Any downsides to a gas block that is clamped vs pinned?

[UserM4]

I'm looking to replace my A2 front sight with a Vltor VST but it's available in a clamp down with allen screw style and a standard pinned version. Could the allen screws back out over time? Maybe I need high temp loctite?

[-hanko]

I'm looking to replace my A2 front sight with a Vltor VST but it's available in a clamp down with allen screw style and a standard pinned version. Could the allen screws back out over time? Maybe I need high temp loctite?

You've answered your own question.

Clamping works, but un-clamping is possible. My recommendation would be to find some to drill and pin the front sight. One less big thing to worry about.

-hanko

[slappomatt]

I will go the other way with it. as long as you aren't heading to Afghanistan anytime soon I would say get the clamp on one. not the set screw or the pinned one. Its the best method of attaching a gas block without warping the bore. I saw a write up a while back where they could actually see the crimps in the bore with a borescope from using a set screwed gas block. Pinned would be my 2nd choice. Both are solid connections but the clamp on version would be best from an accuracy standpoint and also user installation.

[C_1]

If you dimple the barrel, and loctite the screws, it should be pretty strong. But at the same time, the VLTOR bolt on one is pretty strong; theres torture test someone did somewhere.

[tomd1584]

Rocksett and stake the screws and you'll be GTG.

[UserM4]

Ahhh.. haven't thought about staking the screws. Good idea. I guess the clamp style it is. Thanks everyone!

[dfletcher]

I know it's ugly as hell, but the one on the far right is all steel, has very coarse threads and stays put: http://www.model1sales.com/index.cfm...ategory_id=409

[dfletcher]

Ahhh.. haven't thought about staking the screws. Good idea. I guess the clamp style it is. Thanks everyone!

When you stake make certain the GB is sitting against a solid flat surface - you don't want to whack the screw heads with a hammer and have the GB turn a bit on the barrel.

[UserM4]

When you stake make certain the GB is sitting against a solid flat surface - you don't want to whack the screw heads with a hammer and have the GB turn a bit on the barrel.

I'll have to remember that. Is there a trick to lining up the gas block straight?

[neal0124]

I have a PRI clamp on front sight/gas block. I have final torqued it once and it has not come loose after lots of use.
I didn't stake the bolts and I wouldn't do it until the rifle is properly zeroed.