I sent my M&P 15-22 back to S&W for firing 2 to 3 shells with one trigger pull. It's been a while back. S&W installed updated springs on the bolt and trigger (blue springs).Since the fix my hold open on last rd works with certain ammo. 510 feds, cci mini mags no problems but blazers and a few more brands, I don't remember the brands does not hold bolt open. The new spring must be stronger. Any fix to this problem other than not to shoot this ammo. I don't like dry-firing or counting rds.

Hope mine comes with a fire burst setting i would have kept it lol

Until the wrong person hears and you get a vacation at "don't drop the soap hotel".

I have been having the same problem as of late. Not all the time but often enough to get my attention. I have been shooting only CCI Blazers. I think it might be the mags, need to start taking note of wich mag's it is happening on.

Dirty bolt catch will prevent the magazine follower from pushing it high enough to catch the bolt. Blow back operation puts a lot of crud in that area. Loose magazine can also do this. Check the magazine catch tension.

-- Chuck

If you change ammo from the blazers you will not have this problem. 510 feds ,cci mini-mag,Gb's,PMC zapper's holds the bolt open. I quit shooting the bulk feds so I don't remember if they will hold bolt open. But blazers sometimes will hold bolt open maybe 25% of the time, I like the blazers been finding deals on them $15 a box of 525( no duds) I like the 510's also but they do not come in a bulk box. I don't think its a mag problem I was sent the new mags and I still have a 1st generation mag all 3 mags do it.

That's why I sent mine back. I don't think I would like that hotel your talking about.

Went out and shot 300 rds of federal 510's today the bolt stayed open every time after I emptied the mag. I don't think it is a dirty gun problem. When I first bought this gun I cleaned it so much because of jamming problem. Then I found out to bend the ejector rod. Then the gun stared doubling so i clean very much again, Sented it back now the only problem is mainly shooting blazers . I haven't clean the gun for about 1500 rds now. I guess its time to clean it now. Since I bought a new barrel nut wrench going to take barrel off and clean thoroughly.

Since I had new springs put in.... the bolt hold open works about 50%. It used to work just fine with the old springs. I really don't care one way or the other. I have learned to accept my 15-22 as an enigma.

I trimmed about .050 inch or almost 1mm off the bolt catch spring. Or 1 and 1/2 turns.
It dropped the preload to nearly nothing, so the magazine spring does not have to work as hard. 100% so far.
Don't trim too much off or the catch will rattle. Put the trimmed end in first so the factory end is against the shoulder of the bolt catch plunger.

Attached Images

Clipped Bolt Hold Spring.jpg (38.9 KB, 580 views)

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I'm glad to know mine isn't the only one out their with this problem. My only concern is dry firing it. It eats any ammo i feed it since the springs upgrade and no feeding problems. It will even shoot GB's now.I will quit complaining now thought there might be a fix.

So after the mod, the bolt hold open was 100%. Then I let a friend shoot the rifle.
The bolt would not stay open after the last round on a lot of the mags. Then we only used the last mag that didn't work. Same thing, sometimes the hold open would work, then it wouldn't.
Then I noticed where they were gripping the rifle. On the mag well, mindful of not touching the mag.
The heel of their hand was riding on the bolt release catch sometimes. So the bolt catch didn't have a chance to work because their hand was pressing on the lever.
They changed thier grip to the handguard and the bolt always held open.
Simple mod to the spring and a simple fix to the shooter.

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In the 15-22, what makes it go multiple shots on one trigger pull? Sorry for the stupid question, I know what you have to change in an AR.

If it isn't a faulty trigger assemble letting the hammer go on its own it can be caused by whats known as a slam fire.
It happens when the bolt closing generates enough speed for the firing pin to overcome its spring letting it 'slam' forward into the shell primer.
Oddly enough its how a lot of full autos like the good old grease gun and the Sten gun work.
Except in guns like them they don't bother with an separate firing pin or spring.
They just use a machined bump on the bolt face and fire from an open bolt.

I installed a fore grip on my rail so I never hold back by the mag. Mine only has problem with certain ammo and one of my favorite cheap ammo it shoots it fine but 75% of the time the bolt does not hold open, blazers. My thought that the ammo does not create enough energy to hold the bolt open. I shot some sv and the bolt does not stay open. Now cci mini mags, federal 510's, GB's hold the bolt open.

