CZ P10C Blown Primer / enlarged case

[stever_reynolds]

Pictures of the case with blown primer

What's going on with the rim of the case, it looks pretty dented.  Could the gun have caused that, or did that happen on the ground?

I have to imagine because of the high pressure, part of the rim came off during extraction.


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[Wobbly]

Variances in OAL are SOMETIMES due to how you work the press, as you get move time these usually get less and less frequent.

Good point. We have seen that a lot with novice reloaders. It is common for novices to have a wider tolerance on their OAL's simply because (like a golfer or baseball player)  they haven't developed their "swing" yet. I want you to concentrate on going slow and operating at a steady rate. The movement of the op lever needs to be smooth all the way through the stroke.

Oiling your press and lubing your brass will help tremendously in this effort. And yes, before you ask, most of us lube even with carbide dies. If you have a spray bottle you can make your own from lanolin and rubbing alcohol.

 

[stever_reynolds]

Was this used range brass...Could have been damaged and have nothing to do with your reload, maybe.

Is your Lee a AUTO progressive press, if not possible double charge, IMHO most likely.

How have you checked for bullet set back?

OAL is dependent on ogive and factory ammo is often close to 1.16, even 115 GR and usually works in CZ chamber.  Your Barrel has the final say, if finished rounds plunk and spin then you are OK. 

Variances in OAL are SOMETIMES due to how you work the press, as you get move time these usually get less and less frequent.

On checking for bullet setback I have tested several things from plunk testing the ammo to pressing on work bench (measure before and after) and several rounds slamming into chamber from slide lock (measure before and after).  I did buy a shake brake from Miles Reloading Bench and installed a support brace, so there is now minimal movement and should minimize the variance in OAL on my next loading session.


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[stever_reynolds]

Variances in OAL are SOMETIMES due to how you work the press, as you get move time these usually get less and less frequent.

Good point. We have seen that a lot with novice reloaders. It is common for novices to have a wider tolerance on their OAL's simply because (like a golfer or baseball player)  they haven't developed their "swing" yet. I want you to concentrate on going slow and operating at a steady rate. The movement of the op lever needs to be smooth all the way through the stroke.

Oiling your press and lubing your brass will help tremendously in this effort. And yes, before you ask, most of us lube even with carbide dies. If you have a spray bottle you can make your own from lanolin and rubbing alcohol.

 

Thanks, Wobbly.  I did use Hornady One Shot to lube the cases and am hoping the shake brake from Mike’s Reloading Bench will help as well.


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[stever_reynolds]

Lots of good info and ideas here. I knew Steve would be better off with more CZ minds on the subject.
My thoughts...

• The freebore on my P10c is shorter than that on my SP01. I have to be very careful when loading some bullets, like the RMR 124gr JHP.

• My experience with the Berry Mfg RN products is that they will typically "push test" to an OAL longer than the mag will allow. Out to 1.190" with some bullets in my SP01.

• While learning on a progressive is not optimal, Steve does seem to be on top of things and a knowledgeable student of guns and reloading.

• I'm with TDOGG... how can you be sure the brass was yours ?

• If we assume the brass was yours, it is very clear that specific piece did not fully seat into the chamber before being fired. If that is the situation, then 2 thoughts arise...
1. Where did your brass come from? It seems to be all matching Fed brass, but was it from you and your guns ?

2. I would check the gun. Gun cleared and safe. Allow the slide to move forward in increments as small as possible, and pull the trigger at each increment. Especially the last 0.20" before the slide goes into battery. The question we are trying to answer is, "Will the gun fire OOB ?" IOW, can the barrel be unlocked and the gun still fire ? If so the P10 needs to go back to CZ.


The root cause may never be known, but we can help refine your reloading process to eliminate issues on the bench.

Wobbly, this is exactly what I have seen with a push test in my P10c and P10F barrels - 1.185-1.190 OAL.  I have not tried on my SP01.  My P10S was definitely shorter though - 1.175 OAL on push test.


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[Wobbly]

Oiling your press and lubing your brass will help tremendously in this effort. And yes, before you ask, most of us lube even with carbide dies. If you have a spray bottle you can make your own from lanolin and rubbing alcohol.

Thanks, Wobbly.  I did use Hornady One Shot to lube the cases and am hoping the shake brake from Mike’s Reloading Bench will help as well.

Users report that One Shot has to have a drying time to be effective. The lanolin sprays are ready to use immediately.

[Wobbly]

Since the brass is your own, we can rule out excessive head diameter due to having been fired in an Open Class pistol.




At this point I'd have to say that "start/ stop issues" seem to be the most likely culprit.

[stever_reynolds]

Oiling your press and lubing your brass will help tremendously in this effort. And yes, before you ask, most of us lube even with carbide dies. If you have a spray bottle you can make your own from lanolin and rubbing alcohol.

