SBR: cut barrel, rebarrel, or whole new upper?

[palisut]

Greetings, all.
I have a Colt 6920 that I want to SBR (10.5" bbl). I want the final product to approximate a MK18/CQBR, but I'm not real anal about having an exact "clone." I have some money set aside for this project, but I wouldn't mind saving a few bucks. Having said that, I can't decide whether it would be a better idea to:

1) Have someone cut down, recrown, and thread my 16" barrel. Will require boring out the gas port. (Possible reliability compromise...any companies doing this successfully?),

2) Rebarrel my Colt upper (I've been to Colt armorer course), or

3) just get an LMT 10.5" upper and be done with it.

Any thoughts?
If you advise cutting down the barrel, please let me know who you'd recommend for this.

TIA.

[VA_Dinger]

Greetings, all.
3) just get an LMT 10.5" upper and be done with it.

I'd say this is the easy route.

All the others look like a pain in the ass with nothing gained over a production LMT 10.5" upper.

[Derek_Connor]

I'd say this is the easy route.

All the others look like a pain in the ass with nothing gained over a production LMT 10.5" upper.

ditto

[LukeMacGillie]

I would go the new upper route as well.

Mk18 type uppers are going to burn up much quicker than the longer barrels.

I'd hate to see you spend money cutting down a barrel only to have it burn up in a couple months and you spend even more money to buy a new complete upper.

[RWBlue]

I don't think you CAN cut down that colt barrel.

Isn't that barrel chrome lined? If it is you can't cut it down without screwing it up.

[VA_Dinger]

I don't think you CAN cut down that colt barrel.

Isn't that barrel chrome lined? If it is you can't cut it down without screwing it up.

Yes, you can.

Companies like Adco do it.

[SuicideHz]

I don't think you CAN cut down that colt barrel.

Isn't that barrel chrome lined? If it is you can't cut it down without screwing it up.

Ouch. We're getting "those guys" from TOS that read a rumor and spread it like wildfire.

RW- chrome lining isn't like chrome on a bumper- it isn't a thin brittle flake of shiny metal that will fall apart instantly when attacked.

[Robb Jensen]

It depends on your budget. You can have any 14.5" or 16" M4 profile barrel cut down to 10.3" w/gas port work for about $125 from Randall at www.ar15barrels.com (chrome-lined or not, this isn't bumper chrome). IIRC a M4 profile barrel because of the M203 can't be cut to 10.5" which is why Crane made the Mk18 bbls 10.3" from cut down Colt 14.5" bbls.

Randall cut my 14.5" LMT barrel to 10.3" is works very well both unsupressed and suppressed.

[docsprague]

Personally I would get a whole new upper but if you do decide to get it cut down. Go with Randall at AR15barrels.com . I had him cut down a 16inch LMT to a 14.7 with a permanent A2 and he did a great job.

[Bolt_Overide]

get a whole new upper that was intended and built to be a shorty upper. you'll be a lot happier with it.