JP Rifles AR15 Trigger Springs

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JP Rifles AR15 Trigger Springs

Postby onebohemian on Thu Jul 03, 2008 6:39 pm

I was looking for a way to improve the trigger pull on my AR15. Standard parts from factory were giving me a 7 to 8 pound pull. Kind of gritty too. Knowing that the hardened surface of the sear and hammer on an AR are typically very thin, I didn't want to stone the mating parts to change their geometry to improve the pull because chances are it would have left the parts soft and possibly leading to doubles, etc.

After a few nights of sitting in front of the t.v. drying firing the lower (with a stop to catch the hammer so as not to damage the lower or the bolt catch), the pull got better. (Dry firing was cheaper than running ammo through it.) I then put an almost-mirror polish job on the stock parts with simi-chrome. I ended up with about a 6 pound pull. The creep from the stock parts remained but at least it was smoother. I decided I wanted it lower in poundage so I jumped online. I found instructions for some guy's "15 minute trigger job" that required one leg of the hammer spring being trimmed off and the trigger spring's arms being bent at an angle. I read some bad reviews though of the effect of having the hammer spring with only one leg so decided against that.

I had read some great reports about JP Rifles trigger groups, and since they are in Hugo, I thought I'd throw some business to a local shop. I checked out their website and decided against the price of a complete trigger group. Although I've read that JP's complete groups are the best single stage ones on the market, I decided I might buy those parts all later. For now, I wanted a less expensive option even though I knew it wouldn't be as good as a new complete group. I settled on JP's replacement spring kit, the JPS3.5.

The kit comes with reduced strength hammer and trigger springs as well as a new disconnector spring. You use your stock trigger, disconnector, and hammer. Installation was a simple drop in. You need to remove the rifle's safety, hammer, trigger and disconnector from your lower to install the parts, but it's very basic work if you have even a little mechanical skill.

Price for the kit was 9.95 plus MN sales tax. When I called the shop to see if I could stop by the Hugo store to pick it up so as not to have to pay shipping, the sales guy said he'd waive the shipping for my local purchase because they don't have a store front for retail sales. Ended up being a total of $10.60 and took two days for mail to deliver it.

The difference with the new springs is amazing. Although its product name--"JPS3.5"-- indicates a 3.5 lb pull is possible, the instructions online say it should provide a 4 to 4.5 lb pull with stock parts. Notwithstanding the instructions, I'm now getting an average 3 lb pull, with some readings as low as 2.6! I'm using a Lyman digital scale to test. Obviously this trigger set up shouldn't be used for combat purposes, but for punching paper or some varmit shooting, it should be a big improvement over the stock pull. (JP offers separate kits that have names including "4.0" and "4.5" so those probably provide higher pull weights.) Again, I still have trigger creep while the hammer gets cantilevered during the pull, but I can live with that due to the lightened pull.

I highly recommend this product if you're looking to reduce the pull weight on your stock AR trigger.
Mark

"Edited to remove prohibited content."(2009).

"It turns out that what you have is less important than what you do with it." (In honor of 'Goalie,' 2013).
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Re: JP Rifles AR15 Trigger Springs

Postby 1911fan on Thu Jul 03, 2008 10:09 pm

John is a straight up guy, he was the proprietor of the Lloyd's gun shop on north Lyndale when the murders of two of his employee's took place.

Since then he has started up JP products and seems to be getting along. I know it took a while though.
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Re: JP Rifles AR15 Trigger Springs

Postby David on Thu Jul 03, 2008 10:13 pm

I had no idea John was the guy who owned Lloyd's at that time. I'm not surprised he didn't stick with a retail shop. That whole deal was a huge bummer.

I put a JP trigger kit in my M4 as well, although I got something entirely different than you did. I got heavier springs and a lighter hammer, which reduces lock time and in theory improves accuracy (heavier spring makes the hammer drop faster, while reduced weight makes it hit the firing pin with the same force). The trigger is as crisp as you can get, and is super light. I highly recommend JP trigger kits (and other replacement parts by them).
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Re: JP Rifles AR15 Trigger Springs

Postby Fast351 on Mon Jul 07, 2008 4:04 pm

The one thing you can do to get rid of trigger creep is to get a lower that has a pretravel adjustment. I have that on my two SLR15 rifles and there is absolutely no trigger creep. Even with stock mil-spec springs, they do great for competition style shooting. They are both Superior lowers, but I know SLR15 has their own lower now that has this same feature.

Ditto on JP springs btw. They are known for some of the most reliable aftermarket springs for AR15 triggers on the market.
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Re: JP Rifles AR15 Trigger Springs

Postby JFettig on Mon Jul 07, 2008 7:58 pm

I've done the bend and cut trigger job on one or two as well as honed my sear surfaces. I've been able to get my pull down there way lower than I wanted it, but the creep and over travel is still there.

If you keep your rifle clean, the cut and bend job can work, I noticed that after a few hundred rounds of wolf ammo, there wasn't enough to get consistent ignition.



