Short stroke on new build

[High_n_Dry]

Hello all and happy holidays!

After a LONG wait, I finally got the parts for my build
JP 18" barrel with rifle length gas
JP Adj gasblock
Wilson Combat billet receiver
Aero Rifle buffer
JP Rifle buffer spring.

Went to the range today and even with the gas block all the way open, the round would eject, but the bolt would not lock all the way back.

I was reading various threads and a lot of people have enlarged the gas hole. However, wouldn't it be easier to go with a lighter buffer?

Thanks!

[A5BLASTER]

Put in a standard rate rifle spring. The jp rifle spring if I remember correctly is a stronger then normal rate spring.

[High_n_Dry]

Will clipping a few coils work?

edit: was reading that this actually does not do much for short stroking...

What about using a lighter buffer? The only reason I'm asking is that all stores are OOS on rifle buffers and I thought I could stick in one of my carbine weight buffers.

[Klem]

Use a $5 MILSPEC spring instead. Don't damage that expensive spring, use it in another build.

[High_n_Dry]

I just find it strange that the 6.5 wouldn't have enough gas to lock the bolt back.
I used this lower on my .556 with carbine length gas system with no problems.

[A5BLASTER]

I just find it strange that the 6.5 wouldn't have enough gas to lock the bolt back.
I used this lower on my .556 with carbine length gas system with no problems.

Yes but your 556 had a gas length that is standard for it's over all barrel length.

Your grendel barrel has a longer then standard gas length for its length.

I had that same barrel and gas block and had the same issues as well with the jp spring. Now it could be something else but changing out the spring is a cheap and easy thing to test before trying other things.

Changing it out to a standard rate rifle spring fixed the issue.

I have since move on to the jp scs systems for all my ar grendels.

[High_n_Dry]

I was thinking of the JP SCS system, but the price made me hesitate.
Did you go with the JPSCS2-15H2?

[Bigs28]

I use the jpscs h2 but i shoot suppressed.

[A5BLASTER]

I was thinking of the JP SCS system, but the price made me hesitate.
Did you go with the JPSCS2-15H2?

No I use the standard weight scs.

[Old Bob]

JP website recommends the H2 SCS for calibers larger than .223/5.56. You can start with the H2 to see how it works in your rifle. If it's too heavy, you can get replacement springs & weights from JP to convert the H2 to standard weight. There are instructions for changing out springs & weights on their website.

I have a standard weight SCS in my 3 gun .223 Wylde AR. Works great!

[Bigs28]

JP website recommends the H2 SCS for calibers larger than .223/5.56. You can start with the H2 to see how it works in your rifle. If it's too heavy, you can get replacement springs & weights from JP to convert the H2 to standard weight. There are instructions for changing out springs & weights on their website.

I have a standard weight SCS in my 3 gun .223 Wylde AR. Works great!

There is more to that equation then just caliber.

[High_n_Dry]

The stock I have is a smoke composite with a Magpul buttpad. The website states: When you purchase a Rifle Length Stock we shorten the stock so that when the rubber buttpad is added, the overall LOP remains the same as our standard rifle length buttstock (11.00"). https://www.smokecomposites.com/parts-and-accessories

I was thinking that the shortening the stock .5" likely also contributes to the short stroking?

[Mad Charlie]

The stock I have is a smoke composite with a Magpul buttpad. The website states: When you purchase a Rifle Length Stock we shorten the stock so that when the rubber buttpad is added, the overall LOP remains the same as our standard rifle length buttstock (11.00"). https://www.smokecomposites.com/parts-and-accessories

I was thinking that the shortening the stock .5" likely also contributes to the short stroking?

Whether it does or not, the first thing you need to do, as suggested above, is install a standard spring and buffer, then see how it works. Don't start chopping on anything.

[sbowhuntr]

Had that issue years back, similar set up.. 18" bbl runs most efficiently with a mid length gas system, 20" and up rlgs, 16" clgs. Like Klem said, $5 standard spring and problem solved.

[Bigs28]

I use a smoke composites stock with butt pad and jp adjustable gas block as well. Im using jpscs h2 in it, suppressed sbr, and have no issues.

[High_n_Dry]

Whether it does or not, the first thing you need to do, as suggested above, is install a standard spring and buffer, then see how it works. Don't start chopping on anything.

I know, but all the stores are OOS and I have to wait until Jan 7 for my 3 dollar spring with 6 dollar shipping! Just trying to pass the time lol

[Mesa1978]

I've used Mispec springs and JPS captured in RLGS, there isn't any difference in function between them.

[mtnlvr]

I take it you don't have another AR with mil spec spring to temporarily swap in? Or a friend's?

[sbowhuntr]

Another thought as well, are you 100% sure your gas block is in perfect alignment? JP is known for anemic gas ports, a very small amount of misalignment could make the gas system suffer. Just a thought.

[High_n_Dry]

My other AR is carbine length.

I did take time to mark and line up the port. Did the compressed air test and it "seems" to work fine. I may take it off and re-do it- just to waste some more time