Thanks, Wobbly.  I did use Hornady One Shot to lube the cases and am hoping the shake brake from Mike’s Reloading Bench will help as well.

Users report that One Shot has to have a drying time to be effective. The lanolin sprays are ready to use immediately.

Correct.  I spray and shake up with cases in a big zip lock and let sit for at least an hour before using.


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[stever_reynolds]

Since the brass is your own, we can rule out excessive head diameter due to having been fired in an Open Class pistol.




At this point I'd have to say that "start/ stop issues" seem to be the most likely culprit.

That’s what I am thinking.


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[Auslander]

Just an observation.  Like the others, I believe it was just a faulty round.  Probably too much powder, but projectile set-back could also be an issue.   I'm not experienced with CFE but as I found out the other day, some powders build pressure very quickly.  Looking at Hodgdon's data for the 115 Gold Dot, it has a pretty narrow band.  5.3 to 5.9  grains.  For lead RN its even tighter, 4.9 to 5.4.  Wouldn't need much to cause trouble.   

The OAL you are using is in line with X-Treme's load information (OAL) with their 115gn Heavy Plate Bullet.  I haven't shot Berry's 115grain projectiles, but found that the load data for Extreme and Berry's projectiles are very close with the powders I have tried in other Berry's projectile weights. 

I started reloading with a Dillion 550B that I picked up at an estate sale.  I tried learning on it, but way too much SGO.  Found out that I could make a lot of bad rounds very quickly.  Moved to a single stage with the Dillion dies to learn each process and die set-up peculiarities. (Especially with case expansion and the taper crimp).  When I moved back to the Dillion, I was then better prepared to deal with the "flex" that is inherent with progressives.  After 3 years, I'm still learning.   

I've shot the 1.15" +/- OAL in several of my CZ's to include a P10c, 75BD, PCR and RAMI.  No issues.

I will say that this is a testament to how well the P10's barrel supports the cartridge case.  From the pictures, the case was very well supported by the chamber.  I've seen a Sig and a Glock blow out the magazines and crack the frames from excessive pressure blowing out at the feed ramp (thankfully only observed on LE ranges).  Thoroughly impressed with the design of the weapon's chamber. 

 

       

 

[stever_reynolds]

Just an observation.  Like the others, I believe it was just a faulty round.  Probably too much powder, but projectile set-back could also be an issue.   I'm not experienced with CFE but as I found out the other day, some powders build pressure very quickly.  Looking at Hodgdon's data for the 115 Gold Dot, it has a pretty narrow band.  5.3 to 5.9  grains.  For lead RN its even tighter, 4.9 to 5.4.  Wouldn't need much to cause trouble.   

The OAL you are using is in line with X-Treme's load information (OAL) with their 115gn Heavy Plate Bullet.  I haven't shot Berry's 115grain projectiles, but found that the load data for Extreme and Berry's projectiles are very close with the powders I have tried in other Berry's projectile weights. 

I started reloading with a Dillion 550B that I picked up at an estate sale.  I tried learning on it, but way too much SGO.  Found out that I could make a lot of bad rounds very quickly.  Moved to a single stage with the Dillion dies to learn each process and die set-up peculiarities. (Especially with case expansion and the taper crimp).  When I moved back to the Dillion, I was then better prepared to deal with the "flex" that is inherent with progressives.  After 3 years, I'm still learning.   

I've shot the 1.15" +/- OAL in several of my CZ's to include a P10c, 75BD, PCR and RAMI.  No issues.

I will say that this is a testament to how well the P10's barrel supports the cartridge case.  From the pictures, the case was very well supported by the chamber.  I've seen a Sig and a Glock blow out the magazines and crack the frames from excessive pressure blowing out at the feed ramp (thankfully only observed on LE ranges).  Thoroughly impressed with the design of the weapon's chamber. 

This is exactly why I selected a CZ to shoot my first loaded rounds (barrel on right) vs Glock (barrel on left).

[stever_reynolds]

Just an observation.  Like the others, I believe it was just a faulty round.  Probably too much powder, but projectile set-back could also be an issue.   I'm not experienced with CFE but as I found out the other day, some powders build pressure very quickly.  Looking at Hodgdon's data for the 115 Gold Dot, it has a pretty narrow band.  5.3 to 5.9  grains.  For lead RN its even tighter, 4.9 to 5.4.  Wouldn't need much to cause trouble.   

The OAL you are using is in line with X-Treme's load information (OAL) with their 115gn Heavy Plate Bullet.  I haven't shot Berry's 115grain projectiles, but found that the load data for Extreme and Berry's projectiles are very close with the powders I have tried in other Berry's projectile weights. 

I started reloading with a Dillion 550B that I picked up at an estate sale.  I tried learning on it, but way too much SGO.  Found out that I could make a lot of bad rounds very quickly.  Moved to a single stage with the Dillion dies to learn each process and die set-up peculiarities. (Especially with case expansion and the taper crimp).  When I moved back to the Dillion, I was then better prepared to deal with the "flex" that is inherent with progressives.  After 3 years, I'm still learning.   