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Re: JP Rifles AR15 Trigger Springs

Postby onebohemian on Mon Jul 07, 2008 8:38 pm

Fast351 wrote:The one thing you can do to get rid of trigger creep is to get a lower that has a pretravel adjustment. I have that on my two SLR15 rifles and there is absolutely no trigger creep. Even with stock mil-spec springs, they do great for competition style shooting. They are both Superior lowers, but I know SLR15 has their own lower now that has this same feature.

Ditto on JP springs btw. They are known for some of the most reliable aftermarket springs for AR15 triggers on the market.


Is the pretravel adjustment on your lowers just a set screw of some kind? Is it actually in the lower or somehow part of the trigger? I'm imagining some kind of set screw that could be adjusted to stop the trigger from resetting all the way forward, thus shortening the amount of contact the sear part of the trigger has with the hammer and thus eliminating that creep / pretravel. Do you think the set up on your rifles would be capable of being duplicated on other lowers or is it too complicated to even try for? Anybody know of an aftermarket set up to reduce pretravel on an AR, other than replacement match grade triggers/hammers?

EDITED: O.k., I went and looked up the Superior Arms lowers. There is a set screw under the grip that you use to adjust the pretravel. I can't find a diagram showing how it works, but I have to believe it must just keep the trigger from fully resetting. That would make sense for removing pretravel. I wonder why no other manufacturer has added this feature to its lowers or whether any DIY'ers have figured out a way to do this to other lowers????
Mark

"Edited to remove prohibited content."(2009).

"It turns out that what you have is less important than what you do with it." (In honor of 'Goalie,' 2013).
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Re: JP Rifles AR15 Trigger Springs

Postby Fast351 on Mon Jul 07, 2008 9:00 pm

It's a set screw in the lower itself. The trigger, disconnector, and hammer are all standard milspec parts. The screw is right next to the grip screw hole and in the same direction. It's a simple design, but works really well.
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Re: JP Rifles AR15 Trigger Springs

Postby Jeff Bergquist on Mon Jul 07, 2008 9:31 pm

The Jard trigger I installed in my Colt has a take up adjustment screw that actually goes in the same screw hole used by the pistol grip. I had to use a tap to extend and thread the hole into the body of the lower, (I don't think this is necessary for most lowers), then the set screw goes in first, is adjusted, and lastly the grip goes back on.
The bold type giveth, the fine print taketh away.
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Re: JP Rifles AR15 Trigger Springs

Postby hicap45z on Tue Jul 08, 2008 9:09 am

For pretravel adjustment, I've noticed that Brownells sells a "drop-in trigger adjuster" (their stock # 072000001) that replaces the grip attachment bolt. Inside this bolt is an adjustment screw that protrudes to provide a pretravel stop for the AR trigger.
I haven't tried one, but I probably will. Or try to build my own since the list price is $44.20.

Back on the subject of the JP springs, has anyone had any ignition issues using them with various ammo brands?

Z
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Re: JP Rifles AR15 Trigger Springs

Postby onebohemian on Thu Jul 10, 2008 12:21 pm

This product review has taken on a different turn, so if the mods want to fix that, please feel free to move the following (or some of the earlier stuff) regarding improved AR triggers to a new topic.

Here's what I've discovered as I continue to try to improve the trigger on my AR.

Because of the Brownell's product that has a set screw inside of the grip screw, and because I saw some related posts about using the grip screw hole for pretravel adjustment, I figured out the following. My grip screw hole is directly underneath the end of my trigger. Theoretically, this means that by adding a set screw into that hole, one could adjust the height of the set screw so as to push up the rear of the trigger slightly and remove the pretravel.

My stock grip screw is 1/4" x 28 x 1". About 1/16" of the top of the part of the grip screw hole inside the fire control group had not been tapped from factory. I chased the threads from the bottom of the lower with a tap, all the way up into the FCG to finish the threads off. Because these are common threads, the tap cost me $4.00. I then screwed into the hole from the bottom of the lower a 3/8" set screw of 1/4" x 28 size. I put my trigger and hammer back in to test fit everything. With an allen wrench on the set screw, I could adjust all of the pretravel out of the trigger pull. It worked just like I thought it would. I had read reports of trigger jobs where someone built up the bottom of the trigger with some weld and then sanded the weld down to the appropriate height so as to remove the pretravel. This set screw modification works much better than that because it allows you to adjust the pretravel. I also bought a new grip screw of 3/4" length so it wouldn't butt up against the set screw in the same hole. The two screws cost me a dollar total. But . . .

This isn't just going to be a simple drop in job afterall. I then proceeded to install my safety (without detent and spring) to see how that would interact. I learned that the safety's close proximity to the rear of the trigger limits the amount of pretravel you can take out with the set screw. In other words, if you screw up the set screw where the pretravel is almost all gone, the rear of the trigger sits too high for the safety to be installed. I ended up leaving the set screw in the gun and set it so as to remove the tiny bit of pretravel that I could but so the safety would still work, but I still have pretravel because of the safety not allowing the rear of the trigger to be set high enough.

