In my original post titled -First post- I explaned how I did my 15-22 trigger job. It gained alot of interest.

People wanted to see how I did my "speed" hammer". Well, here ya go. I finally got some pics up as promised.

My 15-22


This is the modified "speed hammer" The rear "hook" has been removed to lighten the "mass".



This shows the JP reduced power springs installed.


Another view


This shows the foil tape I installed to fix the stock "wobble".


Vortex Strikefire - perfect co-witness.


UTG weapons light. Love this light!


ERGO Tactical grip.


Gripod - Yep, it's a real one!

Allen, thanks for taking the time to post the pictures. As they say "A picture is worth a thousand word".

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M&P9/9C/Shieldx2/Sportx2/15-22

Nice. I really liked your tape fix for the stock wobble. It's definitely on my "to do" list. Filling the buffer tube with ammo to balance out my rifle is another one of your nifty ideas that I incorporated. Thanks!

Thanks Allen 1 for the pix, very helpful!

Sorry I took so long on the pics. Been busy around here.

I just hopes these pics help you all with your trigger projects.

If anyone has any questions or need to see other pics just let me know and I will help.

God bless.

Very nice, the hammer looks like it grew there, thanks pghrich

Worked on Mine a BIT today.... and Also re-adjusted my JP trigger system

See what she does this week....


Stav

What is the purpose of moding the hammer - decreased lock time?

When you do a trigger job using the JP reduced power springs you need to remove "mass" from the hammer.

The stock hammer spring works well with the stock hammer but we are no longer using the stock hammer spring.

We are now asking a "reduced" power spring to move the same "mass" as the stock spring.

This is where we run into trouble with "light strikes". The hammer never achieves full power to make a reliable strike.

So to overcome this, we must reduce the "mass" we are trying to move. So, by reducing the "mass" of the hammer we get it moving much faster and with a much more powerful "strike" resulting in reliable primer ignition using a reduced power spring.

What we are looking for is a relationship between parts that produce a lighter trigger pull and reliable ignition. This modification achieves this.

Counting the rounds I fired this past weekend, I have put well over 2000 rounds on this trigger and hammer and it has been flawless.

Stay safe and God bless.

Thanks for the explanation.

Thanks for the info. Allen1, how ever I have one question, what did you use to remove the "hook" from the hammer? I do know this much it is a hardened piece. I wish I would have had this info. when I first tried installing the JP yellow springs in my "rig".

I simply used a Dremel Tool and the reinforced cutoff wheel. It cut pretty easily.

Once I had it removed I rounded the cut off with a sandpaper roll that came with the Dremel.

I then used some "cold blue" to finish it. Looks like a factory piece.

Thanks Allen 1, I'll give it a shot (no pun inteded).

I'm well over 5000 rounds on this trigger now and she runs like a clock.

Go for it guys!

Did this trigger job last week and took it out today. Noticeable difference in the feel of the trigger and not one issue

Excellent!

Did you also do the hammer modification?

I did the JPE spring job, but kept the hammer stock. who would have ever thought $10 would make that much difference? I did not bob the hammer, and not experiencing any problems, but if I come across another hammer on the cheap, I might give it a try.

you could also drill some holes in the trigger to lighting it. pyper

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N2GUNS

I assume you mean hammer as apposed to trigger?

Remember that when you start drilling holes you weaken that part and open the door to "stress" fractures.

It's like taking a 2 foot long 2x4 and drilling holes in it. Indeed you have lightened it, but, you have also "weakened" it considerably. But, if you take that same 2x4 and cut it in half you not only "lighten" it you also retain its strength.

Now, if you indeed meant to drill holes in the trigger blade, that only makes a cosmetic / appearance change and weakens the trigger blade. It will in no way reduce the trigger pull. It would reduce the overall weight of the gun however, be it ever so minimal.

Well, Allen.... I did it.. Won't get to test fire until this weekend, but no issues.

I used a dremel cutoff disk, then did a small amount of sanding, and rounded the edges just a bit, and then polished with some fitz and hit it with my bluing pen.

I went for a bit more of the angular corners than you, trying to emulate the factory edges.

