New Build Recoil

[keystone183]

Just got a new build together on a lilja 319 barrel. The upper is a crosshill abmi sidecharger. In breaking it in, i notice it has pretty significant recoil. This is compared to a 24" barred build with a JP LMOS carrier i also have. I have the gas adjusted properly, and it is running a JP Silent capture spring. Is this just a function of it being significantly lighter rifle with a heavier bcg? Any ideas on how to reduce it?

Don't mean to come off as a sissy here.....but the the old rifle had next to no felt recoil. This one surprised the hell out of me when i touched off that first primer.....It isn't 300wm or anything, but still, fairly significant.

[molar]

The grendel doesn't recoil. If you were near me I would let you shoot the 5.5 lb 458 SOCOM I built with 400 gr bullets and you wouldn't even notice the grendel after that

That said, there are some excellent brakes out there that will reduce recoil. Is the Lilja threaded 5/8x24 or 9/16"?

[rickOshay]

You might try the MGI buffer.

[lead chucker]

I get what your saying keystone! I have a 18" with mid gas system with a rifle length stock and buffer. I built my dad a 16" also with a mid gas system with a carbine length stock and buffer. I used a H2 buffer in his because at the time they was sold out of H3 buffers. Both rifles have adjustable gas blocks adjusted for bolt lock back. But his 16" has quiet a bit more felt recoil. Im getting ready to swap out his H2 for a H3 and see if that helps some.

[LRRPF52]

The 18" MLGS is gassed pretty hard, much more so than a RLGS, so you will have to address it from a number of angles. If you are comparing a traditional set-up AR15 in any centerfire caliber to a JP LMOS with SCS with adjustable gas block, it is going to have more perceived recoil no matter what you do.

The JP LMOS + SCS + Adjustable Gas block feels like snot on a mirror, sliding inside your rifle, but with nothing moving in your reticle. It's a beautiful thing to behold, and feels nothing like shooting an AR15, which is already a very mild recoiling system with in-line recoiling and reciprocating forces.

I'm in the process of several 18" MLGS projects. Here is how I am approaching them:

I already know they are gassed hard, so I have an array of several different buffer and spring options.

* JP SCS for AR15 with standard spring weight captivated from the factory
* MGI RRB, with spacer for rifle tube, as well as carbine and rifle springs
* H2 buffer with carbine springs
* Spike's ST-T2 buffer with carbine springs

I'm still looking at buttstocks, and have a bunch to choose from, but I will be focusing on reliability, accuracy, and weight/balance. I want the JP SCS to work because it feels so amazing in these rifles. With 18" MLGS, I will be using some method to dial down the gas, and I am looking at the RCA adjustable gas key and Lo-mass BCG right now, nitrided.

I also have a Seekins ATC muzzle break, even though I'm not a huge fan of breaks for practical use. I'm considering installing it on one of these 18" guns.

[keystone183]

I is threaded but i don't really want a break on it. Not worried about follow up shots. Make no mistake, the recoil is far from punishing, but i'm spoiled.

I have read extensively on the subject and have a pretty good handle on the physics (i believe), but just don't have any real world experience here. My guess is, the difference is mainly about the heavier bcg, and going from rifle gas to midlength. Just looking for some solid advice before i go drop any more coin on a bunch of springs and buffers to play around with.....

[keystone183]

The 18" MLGS is gassed pretty hard, much more so than a RLGS, so you will have to address it from a number of angles. If you are comparing a traditional set-up AR15 in any centerfire caliber to a JP LMOS with SCS with adjustable gas block, it is going to have more perceived recoil no matter what you do.

The JP LMOS + SCS + Adjustable Gas block feels like snot on a mirror, sliding inside your rifle, but with nothing moving in your reticle. It's a beautiful thing to behold, and feels nothing like shooting an AR15, which is already a very mild recoiling system with in-line recoiling and reciprocating forces.

I'm in the process of several 18" MLGS projects. Here is how I am approaching them:

I already know they are gassed hard, so I have an array of several different buffer and spring options.

