Hi,

For almost a year I’m the owner of a (2nd hand) 15-22 and like it a lot. I use it for speed shooting and my setup is: standard M&P 15-22, Konuspro M30 1-4x24 scope, ARMS rings, Magpul CTR carabine stock, JP EZ trigger, Magpul BAD lever. It has the blue bolt spring and the new type firing pin.

My problem is that I’ve now twice had an accidental discharge when closing the bolt using the BAD lever after placing a full magazine. I

I checked the trigger, but when cocked, the hammer won’t fall when the rifle is bumped on the floor. The bolt closes when the rifle is bumped on the floor, but I think that is normal.

Reading on the internet that a dirty firing pin could be cause, I disassembled the bolt end firing pin. The firing pin end spring were not clean, but not very dirty (in my opinion). I cleaned them.

I don’t know if the problem is now resolved by cleaning the firing pin and spring (because the AD’s are (luckily) very rare), so I would like to know if there are other possible causes for the AD’s.

Thanks,
Willem

It should not be doing that!
I am not familiar with the mods which were made to your rifle , but that would be where I`d look first . I don't think it is normal for the bolt to close just from a bump on the floor.
AD`s are scary and I wouldn`t be comfortable until I found the cause and solved the issue.
Actually now that you have experienced it twice the next time it happens it will be a Negligent discharge not an AD since you have been forewarned.

How can you do that with all the 3rd party parts that have been put on the gun? The problem has to do with the fire control group and that is what the OP changed out & modified.

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Put everything original back in the rifle and see what happens. The problem will probably disappear. The bolt closing when the rifle is bumped is NOT normal, but why are you bumping the butt on the floor anyway?

Also, it's not a dirty firing pin that may be causing the problem; it's a dirty firing pin CHANNEL. It should be clean and DRY, with NO wet lubricant in it.

Also, as manufactured, the MagPul BAD lever does not fit or work correctly with the 15-22. The NDZ Speed Bolt Release does.

It is completely normal for the bolt to go forward when the butt is bumped on the floor or with your hand on almost every AR platform rifle.
If there is not an empty mag in, there is nothing to keep the bolt catch up and in the way of the bolt.
When you bump it, the bolt moves back, relieving pressure on the bolt catch. That allows it to drop out of the way and the bolt to slam home.

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So is the hammer falling when the bolt closes?

Sent from my ADR6350 using Tapatalk 2

I stand corrected ...

The only 3rd party part that is internal is the JP EZ Trigger. I would change back to factory trigger and take off the BAD Lever and see if it is still doing the accidental discharge. If so then I would call S&W and send back. Just my thought

Change 1 thing at a time.
I learned the bump trick when I was in the Air Force as a Security Police / Security Specialist in the mid 80's
I had a LOT of firearm time with all kinds of goodies.

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Take that rifle out of service until it is proven safe after repair.

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How about u

Willem,

I noticed you said you replaced the stock and recoil spring. That may be cause of the bolt going forward when "bumped".

First, let me say I don't have the military experience that tacticool22 has and he is undoubtedly more experienced with ARs, this is just my experience:

I had a similar situation with a bolt closing when "bumped" with the first AR I had. It was an AR15 A1 that was built by a US importer/manufacturer from late 1970s USGI M16 Colt Hartford parts on a new AR15 lower. The barrel was also new. The upper, bolt, stock, triangular handguards, etc were all USGI, including the recoil spring in the stock and the bolt. I found that if I opened the bolt, removed the mag, and set the butt down on the floor--gently, not bumping it--the bolt would go forward. To me, not familiar with ARs, it seemed that the rifle's action should be able to be open and stay that way if only to comply with range safety requirements. I sent the AR back to the manufacturer who returned it without reparing it stating nothing was wrong. The actions on my M1 Garand and M1Carbine both stay open when set down on the butt or on the side, as well as other semi-autos I own.

I eventually determined after a lot of internet search that the 1970s recoil spring in the butt stock was weak and would partially retract when the rifle was set down on the butt. That partial retraction of the spring allowed the bolt catch to retract, clearing the way for the bolt to go forward. I replaced recoil spring in the stock with a Wolff spring. That allowed the rifle to be set down without the bolt automatically closing. I could still close the bolt by slapping the butt, as tacticool22 describes, but the slap had to be intentional.

I never had an AD/ND because of the touchy bolt. But since you changed the butt stock, bolt catch, and spring, you might try re-installing the original items and see if the problem continues (without live ammo in the mag, of course!--try two snap caps in the mag). If the problem goes away with the original parts, then have a gunsmith fit the new parts.

Check to see that the firing pin moves freely in the bolt. If it is stuck in in the forward position this could cause a slam fire when the bolt chambers a live round. If not you may have other problems going on with the fire control mechanism.

Spad, I think you are talking about the Buffer spring? That would work with a standard AR, but the 15-22 does not have a buffer spring If that is what you are describing.

Chad

Willem:

The bolt thing is normal. I sent my rifle back to S&W and they told me there was no problem with it.

