Ammo problem P-07

[warriorsoul]

He guys,

Today I went to put 200 rounds through my P-07 and had a situation I've never encountered before. I had remanufactured ammo that ran perfectly and some reloads that were struggling. The reloads were 124gr flat nose 9mm with I believe 4 grains of titegroup. Anyways, many of the reloads were not going fully into battery. At times it was hard to even bump it in and I'd need to let it sit a bit. Meanwhile my Shield sucked them down without a pause. Is this possible not fully resizing the casing or not crimping enough or what would you think?  I don't think it was the gun since it ate the other rounds no problem and I even mixed them up in magazines and got the same results.

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[Raining_Brass]

Check cartridge oal? CZ's tend to have tighter chambers than other gun manufactures, which could be why the rounds worked fine in the Shield but had hiccups with the CZ.

[JonFrost]

I tried to shoot reloads through my 75 police when I got it. The gun wouldn't go into battery with them even though my Sigs and other guns had no problem. Had the same thing happen with my p09. I just use factory now.

[lala land]

I've had the same problem here with reloads.  It doesn't seem to be OAL related, it's just the occasional slightly bulged brass.  Our chambers must be a little tighter than usual.  The ammo runs fine in my glock, shield, and 1911.

The really odd thing though is that I had the same problem with Fiocchi 124gr factory ammo.  If fact it was even worse than with reloads, because the slide would get jammed so tightly I could barely get it open.

I've been considering getting an undersized die now that I reload myself, to see if it eliminates or reduces the problem.

[M1A4ME]

My P09 9MM eats (so far) everything I've tried in it.  Even the 147 grain lead and plated hollow points I loaded for my M&P 9MM and XDM 9MM.

The issue might not be the brass case diameter.  It might be the bullet shape and how much of the bullet is sticking out of the brass.

Remove the barrel from the slide and drop some of your reloads into the chamber.  They should easily drop in, all the way, so that the bottom of the case is flush with the back of the barrel hood, or just slightly below it.  But you've got to look at overall length of the cartridge as well as you can't just seat the bullets deeper to keep the bullet from contacting the lands or it may cause higher chamber pressures.

There are a lot of threads here about how to check your reloads (or even factory load as some pistols have issues with some factory ammo, too) and even more threads about recommended cartridge overall length.

Sometimes a search is a quick way to find good history/details to help you figure out problems.  That gives you some better understanding of what is going on and what kinds of questions to ask folks.

[lala land]

I can't speak for OP, but for me it's definitely not an OAL issue. I do the push test for all my new loads, and then back off 0.015.

99%+ of the rounds I load are fine. Then occasionally one stops the slide just short of battery. When I get home I measure OAL and crimp and they are within spec, but it fails the plunk test.

[Wobbly]

Today I went to put 200 rounds through my P-07 and had a situation I've never encountered before. I had remanufactured ammo that ran perfectly and some reloads that were struggling. The reloads were 124gr flat nose 9mm.....

This is a very common problem for new CZ reloaders. See the cartoon below...



In Europe, nothing but FMJ RN is available, so the CZ rifling is brought up nice and close the the ogive of the RN bullet, as per the center example.

If you were using true FP, then those usually they have a sharp shoulder that brings the .355 diameter forward of the case mouth, as in the example on the left. So your issue will be collision of the sides of the bullet with the rifling.

If you were using RN FP, like is common to 40 cal and 357Sig, then your bullet may look more like the example on the right. So your issue will be collision of the bullet's ogive with the rifling.


How can you tell if the bullet is good for the CZ before you buy the bullets? It's not exactly a roll of the dice, but it's close. The only way to know for sure what the best OAL is going to be is by working with a physical bullet sample in your barrel. Or you can always ask here is anyone else has loaded the bullet.

As for diagnosis of the present issue... blacken the bullet with a Sharpie marker. Then drop it in your naked chamber and turn it back and forth about 15 degrees while pushing the bullet into the chamber. The area of contact will be VERY apparent.

Shorter OALs do help in a lot of situations, but NOT every bullet made is suitable for reloading in the CZ. Each bullet has to be taken on a case-by-case basis. It's important to remember that before ordering 3000 bullets from a company no one here has heard of or tried. A "greats deal" on a big batch of bullets that can't be shot is not a great deal.

Hope this helps. 

[M1A4ME]

Great diagram Wobbly.  Hope you don't mind, I just saved it to my PC for future reference.

