Guys,

I bought a couple of these yellow JP Enterprises reduced force hammer springs from Brownells a while back and did some shooting this weekend.  I was shooting PMC ammo and had 4 or 5 misfires due to light primer strikes.

That's a number that's too high for me.

Have any of y'all experienced this with this type of  reduced force hammer spring?

Thanks,
CMOS

i have had bad results with pmc regardless, remember reading something about hard primers or something. i dont use pmc no more so i dont really remember.



that coupled with your lighter springs would be your culprit.

I've also heard that PMC can have hard primers.  Still, 4 rounds out of 60 is waaaaay too high for me.

Anyone else?

CMOS

went shooting with a fellow board member the other week and he was having the same problem as you with factory power springs

I did a 15-Minute trigger job on my carbine and it's never had a problem failing to fire.  I've used Wolf, Q3131A, Winchester, and Xm193, all of which fired flawlessly.  If I understand correctly the 15-minute trigger job reduces hammer force even more than 10%.  Sounds like the problem is in the priming.  MJD

i have had a lot of problem with PMC.
wolf, rem, win, fed.  lake city demill all work fine.

CMOS,
Been running the same yellow springs from Brownells for a
couple years now & no failure to fires.
Have also installed them in a few of my shootin buds'
AR's & haven't heard any complaints.
Of course I only shoot XM193 so don't know if this helps.

Some folks switch to a lightter hammer as well when they go to the lighter spring -- they whack off the back of the hammer or buy a replacement.

I have the yellow JPE TRP springs in three lowers, with no problems.

Yeah, but your trigger feels more comfy, right?

Quoted: Some folks switch to a lightter hammer as well when they go to the lighter spring -- they whack off the back of the hammer or buy a replacement.

whack off the back of the hammer...
oh yea.  cut that big ugly hook clean off.  
you want to keep the hammer the same length but you don't need any of that extra mass.

Quoted: Quoted: Some folks switch to a lightter hammer as well when they go to the lighter spring -- they whack off the back of the hammer or buy a replacement. whack off the back of the hammer... oh yea.  cut that big ugly hook clean off.   you want to keep the hammer the same length but you don't need any of that extra mass.

I hope that's a tongue-in-cheek statement.  

Wacking off the hammer is not a good option.  That reduction of mass will only increase the number of light primer strikes.

CMOS

Well, I just wen to the range again and had about 6 misfires due to light primer strikes, out of 60 rounds.  

I'm taking these springs out and going to install the mil-spec spring again.

While these springs would probably be good for reloads and target shooting, I'vbe learned that there're not good for a CQB SHTF type of weapon.

Shoot well.

CMOS

Quoted: CMOS, Been running the same yellow springs from Brownells for a couple years now & no failure to fires. Have also installed them in a few of my shootin buds' AR's & haven't heard any complaints. Of course I only shoot XM193 so don't know if this helps.

+1, look at the ammo. I used them in my last build & put some in a friend's ar with great results. A great, economical upgrade to your AR IMO.

Quoted: Quoted: Quoted: Some folks switch to a lightter hammer as well when they go to the lighter spring -- they whack off the back of the hammer or buy a replacement. whack off the back of the hammer... oh yea.  cut that big ugly hook clean off.   you want to keep the hammer the same length but you don't need any of that extra mass. I hope that's a tongue-in-cheek statement.   Wacking off the hammer is not a good option.  That reduction of mass will only increase the number of light primer strikes. CMOS

JP Link

As you can see JP lightens the hammer in their trigger upgrade package featuring the lightened "yellow" spring kit.  While the lightened springs offer lighter pull weights, they may not always have the power needed to accelerate the stock heavy hammer to sufficient velocity to get a good primer strike on hard primers.  Lightening the hammer provides greater hammer velocity.  This approach is common in match triggers and hammers, whether a Giessele AR match trigger or a skeletonized 1911 hammer.

I'm not going to argue that use of such a trigger is appropriate for a battle rifle, that's a different topic altogether.  But if you still want the benefit of the lighter weight trigger, then pair the lightened springs with a lightened hammer first before you give up.

Lesse... you reduced the spring strength and left the mass the same.  Fail to ignites?   DUH!

I bet lock time is now glacial, too.

I have like 5 or 6 JP triggers installed, including one with the lightest JP springs.  I've had ZERO ignition problems in the last two+ years.

Quoted: Quoted: Some folks switch to a lightter hammer as well when they go to the lighter spring -- they whack off the back of the hammer or buy a replacement. whack off the back of the hammer... oh yea.  cut that big ugly hook clean off.   you want to keep the hammer the same length but you don't need any of that extra mass.

A great big +1

Lighten up the hammer by modifying the original one or switch to a low mass hammer...

Thanks for the replies guys.

For simiplicity, I'm going to go back to the mil-spec spring.  I can do a pretty darn good trigger engagement surface polish job that will make things pretty good - for a battle ready rifle.

