"15 minute trigger pull" problem

[tsisco]

I just got my 15-22 and did the "15 minute trigger pull" routine on it. When I got to the range I found that reducing the factory hammer spring tension by half resulted in the rifle failing to strike the primer at all. I had read others' posts about successfully doing this work on their 15-22's successfully but my efforts didn't work. I didn't have time to do anything but replace the spring with a spare that I had brought along just in case so i could shoot. I'm not bashing the procedure because it really helped on my M & P Sport, just giving you a heads up to be prepared with a spare spring just in case.

 

[rojodiablo]

The spring is not really where the issue is. For a better breaking trigger, get a 'smith to clean up the contact points on the sear. Lightening up the spring WILL lead to misfires. Last weekend, I had 2 rounds that FTF due to rock hard primers. The pin barely even dented them. Now, these were just bad primers. But if'n I were in a fight, or the deer of a lifetime walked by me......... I would not want to chance a hammer throwing weak sauce at the firing pin.

 

[Aceman58]

My experience in dealing with all attempts to make for a lighter trigger pull has ended up in making the rifle a stick. The stock trigger pull on the M&P is a direct copy of the full size AR15. This is a COMBAT TRIGGER, designed as that. In combat, you don't want a 3.5 lb. trigger. In Bullseye, you do, but in doing so makes the rifle prone to misfire (who cares shooting targets, but you will when you are defending your life). My response to any modification on the trigger of a rifle for combat is "Leave it alone". The 22lr rim fire is already subject to mis-fires, playing with the springs and such, you will end up with a junk weapon not worth using for defense of even targeting. Just my .02 cent. KISS, Keep it Simple Stupid... works for me..

 

[Juvicator]

Did the same thing. Trigger spring mod was ok. But that hammer spring needs the power to pop. Reverted the spring back and now have no problems.

 

[chuck s]

Spring pressure on the sear surfaces does affect trigger weight due to increased friction.

There may have been bolt and firing pin redesigns by S&W to cure the out-of-battery firing issue (which is much less common since two years ago) and those could affect ignition with lighter weight springs.

Both the "15 minute" and "JP Yellow Springs" solutions work on all my AR15s and my two year old M&P15-22.

-- Chuck

 

[Gopher Slayer]

I put JP yellows on my aluminum can combat rifle and it runs flawlessly. I still don't shoot deer with it though.

 

[soupy]

Lightening the spring tension yourself is the problem here. There needs to be a perfect balance between the weight of the hammer and the tension of the spring. If you reduce the tension on the spring and do nothing with the hammer, what you end up is a hammer that doesn't have enough momentum for a proper primer strike when you fire. If you take a look at some match-grade triggers for sale online, a lot of them will have the hook of the hammer cut into a rectangle to accommodate the lighter spring tension. That said, you could possibly cut the hook off the rear of the hammer yourself to remedy your light primer strikes with the spring tension you currently have, but replacing ruined hammers costs a little bit more than ruined springs. I personally just cleaned up the sear on the trigger with some light polish and a dremel buffing wheel and installed J&P 3.5lb springs. It runs perfectly for me with Federal Bulk ammo.

If you end up getting serious with your trigger though, you're just better off buying a drop-in that works like a Rock Rivers Arms 2-stage or a Timney single stage. If this rifle is a SHTF gun for you and you want something combat worthy and reliable, get a Geissele and never look back.

 

[riderrick65]

Lighter springs

My experience in dealing with all attempts to make for a lighter trigger pull has ended up in making the rifle a stick. The stock trigger pull on the M&P is a direct copy of the full size AR15. This is a COMBAT TRIGGER, designed as that. In combat, you don't want a 3.5 lb. trigger. In Bullseye, you do, but in doing so makes the rifle prone to misfire (who cares shooting targets, but you will when you are defending your life). My response to any modification on the trigger of a rifle for combat is "Leave it alone". The 22lr rim fire is already subject to mis-fires, playing with the springs and such, you will end up with a junk weapon not worth using for defense of even targeting. Just my .02 cent. KISS, Keep it Simple Stupid... works for me..

I agree Aceman, I changed my springs to the yellow JP's now I have had more miss fires than I had with the orginal ones. So this weekend I'm changing back to the orginal springs then hitting the range on Tues.