Thanks

[warriorsoul]

Thanks for all the info guys.  I'll have to switch back to round nose for my cz loads. Just hate having to buy another batch but at least my Sig & Shield will take the flats.

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[Wobbly]

Thanks for all the info guys.  I'll have to switch back to round nose for my CZ loads. Just hate having to buy another batch but at least my Sig & Shield will take the flats.

That may, or may not, be true.

Most of the members of this forum are shooting FP bullets in their CZ's on a regular basis. You won't know if it's possible until you Push Test your particular bullet into your CZ chamber.

See this thread right here.

 

[warriorsoul]

I shortened my oal by a tiny amount. Then I increase the crimp which actually seemed to have done the trick. The dummy round was getting easier to go in each small increase in the crimp die. I was barely crimping before. Now it passes the plunk test, but I haven't loaded a batch to range test yet.

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[1SOW]

With 124gr flat nose 9mm,  the "crimp" is a "taper Crimp" that only closes the case mouth belling added by the powder die  to allow the bullet to be started more easily into the case for seating. 

If your increased crimp is going down to .355" or less,  you're probably distorting the bullet base. .376 to .378" should feed smoothly IF the oal is proper.
As Wobbly said,  the "Push Test is a simple reliable way to determine. the max usable oal 'that' particular pistol will accept. 

This darn cell phone's auto corrections are AGGRAVATING!!!

[Wobbly]

I shortened my oal by a tiny amount. Then I increase the crimp which actually seemed to have done the trick. The dummy round was getting easier to go in each small increase in the crimp die. I was barely crimping before. Now it passes the plunk test, but I haven't loaded a batch to range test yet.

Friend, you are possibly making things worse, not better. As 1SOW said, taper crimp and OAL are 2 different beasts, totally unconnected in their use and application. In effect you are trying to relate height and shoe size !

? Taper crimp is a function of the chamber diameter. Once it is set (usually between .376 and .378") it is never changed. You might need to check it once a year to make sure any die wear is accounted for, but that's it.

? OAL is a function of available chamber length, as determined by the bullet-to-barrel fit. Every time you change bullets, you need to check this fit.


Did you follow that ? Don't load anything until you get this drilled into your head or you'll simply make a batch of ammo you'll be forced to take apart. Dis-assembling ammo is not nearly as much fun and loading correct ammo.

 

[joedirt199]

I loaded up some xtreme 125 gr 38 flat point for my 9mm p09 and they shot well with 5 grs of cfe pistol. OAL was 1.05 even though the manuels say 1.069. Bullet profile was hitting the rifling and having trouble closing all the way. CZs have tight chamber specs.

[Wobbly]

I loaded up some xtreme 125 gr 38 flat point for my 9mm p09 and they shot well with 5 grs of cfe pistol.

Joe -
You have evidence of several misunderstandings in your post. Not to be negative, but to help you understand your errors so that you can grow as a reloader, below are my comments...

OAL was 1.05 even though the manuals say 1.069.

The manual may well say that, but they are in no way recommending an OAL of 1.069", or any other OAL. They are merely reporting what they used. Big difference. So why do they "report" the OAL? Because the OAL is part of the load data, as much as the powder load or bullet weight is.

Bullet profile was hitting the rifling and having trouble closing all the way.

I hope you didn't shoot these because that's a VERY dangerous situation. The Number 1 Objective of your reloading should be Safety. And the Number 1 Safety Rule is don't load cartridges that won't allow the gun to go fully into battery. Have you ever been blasted in the face by an air hose? Well, as uncomfortable as that was, it was probably only 90-100psi air. Inside the 9mm chamber are hot gases up to ~33,000psi !! If the gun does not go into battery and "lock up" then the back of the case can blow out, peppering your face and eyes with red hot bits of flying brass. This because the cartridge case was "unsupported" by the steel of the barrel.

So how do you determine the correct OAL for your bullet in your gun? You start by reading the sticky at the top of this forum entitled "How to determine Max OAL for a CZ Pistol".

CZs have tight chamber specs.

No, actually the chamber size is set by SAAMI. Manufacturers must comply with SAAMI in order to import their gun. What CZ and several other eastern European barrels have is a short "freebore". Freebore is not standardized among barrel makers, as you can see in the cartoon below...




The bottom line is that until you learn to reload correctly, you are a danger to yourself and those around you. You need to invest some serious time reading and learning to reload correctly before you shoot another round.

Regards