PX4 Storm .40 Failure to return to battery


September 9, 2011, 03:41 PM
I have had a few insidents of failure to return to battery with my reloads, maybe 2-3 rounds out of 50, and this has never happened using factory ammunition. All it taked to return to battery is a very very light push with my thumb.

The rounds that I have checked drop easily into the barrel and my OAL is very consistant, last batch was 1.127 +/-0.001, better than factory loads I have checked. My loads were a little on the light side, 165 grain plated FP, loaded with 7.4 grains of HS-6. Brass was all run through Lee's bulge buster as it was range pickup to begin with.

What should I be looking for? As the rounds seem to fit the barrel just fine, could something be going on with the extractor? I suspect this since I did have 1 round that would not go into battery even with pressure, I saved this round and it easily dropped into my barrel. It seemed that it would not slide into the extractor fully, seemed strange to me?

If you enjoyed reading about "PX4 Storm .40 Failure to return to battery" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
September 9, 2011, 04:28 PM
as it was range pickup to begin with
See if you can isolate it too one particular Brand of cases.
Also look at the ones that didn't feed for any sign of bent rims or extractor damage/burrs from some other gun they were fired in.

Also roll them on a flat table and look to see if the case rims appear to be 90 degrees from the case walls.
Some guns can bend case heads because the breech face isn't perfectly square with the chamber.

Could be goofy rim variation in one brand of brass, or crookedness causing them to hang up while sliding under the extractor.


chris in va
September 9, 2011, 04:28 PM
OAL might be a bit off. Was it almost chambered or kinda jammed on the feed ramp?

September 9, 2011, 04:40 PM
OAL was my first suspect, I check many of the rounds and they are right where they should be. My PX4 has chambered many rounds from 1.120 to 1.130, these were 1.127 +/- 0.001.

Not sure about the feed ramp, what should I be looking for? The Beretta Storm has a very short feed ramp that is partially polymer, so I really can't polish it?

September 9, 2011, 04:53 PM
Stormin.40 ........

I recommend making sure each of your handloads fit inside a "drop-in" case gauge (like Wilson's). If any rounds don't fit, it would be good to pull those bullets and start over. The .40S&W cartridge is a very high pressure round, and you don't want to experience a round firing when it's not fully in locked position. My website has a good article about the subject on firing bulged cases.


Bulged cases are not always detectable without actual measuring. Glock chambers are the most apt to cause bulged cases, but it's not just Glocks. Sometimes a gunsmith with an over active Dremel tool can create an oversized feed ramp. This will make any handgun bulge cases.

Be especially careful with high pressure calibers like the .40S&W.

- Good Shooting

September 9, 2011, 04:58 PM
find a good synthetic slide lube

September 9, 2011, 05:06 PM
Since I use a lee bulge buster I thougth I would have taken the any potential bulges out, I don't check every round in my barrel but will on the next batch and see if I come up with anything.

My pistol doesn't like light loads, fails to eject regularly, so since I am just in the mid range now maybe I need to up the powder charge a bit, this along with a "slicker" slide might fix the issue.

Thanks for the suggestions!

September 9, 2011, 05:15 PM
I think what "Chris In Va" was refering to if I may interpret his response, is what ever OAL has worked in the past with other bullets isn't relevant. This is because most all bullets have different olgive locations, so what may be a functioning OAL with brand X and that bullet weight, isn't likely to be the same with brand Y. This is why each and every time we pick up a new box of bullets, even if they are the same brand and part #, they may have a sightly different olgive location unless from the same lot #. Though this is not so much a factor with exact same bullet manufacturer and part #, it deffinitely applies to other brands and part #'s.
So in this respect it is vital to go through the entire OAL process each time you use a different brand of bullets, and as well things can change with brass too. It was just yesterday I was loading up some rounds and when I switched brass head stamps I forgot to check my OAL and ended up pulling a bunch of rounds a little bit and re-designating OAL because they were jamming into the lands. It's a normal and regular practice when I have my thinking cap on, and haven't forgotten to do it.
And another already possible is the brass may in fact be out of square. That to is a common issue I encounter when using range pick up brass.
And not knowing the history of your firearm, is something you could better evaluate regarding the extractor. Has this firearm ever given you a simular problem since having reloaded for it, or at all in the past? If yes, you might be dealing with an extractor issue, the spring possibly being too heavy, or maybe the extractor has a small flaw, maybe a rough spot on the outer contact surface.
And here's another rather common possible cause. Are you crimping your brass or closing the mouth belling, likely so. And if so, do you trim your brass to same lengths? I find this to be a common cause of many issues simular to what your experiencing. Even if all you are doing is closing the bell on the mouth, if you have range brass that some is considerably longer or shorter than others, it can interfere with the action returning to battery. And in all honesty, I find this problem more often than not to be the culprit. It doesn't take a whole lot, .002"-.003" to cause an over crimp. And on the flip side of the coin, if the brass is a little bit too short to completely close the bell, that slight discrepancy can interfere with the action completely closing, or returning to battery.
Usually when something like this is popping up and the firearm has always functioned reliably in the past, we can pretty much narrow it down to something we are or aren't doing, or seeing.

