Recoil spring recommendation

[se3388]

I am putting together an 18 inch (mid length gas system) 6.5 Grendel just for casual plinking and some Deer hunting and was wanting to hear some advice on a buffer and recoil spring. I'll be shooting primarily 100-120 gr bullets. Will the standard (16 inch) carbine buffer and spring work for my needs?

Steve........

[LRRPF52]

With an 18" MLGS, you are going to have more dwell time, which will run the action harder. For these barrels and gas system lengths, they like to have some mass behind them in the recoil weight and spring weight departments.

If you are using a carbine length extension tube (for the buffer/recoil spring), I would consider the following options:

* High quality tuned JP recoil spring + H2 or H3 buffer. http://www.brownells.com/rifle-parts/rec...41074.aspx



* JP Silent Captured Spring system http://www.brownells.com/rifle-parts/sto...53853.aspx

* Quality recoil spring, plus an MGI Rate Reducer Recoil Buffer



I think a standard 2.9oz carbine buffer is going to allow the system to unlock earlier. You will also want an M16 carrier, unless you plan on tuning the system with an adjustable gas block, low mass carrier, and balanced recoil spring system.

For casual plinking and hunting, I would lean on reliability and economy, with the H2 and increased power recoil spring.

[mongoosesnipe]

I run the tubb flat wire springs in all my rigs they are a little bit heavier and a whole lot smoother
http://www.midwayusa.com/product/693755/...me-silicon
combine that with a heavy carrier and or buffer if that doesn't get you running to satisfaction you can go adjustable gas block or adjustable tube

[usmc1371]

I am building an 18 inches with rlgs. I plan on using a carbine lower. I have m16 bolt carrier. Which buffer would work best?

[se3388]

After everyone's advice here and some more research I am going with an H2 buffer
(4.5 oz.) and an M16 carrier for the extra reciprocating mass. I'll keep a close check on things to see if I might need a heavier spring or an adjustable gas block.

Steve............

[LRRPF52]

I am building an 18 inches with rlgs. I plan on using a carbine lower. I have m16 bolt carrier. Which buffer would work best?

What gas port diameter? Have you already had the barrel profiled?

With 18" RLGS, they run better with longer bullets in the 120-129gr range, with a larger port, since port pressure is lower than MLGS. You might consider lower weight carbine buffer here, and have an H2 on hand in case you get early unlocking, but 18" RLGS Grendel's tend to be under-gassed a bit without attention to the gas port, especially if you shoot lighter pills with weaker charges.

[se3388]

LRRPF52
How do you think mine will run with the setup I am putting together, my gas port is .098, H2 buffer, M16 bolt carrier, I do have a standard buffer to try if need be. Any recommendation on bullets with this setup?

Steve..........

[usmc1371]

I haven't received my barrel yet. Not sure what the gas port size is. The barrel is a bull bbl. The lower will also be for my 556 m4.

[LRRPF52]

LRRPF52
How do you think mine will run with the setup I am putting together, my gas port is .098, H2 buffer, M16 bolt carrier, I do have a standard buffer to try if need be. Any recommendation on bullets with this setup?

Steve..........

With an 18" MLGS, your pay is way oversized, so you will need an adjustable gas block, and dial it down to some of the lowest settings. A .098" gas port is larger than a 20" or 24" RLGS, where the port pressure is lower than a MLGS.

You're going to need all the weight and recoil spring strength you can get, within reason. I would look at the MGI with a JP tuned flat wire spring, or a JP SCS with spring kit so you can try some of the heavier spring set-ups.

A .098" gas port/MLGS is going to want to drive the carrier rearward quite violently, which will lead to early unlocking. It usually causes extraction problems, mangled rims, failure to extract, or successful extraction with permanent case obturation just above the extractor groove.

Get one of the reputable adjustable gas blocks form JP, SLR, Seekins, PRI, etc., and make sure you absolutely get a steel one. Clamp-on is preferred, unless you have limitations with the ID of your free float tube.

[se3388]

I ordered a micro adjustable gas block from BTE. All the reviews I could pull up were positive for BTE gas blocks. It's stainless and clamps on too and should fit under any forend.

Steve..........