Jake TN Wrote:Well now I am curious now since I am a case study of one. Has anyone on here had an adjustable gas block plug up on them.
They don't plug up per se, but the adjustment screw can accumulate so much carbon build up after a lot of use, they will stop turning, hence carbon freeze.. Adding a drop or two of oil and running the adjuster in and out after use will go a long way to prevent carbon freeze..
I still have some older Syrac adj gas blocks in my storage box I removed from my rifles years ago..My brother never oiled or maintained his Syrac adj gas block on his AR and he broke the adjuster screw trying to force it open..He should have called me first lol.. Every adj gas block I have used has had carbon freeze including the Superlative, which is why I value adjustable gas blocks that are easy to maintain, disassemble, and replace parts when needed.
Adj gas blocks can be exposed to a lot of heat and any internal springs used in them will fail after time..I have had two SLR leaf type springs fail after a lot of use, but SLR replaced them without question..The adjuster screw tips will erode with use, but can be screwed in more to compensate or be replaced if the design permits..Many adj gas blocks will break when exposed to high heat full auto fire, including the SLR..I have a friend who had two SLR adj gas blocks break in half and he refuses to use any type of adj gas block anymore..He does a lot of full auto..I won't let my barrels get that hot..
I have yet to replace any parts on my Rifle Speed and it is the easiest adj gas block to work on..It is a well thought out design..I have had it carbon freeze, but it was easy to break the carbon loose and clean by design..
Pick the parts for the rifle's use..One fit all does not always apply, especially with gas blocks..
Jake TN Wrote:Well now I am curious now since I am a case study of one. Has anyone on here had an adjustable gas block plug up on them.
I have had them carbon-weld, to where penetrating oil did not help me, and I broke wrenches, stripped out the tiny screw head.
Ive heard some trying certain high-temp greases, but the gas block gets really hot from bore temperature and pressure evacuating through it and the gas tube.
This is why I tend to steer away from them nowadays. If they are farther away from the chamber, like RLGS and ELGS, then the temps and pressures are lower and easier to deal with.
SOTAR had a really good recent video where he bore-scoped 2 LE department carbines and you could clearly see erosion of the gas adjustment screw as well. Looked like it had been blow-torched....because it had.
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Okay- all that makes perfect sense. Very familiar with the carbon lock up. Never had it plug up on me. If I ever replace my syrac, it will be with a rifle speed. I bought the PWS long stroke upper to test out next year (11.85 inch) so not sure if will be worth messing with my old upper that much if the PWS does well. Wish they made a 12.5 inch Grendel upper with the long stroke piston. I hope everyone has a blessed thanksgiving and happy hunting this year.
Here is what Rifle speed says about their adjustment plungers.
Plunger service life varies from 10,000 to 25,000 rounds, depending on your firing schedule. When you replace a worn-out barrel or bolt or when the working end of your Plunger has been worn away by half, then it's time for a new plunger.
The SLR's I've had experience with have all worked, however one did carbon-up to the point you could no longer feel the tactile increments when adjusting. I don't know whether it was the tiny dimple rubbing against its channel (it's a tight fit), or carbon building up in the two dimple trenches in the plunger itself. I was playing around with a vice and pliers trying to get a curve in the leaf spring and broke it. So sourced some 65MN spring steel plates and fashioned a slightly thicker replacement. The tactile clicks are more solid now, but time will tell.
[ATTACH=CONFIG]20081[/ATTACH][ATTACH=CONFIG]20082[/ATTACH]
I can see how the lighter AGBs might not suit duty guns where operators push the limits and occasionally mag dump. If the rifle is more for precision shooting then seizing/breaking in an AGB is less likely.
I have no experience with Rifle Speed but it all looks pretty bomb-proof.
As for short stroke pistons I do have experience with the Adams Arms original 3-setting spigot system. That is incredibly bomb proof, but it needs to sit out the front of a handguard (can't go under one), and did not have enough settings to finely tune. It also requires its own carrier. A big solid chunk of steel forward on the barrel, and has a straight line piston back to the receiver. Their more recent lower profile 'P-Series' looks interesting, and you can see in this they're trying to make it more compact, lighter, and fit under handguards. No experience with the P-Series and would like to hear from anyone who has.
Strike Industries makes a collar adjustable block that I think is a good design. The one I have is working well. It's a series of different sized holes in a rotating sleeve. The only other one I'd consider at this point is the RifleSpeed.
That looks pretty neat...I wasn't aware of this, thanks. I like its lack of threads and small parts near the gas. Just that spring ball at the bottom which is away from the gas. Do you think it could carbon seize with long shooting sessions?
Is there a dimensions diagram somewhere? For example, will it fit over a 1.3" handguard free-float?
Is it easy to change settings through the handguard?
I am running the Superlative Arms bleed off AGB on the kids 6.5G. 20" RLGS. It is shot suppressed mostly but not always. I am happy with it. Fits a pretty small id handguard and easy to adjust/tune. Took me a bit to fully understand their restriction vs bleed concept when I started looking at AGB's. There is a good video on U tube that describes it, I think Mike Bell is the guy that did the video.
The Riflespeed and bootleg carrier also intrigue me.
That looks pretty neat...I wasn't aware of this, thanks. I like its lack of threads and small parts near the gas. Just that spring ball at the bottom which is away from the gas. Do you think it could carbon seize with long shooting sessions?
Is there a dimensions diagram somewhere? For example, will it fit over a 1.3" handguard free-float?
Is it easy to change settings through the handguard?
The handguard it's under has a 1.32" inside diameter. I can adjust gas through the handguard with a punch or similar tool. I think you'd have to be unlucky to not be able to reach the slots through a handguard, but it could happen.
I do not think seizing will be a problem. It's been well over a year and several hundred rounds with no lube or adjusting. I just checked it. It moves freely.
This site lists dimensions. I can't verify them, but they seem right.
GrendelHunterDotCom has generic adjustable gas block with gas tube already installed for about $40 today.
Nice thing about getting older and lazier is I become more motivated to find deals like this. LOL
PS I bought their 16" upper around 2015 and it is the most accurate upper I've ever owned. 1 MOA at 100 yds is near zero effort. I'd get sub 1 MOA if I were not so lazy.
I view AGB as expendable part. Periodically I will adjust it to each extreme end of screw travel and replace it if it has any issues. I always keep a spare AGB with gas tube already installed in my spares kit, right next to the 7.62x39 bolt (that will eventually self-destruct).
Just cost of doin' b'ness
Grendel Huntrer sells AGB with gas tube already installed for about $40. Seekins is another reliable one. I have to have a gas adjustment on the side, due to suppressor.
Plenty of good advice here. I really like the Aero Precision AGB. It's easy to get it tuned just right with the front adjustment screw. Way easier than the side-mounted adjustment screw on the Seekins AGB. I'm going to replace this with an Aero AGB on my 300 BLK as soon as I can. I caught a deal on the Aero Precision for $34.95 each on sale a few months ago on AR15Discounts.com. Between them and Primary Arms, you are bound to find a sale you like.
For the record, I run the Aero Precision AGB on my 12-inch Grendel with a Dead Air Sandman S. Less gassy than a standard gas block and softer to shoot.