Attached Images

photo(1).JPG (76.4 KB, 369 views)

Don't know why you bother to do this actually. While I had the JP springs on my PC model's RRA 2-stage trigger I never had a light strike with either Fed 550 or CCI Mini-Mags. Did not have any either when I put in the Geissele Super 3-Gun trigger and added the JP springs for a 1.25# trigger pull. JP only recommends some optional polishing if I remember. While I agree with the idea on how the springs change the action of the hammer it does not mean you will have a problem. One thing you have to remember about triggers and AR ones in particular. They are only surface hardened to a depth of maybe .003" Once you remove that off any critical surface the trigger will wear out and fail within maybe 6 months depending on use. Bobbing the hammer is not done on a critical surface however it probably does weaken the structure of the hammer some. Myself I prefer to let the action wear in some before considering any mods. And I only do them to cure a problem.

Nice job! You'll be very happy with this setup.

I'm way up there in round count with mine now and zero issues!

Trigger feels awesome.

Not to be argumentative, but you state that the hammer lightening speed mod is necessary but simply not true. I have had J&P springs in mine for well over 10K rounds and not anymore issues than the norm. with maybe one light strike every 500 rounds. I use mine for lots of training and Tac rifle matches and definitely pull the trigger as fast as possible at lot of the time.

Hello Boxerglocker.

I agree with you 100%. I never said it was absolutely necessary at all. I only described what I did to MY trigger group and MY results. I then went on to explain why I did the modifications I did. I also included some pics so that others that wanted to learn from my experience and maybe try this on their own had a guideline.

I then explained why I personally feel the "speed hammer" is worth doing to take full advantage of the reduced power springs and its benefits.

I went into much detail explaining "mass" and "force" and how it relates to this setup.

But, like I said, I agree 100% that you could only install the JP springs and be happy. But you'll be missing out on a much better setup without the hammer mod.

I've tried it both ways and the hammer mod is WAY better and more reliable in my findings.

I'm not forcing my ideas on anybody here, we're all adults and you can all make an educated decision on what has been presented to you.

Below is a direct quote from JP's web site regarding the Reduced Power Springs:

"Note: Use of this spring kit requires the use of US manufactured (domestic) ammunition or reloads with domestic (non-NATO spec) primers as ignition reliability will be reduced with hard low sensitivity primers as found in many foreign made amunitions and NATO specification ammunition. Use these parts only in rifles for recreational or competition shooting. Do not use this spring kit for any defense or duty applications or any AR-10 type rifle. Order the JPFC-1T or JPFCP-1T for AR-10, duty or defense applications."

The key words here are "as ignition reliability will be reduced"
Their telling you right there that you could possibly get "light strikes" when using these springs only!

Now, I don't know about you but I don't want "light strikes", I want consistent and reliable strikes. So, what I found to work 100% so far is the "speed hammer". And, being the "nice guy" that I am, I shared it with you.

Good debate Boxerglocker, thank you!

Be safe out there and God bless.

Allen I read all of you post on this thread. It's been a great read. If you are not a physics teacher maybe you should become one. My college physics teacher put thing in a perspective that we could relate to, which you have done with this topic. Use everyday situations and conditions that people can relate to and they will understand.

All good stuff!

I do think though J-P is concerned about .223/5.56 ignition.
I've ran the springs on my 15-22 with a stock fcg for thousands of rounds without any major problems(the rare occasion of a errant .22 not lighting off).
That being said, nice competent job and explanation of why you did it.
Thanks for your time!

Hobie

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Laissez les bons temps roulez!

Thank you for the kind words.

I do realize that JP was referring to .556 but rimfire ammo is notorious for bad primers.

But, a "light strike" is a "light strike" regardless of ammo being used. Agreed?

If you ever get the chance to look up how .22 ammo is made take the time to do that.

.22 is the hardest and most complex to produce. You'll have a whole new appreciation for this little round we all love.

photobiker, I'm not a physics teacher at present. I do however work in the medical field on the mechanical end of the business. I have won 2 "Innovation of the Year" awards from the company I work for and the medical industry.

I am also a member of the "NASA Space Technology Hall of Fame", for research I was involved in regarding lubrication and its application on the NASA Space Crawler from a time when I worked for a "specialty" lubrication company.

So, if you guys ever want to discuss lubrication and its applications as related to firearms just let me know.

God bless.

Nice job, and well written. I look forward to reading your future post!