CMOS

Quoted: Quoted: Quoted: Some folks switch to a lightter hammer as well when they go to the lighter spring -- they whack off the back of the hammer or buy a replacement. whack off the back of the hammer... oh yea.  cut that big ugly hook clean off.   you want to keep the hammer the same length but you don't need any of that extra mass. JP Link As you can see JP lightens the hammer in their trigger upgrade package featuring the lightened "yellow" spring kit.  While the lightened springs offer lighter pull weights, they may not always have the power needed to accelerate the stock heavy hammer to sufficient velocity to get a good primer strike on hard primers.  Lightening the hammer provides greater hammer velocity.  This approach is common in match triggers and hammers, whether a Giessele AR match trigger or a skeletonized 1911 hammer. I'm not going to argue that use of such a trigger is appropriate for a battle rifle, that's a different topic altogether.  But if you still want the benefit of the lighter weight trigger, then pair the lightened springs with a lightened hammer first before you give up.

jmart,

I just read that JP link.  They say that their reduced mass happer is not compatable with the other mil-spec trigger group parts.  Does anyone else sell a reduced mass hammer that can be used with the existing pins and the JP reduced froce springs?

Thanks,
CMOS

Quoted: Quoted: Quoted: Quoted: Some folks switch to a lightter hammer as well when they go to the lighter spring -- they whack off the back of the hammer or buy a replacement. whack off the back of the hammer... oh yea.  cut that big ugly hook clean off.   you want to keep the hammer the same length but you don't need any of that extra mass. JP Link As you can see JP lightens the hammer in their trigger upgrade package featuring the lightened "yellow" spring kit.  While the lightened springs offer lighter pull weights, they may not always have the power needed to accelerate the stock heavy hammer to sufficient velocity to get a good primer strike on hard primers.  Lightening the hammer provides greater hammer velocity.  This approach is common in match triggers and hammers, whether a Giessele AR match trigger or a skeletonized 1911 hammer. I'm not going to argue that use of such a trigger is appropriate for a battle rifle, that's a different topic altogether.  But if you still want the benefit of the lighter weight trigger, then pair the lightened springs with a lightened hammer first before you give up. jmart, I just read that JP link.  They say that their reduced mass happer is not compatable with the other mil-spec trigger group parts.  Does anyone else sell a reduced mass hammer that can be used with the existing pins and the JP reduced froce springs? Thanks, CMOS

I guess I'm not understnading what you're trying to accomplish.

If you want to stay with the reduced force springs, then pair it with their LW speed hammer.  Is your problem that your existing pins isn't compatible with the Speed hammer or is the problem the price of their package?  If the latter, then just have a smith remove the spur or tail from your existing hammer to lighten the weight.  If you end up not liking it, you'll need to get another hammer of course, but that would probably be the lightest on your wallet.

If you want to keep your system stock, then abandon the reduced force "yellow" springs and re-install your stock springs.

Other spring options are do it yourself jobs where you trim and bend some spring legs (referred to as "The 15 minute trigger job" or something like that).  I've never done it but enough people have that it has a following.  Again, I'd be very reluctant to try something like this on a social rifle.  Also, Tubbs sells some chrome silicon springs that are drop in.  Not sure how much they reduce weight if at all, but they are advertised to last through thousands of cycles without losing tension so at least you would have a consistent trigger.

My IPSC/3-gun rifle has a JP trigger/"yellow" spring set with a regular GI hammer. I love the feel of this combo. It works OK with Winchester and Remington ammo, but can give ocassional light-strikes (say 1%) with XM193. As I choose not to use XM193 in this rifle, I have no need to play around with a lighter hammer. As always, YMMV.

By the way, my SHTF rifle has stock parts... this makes for a heavier trigger pull, but I trust it to go bang when I really need it. Not part of the discussion here, I know.

I guess I'm not understnading what you're trying to accomplish

Basically, SHTF reliability with an improved trigger.  I'll probably end up with the stock spring and just bend it a bit to slightly reduce the force.   Did that on another one of my M4's with good results.

Quoted: By the way, my SHTF rifle has stock parts... this makes for a heavier trigger pull, but I trust it to go bang when I really need it. Not part of the discussion here, I know.

Well, actually it is the discussion.  Thanks for your input.

CMOS

Quoted: I just read that JP link.  They say that their reduced mass happer is not compatable with the other mil-spec trigger group parts.  Does anyone else sell a reduced mass hammer that can be used with the existing pins and the JP reduced froce springs? Thanks, CMOS

Brownells has the JP hammer that will work with your standard trigger...
www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=7590

I'm using the JP adjustable trigger kit.  It includes the low tension springs, the light-weight hammer, and an adjustable trigger (sear engagement and over-travel). I love it.  About a 3.5lbs pull on a single stage trigger with just enough over-travel to catch and release the disconnect.

I haven't had a single misfire after several thousand rounds of S&B, XM193PD, and IMI .223.  

However I have a little KelTec P-11 that choked on at least half of a 50 round box of PMC.  Granted, it's a cheap little gun (that's what makes it great for pocket carry), but it doesn't have any problem with better quality 9mm ammo.  

Short version... I'd guess it's more the ammo than the springs.

HTH

Correction: The reduced mass hammer does not come with the kit.  I purchased it seperately

JP spring, trigger groups,  and reduced mass hammer are great if you bear in mind that you are tuning your rifle for optimal performance in one facet of the entire performance perspective. If you are seeking optimal accuracy, and are not using hard mil spec primers, JP is excellent. They are not well suited for always work, all the time, with any ammo you grab. Think of it as tuning your 1967 426 hemi  for optimal performance, and then express frustration at running ethanol blend gas in it to go to the corner store. 67 426s were better than 68s, by the way. from 68 on it was all down hill.