planning a barrel transplant

[The Cat]

Hey!
For many reasons I'm looking to replace my upper with a 16 inch barreled upper from BCM.

Two questions:

1. Should I go standard M4, SOCOM M4, or lightweight, as in back-in-the-day carbined?

2. I'll be changing from 1/9 to 1/7. How will this affect the accuracy of a .22lr Colt conversion kit? Many thanks in advance!

[Dunderway]

1. I like M4s for whatever reason, but the lightweight profile seems to be very popular with people here. Unless you plan on doing a really high volume of shooting (be honest with yourself) you probably don't need a SOCOM. Do a search for "SOCOM barrel profile" and you will get lots of good discussion on all of the above.

2. I would assume that it may hurt accuracy but have never run a .22lr conversion kit in any of my ARs.

3. Also consider a Mid-Length upper if you are going for a 16" barrel. Do a search on that here for hours of reading enjoyment. The concensus among most is that if you are going with a 16" barrel, the mid gas system is the best.

You made a smart decision with BCM, and could really buy any of the above and have a good solid upper that would serve you for many years.

[Eric D.]

It all depends on what you want the weapon for. Like Dunderway said, the SOCOM profile isn't necessary unless doing high volume shooting. If its a patrol weapon or something you're gonna put lots of goodies on, lightweight may be the way to go.

I would also suggest you take the midlength into consideration. I have a BCM M4 upper and I love it, but I will be getting a middy for my next build.

[Col_Crocs]

I agree with the above posts. To add to the SOCOM profile being unnecessary, the m4 barrel is too without the possibility of ever mounting a 203.
If youre still in the process of figuring out what you want from a shooting/handling stand point, and if youre not going the sbr route, the 16 would allow more flexibility.

[The Cat]

Thanks for your input, guys. I think you've talked me out of the socom. It would be extra weight that wouldn't be of any benefit to me except to give me something to cuss during carbine classes :p

I wouldn't mind going Middy, but I'm planning on taking my Larue 7.0 off my current upper and putting it on the new one.

Right now, you have me leaning toward the Lightweight.

[UsnRoberts]

It seems the lightweight middy is all the rage and I think it gets my vote also.

On another note, my target 22 gun has a 1 in 16 twist out of 18" barrel. I don't have experience shooting 1-7 twist or 22 conversion kits but I would assume going up in twist rate is going to slow your round a touch. Now i think 50 yards with a 22 is no problem no matter what twist rate, but if you are pushing 150+ yards I think you will have power issues. So plink with it but don't expect to knock a rodent dead at distance. Go back to 223 for that i assume. I don't know if this relates (or helps) at all but I figured id jsut throw that out there.