I am a new owner of a M&P 15 sport. What height riser do I need to use a Bushnell TRS-25 red dot sight that will line up with the front sight. I have seen both .75" and 1" risers recommended.

Any good advice.

I am looking at two different risers, both by UTG.

MNT-RS10S3 - 1"
MAD 0340 - .75" (I believe)

I know, UTG is not a cadillac, but I am on a tight budget, thanks.

Depends and I don't know specifically with that optic.

The reason you may get two different answers is that there are two types of "co witnessing" for a red dot sight. The shorter riser is most likely to give you a "lower third" co witness and the higher, an "absolute" co witness where the front sight and red dot are both identically aligned on the target. Hope that clarifies it.

shady...you dont have to apologize about being on a budget, alot of us are and times are tough in our country.

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Grover Oathkeeper

Amen! ...and a good question, too!

Hog

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Isaiah 55:8-9
Phil. 4:13

Shady, do you want absolute co-witness or lower third? I have that sight on my son's M&P 15-22 and I would recommend absolute co-witness. He is set up right now for lower third, and the part that projects the dot cuts off part of the sight picture for the front sight when using the irons, looking through the red dot. Currently have him on the 1", RS10S3 mount and I will be going to the lower mount. The UTG riser works great with this sight. Has a good look. Wishing I would have purchased the same set up for my Sport.

This is confusing me unless I am reading it wrong. The TALLER mount would absolute co witness, NOT the shorter one which would give a lower third co witness, no?

No, the taller riser would raise the red dot sight so that the front sight appears lower when looking through it...

Try this...extend your left arm and point your pointing finger up. This will represent the front sight. Now, with your right hand, form a circle with your pointer and thumb and hold it back away from your "front sight" hand. Align the circle and the front sight hand so that when looking through the circle, your pointer finger is in the lower third of the circle, or lower third co-witness...now, without moving your front sight hand, move the hand that represents the red dot so that the "sight picture" is now a absolute cowitness. You should have moved your right hand down. That would simulate going to a lower riser.

At least that is how I have it worked out in my mind. Otherwise, I would have to go to a taller than 1" riser, and that doesn't seem right.

DUH! Thanks, I claim a "Senior Moment".

No worries....I was second guessing myself when I was trying to type the explanation.

dont knock UTG Leapers equipment... i have a UTG red dot on my M&P15OR and i love it... its not bad for a $50 scope

Hey UTG is home grown just like our rifles. I have a few of their products and I am very satisfied with the outcome. Their prices always keeps me coming back.

I have a UTG mount on my OR, I think its a .83". Works well, I did Locktite it too. In 700 rds its as solid as ever.

Sent from my DROIDX using Tapatalk 2

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Improvise, Adapt, Overcome

I have a Bushnell TRS-25 on my M&P MOE and I use the 1" UTG riser.
I have tried both the medium and the high and found the higher mount works best for me. I got mine at Cheaper Than Dirt and they are cheap enough that I bought both heights.
For me, the taller mount allows me to co-witness the sights. Hope this helps.