Clamp vs Set Screw gas block
- Thread starter Vwork
- Start date
Either work just fine. Some prefer one over the other. I have both and used both heavily. They both work just fine
On a DI it doesn’t really matter, I feel like solids are easier to line up the gas ports but whatever floats your boat. on a piston I much prefer the solid with a properly dimpled barrel.
I read once that the set screws could "wreck accuracy." The block on my RRA predator pursuit had set screws, and it shot sub 3/4 moa. I aways by clamp on as a result of one stupid thing I read, that may not be true.
I have plenty of both, the only notable difference is that the set screw type gives you more clearance in a small ID handguard.
I read the same thing years ago and it made sense at the time but hasn’t played out to be true in my experience. YRMV
I have used both on steel barrels. But don't think that I would really want to dimple a Proof carbon barrel, so would opt for the clamp-on verses the set-screw.
I had to look at what you're working with because I have not seen one of these barrels. This is what I found:
So based on this you won't be dimpling the carbon fiber. However, you will need to be more careful setting up the barrel to do the dimples if you choose to use set screws. Some prefer this type because there is less chance for the gas block to slide toward the muzzle as the set screws in the dimples will prevent that. If you get the dimple in the wrong location the gas block will try and migrate in the direction of the center of the dimple and changing the dimple location can be tricky as the drill will try and do the same. This is why some prefer the clamp on version, easier to readjust if needed and no need to drill dimples in the bottom of the barrel.
So based on this you won't be dimpling the carbon fiber. However, you will need to be more careful setting up the barrel to do the dimples if you choose to use set screws. Some prefer this type because there is less chance for the gas block to slide toward the muzzle as the set screws in the dimples will prevent that. If you get the dimple in the wrong location the gas block will try and migrate in the direction of the center of the dimple and changing the dimple location can be tricky as the drill will try and do the same. This is why some prefer the clamp on version, easier to readjust if needed and no need to drill dimples in the bottom of the barrel.
Read the same thing about set screws and accuracy...only reason I use clamp on as well. May be a myth but I have no proof nor reasons to change.
...used both and have since preferred to use the clamp type. Reason: Better gas journal seal with clamp type. Barrel gas journals will differ in OD dimensions just as gas blocks will differ in ID dimensions. The clamp type can accommodate those differences better, providing a better seal from the get go. Caveat: Gas leakage will eventually accumulate and build up into a seal with set screw type as well, but it can be disconcerting when you see that initial leakage evident on a new assembly. When you have minimal effort required (loose fitting) when you slip the gas block over the barrel gas journal, that indicates a dimension mismatch. As you tighten the set screws the gas block upper section is "pulled down" for a closer fit, but the lower half is "pulled away" and increases the gap between the outer portion of the gas journal and the inner portion of the gas block.
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The issue some are reporting with a set screw affecting accuracy would be related to inexperienced builders tightening the shit out the set screw creating a pressure point in the barrel.
Properly tightened there is no issue and either work fine just choose which one you prefer.
Properly tightened there is no issue and either work fine just choose which one you prefer.
This, plus you have more clamping force with a clamp on vs set screw. I've also had pre dimpled barrels work against me for set screw positioning. I buy nothing but clamp on now.
1.) you wouldn’t be dimpling the carbon fiber. The gas block location is all stainless. I mean, really? Is that not obvious from the pictures!?!
2.) my Proof Carbon Fiber wrapped barrel came dimpled for a set screw gas block. I put a Ti SLR set screw block on it because I’m running a 15” KMR A. Works great. Clears great. SLR sends instructions on what to torque the set screw to in in/lb. I rocksett the set screw and beddedthe block w/rocksett.
2.) my Proof Carbon Fiber wrapped barrel came dimpled for a set screw gas block. I put a Ti SLR set screw block on it because I’m running a 15” KMR A. Works great. Clears great. SLR sends instructions on what to torque the set screw to in in/lb. I rocksett the set screw and beddedthe block w/rocksett.
I've used JP Enterprises and Superlative Arms clamp-on gas blocks and have never had a single issue with them on any of my builds. The only thing that I learned is not to use Loctite on the screws in the gas block. Rocksett is apparently the way to go for gas blocks since it is unaffected by heat. I've used Rocksett on 3 builds and over years of shooting thousands of rounds they've been reliable.
I like the idea of clamp on because I feel it allows for a tighter fit and also seems less likely to loosen once properly torqued, BUT they typically don't fit under the slim handguards so popular today. I'm pretty much stuck with set screw since my handguards require it. I've never had a problem with either coming loose.
