6.5 Grendel Buffer Change?

[AzShooter]

Hey im new to the 6.5 Grendel and looking at creating an upper for the AR-15 platform. I have a couple questions about necessary parts. First off, will the stock buffer for a 5.56 round be compatible or will i need to change it out for a different weight?

[leopard6.5]

AzSooter: It depends on what kind of 5.56 buffer you have.

If you have the full size buffer from a rifle length buttstock you should be good to go with that buffer and spring.
However, if you have a collapsible or carbine buttstock, the buffer will probably be too light.

Hopefully I have my weights correct for you and someone feel free to correct me if I'm wrong.
The rifle buffers weigh approx. 5.2 ounces while the carbine buffers weigh around 4 ounces.

If you have a carbine buttstock you can put in a heavier buffer like the one from Spikes to help slow down the action.

The other thing that helps is having a true M16 Bolt Carrier instead of the lighter AR-15 version.
The M16 Bolt Carrier weighs more than an Ar-15 Bolt Carrier.

Good Luck and keep those questions coming.

Lee

PS- Welcome to the Horde!

[Drifter]

Several variables come into play, so difficult to say with certainty. Might be a good idea to try what you have first. Pay attention to function, reliability with ammo you plan to use, "feel" (or smoothness of operation), and ejection pattern. The rifle's behavior will often tell you what it needs for fine-tuning.

All that being said, it's usually recommended (if starting from scratch) to use an M16 bolt carrier and H3 carbine buffer, especially if the gas system is midlength. If using a rifle-length buffer system, the standard buffer often works fine. I like the Tubb / SSS flat wire buffer spring regardless of buffer weight and tube length.


Edit- leopard6.5 was faster on the trigger with a good reply. I'll leave my reply as is so that perhaps you'll recognize some similarities in recommendations.

[LRRPF52]

Welcome. These guys are steering you right. Most carbine buffers for the 5.56 AR15 are 2.9 oz., which I personally feel is too light for the Grendel, but could be made to run ok over the long haul with an adjustable gas block.

+1 on using an M16 carrier
+1 on using a heavier buffer, such as an H3

Let us know what barrel length you're looking at, and what you intend to use your Grendel upper for....

Recreational Target Shooting?
Hunting?
Competitions?

[AzShooter]

Thanks all for the info.
LRRPF52, mostly for recreational target shooting but the occasional hunting. Ill probably be getting either a 20" or a 24" barrel. I'm glad you brought up the gas block. What would be a good company to go with for the gas system? right now i am looking at Alexander Arms because that is the make of the barrel i am going with.

[LRRPF52]

For an adjustable gas block, I would go with JP or PRI. Make sure it's steel. I would steer you towards a 20" barrel, since you get velocities pretty close to a 24". If you're going to hug the bench a lot, the heavier the barrel, the better. For hunting, you can still run that set-up in a stand, but a heavy barrel will suck to carry around.

Now that I look at where you're at, you might want to go with a 24", since you have access to a lot of wide open terrain, and much longer shots than those across the Mississippi. If you play around with some of the VLD-type bullets, you can get very respectable results at 800yds, and 1000yds on calm wind days.

[AzShooter]

Ok, i dont know the little details very well, will an adjustable block from one of those companies be compatible with an Alexander Arms barrel?

[leopard6.5]

AzShooter: Compatible yes, as long as the inside diameter of the gas block matches the outside diameter of the barrel where the gas port is.

You'll want to ask that when you purchase the barrel.

If you go on AA's website and look at the barrels you will see that they usually tell you what size gas block to use for each barrel.

Hopefully this helps clarify it for you.

Good Luck.

Lee

[LRRPF52]

The main gas block diameters are:

.625" This is what was on the M16A1 and early model military guns with lightweight barrels. Not common on a lot of modern guns, but seeing a resurgence in new lightweight barrels chambered in 5.56 NATO.

.750" This is what became the standard with the M16A2 and its heavy fore end, and is the most popular 5.56 barrel gas block diameter.

.875" This is used on some medium-heavy contour barrels on target guns.

.936" This is used on heavy barrels meant for target shooting.

[sneaky one]

And, AA uses .906 on the 6.5- 19.5 bbl.,, I read Warped/WCI- made an adj. block in that I.D.---- I'm having a machinist pal of mine investigate honing out a JP unit- starting with a .750 I.D.- steel . I'll report back asap= I want to try one ! Probably don't need it.