I am replacing the barrel on my AR-308, and was wondering which type of gas block would be better. The clamp-on type, or set screws. Steel or Aluminum. Could accuracy be effected by either?
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Opinions on Gas Block
- Thread starter captain23steve
- Start date
Adjustable!
What benefits would there be in an adjustable gas block.
It's all about harmonics. An auto is very challenging to get to shoot with a bolt and an adjustable gas block, I prefer clamp on, is another tool in your shed. I run them on all my uppers and have found an improvement in accuracy with all of them. It will also help with unnecessary battering of components. You asked for my opinion and now you have it and with another buck and a half you can buy a cup of coffee.
I'll hold my tongue on the last posts. Yes clamp on! Adjustable is a good idea to save your brass. ARs tend to have case head swipe and beat up necks unless the gas system is tuned to the load. Without a ton of further information of replacement selection or intended use I'll hold my tongue on making any suggestions.
-Mac
-Mac
MMMMMMMM......Coffee
This rifle will be used primarily for hunting. 300 yard shots would probably be the furthest shots, but nowhere close to the norm, 60 to 150 yards would be normal shots. The barrel is a 20" barrel that is .700 under the float tube, and in front of the gas block(.750). Not a heavy barrel, but am trying to make it as accurate as I can. I'M new to the gas gun game, just trying to get it close to my bolt guns. Some people say that the set screws can put stress, and actually distort the bore of the barrel. Have not read to many bad things about the clamp on.
Id shy away from the adjustable for a hunting rifle. It'll save brass target shooting; but could reduce reliability for a fast follow-up. A good clamp on, properly adjusted and aligned will do just fine. Your mileage may vary.
I'm assuming it's a rifle length gas port? If so, start with a powder burn rate around imr4895 and work around there, or test the factory ammo and pick your bullet and look for extractor / case head swipe. Truth is some marks aren't always a bad sign in an AR; a good sign though is if shooting from bench: all your brass ejects into a nice neat pile.
-Mac
Well, Thank you all for your input. Think I will go with the clamp on.
Another vote for clamp on.
Adjustable gas blocks have come a long way since the single set screw style of the past. Several of them include positive locking of the adjustment screw and detents to make repeatable adjustments possible. They are also much more reliable. Hopefully your rifle does not need one to run 100%, some 308 AR's can really benefit from them.
What brand barrel did you get?
Adjustable gas blocks have come a long way since the single set screw style of the past. Several of them include positive locking of the adjustment screw and detents to make repeatable adjustments possible. They are also much more reliable. Hopefully your rifle does not need one to run 100%, some 308 AR's can really benefit from them.
What brand barrel did you get?
Fast14riot
Gold $$ Contributor
Clamp on adjustable. That's what I run on my rifles. Not just to save beating up brass, but also makes for a smoother cycling gun. If adjusted properly, there are no reliability issues. Best part, all my brass ends up in a nice neat pile 3 feet away at 4 o'clock when shooting prone. Lessening cycling impulse allows me to stay on target better, so can actually improve follow up shots!
I use Syrac GenII gas blocks.
I use Syrac GenII gas blocks.
I ordered a lightweight barrel from X-Caliber
itchyTF
Gold $$ Contributor
Looks like JP has one.
http://ads.midwayusa.com/product/83...ses-_-838595&gclid=CMGb0u76rM8CFUc8gQodfoMCYg
http://ads.midwayusa.com/product/83...ses-_-838595&gclid=CMGb0u76rM8CFUc8gQodfoMCYg
"a good sign though is if shooting from bench: all your brass ejects into a nice neat pile."
An even better "sign" is if all your bullets eject into a nice neat pile on the target!!!! I am always a whole lot more worried about that than how or where any empty brass lands.....As to gas blocks, I have used them all and I am unable to see any difference in accuracy. I never have, but I guess you could hog down on the set screws enough to make taking it off difficult...but why would you need to????
Nothing against adjustable ones, but they are not a necessity. I will say this...the surest way to know if someone is a real AR expert is mention a jamming {or any other} problem with your AR and they immediately tell you that you need an adjustable gas block. The be all and end all of fixes for an AR.
An even better "sign" is if all your bullets eject into a nice neat pile on the target!!!! I am always a whole lot more worried about that than how or where any empty brass lands.....As to gas blocks, I have used them all and I am unable to see any difference in accuracy. I never have, but I guess you could hog down on the set screws enough to make taking it off difficult...but why would you need to????
Nothing against adjustable ones, but they are not a necessity. I will say this...the surest way to know if someone is a real AR expert is mention a jamming {or any other} problem with your AR and they immediately tell you that you need an adjustable gas block. The be all and end all of fixes for an AR.
itchyTF
Gold $$ Contributor
The tolerance between my "set screw" gas block and the barrel was very close. Perfect fit in my mind. I didn't hog down on the set screws but they were snug. That created a dimple/burr (or whatever you want to call it) that now was in the way of a smooth removal of the gas block. If I remember correctly it messed up the inner surface of the gas block and was harder to get off. A clamp-on eliminates this. That's all.
I have built and own/owned many AR's over the years...have tried all kinds of parts/accessories. I have to ask...just how often do you guys feel like you need to remove and reinstall the gas block on your rifles???? I mean if it's something you have to do every few days or once a week then yeah...go for the clamp on type to make things easy, but gas blocks are one of those parts that in my experience it generally just gets put on and left there. I don't know what the guys do with the ones I have assembled for them over the years, but I built the five AR's I currently own, so I have installed those 5. Even if I include the ones I have had and sold I don't ever remember taking one back off. I guess my second question is why are so many gas blocks being removed???? Doesn't seem like a wear out type part?????
JP clamp on is what I use. They have several different styles.
https://www.jprifles.com/1.4.6_gs.php
https://www.jprifles.com/1.4.6_gs.php
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