[domzilla9]

I bought a new KelTec P3AT and took it to the range today after stopping home for a quick cleaning (no fluff-n-buff).

I fired 228 rds of ammo through it at the range. 50 rds S&B, 50 Rds Winchester White Box and 28 rds of Corbon 90gr +P. I expereience four failure to ejects, all on the **corbon** ammunition.

Here are the empty cases from the last seven rounds of corbon that I fired through the gun:

and

Note that I fired only about 28 rds of FMJ through the gun before trying some Corbon. All of the Corbon brass was bulged this way, but most extracted and ejected flawlessly.

I thought that this bulging and case deformation may have been caused by the feed ramp impacting the bullet head of the next round in the mag and causing it to be seated deeper and thereby increasing the case pressure. But how far down does the bullet have to go before the pressure is increased? I checked for the "smiley syndrome" on both the FMJ and the JHP rounds frequently and only noticed a hair trace of it on the Corbon JHP ammo and none on the FMJ. The JHP bullets did not appear to be pushed in as the cartridge in the mag appeared to be the same height as one fresh from the box to my naked eye. Unfortunately I did not have calipers with me.

Does anyone know what could be causing this? I would like to carry Corbon in my P3AT but will stick with S&B FMJ for now. Thanks for your time. KTRange is a great place!

 

[flyandscuba]

Wow! That is some serious case bulging. It looks almost like the rounds are being fired without the slide being completely in battery...

 

[domzilla9]

I know that's what it looked like. These were all shot slow fire. I noticed the case bulging right away and I checked to make sure that the slide was in battery each time. Also, there was no case deformation on the standard pressure FMJ rounds fired (200 of them).

 

[Midiman]

Then the only other explanation is... the cases are being bulged after partial ejection. I've only been able to find one box of .380 Corbon so I haven't fired any of it yet. It's functioned fine with UMC ball and Fed. Hydra-Shoks. It's currently in my pocket with the Federal.

 

[diamondmike]

CorBon

I used to do alot of reloading, I had a book that showed you what to look for on the cases before reloading then.

I remember seeing a rifle case with a bulge on it with a crack in the middle, it said that the rifle that fired that case is unsafe and could blow up, it said the cause was a loose chamber from where hot loads had blowen the walls of the chamber out!, I would not shoot it anymore until you get it checked out!, they say your gun is only as strong as the bullet case in the gun.

I use only CorBon for selfdefense and have had no problems!, all my empty cases come out with a dent in the top but never a bulge, BE CAREFUL!

$800 Box

 

[Flyer]

Yep, your slide is definitely unlocking before it should... some of those rounds look seriously on the verge of case rupture.
One possiblity to consider is that you've simply got a P-3AT with a bigger-than-spec chamber.
At any rate I'd wait till Bloodwalker (Marty) sees these pics... it's possible you need a new barrel.
That kind of deformation is simply NOT acceptable.
Flyer

 

[flyandscuba]

Hey Domzilla,

You sure you didn't get the new prototype P-3AT with the MAK barrel?? :shock:

Seriously, have you taken the barrel out and placed a round in the chamber to check the fit? Maybe it isn't a snug fit (oversize chamber), or the headspace isn't correct (maybe the headspace is too short) -- either way, you can probably expect a new barrel from KT.

 

[Guest]

Fly, are you kidding me.....is there really a P3AT coming out with a 9X18 mak barrel?

 

[Flyer]

Nope, no 9 Mak barrels.
Flyer

 

[Guest]

shitake.....what a great idea....that would in essence be the 9mm single stack from Kel Tec that everyone wants.

 

[domzilla9]

Headspacing?

crap.....what a great idea....that would in essence be the 9mm single stack from Kel Tec that everyone wants.

I couldn't agree more! What a great single-caliber pairing that would be! Here's a photo of my "carry mak" with my p3at:

The photo below shows a .380 WWB cartridge resting in the chamber of my p3at barrel:

There is a little side to side play between the cartridge and the chamber walls, but no more that there is in with a 9x18 cartridge in my makarov.

However, note the amount of cartridge walls that are exposed when the cartridge is resting in the chamber (inverted, resting on muzzle end). Is that normal? Is this chamber properly headspaced?

One day, when the stars are in alignment, I'll be able to buy a KelTec product that is NIB that functions as it is supposed to. So far I am 0 for 3. Three new in box purchases and five trips to the factory. I know that KT will make it right. In fact, I am tempted to splurge on another P3AT this afternoon - I decided this morning that a second P3AT is in my future after sent my recoil guide rod sailing to the nether regions of my basement work room when I was disassembling the gun to take the picture above. I could order the spare parts, but it makes more sense to just buy a second gun.

 

[domzilla9]

I assumed that the cut away on the sides of the chamber was essentially a "visual loaded chamber indicator".

 

[flyandscuba]

I think you may have a headspace situation there. Here are a couple of pics of my new HC barrel. Sorry for the quality -- but my reources are limited here in the hotel room.

 

[Flyer]

but my reources are limited here in the hotel room.

Gee, that's funny... a hotel room is about the only place my resources are really put to full actio -
Oh nevermind.
Flyer

 

[domzilla9]

thanks F&S! I've messaged Bloodwalker (Marty).

Did you notice the difference in my barrel hood from yours? The corner of mine bevelled. What is up with that?

 

[Midiman]

Re:

I think you may have a headspace situation there. Here are a couple of pics of my new HC barrel. Sorry for the quality -- but my reources are limited here in the hotel room.

Are those Corbon rounds in your pics, Fly? I'll try to get some of mine up tonight if they look noticeably different.

 

[diamondmike]

Ammo bulge

I was too lazy to take mine apart to look!, I have no way to post a picture anyway.

I would take a flashlight a piece of white paper and look down the barrel for maybe a small burr or even powder and copper build-up where the chamber meets the rifling

$800 Box

 

[domzilla9]

I am not sure that I follow you Diamond Mike.

Fouling in the rifiling could cause this case deformation? Please elaborate. I don't understands. Thanks!

 

[flyandscuba]

Dom -- Not sure about the barrel hood difference -- it is noticable. I will say that at one point I had four P-40s in my possession at one time -- none of the feedramps were identical and two barrels had right-hand rifling, while the other two had left-hand rifling...

Midi -- normally, I'd have Cor-bon -- but this trip I'm carrying some of the new S&B JSP ammo I bought from SG.com

Any differences in the case design may make a difference.

If I can scrounge up some Cor-bon tomorrow, I'll try to take a few more pics with it in my barrel.

 

[diamondmike]

Build-up

domzilla9,

Not so much in the rifling, but inside the chamber it is smooth, then just before the rifling there is kinda a ring like where the rifling begins, this area is always a trap for debris. If there is debris in this area it will not let your bullet go all the way down, holding the bullet up from seating in the chamber correctly.

$800 Box