Adjustable gas block... is it worth it?

[sniper20]

Hey guys,

I am looking at possibly upgrading my gas block in my 6.5 Grendel to try and save on brass. When it fires, the brass spits out and gets dents from hitting the shell deflector. I can't say I'm a fan and would like to try and save this from happening.

I was looking at JP adjustable blocks. I was thinking JP because they had the best reviews and they seem to be pretty easy to adjust. My question is... is it worth it? Does it justify the extra expense for this option? Is it going to help reduce recoil? Is it going to help save my brass? What are the benefits of having an adjustable block vs non adjustable?

Thanks so much for any input.

[rabiddawg]

I have swapped out one because the block on the gun was leaking and under gassing my gun.

I can't say I that I experienced any other benefit than my gun functions properly now. So based on my experience, I'm not changing out something that is working.

As for denting the brass. The fuzzy velcro works for me.

[VASCAR2]

You didn't mention what barrel length your using. The 6.5 Grendel with shorter barrels benifit from an adjustable gas block especially if you intend on running a suppressor. There are 18" 6.5 Grendels which are sold with large gas ports and benefit from an adjustable gas block. I have a J&T 6.5 Grendel 16" CAR gas system barrel and it could benefit from an adjustable gas block. I 've loaded lighter charges of CFE223 powder with 123 grain bullets. This powder is slow enough I was getting malfunctions because with this load the rifle is under gassed. This 16" 6.5 Grendel doesn't exhibit this problem with faster powders like H-335, TAC or Accurate 2230.

With full power factory loads like Hornady A-Max the 16" barrel kicks the brass out at 2 O clock and the brass gets dinged up. Alexander Arms only sells midlength 16" 6.5 Grendels to better balance the gas system. I also have a 20" 6.5 Grendel and put a JP adjustable gas block on it. I have not had to adjust the gas since the initial setting but I don't run suppressed.

My suggetstion is if your using a carbine gas system on a 16" or less length barrel and especially reload or run a suppressor an adjustable gas block is desireable. Most 18" midlength and rifle length 6.5 Grendels I'd probably use an adjustable gas block. On 6.5 Grendel barrels 20" and longer without a suppressor I don't think an adjustable gas block is needed.

[Keep The Change]

You could try the velco trick as a cheap experiment and if it works you saved a lot of money. Is your Grendel a carbine with a carbine gas system?

You can't go wrong with JP, and for the price it is uncharacteristically inexpensive for a JP part. There are other adjustable blocks out there as well. Seekins, SLR, Syrac, and Odin.

Just maker sure you get the height of the gas block from the OD of the barrel and make sure it fits from the OD of the barrel to the handguard.
What is the OD of the barrel? I have an SLR still in package that didn't fit under my handguard so I learned from experience. It is a previous model as they changed them a little within the last year or so.

[Joseph5]

I will agree that an adjustable gas block is not needed. I have one on my rifle so I can fine tune it for different loads. Hornady factory ammo, AMAX & SST both work on the same setting. My reloads which are at the upper end of pressure were getting dinged up and ejected hard. The best setting for my reloads also works with factory SST but not AMAX. I need to open it up one more click when shooting AMAX. I want to develop a hot load with the 130gr Berger Hybrid OTM and I will be able to fine tune the gas system to minimize stress to my rifle and keep my brass from getting beat up. It just depends what you are wanting to do with your rifle.

[LRRPF52]

Another plug for Velcro pile tape on the deflector, although this doesn't get rid of the more likely place of denting at the trail edge of the ejection port, which will dent brass even on old school uppers with no Brunton bump (brass defelctor).

Another thing you can do is cut coils on the ejector spring, and this is pretty common with some AR15 competitive shooters who like to keep account of their brass.

My Lapua brass comes out looking almost unfired with 31.2gr CFE223 under the 123gr AMAX.

You can also increase buffer weight and spring weight, as long as the gun still runs.

[Klem]

My thoughts too.

Cheapest solution is to cut the ejector spring shorter by the length of the spring that sits proud of the bolt face when uncompressed (a couple of coils). That will fix your dented brass.

Try a heavier buffer if concerned about recoil. Cheaper than an adjustable gas.

Truth be known, recoil is the same regardless of gas blocks and buffers. For every action there's an equal and opposite reaction. It's the felt recoil and the battering the receiver gets in the auto cycling system that you are trying to tame.

[sniper20]

Thanks for the input guys. I'm running a rifle length system, 24"bbl. I have converted some of my brass from 7.62 brass, and using 29gn of Leverevolution powder, it gets spit out at the 1:30-2:30 position and doesn't look bad. When I run a full load of CFE , about 31 grain, it starts to ding it. I will try cutting a coil off my ejector spring and see how that works. I don't plan on running suppressed, yet...