Gas Block clamp on or set screw?
- Thread starter Brianma65
- Start date
six of one, half dozen of the other.
I like clamp on, but you'll get a dozen arguments for why one is 'better' over the other.
They both work essentially the same when installed correctly.
If you go set screw, make sure you dimple the barrel.
I like clamp on, but you'll get a dozen arguments for why one is 'better' over the other.
They both work essentially the same when installed correctly.
If you go set screw, make sure you dimple the barrel.
Blastattack
CGN Ultra frequent flyer
- Location
- Winnipeg MB
Clamp-on. No dimpling, better hold. If everything is done right, clamp on is much stronger.
Clamp on is using the screws to squeeze the gas block to hold onto the barrel. So the stress is on the screws. Depending who does it, some people tend to use generous amount of more permanent loctite. It is kinda a pain to work on later.
Set screw gas block is not using the screw to "squeeze" the gas block around the barrel. These gas blocks are usually made tightly fitted over the barrel already. The screw is there to prevent the gas block from rotating around the barrel (with dimpled barrel), when the barrel and gas block are contracting and expanding over the heating/cooling cycle, or got knocked mechanically.
Personally set screw ( with dimple on the barrel) gas block is much preferred over clamp on. if the set screw gas block is under handguard, it is pretty bomb proofed if installed correctly.
If the gas block is exposed outside of handguard ( especially a tall one incorporating front site), I will go for pinned gas block as much as possible. If it is just a low profile gas block, I think clamp on is ok. My personal MK12ish clone uses a clamp on.
Set screw gas block is not using the screw to "squeeze" the gas block around the barrel. These gas blocks are usually made tightly fitted over the barrel already. The screw is there to prevent the gas block from rotating around the barrel (with dimpled barrel), when the barrel and gas block are contracting and expanding over the heating/cooling cycle, or got knocked mechanically.
Personally set screw ( with dimple on the barrel) gas block is much preferred over clamp on. if the set screw gas block is under handguard, it is pretty bomb proofed if installed correctly.
If the gas block is exposed outside of handguard ( especially a tall one incorporating front site), I will go for pinned gas block as much as possible. If it is just a low profile gas block, I think clamp on is ok. My personal MK12ish clone uses a clamp on.
Odin Works makes both a clamp on and a set screw style, in a bunch of different sizes. Have a set screw style - bought it before the clamp ons were available, and some clamp on ones on other rifles. I personally like the clamp on style myself, and have never had one back off, I have had my set screw style one back off, with dimples in the barrel.
- Location
- Red Deer, Alberta
In addition to all the reasons above. Some expert AR15 builders with lots of experience say to use a clamp on if accuracy is your ultimate goal. They claim a set screw style gas block introduces a stress point on the barrel. Having a bit of experience in a dimensional metrology lab I would tend to believe them.
- Location
- Red Deer, Alberta
It should say on the installation instructions.
- Location
- Red Deer, Alberta
I don't know what you bought, it may or may not come with instructions. Every gas block I have ever bought that uses some type of threaded fastener has included instructions offering their advice on how to install their product. If instructions are not included with their product check their website. If not measure the size of the threaded fastener, make a educated guess on the material of the fastener, then google a bolt (or machine screw) torque chart.
