder junction. The best system is to use the same brand and lot of cases, measure some, and use one to set your headspace. New brass may be considerably shorter shoulder to head than SAAMI spec, for you chamber's minimum headspace.

 

[Greyfox]

Its thick cup primers vs. AI fireforming from shallow angle parent case. ZERO to do with headspace. ZERO to do with primer seating.

The reduced sensitivity/increased strength form the thick cup SR primers (7 1/2, 450, BR4, Tula) allows the pin strike to shove the entire cartridge forward without setting off the primer. Problem is 100% gone using normal cup thickness primers. NOT related to headspace, crush fit going in, neck is .020" longer coming out with an unfired primer.

Not arguing or disagreeing, but maybe seeing a learning opportunity here. If the pin strike is able to drive the case forward without setting off the primer, why is this not a headspace problem?

Rick

 

[GrocMax]

Measured headspace and cases till I was blue in the face, it had proper AI crush fit. Necks come out .020"+ LONGER on unfired cases (explain THAT!). A brand new case with a FTF primer with a light strike, significantly longer neck and .080" pin protrusion?
Switch to a primer other than a 450, 7 1/2, Tula SRM/5.56 or BR4, PROBLEM DISAPPEARS, ZERO FTF!!!!!!!!!!!!!!!!!!!!

Not talking about a normal situation here, specific to AI chamber and shallow shoulder angle fairly thin walled parent case, everything can be perfect and still end up with a very high percentage of FTF's. Switch back to normal thickness primers, PROBLEM GONE. Putting the bullet hard into the lands isn't a possibility at times.

edit: These are all new 223 cases that are .374"ish at the base in a .376"ish AI or TCU chamber so there is nothing restricting a bit of forward movement other than the neck/shoulder junction.

 

[dkhunt14]

Measured headspace and cases till I was blue in the face, it had proper AI crush fit. Necks come out .020"+ LONGER on unfired cases (explain THAT!). A brand new case with a FTF primer with a light strike, significantly longer neck and .080" pin protrusion?
Switch to a primer other than a 450, 7 1/2, Tula SRM/5.56 or BR4, PROBLEM DISAPPEARS, ZERO FTF!!!!!!!!!!!!!!!!!!!!

Not talking about a normal situation here, specific to AI chamber and shallow shoulder angle fairly thin walled parent case, everything can be perfect and still end up with a very high percentage of FTF's. Switch back to normal thickness primers, PROBLEM GONE. Putting the bullet hard into the lands isn't a possibility at times.

edit: These are all new 223 cases that are .374"ish at the base in a .376"ish AI or TCU chamber so there is nothing restricting a bit of forward movement other than the neck/shoulder junction.

Maybe because the case is being driven forward and stretching down the body and letting more brass to go in neck. Just a wild guess. Matt

 

[GrocMax]

Maybe because the case is being driven forward and stretching down the body and letting more brass to go in neck. Just a wild guess. Matt

Exactly. The thick cup primers are stronger and less sensitive to a pin strike. Without a true shoulder to hold it or a bullet hard in the lands it shoves the case into the neck area of the chamber before initiating. Normal fully case formed loads have zero issues with thick cup primers, regardless of a few extra thou headspace or not.

Check headspace and case size till I'm blue in the face.
New empty case, 450 primer, .080"+ pin protrusion (excessive on purpose), first try no fire light strike, 2nd try it fired, after removing case, the neck was longer by the same amount the primer was forced out of the case by the gas pressure from the primer alone. Epiphany. Switch back to thin cup SR primers for fireform loads, zero FTF's since. That light primer strike had nothing to do with pin protrusion or spring tension or pin mass.

This may also be the reason why I had a higher than normal case head separation issue with a batch of once fired brass fireforming into 223AI. There weren't any FTF's but there were 5% case seps. These were all body sized due to being a bit large. Up to that point this had never happened to me, puzzling, blamed it on once fired brass, that may not have been the root cause at all.

 

[Webster]

I'm saying they are misfiring... but it's probably not the primers.... surely not... probably something else. I have been using cci 200 primers in my 20-250AI, without any problems, but I ran out of them, and bought some BR primers instead. I'm having 2-3 misfires out of every 10 shots... but the firing pin indent is very shallow on them, and even on the ones that do fire.

What else could my problem be...?

thanks...Dan

I had the same problem with primers. I found I was seating them with too much pressure. They didn't look flattened from pushing to hard but the anvil must have been pushed too far into the priming compound. I backed the priming tool off until the primer protruded then adjusted in small increments by feel and how far it was in the case to get what seemed like a good depth and feel. When it felt good and the primer was at least several thou below the case head I locked the setting on the tool. Never had a misfire or hang fire since I did this. All primers don't have the same feel since the primer pocket is swagged into the case. The primers are more uniform than the case pocket diameter. A primer pocket uniformer only cuts the bottom of the pocket. The diameters vary a tiny amount. Firing pin protrusion is about 0.065" If the case is a loose fit in the chamber the firing pin can push the case forward losing striking energy. That would be my last guess at the problem. Don't bump the shoulders too much.

 

[ttfreestyle]

I have several thousand br4s in 3 different lot numbers. Lot "A" has 3 to 5 failure to fires per 100 in my two Bordens, luckily I only have 1500 of these left. I switched to lot "B" and have shot a few thousand without a misfire. I haven't opened lot "C" but I'm hoping they are like lot "B"and not lot "A".

 

[TikkaSporter]

I went down this road recently with misfires and CCI BR4/CCI 450's. There's a lengthy and informative thread on it here:

http://forum.accurateshooter.com/th...l-it-with-custom-action-6-5x47-lapua.3920867/

I solved my issue by replacing the firing pin spring and lapping/polishing the back of my firing pin where it was dragging in the bolt shroud. The firing pin spring that came with it was either a light spring or well worn.

Where you're experiencing this with fire-forming loads, it seems more likely that it's a headspace issue. That said, there's probably more than one thing contributing... Like the harder cup on the CCI BR primers, plus headspace on fire-forming loads, plus primer seating depth, plus maybe something else.