Adjustable gas blocks.
- Thread starter redtail
- Start date
Eddie Gunks
.338 Win Mag
Imo adjustable gas keys are far better.
meketrefe
.450/400 Nitro Ex
hi, If you have concerns about the gas port being oversized then the gas block might help.
It will not do anything for recoil.
It will not do anything for recoil.
I'm no expert but understand main use for adjustable gas blocks are to reduce the additional back pressure to BCG created by using suppressed rifles. Other reasons would include ability to fine tune cycling for hot reloads or if you are using light recoil springs or low mass BCGs. I suppose they would also be useful for shorter barrels. I have two rifles with AGBs it just so happens one of those is the only rifle I've ever had issues with short stroking have no idea if it is from the AGB or something else it seemed to make no difference how the AGB was adjusted. Issue seemed to resolve itself after a period of break-in but I would not rely on that gun in a SD or SHTF scenario.
I put one on my 6.8 and one on my 204. I personally believe they do help with recoil. The bolt bounces back not as hard as without one which in turn makes the rifle kick less. I researched different ones before I purchased the 2 I got because some are junk. These are the ones I bought.
https://www.odinworks.com/Adjustable_Gas_Block_p/gb-adj.htm
Is the difference in recoil noticeable,,, Yes --- Is there much more difference,,, No
Another benefit is the empty cases dont go flying which allows me to save brass easier
https://www.odinworks.com/Adjustable_Gas_Block_p/gb-adj.htm
Is the difference in recoil noticeable,,, Yes --- Is there much more difference,,, No
Another benefit is the empty cases dont go flying which allows me to save brass easier
timboy
.44 mag
For $15 I would go for it,I have used one and would again,if I was starting from scratch I would try a adjustable key like Eddie said just to try something different.
One benefit of adjustable gas key vs adj gas block is you can replace it if AGB gets clogged from carbon and comp is pinned and welded under prior law... also less expensive.
Disadvantage is gun may run cleaner with AGB vs AGK.
In the end they both accomplish the same thing.
Disadvantage is gun may run cleaner with AGB vs AGK.
In the end they both accomplish the same thing.
Eddie Gunks
.338 Win Mag
1. easier to get to. When the gas block screws fail (i see it happen alot) you usually cant get to the screw at the block if you are not tooled up for it....,shit only breaks at a Match, far away from home
Etc etc.
2. If the key fails you could drop a regular bcg and buffer in and she will run. If a gas block fails (i have seen it alot.....like the screw falls out) you are fucked.
3. If you missed tuned it and it starts to fuck up and you can not access the screw in the block (handguards in the way) and u r running a light weight bcg you are dead in the water. You can not simply change out the bcg and buffer and make it run. (Yes. At matches you can usually borrow thos two items!)
4. My gas key has never failed. No screw issues etc etc.
5. Easy to tune the key as the handguard is not in the way. No special tools needed. Small allen key....so if you need to open it up more cause you miss tuned it it is a bit easier, at a match.
I run Seekins adjustable gas blocks on everything that has .750 at the gas port. I prefer them to all other brands. Too bad they don’t make them for .936 sized barrels.
BDinPutnam
.475 A&M Magnum
Probably because I've never looked for them- who makes the adjustable key?
Has anyone tried the "tunable" block (I forget who makes it)?
Getting ready to build a 1:8 twist 18 inch .223 and trying to decide if I care enough or just want to go with a standard block. I do have an adjustable block on my existing .223 and once I got it dialed I haven't really changed it ever, it is pretty predictable where it throws brass, but I don't run suppressed and I generally don't do much above 62 grain so I don't know if it really matters?
Has anyone tried the "tunable" block (I forget who makes it)?
Getting ready to build a 1:8 twist 18 inch .223 and trying to decide if I care enough or just want to go with a standard block. I do have an adjustable block on my existing .223 and once I got it dialed I haven't really changed it ever, it is pretty predictable where it throws brass, but I don't run suppressed and I generally don't do much above 62 grain so I don't know if it really matters?
meketrefe
.450/400 Nitro Ex
the adjustable gas block will not reduce the recoil.
Most of the recoil comes from the actual thrust produced by the bolt and the best to atenuate that is with additional mass. A brake too.