 

[gunsandjeeps]

I have JP yellow's in my 15-22P, 15-22,and 15 Sport with no problems.

 

[2hawk]

I've done the "15 min" job on most of my AR's, and they are reliable, with pull weights at about 4#, crisp with very little over travel.

I'd recommend anyone thinking about doing it to have a complete set of spares in case you go to far, but if you study how the parts work together, and take your time, you should be able to get good results.

One thing I do is cut the hammer hook off, so the hammer looks like the "competition" hammers JP sells for $50 :/ And, I do not use the notched hammers.

This seems to make a difference in the reliablility, I use CCI SRM primers as a rule, and I do not have any misfires, ever. Speeds up the lock time, too.

ETA I realize the term "hook" might be confusing, I don't mean the sear hook. Modified hammer below:

 

[riderrick65]

I have JP yellow's in my 15-22P, 15-22,and 15 Sport with no problems.

Well I guess some weapons like the JP yellow springs and some don't, I just happen to have one that doesn't.

 

[Gopher Slayer]

Well I guess some weapons like the JP yellow springs and some don't, I just happen to have one that doesn't.

What kind of ammo? My yellow springs work well, but I only shoot Blazer, so I can't say it feeds all ammo as reliably as it did before the trigger job.

 

[riderrick65]

What kind of ammo? My yellow springs work well, but I only shoot Blazer, so I can't say it feeds all ammo as reliably as it did before the trigger job.

I was using CCI Blazer, CCI Mini Mags, & Federal Bulk. I changed back to the original springs over the weekend and went to the range today (Tues.). The ammo I used this time was Winchester Super X HVHP and CCI Blazer's again, so out of 120 rds. I had only one problem (a stove pipe) the rest of the rounds fired flawlesly! So if you know of anybody looking for a set of the JP Yellow Springs, I'm selling mine cheap!

 

[pyper22]

My experience in dealing with all attempts to make for a lighter trigger pull has ended up in making the rifle a stick. The stock trigger pull on the M&P is a direct copy of the full size AR15. This is a COMBAT TRIGGER, designed as that. In combat, you don't want a 3.5 lb. trigger. In Bullseye, you do, but in doing so makes the rifle prone to misfire (who cares shooting targets, but you will when you are defending your life). My response to any modification on the trigger of a rifle for combat is "Leave it alone". The 22lr rim fire is already subject to mis-fires, playing with the springs and such, you will end up with a junk weapon not worth using for defense of even targeting. Just my .02 cent. KISS, Keep it Simple Stupid... works for me..

very well said... why does one want to start changing springs and stuff. they have this trigger pull like it for a reason. you would not believe some of the changes some guys do on thier Glocks, then they go back to the ORG. set up.some time it works and sometimes it doesn't.if you want a better trigger buy one for the ar15. expect to pay $150.00 or more. i will not change any springs on my 15-22.. just my 2 cents, good luck..

 

[Aceman58]

Guys, I'm not saying don't upgrade your trigger system, I'm just saying don't do "Garage Engineering", purchase a system that is proven and designed by engineers to work. As one member stated, the hammer has to be lighten as well as the springs, it's a system that is in harmony with each other. Snipping away from someone's, "I did a trigger job, and wow" on the web is not a good thing. You start messing with trigger, buffer springs etc. etc. and you will see that your shooting experience will be a day of frustration with the rifle ending up on the floor and the owner with a red face, trust me, I've seen it before on guys that thought they were making their rifle the "Glass trigger" king of snipping.. It always back fires.. Why are you spending $250 on up for a good trigger, it's engineered by ENGINEERS, and tested to work.. So upgrade like a drunk sailor, just be aware of how you upgrade... Keepem in the X...

 

[air8]

I too tried the JP yellow spring. Worked well at first. But now the spring is broke in I think it lost a little tension. I'm getting FTF at a rate of 4 out each 25 round mag.

I'm going back to the stock spring.

 

[Dead eye 22]

I thought serriously of changing to the yellow springs, but I read on a thread that the company didn't recomend the yellow springs for rimfires because they could cause misfires. So I held off and now have noticed that eathor the trigger has become lighter over time or I have just gotten use to it. At any rate I like it just fine now and will keep it as it is.