overgassed

My 6.8 has always ejected at 1-1:30 and I never cared because it cycled & killed pigs. I can only imagine the addition of a suppressor and handloads (probably hotter than factory) has added more gas. I found the broken lower & rear takedown pin and now I care. I have heard adjustable blocks can be a pain. Should I try the heavy buffer and/or spring instead? If you've been down this road, please share your wisdom.

Both of your takedown pins were broken into?

I went with a heavy buffer and spring in my AR308, it helped but I have since added an adjustable gas block and it really tamed it.

I would definitely add an adjustable gas block
Adding a heavier buffer is just slowing the bolt down but a gas block is reducing the pressure going into the system.
I run a VLTOR A5 buffer system on my 6.8 along with an adjustable GB. On my son's I run a normal carbine setup along with an adjustable GB.
Cans are always on.

I shoot for 3:30-4 for brass ejection.

Adjustable gas blocks are not a pain, and an absolute necessity when running an AR, especially with a suppressor, in my opinion. LR-308 has a great hand load made for it, not loaded to published max, and it was ejecting at 1 to 2 o'clock. Adjustable gas block, one click open, and it ejects at 3 to 4 o'clock like it should. Jist make sure and buy one that has the adjustment screw facing forward.

https://shopwilsoncombat.com/Wilson...justable-Gas-Block/productinfo/TR-AGB-9/

Already been said but I'll second. They are great and much easier to set up than one initially thinks.

I've built a few at this point but only one adjustable setup and I concluded that everything but a "standard 5.56" setup should have an adjustable block. They're more affordable now than ever. I have an Odin Works version, the really simple style. I has a screw for a simple adjustment and a set screw behind it to hold in place. That said, i don't have a centerfire can and would love one of those switchable ones for some setup.

I have some JP enterprise adjustable gas blocks and they are great. Setting them up takes only a few shots and I have not had to mess with it since. Guns have less recoil after also.

The 6.8 history with load data has been a rocky one. Most load data is with the 6.8 SPC I (one) pressure. Most 6.8 rifles are SPC II (two) chambers. The SPC 2 chamber will allow about 2-3 grains extra powder to equal the same pressure. I know some shooters who run a VERY stout load, even for an SPC 2 chamber. Adding a suppressor generally adds about 3K-5K psi to the round. So adding a can to an already stout load can cause over pressures. Having an adjustable gas block is a great addition. It will allow less gas back, but won't help if the load is already a warm load.

nope, just the rear

looks like I'm in the market for an adjustable, something I should have done long ago no doubt

I use SLR Rifleworks adjustable gas blocks and have never had an issue. Plus the adjustment screw is forward facing and detents so it's easy to go from suppressed to unsuppressed.

You do not have to go with an adjustable gas block. You can definitely fix the issue with a combination of: heavier buffer, heavier spring, heavier carrier. Lots of people fix it that way. Many AR guys will say do not go with an adjustable gas block because you don't need it.

Now, if you want to go with an adjustable gas block, then you can go that route. I prefer to go with a heavier buffer and then fine tune with an adjustable gas block if needed. I have one on a 6.5 Grendel and a 458 socom, both run suppressed. Adjustable gas blocks can get expensive. They are easy to install and set up. Like mentioned, better to get one adjustable from the front, but not required if you always shoot suppressed. Just leave the hand guard off while you adjust it.

I have no idea whether these specific one is are good or have any thing made by Radical Firearms for that matter but at least it's cheap.

https://www.primaryarms.com/radical-firearms-low-profile-adjustable-gas-block-750-set-screw-style
The way I figure that if Radical Firearms can make a regular gas block that can seal, then this is very basic one simply has a screw to partially cover the hole and a set screw to security.

I own several and would never advise not to go with the adjustable gas block. Why bring multiple components into the mix when you can solve the problem with one? And when you start replacing carrier groups etc... your not saving money.

And then change a load/ammo, and ejection changes. Add or take away a suppressor and ejection changes. Much easier to make a click or two, than to mess with all those parts.

Heavier buffer or AGB will each help on their own, but they’ll work a lot better together. I’m a big fan of the Tubb springs. I’ve got two different Odin blocks, a PSA, and a Seekins. All work equally well with some nuanced differences in operation, but they all work better with a quality spring and heavier buffer.

Ejection location is a range, not a specific point. You can change ammo or add a suppressor and still be in the range.

I can shoot subs, supers, 110g, 150g, 200g, 220g, with and without a suppressor in my 300 blackout, no AG, and don't have an over gassed or under gassed problem. Empty brass will be in a nice pile after I'm done shooting.

You can buy a set of buffer weights to adjust your buffer yourself. Much cheaper than a gas block and that is usually all that is needed. There's the one component change you asked for.

I've got two Wojtek Weaponry adjustable gas blocks on my suppressed ARs and they are fantastic. They're like $40 and the owner is a real stand up guy.

That said, I think the post above (if it's to be believed) is an outlier. Unless he's running a 20" barrel with quick-burning powders in .300blk there will always be a large variation in ejection patterns, greater volumes of gas, and increased bolt velocity when running suppressed. A buffer can help but an adjustable gas block is the best because it will actually cut down on the amount of gas that reaches the action instead of just delaying the unlocking by a few thousandths of a second.

I run my 6.8 and 5.56 SBRs suppressed only and I had to do something about the gas because I nearly choke on it as a lefty. I made some lighter handloads (about 5% slower than my normal loads), set the gas block to its lowest setting, and then turned it up with each shot until my bolt just barely locked back. Now with my normal handloads I have light recoil, much less gas in the face, and my case mouths aren't getting destroyed on the brass deflector. I run an H2 buffer not because it helps with reliability, but because I like the recoil impulse of more mass vs less mass.

Have you tried the same "correction" on 5.56mm 16", .223 Wylde AR pistol, LR-308?

Your solution is not a one size fits all, but an adjustable gas block is. And it reduces trauma to the bolt, and upper.

Different weight buffer or spring is not a fix, it’s a bandaid. The same amount of gas is coming back to the carrier and the buffer and spring have very little affect on the carrier for the first part of it unlocking and cycling. A heavier buffer and spring change the ejection pattern but not the overpassed problem.

This sounds like some made up conspiracy by free mansons, firemen and the evil adjustable block industry. Don't believe it for one second.

I have one of these for sale in the classifieds for 150 bucks
they work great! all mine have an adjustable GB


just move over your bolt
https://www.silencershop.com/gemtech-5-56-suppressed-bolt-carrier.html

You're smart enough to figure it out. Eric is right. Same amount of gas is comin in, it is just up against more resistance.

Yes enough over gassed and you can have a bolt trying to open while the chamber is sill under pressure and with a heavy enough buffer spring still get ejection right around the 3 o'clock position.

Adjustable gas block , Sprinco Red spring , H1 buffer. Good to go.

With an adjustable gas block you can run a normal spring and buffer. If you’re running a heavier H buffer you are still more than likely have to much gas.

Object is to run as little gas as possible to reliably cycle the BCG. Use a standard weight spring and buffer and then tune block to that combination.

I put the AGB on and it works great. Now I have another question. I see carbon residue leaking under the block towards the muzzle. Did I not install correctly? Is this somewhat normal?