Seeking opinions on out of battery fire

M

Mike38

New member
First a little info. Pistol, Benelli MP95E Atlanta. This is the less expensive version of the Benelli MP90 which is used in Olympic competition as well as Precision Pistol competition. Ammo case in image, Eley Practice.

Normally, CCI-SV passes a "plunk test". Eley fails the plunk test, but experiences fewer failures, so I have been using Eley.

I have been experiencing "light strikes" with CCI-SV, and less frequently with Eley Practice. Something in my cranium told me this was happening because the cartridge was not fully entering the chamber. So I super cleaned the chamber with a .25 bronze brush. Fewer light strike problems, but start up again after 50-60 rounds.

Yesterday at a Precision Pistol match I believe I proved my theory. Please look at fired case. You will see what appears to be an out of battery fire. I caught it this time because the empty ejected into my forehead and landed on the bench directly in front of me. Being the last round of a string, I picked it up to examine.

So, my question is, what do I do?

Others believe that I should replace the recoil spring which may be weak, not letting the action close fully. While this may be true, it will also dampen the rearward movement and I may experience failures to eject. I have an occasional failure to eject already (stove pipe) and don't want to add to it.

Also in the picture, notice the length wise scratches. Where are these coming from? Dirty chamber? Rough chamber? Happens during an out of battery fire?

Thanks for any replies.
 

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I should also add, one person on a different forum doesn't think it's out of battery firing. He believes it's opening too soon / not enough delay on the blow back. Which leads me back to a weak recoil spring. Right?
 
Light strikes + cases that look like your picture strongly suggest out of battery/partially out of battery issues. If you weren't having light strikes and your only clue was the case appearance then early opening would be the more likely cause.

I would go ahead and replace the recoil spring just because it's probably cheap and easy to do so. But I don't think that's going to make a big difference.

Here is the problem. "Eley fails the plunk test..." The plunk test determines whether or not the ammo in question is compatible with the chamber in question. You're using ammo that is incompatible with your chamber. If you want to use ammo that won't chamber properly then you should see about having your chamber reamed (by a well-respected rimfire gunsmith) to accommodate the ammo.
 
I don't claim to know much of the pistol other than what I recently looked up. A striker fired pistol like my Glock or Raven 25ACP IMO are much more dependant on the state of the recoil spring to function/cycle properly. On the double action trigger of the Glock the slide will move out of battery as the trigger is pulled with recoil spring removed. This may cause lite strikes or a out of battery firing when the recoil spring is too weak.

A new inspec recoil spring should not cause ejection issues. Likely cause may be ammo, ejector or extractor.

The higher the overall precision of the arm the more picky it would likely be of make and model of ammo.
 
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Excessive headspace is also probable. Take it to a competent gunsmith, and he should be able to take care of it for you.

-TL
 
My experience with headspace problems resulted in the rim of the cartridge blowing out, or completely off. Had it happen with two different pistols.

Take it to a good gunsmith is a great suggestion.
 
Excessive headspace is also probable. Take it to a competent gunsmith, and he should be able to take care of it for you.
Click to expand...

Correct me if I'm wrong here, and forgive my misuse of proper item names, but a .22LR headspaces on the rim, right? This pistol has a flat breech face, no recess for the rim. The recess or relief for the cartridge rim is in the bolt face. The depth of the recess or relief in the bolt face is 0.037. Rim thickness of this Eley ammo is ~0.038 and the CCI is ~0.039. So the head space would be zero, or even negative 0.001 to negative 0.002.

Am I making any sense here?

If I'm correct, there is no way I have a head space problem, right?
 
I should add, doing a "plunk test" the CCI drops into the chamber fully, all the way down to the rim. So chamber depth should be just fine. The Eley stops short of the plunk test, but can easily be pushed down fully. The failure of the plunk test of Eley is due to excessive wax bullet lube. If I wipe off the Eley bullets, it passes the plunk test.

All this still leads me to believe the bolt is opening too early, and the pressure is still too high in the cartridge. A new recoil spring should prevent early opening, correct?

Or am I totally wrong?
 
Your assessment on headspace is correct. Headspace is unlikely.

How is the chamber mouth? Does it have chamfering all around?

It is a direct blowback action. The bolt opening is mostly dictated by the bolt's mass. It is rather unlikely the action opens prematurely.

-TL
 
The chamfer of the chamber mouth appears to be even, and of the same angle and depth of a High Standard Citation that I have. A Ruger 22/45 I also have appears to have quite a deep chamfer, but I've never noticed problems with it.

I should receive the new recoil springs Friday, and will install one then report back. I may try a few rounds tomorrow anyhow. I cleaned the chamber again today, (even though it didn't look that bad) hoping that will eliminate most if not all problems.

Thanks.
 
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I suspect the problem is that the bullet shape is preventing the slide from closing completely; this is worse after a little lead and crud buildup in the chamber. A gunsmith "quick fix" would be to run in a chambering reamer, but barring that, I would replace the recoil spring so the slide will be forced into battery. Frequent cleaning would probably help but would be a large PITA.

Since that pistol is made for match use, it probably was set up with minimum tolerances, so be warned that you might end up with a choice - reaming the chamber will probably correct the seating/misfire problem, but possibly at the cost of slightly reduced accuracy. And you can NOT undo the reaming. Try the new spring first.

Jim
 
The failure of the plunk test of Eley is due to excessive wax bullet lube. If I wipe off the Eley bullets, it passes the plunk test.
Click to expand...
If your ammo won't pass the plunk test you're going to eventually have problems. Maybe not when the chamber is perfectly clean, maybe not when you've wiped all the lube off the bullets, but eventually. If the results of the plunk test didn't mean anything no one would have ever come up with it.
 
Thanks much for the replies. Drove to the range this morning to try the Benelli with a cleaned chamber, no new recoil spring yet, and the range was closed. Bad storm took down many trees. Couldn't even get into the driveway. Will try my luck Sunday I guess.
 
Update: Made it to the range this morning. New recoil springs came in, but as I learned years ago when troubleshooting any piece of machinery, do one thing at a time, then test. If you do two things and the problem goes away, you'll never know which one cured the problem. So with a clean chamber and old recoil spring, I started my weekly training session, with CCI-SV ammo. Got to round 50, no problems with light strikes or extraction. I stopped to do a "plunk test". All's good so far. Another 50 rounds, no problems what so ever.

Larry's Guns Inc. sent a Questions/Answers/Trouble Shooting guide for the Benelli MP95E along with the new recoil springs. After reading it over, it looks like 90% of problems with these pistols can be blamed on a dirty chamber. They aren't kidding one bit. I've never owned an European target pistol until now, so I can blame this on inexperience.

Got home, cleaned the chamber real good again, installed new recoil spring, should be ready to go.

I hope my ignorance / inexperience will help someone else later down the road if they find this thread on a search. Clean the chamber, then clean it again, maybe even a third time. It just may solve your problems.
 
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