Changing the barrel on a M&P 15 Sport

[Chinook1717]

O.k. folks I'm new to the AR world so forgive me if my terms are not correct.

Recently purchased a M&P 15 Sport and want to put some optic on the weapon, however I'm worried about the front sight being in the way visually. I've been told I can cut the fixed front sight down and it will be out of the way but I'm not sure I want to modify it in that manner. Can the barrel be changed and if so any suggestions on a comp barrel??

 

[shawnfergie]

The barrel can be easily changed BUT I cut down the front sight to make room for a 15" Troy Vtac handguard. It was fun and relatively easy with minimal tools. The tools will be the same if you shave down the block or change the barrel and the barrel is pretty nice on the Sport. I have the 1/8 twist and wasn't about to change that out.

 

[tbgunner88]

Are you planning on using a scope or a red dot? If you use a scope you won't even see the front sight because of the magnification. If you use a red dot you can use a riser of the correct height and just co-witness with the front sight.

 

[cyphertext]

Why in the world would you change the barrel out, when you could either cut the FSB down, or just replace it with a low profile gas block?

 

[Chinook1717]

I was given this advice (cutting it down) by a reliable person.

Co-witness???? Is that 2 people preaching the gospel to you? LOL! Told you I wasn't savvy on the lingo.

I'm planning on a red dot or something along that lines. I don't think I will be using a scope, at least not at this time.

As I have seen others asking on here for various questions, this will mostly be a range gun. Once more comfortable with it (don't think that will take much doing) may jump into something more serious with it.

 

[MichiganScott]

I was given this advice (cutting it down) by a reliable person.

Co-witness???? Is that 2 people preaching the gospel to you? LOL! Told you I wasn't savvy on the lingo.

I'm planning on a red dot or something along that lines. I don't think I will be using a scope, at least not at this time.

As I have seen others asking on here for various questions, this will mostly be a range gun. Once more comfortable with it (don't think that will take much doing) may jump into something more serious with it.

Absolute co-witnessing is when the dot seems to sit on top of the front sight. Lower 1/3 co-witness is when the dot is in the center of the optical field and the front sight is in the lower 1/3 of the optical field.

 

[crracer_712]

Since using a red dot, I'd prefer to just do a lower 1/3 co witness (taller mount for the red dot), others prefer the absolute co witness. I wouldn't change the barrel, and I wouldn't cut the FSP down just to use a red dot.

 

[Chinook1717]

O.k. to change up the scenario if I were to use it for hunting then a scope would be the way to go correct???

 

[Chinook1717]

Michigan Scot, thanks for the information and visual. I don't think I would have figured it out is you hadn't put that in there.

 

[crracer_712]

O.k. to change up the scenario if I were to use it for hunting then a scope would be the way to go correct???

Most likely, but even then, you don't need to remove the FSP. Some claim to not see it due to magnification. To me, any I have scoped, at 3x magnification, I can see ghosting of the FSP. Greater than 4x and I don't really notice it. This ghosting annoyed me enough that I decided to try some 1/2" risers underneath the standard AR high rise scout mount, and this completely eliminated and FSP ghosting.


This shows the use of the tru glo 1/2" risers with the Nikon P22 mounts and M223 scope. I also added a riser for my cheek to get a better cheek weld

 

[tbgunner88]

O.k. to change up the scenario if I were to use it for hunting then a scope would be the way to go correct???

You are correct.

 

[Rastoff]

I'm a big fan of optics, but you certainly don't need them to go hunting. The iron sights work perfectly fine for that.

Of course it really depends on your eyes and how far you're shooting. I can use iron sights out to 200 yards. However, I'm old enough now that I choose not to handicap myself that way and use a scope for 100+.

 

[ChattanoogaPhil]

Don't overthink it at this point.

If you want a 1x red dot get a lower 1/3 cowitness mount for it. Shoot your rifle for a while and see how you like it. Lots of guys enjoy the rifle in that configuration. But if the front sight bothers you there are quite a few different options to chose from. Once you get some time with your new rifle and 1x red dot and see how others have their rifles set up you'll be better prepared to make the right choice if you feel you need to change anything.

 

[Chinook1717]

I would love to see pic of some set ups or list how any of you have yours set up.

 

[crracer_712]

Here's a Vortex Strikefire II Red Dot on my Ruger AR556, this is a lower 1/3 co witness mounting height.

 

[cyphertext]

I would love to see pic of some set ups or list how any of you have yours set up.

Look at the stickies at the top of the forum... there is a picture thread... you can look and see all kinds of setups.

 

[ChattanoogaPhil]

There's endless choices, but there are three general configurations dealing with the front sight that you should first understand.

The Sport has a front sight that incorporates the gas block.

The 15T has a railed handguard to attach a folding front sight with a separate gas block underneath the handguard.

The OR has a railed gas block that can be used to attach a front sight.

As well, there are gas blocks that incorporate a folding front sight.... and and and... the list is too long. But the below three are the basic configurations.

My rifle configuration is like the 15T.
Freefloat railed handguard and folding sights.
Adjustable gas block underneath the handguard.
Aimpoint red dot.

[/URL]

------------------------------------------------------------------------------------------------------------------------

Still, just take your rifle out and shoot it. See other rifles at the range and talk to the guys.
You already bought a rifle in a configuration you think you're not satisfied with.
No sense spending money trying to change it until you know better what you want or don't want.
You may find your rifle wth a red dot on it suits you just fine as it is.
Or maybe you'll hate it and just toss it out in the woods.

 

[ChattanoogaPhil]

Cowitness with 1x red dot and a bit of explanation.

 

[Chinook1717]

Chattanooga I don't hate the gun at all. I just realize that if I want to put optics on it, and I do, the FSB will be in the way. That is all this post is mainly about.

 

[turbo38gn]

Did you ever think to just get another upper... Palmetto State has complete uppers on sale every day that are absolutely amazing.. you can purchase one cheaply to do whatever you want.. all kinds of styles.. take your upper off, 2 pins holding it on... drop a complete new one on..

check it out...

Barreled Upper Assemblies - AR-15