Related to the gas guns and carrier groups, this can be done by
A) Passively... it might be with a heavier rifle. A heavier rifle will reduce effective recoil.
B) 2nd type that is active mass.... also if your carrier gets hammered so bad the first thing is to
make sure you have the right carrier and buffer and port size and use the right specs from the beginning.
That mass creates an opposite force in the opposite direction to the recoil, that is what fights the recoil and it has nothing to do with having extra gas because after the bolt opens it will bleed all out.
IMO the semiauto carriers should have never existed as well as the carbine porting that is harder to balance with the wide range of ammunition
found in the civilian market. People want extra light this, extra light that, well, then be ready to deal with problems.
So put a M16 type carrier, spring and weight and a mid-length or rifle porting and everything will run cooler and better. There should not be interference
and this also will reduce a bit the perceived recoil because of the additional mass. Perhaps you mean with recoil must be the snappiness that
could come with a badly balanced system, normally a mistake, rather than anything substantial and measurable extra torque.
Of course if there is a mistake and the whole thing is snapping badly (just a perception but not much more recoil) one should review
the build to make sure things are well balanced to start with.
Because if one tries to fix a big problem by reducing the amount of gas one quickly might find out that the rifle runs fine with Mil spec ammo
but will short cycle with commercial ammo. Like for example, PMC 55gr fmj might run 300 fps slower than M193 Lake city. NATO Stamp.
193 runs at 62k psi and pmc I estimated 54psi like several other brands.
PMC bronze will not run in suppressed mode w/o a suppressor in many rifles with or w/o piston systems while the M193 will run happy and
unless one has the simplicity of a piston switch or other gas blocks with the 2 or 3 positions I don't see people fiddling with an adjustable screw
very often. I have several with screws and never touched them and they are full open. Have them since I got them bulk at a great deal
but other ones of teh same model I got with the screw run just as fine.
Furthermore, the subsonic uppers for suppressors should be build with that purpose only and anything to run in two modes with a wide
range of ammo will be only trouble. That, or have a system with a dual tandem gas block that is a custom job.
Same considerations when building new uppers. One might wan to use the same carrier and not worry about gas key settings.
All the same directives apply no matter what caliber and barrel, the system must be balanced using the same principal.
Other than that, and 99% of the situations if folks know how to put a standard upper to run smoothly form get go then the adjustable gas
block becomes secondary. But, hey if they are not too expensive? Just like eddie said make sure they are going to stay together so
the best way is to have one made of steel, ideally clamp and those stupid screws that come with them have them replaced by a quality
stainless screw and hopefully a locking nut aside from the blue locktite. Aircraft folks will have them drilled and crossed wired unless
there is another method of locking them to be safe. Personally I stay away from aluminum and set screws and any other Mickey mousing.
But again, more times than not is a bit of snake oil situation. you don't really need them if you follow the best practices for a reliable
gas gun.
Most of the recoil comes from the actual thrust produced by the bolt and the best to atenuate that is with additional mass. A brake too.
Related to the gas guns and carrier groups, this can be done by
A) Passively... it might be with a heavier rifle. A heavier rifle will reduce effective recoil.
B) 2nd type that is active mass.... also if your carrier gets hammered so bad the first thing is to
make sure you have the right carrier and buffer and port size and use the right specs from the beginning.
That mass creates an opposite force in the opposite direction to the recoil, that is what fights the recoil and it has nothing to do with having extra gas because after the bolt opens it will bleed all out.
IMO the semiauto carriers should have never existed as well as the carbine porting that is harder to balance with the wide range of ammunition
found in the civilian market. People want extra light this, extra light that, well, then be ready to deal with problems.
So put a M16 type carrier, spring and weight and a mid-length or rifle porting and everything will run cooler and better. There should not be interference
and this also will reduce a bit the perceived recoil because of the additional mass. Perhaps you mean with recoil must be the snappiness that
could come with a badly balanced system, normally a mistake, rather than anything substantial and measurable extra torque.
Of course if there is a mistake and the whole thing is snapping badly (just a perception but not much more recoil) one should review
the build to make sure things are well balanced to start with.
Because if one tries to fix a big problem by reducing the amount of gas one quickly might find out that the rifle runs fine with Mil spec ammo
but will short cycle with commercial ammo. Like for example, PMC 55gr fmj might run 300 fps slower than M193 Lake city. NATO Stamp.
