I’m wanting to upgrade my CMMG barrel to a BCM middy, and because of the BCM Dissipator thread in the general section (https://www.m4carbine.net/showthread.php?t=62149) I have decided that this is what I want to do. I did some calculations all just using prices off of BCMs site and if I got a mid length barrel, gas block, fsb, mid length tube, and hand guards it would cost around $560. If I go the way of just getting a BCM mid length upper all I’ll have to purchase is the gas block and hand guards and it would only be just at $600.
First question is would a new barrel mate up with my upper with no problems?
Second is it worth the trouble having to have a gunsmith convert an upper instead of paying a little more and only having to move the FSB and install a gas block?
I’m already leaning towards getting a new upper and calling it a day but just in case I change my mind I would like to have the information.
I see no reason why your New BBL will not work on your existing upper ! Take your current upper apart,unscrew the BBL nut and replace,pretty straight forward ! There is tons of info all around. If you do pay a Smith to change the BBL out,it shouldn’t take more than a Hour of Labor,and thats “really” stretching it out,its about a 10 min job !! If you take everything off that you can & hand the Smith your parts,it should save time & $$$ !
As far as getting another Upper,there is nothing wrong with that,nice to have a few options,ya can switch Uppers out with one another and have a couple different rifles in one,not a bad ideal ! I guess it boils down to $$$$,if ya have it and want to spend it,adding to your rifle collection is always a good ideal.
Now I guess the question is whats wrong with your CMMG BBL ??? If its shooting good,functioning good then whats the reasoning,hopefully not just because its a CMMG,LOL. Like they say if it ain’t broke don’t fix it, The BCM is good stuff for sure. Keep us posted on how ya make out.
I’d go for the new upper only so I could build a second rifle in the future The barrel should match up fine, if it comes with a barrel extension installed, you won’t even have to worry about headpsace. All of the tools for removing/installing the fsb, removing/installing the barrel can be had from brownell’s for about $150. I just installed a LaRue free float rail myself and I have no prior gunsmithing experience. Its really not hard and there’s lots of helpful folks on this forum.
For that difference I would get the complete BCM upper. For the slight difference in $ you end up with two complete uppers, which gives you the option to sell the CMMG and really make out, or keep it as a spare.
Yes I put a new bcg in both estimates, but I’ve got a few more months before I will be able to do anything so I have some time to think about it. The network over here blocks the site when I use the search function so I’ll have to do the research when I get back home.
If you take everything off that you can & hand the Smith your parts,it should save time & $$$ !