September 9, 2011, 05:45 PM
Thanks for the clairification gamestalker, I did mis-read Chris In Va's response. The rounds are not stuck on the feedramp they are almost fully chambered, maybe 1/8" out. As the failure rate is so low I thought it must be the brass, but I can only visually inspect and resize so if I can shorten or lengthen the OAL a bit to more reliably chamber I will do so.

This weapon has never had any failures on factory ammo and has been okay on most reloads again only about 3-4% failure and only on returning to battery. I must be my reloads, since factory ammo is 100% reliable:banghead:

I don't know much about extractors so I don't know what to look for nor how stiff it should be. I will do a close inspection and see if I can find anything out of the ordinary.

I don't trim the brass, I do however sort headstamps so my OALs are very consistant. It has also helped with consistant crimps, though not perfect.

Thank you again for the good suggestions.

September 10, 2011, 05:55 PM
Case length, crimp are biggest problems. A case gauge will probably NOT do any good, they check OAL, not crimp diameter. A dirty extractor would act the same on re-loads or factory. Set your taper crimp for shortest cases.

September 10, 2011, 06:12 PM
The Wilson case gauge does check for case diameter. In fact, that's its main purpose. The taper crimp is required for the .40 S&W, and a roll crimp is definitely not acceptable for the .40 S&W. Competition shooters will always check their semi auto handloads with a drop-in gauge.

I've seen more experienced shooters fooled by bulged cases than by failing to get a simple crimp right. Inexperienced reloaders . . . . that's anyones guess.

September 10, 2011, 06:47 PM
The rounds are not stuck on the feedramp they are almost fully chambered, maybe 1/8" out
With the rounds that did not fully chamber, could you do a drop test with the barrel out of the pistol?

I had similar experience with tight chambered Lone Wolf .40 barrels in my G22/G27 and the slide would not return to battery the last 1/8". After some checking, it turned out to be not enough taper crimp. The offending rounds would not drop freely into the chamber with the barrel out of the pistol. Once I adjusted the taper crimp to .420" for .400" diameter bullets (just to un-bell the flare), they all fell in with a "clink".

My loads were ... 165 grain plated FP
If you are using Berry's plated bullets (http://www.berrysmfg.com/products-c58-Berrys_Preferred_Plated_Pistol_Bullets.aspx), they may be sized at .401". I would adjust the taper crimp until the finished rounds would drop freely into the chamber.

BTW, I don't trim semi-auto pistol brass.

September 10, 2011, 07:57 PM
I will use my barrel, removed of course, and drop test every round. If a few don't pass then my guess is this is probably the cause. If everyone passes and I still get a few failures I will have to have my extractor looked at. I still suspect my loads my be on the light side for my pistol.

September 10, 2011, 09:13 PM
Light loads MAY cause the slide to not go into full battery, as the return spring is not compressed enough, but you probably would also get some stove-pipes.

September 10, 2011, 09:31 PM
If you measure the case mouth diameter of a reloaded cartridge, what do you get?

September 12, 2011, 10:21 AM
Mehavey, I am traveling and don't have calibers with me. As this is a new batch of reloads and I reset my seater/taper die for every batch and headstamp, I can't say for sure that this measurement will tell me what the previous batch was. I will measure when I get a chance, and see what I am getting.

I checked many, not all, by dropping in my barrel. All fell in freely but a few didn't fall back out freely so I assume they are boarderline sized.

September 12, 2011, 02:00 PM
Turn your crimp die another 1/4 turn. Set your die for the SHORTEST cases. Straight walled cases get SHORTER with repeated firings. Crimping won't resize the lead bullets. I have a single stage press and can tell by feel if a case is shorter. I don't bother to sort by HS(except to cull FC).

September 20, 2011, 12:59 PM
I still haven't had a chance to measure the crimp at case mouth but I did shoot another 100 rounds without a failure. I have not mearsured the case mouths yet to check my crimp diameter, however, I did drop everyround shot down my barrel (removed from gun). About 4 didn't "tink" but did cycle just fine. The OAL was a little shorter on these rounds so maybe that is the culprit.

Thanks for all the advise!

September 20, 2011, 01:13 PM
I'm not sure how accurate the "tink" method is, but you'll increase the accuracy and reliability of your handloads if you "measure" the crimp at the case mouth. 100% reliability is well worth the extra time and trouble.

Of course, after your die is set perfectly you can get by with the drop gauge.

If you enjoyed reading about "PX4 Storm .40 Failure to return to battery" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!