First time shooting AR, problem.

[G21Shooter]

I hate using ear muffs when shooting a rifle; they just seem to get in my way.

I always try to use foam ear plugs when shooting a rifle now, I just find it more comfortable.

Yeah I use muffs for pistols and plugs for rifles.

OP, take that UTG mount and throw it in the trash. It is junk and you do not want it.

Get a Burris PEPR mount or better yet a LaRue LT104.

[russ69]

Your rings are probably a little low and the scope is not forward enough, just a guess. I use low profile (shotgun) muffs and ear plugs and I can shoot an AR15 in all positions without a problem.

[brassburnz]

With some of my rifles, I can use my MSA Sordin low profile muffs. Otherwise I will use ear plugs. I had some custom plugs made several years ago. They are very comfortable and work very well.