Is the hammer spring on a 15-22 the same as one on a real AR-15?

The M&P15-22 hammer and trigger (and their pins and springs) are straight out of the M&P15-not22. Or any other AR15 fire control parts set.

Whatcha thinking about doing?

-- Chuck

Okay, that's what I needed to know. I did the 15 minute trigger job (see link at the end) and went and put about 75 rounds through my gun and there was about 6 times that the hammer just didn't strike hard enough. I should have only done the trigger spring instead of doing the trigger and hammer springs. I bent the hammer spring around a little bit and it seems to strike a little bit harder, I might just try it tomorrow and see if it works better. The trigger pull does feel a lotttt better though. 15 Minute Practical Trigger Job for the AR-15

While the 15-22 hammer spring is of the same design as a standard AR hammer spring, it was my understanding that it was a lighter spring.

Pat --

I did the same "15 minute trigger job" but only have a couple of test fires on it. If there's an issue with next weekend's shooting we can probably get together on solutions.

I'd rather not spend $100 on another good trigger if this trigger job is all that's necessary. I've fired the Rock River (or ArmaLite, I forget which) two-stage trigger in this rifle with no problems at all. Drops right in.

I need to visit the next gunshow anyway as I need a washer for the compensator for my newly threaded barrel.

-- Chuck

Well I modified the hammer spring a little bit last night and then put 75 rounds through it about 30 minutes ago with 0 problems. You know how on the instructions of the 15 min. trigger job it says to clip off the right leg of the hammer spring? Well after I clipped that and bent the trigger spring is when I had the problem with it not striking hard enough. All I did to fix the problem was bend the left leg of the hammer spring around some more and now it strikes good. The trigger feel is 10 times better than how it was stock. Here's a half *** drawing of what I did to fix the problem:

The one on the left is kind of how it looked stock, the one on the right is how it looked after I modified it. Bending the left leg on around made it hit a good bit harder. Now this is how the spring would look installed looking at it from the left side of the gun, the side where the safety switch is.

The reason it had failed to fire was because you clipped offtoo much of the spring. You may wNtto grab a couple more springs, 1 to try again, and the other in case you mess THAT one up!

I don't think I cut it to short. I didn't even cut it down to 1/4". And what is wntto? I got it fixed now so I don't need to replace the spring.

well.. theres only one way that it wouldnt be strong enough to fire the round. not enough spring strength. it comes out of the factory with two legs, and strong enough to fire the round. if you cut one side, and it doesnt fire anymore, it means too much has been cut.

Give this a read http://smith-wessonforum.com/smith-w...rve-award.html

the main reason I say you should grab another spring is because after clipping and bending, you may have a weak-point in the spring, leading to failure. Its worth the $1.50 to have the piece of mind, knowing that if it breaks, you can swap it out, and not waste a day at the range.

"wNtto" = 'want to' in fat-fingers on an iPhone speak.

Ok I just noticed something. I cut the opposite leg off that you did. Would that make any difference? But on the website I looked at for the trigger job, it said to cut the right leg off, and that's the one that I cut off. But still, I didn't take off as much of the leg that you did. But in the pictures on this website 15 Minute Practical Trigger Job for the AR-15 it shows it being the right leg if you were looking from the back of the gun.

If it shooting then all is good but id still buy the reduced weight springs I think midway has them for 5 bucks just as a "oh **** my spring broke"

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NRA Instructor

Which one would I buy for the 15-22?

I need some suggestions. I have on order JP Reduced Power FCG Springs JP Reduced Power FCG Springs [JP Reduced] - $9.95 : Spikes Tactical for a 15-22. Should I keep the stock hammer spring and just try the JP trigger spring? Or use both JP springs? I’m trying to go the cheap route. Any help appreciated.

Sorry I’m answering my own question but maybe it can help someone. I emailed JP with the same question and here is their very promt reply.

“I would use the stock, full power hammer spring and the light JP trigger spring. Rimfire is ignition-sensitive enough as it is. Reducing the hammer spring tension only exacerbates the issue.”

I will post the result with the new spring after I install it.

I would try both, what is it going to hurt? if you notice rounds aren't being fired then switch back the the original, just my .02

Yeah, try both. And be sure and keep the OE springs handy, just in case your 15-22 needs to take a ride on the FedEx truck.

I clipped the right leg on my hammer spring but 10°F weather has kept me from the range since only firing a few test shots (cases) to determine if the strike is powerful enough.

You need to cut the leg down to 1/4" so the stub doesn't interfere with the trigger. An alternate to cutting the spring leg is to assemble the hammer spring with one leg on top of the trigger pin and the other below it. A bit of cursing usually helps wiggling this into the rifle.

There are "reduced power hammer springs" marketed too. JP with yellow paint as I recall.

-- Chuck

why can't the hammer spring legs be bent a few degrees versus cutting the right leg? i bent mine about 10-15 degrees and so far it has worked just fine. now i'm not working with one leg of a spring. much easier to reassemble too.

FWIW, i bought 2 extra springs in case it didn't work. i left the OE springs alone.

I dont see any reason not to try it that way. youve got extra springs just in case. i say youre good to go!

thanks vitamind3. i've already done it and it works good for me.

i was posing the question of why not bend the springs versus cutting one leg. can anyone think of a reason why cutting would be superior? the only thing i can think of is by bending the legs, you don't know how much reduction in hammer force you will get but the same holds true for cutting one leg. at least with bending the spring, you don't have all of the spring force coming from one side thereby changing the force vector, although i don't know that that would matter.

to me, if the springs were meant to be cut, there would be one legged aftermarket springs available versus reduced power two legged springs. does that make sense?

i think the best way to answer this question is to buy a second 15-22 and cut the spring. fire it about 10,000 times and compare to a bent spring after 10,000 rounds. anyone want to chip in for the gun and ammo? i'll do all the work

I finally got out to the range to try the spring that I installed. I had also done some slight polishing with a Dremel and jewelers polish as described in this thread AR15 Build . I left in the stock hammer spring and only put in the JP trigger spring. The trigger is much better. The pull is noticeably lighter and smoother. Still not great but a lot better.

Trust me. I'm all over it!

Since the revival of this thread I have about 500 rounds out of my 15-22 after performing the 15 Minute Trigger Job. Totally reliable ignition.

A $120 Rock River 2 Stage trigger is no longer on my shopping list.

-- Chuck

YouTube - AR trigger break in / tweaking "MUST SEE"

No idea how well this works, but people seem to think this is a good trigger tweak.

I didn't read thru 3 pages of this thread, but in case you still need the info, the fix is to lighten the hammer by "bobbing" the hook (with a cut off wheel). A JP speed hammer will do the same thing. Hammer speed is reduced by the lighter hammer spring. To get the speed back (and ignition reliability), the hammer mass must be reduced.