M&P 15 Sight Alignment

[Travlgent]

Greetings--newbie here and first time poster, so please be gentle. I bought a nice, used M&P 15 last year and cannot get it sighted in without maxing the rear sight down and adjusting the front sight way above flush, to the point that it wobbles in the recess. I've started over three times and always have the same result when I get my groups dialed in. USMC 83-91, so I'm not totally unfamiliar with this design. Thoughts?

 

[cyphertext]

Can you give us more info? What model M&P 15? What distance are you trying to zero at? Since you said "maxing the rear sight down", I am assuming carry handle sight?

 

[hdrolling]

No wiggle in the barrel is there?

 

[Travlgent]

Can you give us more info? What model M&P 15? What distance are you trying to zero at? Since you said "maxing the rear sight down", I am assuming carry handle sight?

Carry handle sight maxed at bottom, yes. I'm using standard 25m targets at 30 paces. I had the same issue when I put rounds on target at 100m. My rifle is the 1 in 7 twist version.

 

[Travlgent]

No wiggle in the barrel is there?

Everything is tight, groups are good.

 

[cyphertext]

Carry handle sight maxed at bottom, yes. I'm using standard 25m targets at 30 paces. I had the same issue when I put rounds on target at 100m. My rifle is the 1 in 7 twist version.

Fixed A2 front sight? I wonder if it could be as simple as the front sight post has been replaced previously... perhaps you need a taller one? Also assuming that the front sight assembly has not been replaced... Is it F marked?

 

[hdrolling]

My rifle is the 1 in 7 twist version.

I didn't know any of the Sports had a 1-7 twist?

I thought the 1st GEN sport had a 1-8 and the newer sport II has a 1-9 twist.

 

[cyphertext]

I didn't know any of the Sports had a 1-7 twist?

I thought the 1st GEN sport had a 1-8 and the newer sport II has a 1-9 twist.

He didn't say Sport... I'm guessing it is this one... but it might be an archived model no longer made, depending on how old it is.

M&P(R)15 1 in 7" Twist | Smith & Wesson

 

[TX-Dennis]

Is the carry handle mounted properly? Fully engaged in the rail slots, well tightened. You probably already checked that being a Marine and all.

Maybe the carry handle is defective? Try taking it off and trying a different rear sight.

Is the front sight original or has it been replaced?

I'm no expert, but either the front sight or the rear sight has to be the issue assuming everything else is right.

 

[Disabled1]

He didn't say Sport... I'm guessing it is this one... but it might be an archived model no longer made, depending on how old it is.

M&P(R)15 1 in 7" Twist | Smith & Wesson

IMO, I think this is the BEST M&P that S&W has ever made.

 

[hdrolling]

He didn't say Sport... [/url]

Yup, totally missed that.

 

[Travlgent]

As I mentioned, I bought it used. It is NOT a Sport model. My 1:7 twist was determined by the best research I could do at the time. I considered the possibility of the front sight being replaced. Any info on sight posts of various heights would be helpful.

 

[cyphertext]

As I mentioned, I bought it used. It is NOT a Sport model. My 1:7 twist was determined by the best research I could do at the time. I considered the possibility of the front sight being replaced. Any info on sight posts of various heights would be helpful.

Is the barrel marked 1:7? It should be marked. Can you take a pic of the rifle and post it here?