Great write up Allen. Thank you. I did this mod and it looks great.

I would like help diagnosing a small problem. I started with a clean rifle and tested with 400 CCI MM 40gr RN and I did have 2 failures for the trigger to reset. It happened in the middle of the test. The rounds feed %100 but I ejected the live round and chamber the next one to reset the trigger each time.

Any advice?

Little more info?

Did those 2 rounds fail to fire? 2 rounds out of 400 is pretty good.

Rimfire ammo being what it is, is not 100% reliable as we all know. I'd say your fine.

I'm glad your enjoying your new trigger job. How much of an improvement did you obtain?

Yes, the rounds failed to fire because the hammer failed to reset. I think the hammer rode the bolt home. There was no indication of a mark left by the firing pin and the trigger was dead.

I think the mod is well worth the $15 I spent on the JP reduced power springs, Rydon boron nitride, and the shipping. The trigger is much better than OEM and only a small bit worse than the Timney FCG. I don't have a pull gauge but I think it had a nice break @ 3.5# with minimal creep. The Timney is better, just not $180 better on this host.

Update:

The hammer mod + JP springs have solved my trigger reset problem for the last 1500+ rounds. Thanks again Allen for the posts.

my phone sucks. What is the name of the foil tape and where could I find it?

I haven't got any issues with my stock trigger, but I find this discussion interesting.

If I remember correctly you did this mod to reduce trigger pull. Well the hammer only is felt at the trigger because of the very consertiave sear angle. If you file the sear slightly on a better angle it will eliminate the weight of the hammer spring and lighten the trigger with no added cost.

Yes but that info pertains to .223 only because of the harder primers used in 5.56 military ammo (Russian mostly). Has no real effect when shooting .22 rimfire. Your bob job is basically the same thing as buying the JP speed hammer. Triggers like the Geiselle already have a bobbed hammer when compared to standard milspec 1-stage triggers. However one thing you are forgeting is physics. Mass and acceleration are related so if you lighten the hammer the speed will go up but the reduced mass means it will hit with about the same force as a slower heavier hammer. No free lunch.
From my experience, at least with the RRA 2-stage match trigger from the PC model and the Geiselle Super 3-Gun trigger, the use of the JP "yellow" springs in a rimfire will cause no problems that I have seen. The Geiselle is a faster trigger not because of its bobbed hammer or springs but because its mechanics has such a short lockup and reset distance that relaxing your finger by as little as 1/8" is enough to get the hammer to reset the trigger in recoil. Going between the OEM springs (2.5# pull) and the JP (1.25# pull) did not change the speed with which you could pull the trigger, it just reduced the amount of force you needed in your trigger finger. The RRA match trigger, regardless of which springs were in it, would not allow as quick a follow up shot.
As an aside this spare RRA is going into another AR and I may remove some hammer weight just to experiment. I also have a milspec 1-stage that came out of the lower that went into my 3-gun, and it is very similar to the stock non-PC AR15-22 triggers. I may play with that one also.
Another thing to try is to only install the JP trigger spring and leave the stock hammer spring in. This is something a few AR .308 shooters I know do. You get a slightly lighter pull but good strikes on those harder primers.

Smith and wesson recommends a minimum of 4lbs trigger pull

That's a CYA, insurance mandated statement.

My 15-22's Jard trigger breaks nicely at 2.5 pounds.

Wow prior to the last two posts above me this thread was inactive since back in 2012...? Guess most people now run the cmc drop in 3.5 lb triggers?

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Todd
M&P15-22 tweaked

When you buy the Speedhammer for use on the JP 1-stage trigger (kind of a bobbed hammer) the springs they give you are the low power for the trigger and the regular power for the hammer because a lighter hammer needs a heavier spring. Plus I think they give you an extra power hammer spring to use if it is going in an AR.

Only if you have no mechanical skills or intend to use a Slidefire. For speed most uses a Geissele S3G and for accuracy many use the RRA NM or now the Geissele NM is an option.

I did something similar to a mil spec trigger for a build last year that I use with a 22lr conversion. It ended up with a very crisp 4lb trigger pull.

20140322_012214_LLS by Slick_Rick77, on Flickr

20140322_012350_LLS by Slick_Rick77, on Flickr