The Firing Line Forums - View Single Post - A2 front sights on AR-15

10-96 · December 18, 2010, 07:15 PM

No, it's really not all that easy if it's old carbon. But either way, it can be done. Once you get your pins or screws out, set it up on your bench muzzle down, drizzle kroil around the sight and keep it wet for about a day before you intend to really start the process. Once it has soaked, take a wooden hammer handle or something of the sort and just start whacking the crap out of it. Chances are real high that it was press-fit on and then finished as a whole. No, it does not seem like a sensible thing to do- but love taps ain't going to get it to move. You want forceful straight downward strikes and not off at assinign angles so you don't put any influence on your bbl. Oh, and keep your muzzle device on until you get the sight knocked loose- and then take it off. This will help protect the crown of the bbl. Use a 1/16" quality punch to remove the gas tube retaining pin.

Once you get the old sight off- take a sharp pencil and mark centerlines both longways and sideways of the gas hole in the bbl. Put likewise marks on the upper portion of your new sight/gas block. Those holes really need to be lined up or else you'll have a single shot. If you don't have a retaining plate that would hold standard A-2 or M4 type handguards on, you will need to hold the new sight/gas block 7/32" (I THINK!) off of the barrel shoulder- that is the distance allowed for the thickness of those plates. If the gas tube didn't fall out on it's own (with pin removed)- you may have to hold the gas tube with the sight hanging straight down and tap it off as well.

Once you have your sight/gas block/gas tube on and centered- just before final tightening- wrap a fired ctg with about three layers of electrical tape and gently insert in into the chamber to make a seal. Now, blow into the bbl and place your finger inside the receiver over the gas tube- you should be able to feel/hear the air coming out of the gas tube against your finger. If not, you'll have to re-inspect your witness marks or slowly move it around with trial and error until you get maximum airflow. Once that is achieved- tighten everything down per instructions.

Go shoot.

Oh, you may have gotten more feedback on you post if you had not attached to a post over 2yrs old- just sayin. Good luck!

December 18, 2010, 07:15 PM	#13
10-96 Senior Member Join Date: October 19, 2005 Location: Tx Panhandle Territory Posts: 4,159	No, it's really not all that easy if it's old carbon. But either way, it can be done. Once you get your pins or screws out, set it up on your bench muzzle down, drizzle kroil around the sight and keep it wet for about a day before you intend to really start the process. Once it has soaked, take a wooden hammer handle or something of the sort and just start whacking the crap out of it. Chances are real high that it was press-fit on and then finished as a whole. No, it does not seem like a sensible thing to do- but love taps ain't going to get it to move. You want forceful straight downward strikes and not off at assinign angles so you don't put any influence on your bbl. Oh, and keep your muzzle device on until you get the sight knocked loose- and then take it off. This will help protect the crown of the bbl. Use a 1/16" quality punch to remove the gas tube retaining pin. Once you get the old sight off- take a sharp pencil and mark centerlines both longways and sideways of the gas hole in the bbl. Put likewise marks on the upper portion of your new sight/gas block. Those holes really need to be lined up or else you'll have a single shot. If you don't have a retaining plate that would hold standard A-2 or M4 type handguards on, you will need to hold the new sight/gas block 7/32" (I THINK!) off of the barrel shoulder- that is the distance allowed for the thickness of those plates. If the gas tube didn't fall out on it's own (with pin removed)- you may have to hold the gas tube with the sight hanging straight down and tap it off as well. Once you have your sight/gas block/gas tube on and centered- just before final tightening- wrap a fired ctg with about three layers of electrical tape and gently insert in into the chamber to make a seal. Now, blow into the bbl and place your finger inside the receiver over the gas tube- you should be able to feel/hear the air coming out of the gas tube against your finger. If not, you'll have to re-inspect your witness marks or slowly move it around with trial and error until you get maximum airflow. Once that is achieved- tighten everything down per instructions. Go shoot. Oh, you may have gotten more feedback on you post if you had not attached to a post over 2yrs old- just sayin. Good luck! __________________ Rednecks... Keeping the woods critter-free since March 2, 1836. (TX Independence Day) I suspect a thing or two... because I've seen a thing or two.