Grendel buffer...

[gene]

I have heard that there are some issues with the grendels using the short AR carbine buffers... some have to resort to using heavier buffers or even adjustable gas blocks.

Any truth to that? What are your experiences so far?

Thanks.

[glane5910]

I haven't had a problem with the one Grendel I have using a stock carbine buffer with a Magpul UBR on it. It always works like a charm. 18" mid gas..

[gene]

good to know those were evil tongues then...

[glane5910]

Gene, I have read that others on this forum have had problems. Now I don't know if they were fixed with the buffer alone. I'm wondering how much of a weight difference there is on the stock carbine buffers that are currently out there.

[LRRPF52]

http://www.65grendel.com/forum/showthrea...-diagnosis

Read that thread. There have been others like it. Basically, the lightweight 2.9 or 3.0 oz buffers that work well in .223 guns pushing 45-55gr pills through carbine length gas systems on 16" barrels are not ideal for Grendels pushing 120gr bullets out 16" barrels with mid-length gas systems. It might be working 100% for someone shooting in the hotter weather, or a different gas port diameter, or a bunch of other variables, but I think the consensus is that the Grendel usually needs a heavier buffer, standard M16 weight carrier, especially from the 16" middy with large gas port.

There are huge differences in buffer weights on AR15 carbines. They vary from 2.9 oz up to over 4 oz, and rifle buffers are around 5.3 oz. There's a thread where I posted most of the buffer weights out there, to include a few speciality buffers. In my 16", I've only used the Spike's ST-T2 buffer, with great results across bullet and charge weights. Locks back every time, no malfs.

[glane5910]

Thanks..Wondering just how much the carbine buffers, all stock ones, no tungsten etc compare with each other weight wise? Were those weights you gave for stock? Why wouldn't a 18" mid show those same problems if not worse than the 16" mid with a standard buffer?

[LRRPF52]

Thanks..Wondering just how much the carbine buffers, all stock ones, no tungsten etc compare with each other weight wise? Were those weights you gave for stock? Why wouldn't a 18" mid show those same problems if not worse than the 16" mid with a standard buffer?

Not everyone's components are the same, and who knows what gas port diameters different barrel smiths are using. One big variable is bolt carrier weights. The Grendel should have an M16 carrier when using stock AA gas port diameters without adjustable gas blocks.

Different AR15 parts manufactureres cut the AR15 carriers differently when shaving the bottom rear of the carrier to prevent it being functional with the AUTO sear, so even slight variations in the carrier weight will change the cycle of operation time, including unlocking. This is why I prefer the original M16 carrier weight in all my AR's.

[LRRPF52]

This thread lists most of the buffer weights on the market right now:

http://www.65grendel.com/forum/showthrea...er+weights

[glane5910]

I finally used one ofhe M-16 carriers in my 6x45 build I finished up a couple months go. Cycles very nicely.

[glane5910]

Thanks for the links!!

[LRRPF52]

It's interesting studying the history of the development of the original Armalite AR15. As the prototype rifles transitioned to the development of the Colt Model 601, they still used the Edgewater buffer, which is totally different than the standard rifle buffer that was adopted with the Colt Model 603, which covered both the XM16E1 and the M16A1. This was intended to handle the different powder and pressure issues that came with it.

Whatever cartridge and propellant/projectile combination we try with gas guns, a certain balance has to be found to run the gun optimally. It forces us to realize the details of the operating system and become more familiar with them, why they work, and what doesn't work so well.

An example of this became very clear to me this past week as I've been doing load development with new powders and bullets in my .260 AR10. Using really slow-burning powders towards the higher end of acceptable pressures by the book gave me some significant jumps in felt recoil and violent cycling of the action. It seemed like the slower powder was able to affect the gas port pressure enough to really change the effect on the action. I don't recall this happening with the faster powder that I was using, although I did feel the recoil increase slightly with each increase in charge weight. I have also noticed this with the Grendel. For every action, there is an equal and opposite reaction I guess...