The hammer will generally not free from the the sear and cause a discharge.

Mark

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Buffer spring, recoil spring, kind of the same creature from one rifle to the next.
spad124. Try the bump method to close your M1 Carbine bolt. It takes quite a bit more force, but so long as the bolt catch travels far enough up the ramp to clear the stop, it will go.
It works for the 10/22's that have the modified bolt release too.

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Thanks everyone for the answers.

@Majorik
@Ken L
I also cleaned the firing pin channel, but as far as I could see, the firing pin could move easily before my cleaning pin and channel. It certainly wasn't stuck in an forward position.

@Majorik
With a little carefull bending, the BAD lever works on my 15-22. I'd love to have a NDZ Speed Bolt Release, but NDZ doesn't ship it abroad (and I'm in the Netherlands).

@Erik1987
No, the hammer doesn't fall when the bolt is closed. It stays cocked ans doesn't free from the disconnector no matter how hard (within reason) I bump the stock.

Because the hammer doesn't fall, I don't think the Fire Control Group has anything to do with the AD/ND. (BTW the FCG was installed by a gunsmith.)

Could it be a weak (worn?) firing pin spring?

Willem

Sorry to hear that.

That doesn't mean it's not involved.

I can't imagine a firing pin spring getting that weak in less than maybe a hundred thousand rounds. It doesn't take all that much to keep the FP retracted.

Tacticool22, Thanks, I'll try that.

Triggs75, yes, you're right, I missed the "-22" and was thinking of a straight M&P15-- apologies for lots of info that doesn't apply.

When U looked at the cartridges that AD were they hit in the normal fire pin position with the same mark. I understand the BAD does not wobble so much it strikes the trigger. Being in the habit of putting the safety on before changing magazines or sitting / laying the firearm down.

Attached Images

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Sounds more like what is called a slamfire. When the inertia of the bolt hitting the breech causes the FP to move forward and fire the round loading into the chamber. It is not the trigger assembly, but I would suggest you take the Magpul BAD lever off the bolt release anyway. I found that the weight of the BAD lever often times would cause the bolt to release when either I popped the old mag out or when I slammed the new mag home in the magwell. I have never had an AD in either of my 15-22s but it could happen. Another reason I prefer a 2-stage trigger like the Geissele Super 3-Gun.

Yeah but if you are shooting an event like the PSA Rimfire Challenge where you might have to fire 3 mags to clear the targets on a stage you can't do that. I put a BAD lever on to speed up the mag change but eventually took it off due to having the bolt close early from even the shock of dropping the old mag.

The weight of the BAD lever is another reason to use NDZ's Speed Bolt Release. Not only does it correctly fit the 15-22 with no modification (which the MagPul doesn't) but the weight is only 4.2 grams, considerably less than the BAD lever.

slam fire definitely. weight of lever releasing early, stripping off a round and the firing pin not totally retracted. sure there was not a round still in the chamber that you had not totally cleared?

@my_mp15-22
No, I didn't look at the cartridge. Will do next time (but hope there isn't a next time). Tonight someone I spoke to suggested the extractor might have hit the rim and set the cartridge off.
I keep the extractor clean, but will look into it next week. Tomorrow I'm off on a motorbike trip to Germany for four days

@roadkill45
I'm abolutely certain the chamber was empty because the RO checked it before I started shooting and the AD/ND was my "first shot".

@Majorik
If you can persuade NDZ to ship it to me....

I saw a demo of a M&P 15-22 with a dime stuck edge wise in it, the 22 shell unloaded of powder with only the primer, in the chamber and the gun firing the primer. This means that gun would fire out of battery. Try a fired round once or twice and see if UR firing pin is denting deeply the edge of the spent shell when out of battery, again. If so remove the bullet and powder from a shell and test to see if UR firearm fires the primer when out of battery.

Now this young man has hit the nail on the head, you are experiencing a "slamfire" not an AD. A slamfire can occur for many different reasons, but the rimfire primer is in the RIM, get it, got it, good! ALWAYS keep the muzzle pointed in a safe direction, always expect the weapon to discharge when dropping the bolt on a chambered round, these slam-fires have taught you a valuable lesson, ALWAYS keep the muzzle pointed in a safe direction, ALWAYS!

Amen to the extractor being the likely culprit! billy

The shorter firing pin has been in use for at least the last two years. I haven't read anything about a spate of slam fires.

It makes me wonder if something is preventing the extractor from flexing enough to slide around the edge of the case.

I agree the aftermarket parts are more than likely causing the Ad. I have a bent Magpul Bad Lever that works great once I made a bend that would clear the mag release.

If the extractor is stuck in the down position it could strike the side of the head of the casing. There is a ramp it glides up on when empty on the chambers side. Being free to move it should slide up past the rim of the casing and rest behind it not firing the primer. I would look close to see if it is damaged. It then would probably not be able to pull the empty case back out to eject. Maybe after a few attempts it could empty the chamber.

that's one of the reasons when 'topping off' a handgun, never eject the mag and hand feed a round into the chamber and let the slide go. you can have a ND due to the extractor having to 'hop' over the rim thus a possible ND. more so on a rimfire due to just having to be struck on the edge.