I've shot the 1.15" +/- OAL in several of my CZ's to include a P10c, 75BD, PCR and RAMI.  No issues.

I will say that this is a testament to how well the P10's barrel supports the cartridge case.  From the pictures, the case was very well supported by the chamber.  I've seen a Sig and a Glock blow out the magazines and crack the frames from excessive pressure blowing out at the feed ramp (thankfully only observed on LE ranges).  Thoroughly impressed with the design of the weapon's chamber. 

 

       

 

This is exactly why I selected a CZ to shoot my first loaded rounds (barrel on right) vs Glock (barrel on left).


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Picture is having an issue loading.  Barrel lug on CZ is significantly beefier than a Glock Barrel.


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[tdogg]

I'm astounded by the amount that the case head expanded without separating from the body?  I looks like you could fit a large pistol primer in that pocket!
 Kuddo's to Federal for making stout brass!

I'm also confused how the case head could expand that much while supported by the breach?  Does the breach on the P10 not have breach pocket that supports the case head, designed to only fit 9mm case heads?  I'm thinking about folks that take their SP01 in 40S&W and fit a 9mm barrel and it still functions because the breach is larger than the cartridge head but you can't take a SP01 in 9mm and fit a 40S&W barrel.

If it wasn't supported by the breach how did it ignite?  Any chance you had a squib that made it well into the barrel such that the next round pushed it out along with destroying the case?  Did you see where the all the shots hit paper?  Have you inspected the barrel/bore for any signs of damage?

I'd take a look at your process and make sure you have a good light pointed into the case at bullet seating.  You might also want to consider a RCBS Powder Lockout die.  When adjusted properly it will lock up the press if no powder is present or if a double charge is present.  It is my backup to looking into the case before placing the bullet because I'm human and will make a mistake.

Cheers,
Toby

[M1A4ME]

Brass may be Federal but not from the same batch.  9MM on one case 9mm on the other.

Small "dent" in the rim of the "bad" case appears to be an impact to the side of the rim - look at how the C from FC is crushed downwards from the top.

Torn edge on the opposite from and extractor?  If extractors can damage brass like and still extract the case all I can say is I've seen brass left in the chamber of rifles with the primer blown out and the rim didn't have that kind of damage.  Nothing holding a P10 extractor in place except pressure from the spring?  Right??

Can a P10 release the striker with the slide partially to the rear?  Too bad the primer wasn't still in the brass.  It would be interesting to see where the striker hit the primer and if the side walls of the primer expanded like the primer pocket appears to have expanded.

Primer usually blow out when the case stays in the chamber.  If the back of the case is flush against the breech face, how does the primer "blow" out?  Unless the primer was still small and the primer pocket expanded when the brass flew out and to the ground??

With all the blown brass I've seen pictures of I don't think I ever seen a case rim expand, just the case above the extraction groove.  Anyone else see a case rim expand?  That's really wild.

[stever_reynolds]

I'm astounded by the amount that the case head expanded without separating from the body?  I looks like you could fit a large pistol primer in that pocket!
 Kuddo's to Federal for making stout brass!

I'm also confused how the case head could expand that much while supported by the breach?  Does the breach on the P10 not have breach pocket that supports the case head, designed to only fit 9mm case heads?  I'm thinking about folks that take their SP01 in 40S&W and fit a 9mm barrel and it still functions because the breach is larger than the cartridge head but you can't take a SP01 in 9mm and fit a 40S&W barrel.

If it wasn't supported by the breach how did it ignite?  Any chance you had a squib that made it well into the barrel such that the next round pushed it out along with destroying the case?  Did you see where the all the shots hit paper?  Have you inspected the barrel/bore for any signs of damage?

I'd take a look at your process and make sure you have a good light pointed into the case at bullet seating.  You might also want to consider a RCBS Powder Lockout die.  When adjusted properly it will lock up the press if no powder is present or if a double charge is present.  It is my backup to looking into the case before placing the bullet because I'm human and will make a mistake.

Cheers,
Toby

I would upload an image if I could but they stall at 95% upload now.  I’m guessing there is a max on number of attachments in a thread?  Anyway, I can drop and spin a large primer inside that primer pocket.  It is huge.  As for the expansion, two theories, 1) this was an OOB, or 2) over-charge that meant power was still burning and expanding the case as it was being extracted.

As far as the squib, I am 100% certain I didn’t as I was at 8-10 yards from a cardboard target and didn’t have any shots right on top of each other.  I was shooting slowly and could see each shot hit the target.  Also, a squib would have meant significantly lower recoil, right?  All of my shots, except the one that really kicked back felt very similar on recoil impulse.  I never had a cycle issue or other malfunction. 


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