193 runs at 62k psi and pmc I estimated 54psi like several other brands.
PMC bronze will not run in suppressed mode w/o a suppressor in many rifles with or w/o piston systems while the M193 will run happy and
unless one has the simplicity of a piston switch or other gas blocks with the 2 or 3 positions I don't see people fiddling with an adjustable screw
very often. I have several with screws and never touched them and they are full open. Have them since I got them bulk at a great deal
but other ones of teh same model I got with the screw run just as fine.
Furthermore, the subsonic uppers for suppressors should be build with that purpose only and anything to run in two modes with a wide
range of ammo will be only trouble. That, or have a system with a dual tandem gas block that is a custom job.
Same considerations when building new uppers. One might wan to use the same carrier and not worry about gas key settings.
All the same directives apply no matter what caliber and barrel, the system must be balanced using the same principal.
Other than that, and 99% of the situations if folks know how to put a standard upper to run smoothly form get go then the adjustable gas
block becomes secondary. But, hey if they are not too expensive? Just like eddie said make sure they are going to stay together so
the best way is to have one made of steel, ideally clamp and those stupid screws that come with them have them replaced by a quality
stainless screw and hopefully a locking nut aside from the blue locktite. Aircraft folks will have them drilled and crossed wired unless
there is another method of locking them to be safe. Personally I stay away from aluminum and set screws and any other Mickey mousing.
But again, more times than not is a bit of snake oil situation. you don't really need them if you follow the best practices for a reliable
gas gun.
meketrefe
.450/400 Nitro Ex
Stay away from Stupid ideas like this...
BDinPutnam
.475 A&M Magnum
Thanks @meketrefe, I think you just saved me 50-80 bucks.
I installed an adjustable block from Superlative Arms on my 3Gun build. I have a very low profile/slim handguard and it was the only adjustable one I could find at the time that fit under the guard.
.750" Adjustable Gas Block, Bleed Off - Clamp On, Melonite Finish
Runs great but I haven’t put tons of rounds through it yet. Prob 6 or 7 3Gun days plus range work so definitely more than 1,000 rounds.
Design is different than a standard adjustable gas block. A standard adjustable block only allows you to adjust the amount of gas that returns to to bcg. Excess stays in barrel and my understanding is that the heat causes excessive wear on the adjustment screw.
Superlative block works like a turbo. Excess gas is bled off through a valve so theoretically system runs cooler and cleaner than a standard block.
.750" Adjustable Gas Block, Bleed Off - Clamp On, Melonite Finish
Runs great but I haven’t put tons of rounds through it yet. Prob 6 or 7 3Gun days plus range work so definitely more than 1,000 rounds.
Design is different than a standard adjustable gas block. A standard adjustable block only allows you to adjust the amount of gas that returns to to bcg. Excess stays in barrel and my understanding is that the heat causes excessive wear on the adjustment screw.
Superlative block works like a turbo. Excess gas is bled off through a valve so theoretically system runs cooler and cleaner than a standard block.
meketrefe
.450/400 Nitro Ex
The bleed off is built in the original AR design by Eugene Stoner.
If excessive gas is pushed into the group then check for out of spec porting jobs.
The ideal would be an actual regulator but those can be tricky specially for critical duty
and why makers stay way from them even in the piston systems.
The most reliable, battle tested adjustable systems are pistons (like the HK) with preset porting in the
gas block rotating key and not DI adjustable systems.
Original bleed out design works great specially with mid size and rifle port barrels when properly setup with
the proper parts.
(YM, actually very nice machining these guys)
Keep them clean or fancy the mustache!! lol
If excessive gas is pushed into the group then check for out of spec porting jobs.
The ideal would be an actual regulator but those can be tricky specially for critical duty
and why makers stay way from them even in the piston systems.
The most reliable, battle tested adjustable systems are pistons (like the HK) with preset porting in the
gas block rotating key and not DI adjustable systems.
Original bleed out design works great specially with mid size and rifle port barrels when properly setup with
the proper parts.
(YM, actually very nice machining these guys)
Keep them clean or fancy the mustache!! lol
I've got an Odin clamp on adjustable gas block on the way this week. I'll be building a 243 LBC this year and it seems that an adjustable gas block is recommended for this wildcat.
Dan
Dan