I understand that trigger finger is not inside the guard while holding the firearm one handed and inserting the magazine. Sometimes this bad habit exists while using the left hand to load. It also can carry over to handgun operation. Keeping the trigger finger out until ready to shoot ?

although true what you say above to the max, this incident was a def slam fire, it happens. i had a glock go full auto (that was fun) due to debris in the FP channel not letting the FP safety go up. so FP was out during every cycle, engaging immediately. fun slam fire, but would not want to do it again. good thing i was the only one at the outdoor range that is unsupervised.

In 40+ years of shooting, every slam fire I have seen was caused by the firing pin jammed in the forward position; either broken and stuck forward, a broken FP spring, or a FP channel so dirty and gunked up that the pin could not retract.

I have never seen one caused by the extractor hitting the rim and setting off the priming compound.

@bobermo
I have the new shorter firing pin.

@Lorelei
@my_mp15-22_s&w
I haven't looked at the extractor yet, but I allways kept the extractor clean. And my finger was outside the guard.

The BAD lever works great and was bent to clear the mag release. Also the weight of the BAD lever is no issue, because inserting the mag didn't cause the BAD lever to activate the bolt release. The AD/ND occurred when I closed the bolt with the BAD lever.

I'll have a look at the extractor and compare it with an extractor from another 15-22 to see if it's damaged or something.

I have seen one that was causing it but it was damaged. Once it was replaced the gun had no more problems.

My wife hates the word, "discharge".

If it is a slam fire why has it not gone full auto or even a double once in awhile? When it went bang there was no way to check if the hammer dropped or not because it cycled. Take out the mag spring and follower and slap in the empty mag till the bolt drops see if the hammer is down. A snap cap would work but I can't recall seeing any in22. I would not load this gun until it is fixed. I have heard of sensitive primers going off from a drop but it is rare and your gun only fires on insertion of fresh mag not any other time it chambers. After market mag release and fire control happens on mag insertion only just sayin. Just an opinion without being there.

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Was an early adopter of the ACR and pre-recall my rifle would slam fire on soft primered commercial .223 ammo. It was due to a too heavy firing pin and too weak firing spring.

Recall fixed it and no issues since. Gets you attention,when you close the bolt and it goes "boom" on it's own. Thankfully the rifle was point down range like it should have been.

First, sorry about the delay in coming back to you all.

@Gunswater
Slamming the magazine in doesn't close the bolt. Bumping the rifle does close the bolt, but the hammer stays cocked.

@All
Finally I got hold of an other extractor and compared it with mine and saw mine was worked on: the top of the extractor is "lower" on mine and so it is a bit "blunter" than the original. Being "blunter" it slides not as easy over the rim as a more "higher" or more "pointed" one and could result in a AD/ND.

Asking the previous owner about it and he said he did it (himself!) because the extractor was sometimes not getting fully behind the rim of the cartridge and then didn't extract the empty cartridge.

I then said some things to him I'd better not post here.........

Of course I installed an original extractor. Now I hope the AD/ND will not happen again.

Thanks for all your help.

Willem

If you pull the trigger and flip the safety from safe to fire, it will fire.

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After bumping the rifle? Bumping is done with safety off.

No, just pull the trigger and don't let go. Flip the safety off and the hammer will drop.

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sure will! had a bead on a bunny and had pressure on the trigger with the gun on some shooting sticks, flipped the safety and bang! dead rabbit but it will go off. have not tried this with normal AR's (just because i have never thought of it) but i bet it would be the same.

Of course it will.

The AR15 and 15-22 share the same Fire Control Group (largely the same parts). The Selector Switch has a cam surface that simply stops the travel of the Trigger and prevents the Trigger Sear from disengaging the Hammer Notch. IT DOES NOT interface with the Hammer, Block the Firing Pin or any of that other sexy stuff.

This is why the 1/4"-28 set screw in the grip screw hole is effective at reducing trigger creep. It pushes the tail of the trigger up reducing sear engagement until stopped by the cam surface of the Selector and why the Selector will not move to SAFE if the screw it inserted to far.

This is also why the Selector cannot be moved to SAFE unless the Hammer is Cocked and the Sear in sitting in the Hammer Notch. The Trigger Sear bearing on the Hub of the Hammer will not allow the Trigger tail to be ridden down by the Selector Cam.

The trigger and hammer in the Semi-auto weapon is very simple and similar to trigger and hammer first used in Flintlocks. It just works almost all the time.

nitewatchman

When you stripped, cleaned, and re-assembled the bolt did you take notice of the direction of the firing pin spring?

One end is smaller in diameter than the other, that end goes on toward the back of the firing pin. Since it is smaller it will get stuck onto the firing pin.

Hope you don't run into any more issues!

The AD happened before I took the bolt apart, but when I reassembled the bolt, I didn't notice one end of the spring was smaller. I will take the bolt apart again and check it. Thanks.