M&p 15 barrel and gas swap

[Mat Price]

I have an m&p 15 and the barrel is on its last legs. I would like to swap in an 18 inch bbl and rifle length gas tube. Is this doable. And is it a dyi job or no?

[iswope]

It's certainly more than doable if you have the tools. What makes you think it's on it's last legs? Is this the one with the chrome lined barrel?

[Mat Price]

Groups starting to open up and about 20k rounds on the bbl. Nothing I'm looking at doing right away but I figured hell if I going to change the bbl I might as well use the gun as a base for a 3 gun rifle instead of buying another.

[iswope]

You could always just buy a new complete upper if you don't want to get to technical with a barrel change and such. I actually did exactly that as my PSA M4 morphed into a 3 gun rifle over a year and a half before I finally got a Stag Model 3GH complete upper and swapped.

[Mat Price]

That's what I would really like a stag 3g upper

[michael1778]

This BIG "if" is that you would need the right torque wrenches, vise, vise blocks, etc. In my case, I decided that I'd have a local smith assemble a complete upper for me. I don't have any of the needed tools for an upper. I did manage to make my own lower at one point. He built up the upper from a box of bare parts that I selected and purchased for a very modest fee. Less than what AR vise blocks cost.

A good barrel, gas tube, gas block (adjustable if desired), and muzzle device would be a much cheaper route since you already have the receiver, etc. That's be about $500-$600 depending on components, I think. Unless your local smiths charge an arm and a leg.

[ac4wordplay]

This BIG "if" is that you would need the right torque wrenches, vise, vise blocks, etc. In my case, I decided that I'd have a local smith assemble a complete upper for me. I don't have any of the needed tools for an upper. I did manage to make my own lower at one point. He built up the upper from a box of bare parts that I selected and purchased for a very modest fee. Less than what AR vise blocks cost.

A good barrel, gas tube, gas block (adjustable if desired), and muzzle device would be a much cheaper route since you already have the receiver, etc. That's be about $500-$600 depending on components, I think. Unless your local smiths charge an arm and a leg.

I'd add a new bolt too. (Does the current bolt have the same 20k rounds as the barrel?) Replace everything other than the upper receiver, bolt carrier, and charging handle.

If you have the interest, it's easy enough to do the parts swap. Gotta have a vise and a few other minor tools, but very few people actually use torque wrenches on the barrel nut.

Or, buy a new upper.

They both sound like fun. Enjoy!

[EkuJustice]

It's not too hard to do if you have a vice. The tools can be had for under 50 bucks at palmetto state armory. As you need a vice block and an armor wrench. It usually costs more to have it done than the tools cost and once you buy the tools you never have to pay to replace one again.

[troupe]

Do it yourself. That is how you learn, and since you typed this post, the web has the instructions everywhere. It is one of the simplest rifles to work on. The tools are not expensive and the satisfaction that you will gain is worth it.