I think the bolt hold open feature has more to do with the high spring tension of the bolt catch spring and low spring tension of the magazine.
Here's my theory.
When the bolt goes all the way back, there is a limited amount of time for the bolt catch to pop up in front of the bolt. If there is too much spring pressure for the magazine spring to overcome then it takes too long for the bolt catch action to work. When you pull the charging handle back the mechanism works, because of the huge amount of time. You can't pull the charging handle and release it as fast as a gun can.
You would think the lower powered ammo would allow more time for everything to work, as the bolt would be traveling slower. But more force back means the recoil spring has to work harder overcoming that force equaling more time.
Try the spring mod (remove 1 1/2 coils) and the cheap ammo and let us know how it works.

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Never thought of it that way. I thought the bolt was not going back far enough because of low powered ammo. When you say spring mod can you elaborate on this modification?

Check post # 10 in this thread.

Thanks for the info, post 10 sorta blowed over my head,didn't quite understand it.

The bolt release latch on the left side .You drive that pin out to get to the spring?

Yes, it is called the bolt catch pin. You don't even need to drive it all the way out. Use a 3/32" pin.

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Just got done pushing snow and ice on parking lots. Now I am going to trim my spring. Thanks for the information. When you first told me to trim spring it really did not make sense to me after you explained your theory now it makes sense. When somebody talks of trimming springs on the trigger or such I just vaguely read it because when I usually buy a gun I leave it factory. Unless it does not function properly like in this case.

Well I trimmed the spring. It might be a little while before I see if it worked. Snowing again.

Tacticool; I needed to listen to you sooner. After working till 2 am this morning and getting a little sleep, I just had to try out this mod I did on my 15-22. I only put 5 rds in my 3 mags and shot the 3 mags twice. Every last shot the bolt stayed open even under rapid fire. Happy days are here again !!! THANK YOU

I'm glad it worked for you too. Spread the knowledge.
It's a super simple fix at the factory, all they have to do is put a longer core pin in the mold.

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I am so pleased with the fix tacticool 22 told me to do that I have to post 1 more time. With the blue springs and bolt catch spring trimmed my M&P 15-22 ran flawlessly today !!!!!!

I did a lot of 5rds in the mag to get to the last shot hold open feature so I didn't have to shoot a thousand of rds.
I shot different ammo, fed bulk,510b,510,automatch,
Winchester bulk,wildcats,Armscor Precision sv & hv,CCI mini-mags hp & rn,CCI sv,wolf MT,Aguilla,pmc zappers,blazers,
eley,thunderbolts and peters. THE GUN RAN FLAWLESSLY !!!!
No jams,fte,ftf and the bolt held open every time. This definitely was the fix for the bolt hold open feature. Thanks again Tacticool22. HAPPY SHOOTING

Thanks for the information on the mod Tacticool22 and thanks for bringing this problem up for discussion Bulldozerd8t. I was having the same problem with my 15-22 where the bolt would only hold open half the time. I just completed the mod and I will do some testing on it tomorrow and I will let you guys know how it does.

Yes keep me updated it sure fixed mine.

Well I shot 100 rds today. 20 clips of 5rds a piece. Sometimes shooting slow and others rapid fire. Held open 19/20 clips and the one it didn't hold open on, I noticed my hand was putting pressure on the clip. Overall im 100% positive the problem is fixed!!

I also shot mine today and the only one it did not hold open was I was using the mag as a rest.

Good insights as to what are other problems. So far it looks like 3 things.
1) Holding the mag well and your hand touching the bolt release.
2) Holding the magazine.
3) Using the magazine as a rest.
So I guess we need to not touch the magazine area at all and everything should be fine.

Attached Images

clip vs mag any questions.jpg (32.4 KB, 218 views)

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Went out yesterday with 2 teenagers and we shot my M&P 15-22. A 1000 rds later and my 15-22 held open the last shot 100%. Shooting blazers and federal automatch. The boy's had a blast, so did I.

Glad to hear it's working perfectly bulldozer. I have run a few more 'mags' through mine with 100% success rate. What an easy and effective modification!

Shssssss they don't like somebody calling the mag a clip, I'll keep it quite.(Ha ha) Glad yours is fixed too !!! Happy shooting

There we go!

Phil ,No. 10 post is where tacticool 22 tells the mod to do ,you will not be sorry.

We loaded anywhere from 1 to 10 rounds per mag. Slow to fast fire.
A few people loading and somebody shooting all the time. Constantly switching shooters for different styles and not one single problem. A thousand rounds makes for a BUNCH of mag changes.
It was a great execise for control. Dropping empty mags, loading new ones, noticing when the rifle was empty without having to look. No dry fires at all.
No stovepipes or other jams, so no clearing drills. Sure made for a fast fun day.

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Gentlemen,

I guess I must have gotten lucky{so far}, I have a DAV 18--.

I've put around 1000 rounds of everything you can imagine through the gun. This using five mags.

I have not had one hiccup, even with the remmy's. Bolt hold open has never been a problem.

