9mm chamber / barrel question?

[Mstrty]

A little background:
My wife bought a 9mm handgun. I dont want to start a war lets just say its was made in Croatia chambered in 9mm with a 5" barrel and polymer frame. She uses it to compete in IDPA. She started with a sig 226 but wanting a single action (or striker fired) gun she opted to give this gun a go. Rich over at canyon creek installed a bomar sight cut into the slide and did a nice 2.5lb. trigger in it. It has its factory barrel in it.

Here is the issue:
I am having about 1% of my reloads failing to allow the slide go into battery. So I started chamber checking with a dillon chamber die. I discovered a few rounds that had slight resistance but all were able to fit. Next trip to the range it locked up again. It fires and then fails to go to battery about 1 round per 100 rounds fired. Sometimes it locks up so bad she has to grab the slide with her week hand and slam the grip with her strong hand. I bring the failed round home and discover that it doesnt fit into the barrel. So we start checking everything with the barrel. We pulled about 20 rounds out of 100 that didnt fit perfectly. Out of those 20 I started dropping them in again and noticed on some of the slightly oversized rounds if I rotated them 90 degrees they would fall in and fall out. If I rotated them another 90 degrees the wouldnt go in. I took all 20 suspect rounds and tested them on a sig226 barrel and they all fit perfectly. Most of my brass has been used 3-6 times.

The part I dont understand is:
Are some chambers oval? Is there a chance I have a bad barrel? Is this barrel just extremely tight? Im still concerned with the odd barrel shape.
suggestions?

[RollingCode3]

I dont think there is anything wrong with your barrel. Either polish the feed ramp or replace the recoil spring or both. Just my two cents.

[fullrearview]

Even if chambers were oval, common sense tells me they would fail closer to 50% of the time..... I don't know much about reloads, but 3-6 times....Is that a lot??

[Munk]

GLOCK BULGE.

Google it.

Unsupported chamber = bulge at the feed ramp.

Cure = new barrel or not using glock-fired brass. Full length case sizing might do it, if you've got a push through die.

[railroader]

I know on my cz75 I have to watch my overall length with certain styles of bullets. If I load the rounds too long the bullets get into the rifling which keeps the gun slightly out of battery. Also if factory ammo chambers fine try running your finished rounds through a Lee factory crimp die. This die will crimp and resize your cases after they are loaded. I have to use this die on my 45acp ammo I make so they feed 100 per cent. Mark

[willssmithing]

If the cases are correct, the chamber should be reamed with a chamber reamer and checked for proper head space. This problem is not uncommon.

[J-cat]

It is prolly your ammo. Most 9mm dies do not return the case to original factory specs. This is compounded if you use a progressive press as these do not allow the die to size all the way down the case. Lee makes a "U" sizer die with an undersized carbide insert that reduces the diameter of the case by another couple of thousands overy your RCBS/Redding/Dillon dies. It is a cheap and easy fix to chambering issues.

I use a single stage and shaved metal off the top of the shellholder. This allows my cases to do deeper in the sizer die. Being that 9mm sizer dies have carbide inserts with tapered internal profiles, the deeper the case slides into the die, the more it is sized.

[XDRoX]

3-6 times fired brass is fine. I'm over 20 times on some of my 9mm brass and it still shoots. Plus worn brass wouldn't cause this problem IMO.

I also don't agree with the glock bulge post. I know tons of people that reload glock brass with no problems, myself included. Early glocks chambered in 40 did pose a problem and sometimes caused brass to bulge. This was never a problem in 9mm. And with modern glocks this is not an issue any more.

I can tell you with certainty that of my guns, Sig has the most unsupported chamber between XD and Glock and Sig. I once even took a picture of the three barrels right next to each other to show that they are all just about equally unsupported.

To the OP, do you have a case gauge? If so, do the rounds fall completely in and fall out (easily) when the case gauge is turned upside down?

If so, then the problem is your barrel.

My guess is that your rounds will not case gauge properly meaning that your problem lies in your rounds. My guess is that they work in your Sig because the Sig has a slightly looser chamber than your XD.

What are you loading on?
What dies are you using?
Are the problems isolated to one brand of brass?

One last thing. I have run into bad batches of brass that would not case gauge. But they always fired without issue in my XD. I do however have a very early model XD with lots of rounds through it.

I almost forgot, please do not use a LFCD. It will only mask the real problem.

[eaglemike]

Is the barrel really, really clean? Sometimes crud gets built up at the front of the chamber. The can contribute to the problem. The chamber could be a little out of round, or the reload could be a little out of round, or both.

I've seen copper plated bullets bulge the case just below the crimp and bulge out just ahead of the crimp. This resulted in chambering problems similar to what you are experiencing.

[XDRoX]

I've seen copper plated bullets bulge the case just below the crimp and bulge out just ahead of the crimp. This resulted in chambering problems similar to what you are experiencing.

This is what I'm guessing to. And if this is the case, the problem can be fixed by properly adjusting the dies.

[foxtrotuniformlima]

If your reloads don't pass the case gauge test using the barrel out of the gun method, I'd say the problem lies with your reloads.

If you were to use a box of WWB and have the same problems, I'd blame the barrel.

[Dubious_Beans]

I know on my cz75 I have to watch my overall length with certain styles of bullets. If I load the rounds too long the bullets get into the rifling which keeps the gun slightly out of battery.

^THIS^

I also have a polymer "made in Croatia" pistol.
I have to be particularly careful about COAL with some types of bullets.
In particular, the Bear Creek TFN lead bullets I have to load to less than 1.100" COAL or the bullet will stick in the rifling and not always go into full battery.

Remove the barrel from your pistol and drop a load into it and see if it goes all the way in easily. If not, try a slightly shorter COAL. (don't forget to reduce powder charge when experimenting with shorter COAL.)

I've NEVER had a problem with factory loads. Only with reloads using lead bullets and to long COAL.

[Dubious_Beans]

Out of those 20 I started dropping them in again and noticed on some of the slightly oversized rounds if I rotated them 90 degrees they would fall in and fall out. If I rotated them another 90 degrees the wouldnt go in.

Oh, and this sounds like you aren't getting the bullets seated quit straight, so they've got some "wobble".

Maybe just a little more bell on the brass before seating bullets?

I'm curious. What brand and type of bullets are you using?

[bjl333]

I am thinking your sizer isn't doing its job. Sounds to me the rounds need to be skinnier or rounder from your sizer. Have you shot factory loads out of the gun ? Buy a couple of boxes and try, you'll find the factory's will shoot just find. I really don't think your chamber in a XD would be off. It could be a little smaller then the Sig's(I'm assuming same reloads thru Sig), but shouldn't be oval.

[Table Rock Arms]

This is more than likely an issue with reloads. Try a few hundred rounds of factory ammo, and you will know for sure.