I know alot about ar lowers and stuff but never jacked with the upper anyone got any tips and tricks to take the front site post off of a LMT ar and put on the YHM flip up gas block. Thanks.
The pins that hold it in place are tapered. You have to tap them out from the thin side. I don't remember which side that is, mainly because none of my AR's have that kind of gas block. Look at the pins carefully, and tap them out from the side where the pins have the smaller diameter head. If you can get one of these, it would make the job super easy: [url]http://www.brownells.com/.aspx/pid=20727/Product/AR_15_FRONT_SIGHT_BENCH_BLOCK[/URL]
Mine were tapered. I had to tap them out from left to right. Couple of tips. Hopefully this helps things for you.
- Be sure to use a sturdy, tapered punch. You have to hit the pins pretty hard to even get them started. I used the larger of a friend's steel punch from his set from DPMS and it bent pretty quick.
- Use a shock absorbent backing material. I initially tried using the anvil on my vise. I tried and tried just to get it started but apparently it was bouncing back too much. As I was about to give up and decided to give it a last try using a thick rubber sandal. It was out within 3 hits vs. the god knows how many on the anvil.
- Be mindful of when the pin starts moving. I didn't notice on the first pin I removed, and ended up getting my punch stuck.
- Apply a little lube when removing and installing the gas block. Don't want to mar that barrel finish. Plus I think it helped a little getting over the cutout portion of the barrel.
- When installing new gas block, I inserted and held dummy round in the chamber, and then blew down the business end of the barrel. I slowly rotated gas block while blowing and checked airflow with the hand holding in dummy round.
- Tightened set screws to score the barrel, then removed the screws and applied loctite to them. Wanted to properly score the barrel but I don't have a good setup for that. I've had no issues with my setup so far.
I got er done thanks for the help my buddy had a used YHM flip up site and gave me a good deal on it now time to sight it in, the pins came out easy and werent tapered now im thinking of putting a midlenght rail on it and shaving the fsp to make a low profile gas block, once again thanks for the help.