* JP SCS for AR15 with standard spring weight captivated from the factory
* MGI RRB, with spacer for rifle tube, as well as carbine and rifle springs
* H2 buffer with carbine springs
* Spike's ST-T2 buffer with carbine springs

I'm still looking at buttstocks, and have a bunch to choose from, but I will be focusing on reliability, accuracy, and weight/balance. I want the JP SCS to work because it feels so amazing in these rifles. With 18" MLGS, I will be using some method to dial down the gas, and I am looking at the RCA adjustable gas key and Lo-mass BCG right now, nitrided.

I also have a Seekins ATC muzzle break, even though I'm not a huge fan of breaks for practical use. I'm considering installing it on one of these 18" guns.

Oops. Posted over you.

Yeah, i handled a buddy's jp 308 and and it was amazingly smooth. So i dropped the money on the SCS. It is unbelievable the difference it makes in feel. I suspect i'll be putting them in my other rifles now...

Here is my plan, please give me your thoughts. I think buying the jp spring pack and putting in a stiffer spring may be my first move. If nothing else it should slow the impulse down and spread it out. Hoping that will make it right.

Next step would be going to a blue sprinco spring, and maybe a lighter buffer? And possibly a heavier red sprinco and ligher buffer? Seems lightening the reciprocating mass would be good, but the heavier spring would still slow down the action? This is where i'm just shooting in the dark....

[LRRPF52]

I know an 18" MLGS will run like a raped ape with PRI adjustable gas block, rifle buffer, and rifle spring, with a PRS. We spec'd the Lilja 18" MLGS barrels out with the optimum port diameter, whereas some of the 18" MLGS barrels on the market have .094" gas ports, which really needs to be tamed.

If you are using a carbine extension tube, go with at least an H2 buffer. Consider the higher end Tubbs flatwire spring as well.

[lead chucker]

My 18" is suppressed 99% of the time tuned with the adjustable gas block. It has a Grizzly billet side charger on it and is a little heavy, its recoil is very mild. I do want to get a JP SCS sometime soon for it. But my dads 16" mid gas really needs to be tamed.

[Tedward]

Just use your JP SCS you have and see how it goes in your new build. I use them with all of my lowers and one of my lowers has multiple uppers I swap around during a day of shooting. I run a 24" Grendel, 18" Grendel, 20" 223 Wylde and a 16" Beowulf all on my Loki Lower with a JP SCS. They all cycle great and all use the same factory JP spring, I've never changed the spring but have the 3 spring pack still unopened.. Due to the extra weight of the SCS it works flawlessly wether its a rifle buffer tube or a carbine buffer tube, just use the spacer in the rifle and the cycle rate is the exact same. My other lowers are carbine buffer tubes and they have the JP's too. It is worth the weight in gold for reliablity.

Take yours out of the one rifle and give it a shot then order a second one for your other rifle. Once a JP SCS user, you never go back or you'll be disapointed when you do.

[Slappy]

Do not want to hijack the thread but since there is discussion about this. Anyone running JP SCS on a PRS stock and a 24" barrel?? if so how is the function. The more I read about this the more I want one!! BANG BANG!!

[NugginFutz]

Just got a new build together on a lilja 319 barrel. The upper is a crosshill abmi sidecharger. In breaking it in, i notice it has pretty significant recoil. This is compared to a 24" barred build with a JP LMOS carrier i also have. I have the gas adjusted properly, and it is running a JP Silent capture spring. Is this just a function of it being significantly lighter rifle with a heavier bcg? Any ideas on how to reduce it?

Don't mean to come off as a sissy here.....but the the old rifle had next to no felt recoil. This one surprised the hell out of me when i touched off that first primer.....It isn't 300wm or anything, but still, fairly significant.

Just to be clear, your new build is the Lilja barrel, side charger, and the JP silent capture setup, correct?

[wheelguner]

I am using the JP SCS assembly in both of my Gredels using the standard spring. As you can see from the pic, I have both rifle and carbine lengths and both run fine. The only difference is the spacer isn't used in the carbine.

[Buster]

Do not want to hijack the thread but since there is discussion about this. Anyone running JP SCS on a PRS stock and a 24" barrel?? if so how is the function. The more I read about this the more I want one!! BANG BANG!!

Yes. It functions really well in my unit.

[keystone183]

Just to be clear, your new build is the Lilja barrel, side charger, and the JP silent capture setup, correct?

This is correct.