I've come to realize that the key to making the set screw adjuster work would be that the top of the rear of the trigger will need to have some material removed. I think most aftermarket triggers you can buy require some gunsmithing in the area of removing some material from the rear top of the trigger so the safety fits. That same fitting would need to be done to get this set screw mod to work. I have to believe that the Brownell's double-set-grip-screw combo thing must require the same removal of material for the safety to properly work. I want to pick up an extra trigger before I start taking material off the one I have, but I'm still thinking I'm going to try it to see where this mod will take me.

Bottom line (so far) is that a 3 lb trigger with a crisp break and definite reset would be great for paper punching, and as long as I can confirm it's safe (i.e. no bump or double fires), I think I'll end up being happy with this $15.00-in-parts mod ($10 for JP springs; $4 for tap; $1 for set screw and new grip screw).

(It should go without saying, but in case anyone has any doubt, I'm not recommending anyone do any of the above. I'm simply reporting the results of my own tinkering. You know your own capabilities when it comes to smithing on your own guns so to each their own.)
Mark

"Edited to remove prohibited content."(2009).

"It turns out that what you have is less important than what you do with it." (In honor of 'Goalie,' 2013).
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Re: JP Rifles AR15 Trigger Springs

Postby JFettig on Thu Jul 10, 2008 2:52 pm

Did you have the safety in while screwing in the set screw? You could put it on safe then take up all that you can that way.

To take up more, you could either modify the selector or the back of the trigger. I did something similar in one of mine.
Just make sure not to take so much off that the safety doesn't do its job.

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Re: JP Rifles AR15 Trigger Springs

Postby onebohemian on Thu Jul 10, 2008 3:07 pm

JFettig wrote:Did you have the safety in while screwing in the set screw? You could put it on safe then take up all that you can that way.

To take up more, you could either modify the selector or the back of the trigger. I did something similar in one of mine.
Just make sure not to take so much off that the safety doesn't do its job.

Jon


Yep, that's what I was trying to describe. Sorry I got a little lengthy. With the selector installed, I screwed the set screw upwards to take up as much of the space between the selector and the rear of the trigger as I could so that the safety still turned between "fire" and "safe." That left me still with too much pretravel. I know I need to remove material from the top of the rear of the trigger. The plan is to remove some material and test fit everything, then remove more material, etc., etc. I should be able to remove enough material from the top of the trigger so that I've eliminated almost all of the pretravel but still allow the selector to be tight enough to work safely. Thanks for the advice.

EDITED: I followed through on the above plan and removed material from the top of the back of the trigger. That has reduced the pretravel more. I decided to leave some pretravel at this time as I need to test fire the gun to see how it performs before pushing this further. It feels pretty good right now even with a little pretravel so I may just leave it regardless. I'm starting to think, however, that I'm going to need a new upper with a bipod and some high powered glass as this trigger would really compliment some long range shooting. :) I'm going to try to get to the range tomorrow to try it out as is.
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"It turns out that what you have is less important than what you do with it." (In honor of 'Goalie,' 2013).
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Re: JP Rifles AR15 Trigger Springs

Postby SKIDLYMAN on Wed Feb 25, 2009 11:20 pm

have you tested this yet? results?
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Re: JP Rifles AR15 Trigger Springs

Postby onebohemian on Thu Feb 26, 2009 10:02 am

SKIDLYMAN wrote:have you tested this yet? results?


Trigger works great. Since these earlier posts, though, I took it another step to get rid of even more pretravel. I bought an extra selector switch and removed material from it so that I could turn the set screw in farther to remove more of the pretravel. This allowed me to tune the trigger and selector so that the safety has full engagement (i.e., absolutely no slop) and I've elminated all the pretravel or take-up.

One other thing, and I may have already written it above but I'm not going to go back and read the past posts to check. I ended up putting my stock AR hammer spring back in because the JP spring was giving me light strikes on some of the harder primered ammo. I thus ended up losing a little of the lightness in the trigger. I don't recall what my pull weight is at right now as compared to what I was seeing with the JP spring.

Bottomline is that if you're willing to tinker and fine tune via trial and error, the methods described in this post will create an AR15 trigger with a lighter pull, crisper break and clearn reset, and no pretravel. It has its place depending on what you are going to use the rifle for.
Mark

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"It turns out that what you have is less important than what you do with it." (In honor of 'Goalie,' 2013).
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Re: JP Rifles AR15 Trigger Springs

Postby SIGP240 on Tue Mar 03, 2009 10:26 am

Nice thread:

I was doing some cold weather shooting with the AR during our last little arctic dip. I had previously installed TTI Yellow Tavern Reduced springs in the fire control group. I was plagued with light primer hits. I mistakenly thought it ws due to my ammo choice of Soviet Union Steelies; Wrong!. I had erroneously dripped more than one drop of warm-weather lubricant into the firing pin recess and the pin got impinged in the (gelled) "grease". With a couple magazine dumps, it came around. But when she got home, into the Witches' Brew (Injector cleaner/spirits/MEK/Hoppe's) for the overnight soak and toothbrush! Lesson learned: ONLY ONE DROP ULTRA LIGHT OIL, REPEAT, ONE.
Proudly launching lead from a Swiss P-240 at a range near you.
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