I purchased a 20" 1-7 twist A2 upper from Remsport last year. Its a nice upper and proving to be quite accurate (at least to 75').
I am having an issue with the front sight block - it moves, and after a few shots it starts to slide forward, bringing the gas tube with it and eventually the gas flow gets affected and the rifle short-cycles.
It is your standard A2 front sight. It looks like it had the bayonet lug ground off. Curious though is that the sight is fixed to the barrel using two small set screws that press against the bottom of the barrel. It does not have the taper pins installed, and the barrel is not cut to accept the pins either. An acquaintance said this setup is common in competition as a way to gain some windage adjustment in the front sight. Personally I think its too prone to stripping the threads in the bottom of the sight block.
See picture below. You can see the set screws. There are no taper pins in where you would expect to see them.
This setup will never hold still. So I need to replace this sight block. But the complication is that the Carlson mini comp is pinned and welded (thank you state of MA). So in order to remove the front sight, I need to un-pin the compensator which basically means I will trash it if I do it myself. I'm sure a machinist will have a better chance at saving the compensator.
And my goals for this rifle are to use it for high-power target shooting.
So the compensator is fine, the sight block is junk as is.
I'd like to get your opinion on some options:
Option 1) Leave compensator in place. Try to carefully cut off sight block. Replace with a 2-piece gas block/new front sight.
Option 2) Run an end mill through the pin holes on the existing sight block and make the cuts in the barrel. Install pins. Done.
Option 3) Cut off the compensator, dispose of the sight block, replace with a new A2 sight block and a thread protector.
What say ye?
I am having an issue with the front sight block - it moves, and after a few shots it starts to slide forward, bringing the gas tube with it and eventually the gas flow gets affected and the rifle short-cycles.
It is your standard A2 front sight. It looks like it had the bayonet lug ground off. Curious though is that the sight is fixed to the barrel using two small set screws that press against the bottom of the barrel. It does not have the taper pins installed, and the barrel is not cut to accept the pins either. An acquaintance said this setup is common in competition as a way to gain some windage adjustment in the front sight. Personally I think its too prone to stripping the threads in the bottom of the sight block.
See picture below. You can see the set screws. There are no taper pins in where you would expect to see them.
This setup will never hold still. So I need to replace this sight block. But the complication is that the Carlson mini comp is pinned and welded (thank you state of MA). So in order to remove the front sight, I need to un-pin the compensator which basically means I will trash it if I do it myself. I'm sure a machinist will have a better chance at saving the compensator.
And my goals for this rifle are to use it for high-power target shooting.
So the compensator is fine, the sight block is junk as is.
I'd like to get your opinion on some options:
Option 1) Leave compensator in place. Try to carefully cut off sight block. Replace with a 2-piece gas block/new front sight.
Option 2) Run an end mill through the pin holes on the existing sight block and make the cuts in the barrel. Install pins. Done.
Option 3) Cut off the compensator, dispose of the sight block, replace with a new A2 sight block and a thread protector.
What say ye?