I am a clean fanatic, so it gets cleaned after every use, just like my Bushy AR and every weapon I've ever handled. That may be a habit from having to carry and depend my life on a weapon every day, all my life. { there's something wrong with that last sentence, sorry}.

I hope I haven't jinxed myself with this. For the life of me, I can not picture this spring location.

I use a bore snake, very mindful of not letting the snake catch on anything, works perfectly, first time I have ever used one, sort of old fashioned with the patches, brushes and rods, I guess. Starting to show my age.

Oh, yea, I absolutely love the new Tactical .22 by CCI, there is a real difference in feel. This is the first time I have ever endeavored to own over 2,000 rounds of anything except my 223. That's getting more and more expensive every day, pisses me off.

I just added a rubberized 4 by 32 Leapers duel color scope, so I get to start all over again sighting it in. Problem is, it's +4 degrees here.

This is such a neat gun to shoot.

Mark

mrasgt. The bolt release latch on the left side has a spring under the area shown in the pic

Attached Images

AR-15 A1 Upper and Lower Trigger area Spring Note.jpg (14.3 KB, 430 views)

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ummmm....dahhh, thanks, do I feel stupid.

Mark

Did this alteration last night, range today, all is good no more annoying problem. thanks guys.

Something about this has been bothering me for several days until last night I was playing with one of my newly shortened mags and started fooling around with the mag and latch until I figured it out.
Lower powered ammo may not be letting bolt latch hold the bolt open not because it doesn't push the bolt back far enough, because it obviously does.
Otherwise the rifle couldn't eject fired cases or feed new rounds properly.

I believe the bolt latch isn't operating properly with lower powered ammo because its not slamming the bolt back violently enough.

Firing higher speed/power ammo slams the bolt back hard enough to jar the entire mechanism and so helps the mag follower overcome both the metal/plastic friction of the latch in its slot and its spring.

I figured it out when I was checking my newly shortened mags and found that they were not operating the bolt latch correctly when the bolt was manually operated with the charging handle until I put a small drop of oil on the sides of the latch.
Then it started working about half the time.
So I pulled the spring out and cut one coil out of it and it now works 100% of the time no matter how slowly or quickly I operated it.

I think with time and use any latches that are iffy today will eventually wear or break in until they work all the time.

But in the mean time, putting a drop of oil on the side of the latch inside the receiver and cutting a coil or a coil and a half out off the end of the spring will be a good way out of the problem.

Just found this thread. I had one mag that randomly did not hold open. I rotated the mag spring and it has been perfect since. Will only work if you can isolate the problem to one mag.

Hmmm. I think I'm the only one having the opposite bolt problem. My bolt will sometimes jam open after the last round. The catch will not move to release the bolt. Separating the upper is the only way to fix it.

P.S. My rifle is a snob and demands mini mags exclusively.

My rifle will eat any 22lr you feed it. Does your rifle have the upgraded blue springs?

Yes, but it's this dang iphone spell correction got me. I meant to say that I am a snob, and demand mini mags exclusively.

Aah I like mini-mags too but I save mine for hunting. I'm a (tightwad) I'm glad you leave the cheap ammo for me, He He

Thanks Tacticool22!! Just cut about 2 coils off of my spring. Works great.Locks back at the end of every empty mag now.

Mine locks back about 25% of the time using Remington Golden ammo. Just got some CCI Mini Mags to try so we'll see if this solves the problem.

Tacticool22,

Many thanks for your input on this mod, compadre.

Cut two coils (.050 inch) off the bolt lock spring, 100 percent bolt hold open function with blazer ammo even with rearward pressure against mag.

Mag wobble was really bugging me, sos I made an experimental tape shim (9 layers blue painters tape .035" thick) and placed it on the inside front of the mag well near the bottom, problem cured. Mag no longer drops free of the rifle when mag release button pressed, not a problem in my opinion as I would rather remove and retain the mag with my off hand instead of letting it hit the ground. Will make a more permanent shim out of aluminum tape or perhaps epoxy putty.

Smiling Bob

There have been some bolt catches that were molded (yes molded) incorrectly. These and the breech block are metal injection molded.
Contact S&W Customer Service and see if they will send you a new one. There is a thread about your very problem.

My theory about the lower power ammo not working is there is not enough force to push the bolt back for a long enough amount of time for the magazine spring to overpower the bolt release spring.
With a minimum amount of recoil the recoil spring can act immediately. With a bigger recoil the energy of the bolt flying back keeps it back until the recoil spring overcomes the recoil energy and can push the bolt forward.
Just a theory and basic physics.
You could trim the recoil spring, but the bolt catch spring is an off the shelf item.
My rifle loads, shoots, ejects and locks back on anything now.

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