Rebuilding upper - have a question

[MrFeetZ]

I am thinking of changing out the barrel and handguard on my AR. I currently have a colt 6920 with stock 16" 5.56 barrel with a 1:7 twist and a Fortis Rev handguard. I am looking to change to a Faxon Match Series 16" .223 Wylde w/ 1:8 twist and a Centurion HG.

I have the tools, but hardly any experience and I'm happy to try the work myself.

I am wondering if I need to change the bcg (or bolt) when going to this new barrel? Existing bcg does not have very many rounds thru, certainly less than a thousand or so if that makes any difference.

Also, would I need to change buffer? The colt has a carbine length gas system and the new barrel is a mid length.

Come to think of it, I guess I would also need a new gas tube.

Maybe I should get a new, second upper receiver and just have a completely second upper assembly. But then I would need new BCG, charging handle and optic. Boy... this is getting expensive.....

Seriously, please let me know if new bcg or bolt would be needed if I changed barrel as described above. I suppose the big thing driving this change is my desire to change handguard. I'm not really digging a rail at both 12 and 6 o'clock and like the more narrow diameter of the centurion cmr. I'm ok with the existing barrel but thought I may as well change it while I'm there.

[sigstroker]

I did something similar with an M4 type upper that has plastic handguards, front sight post, etc. I would have to remove the sight post, install a gas block, remove barrel nut, install a new barrel nut that goes with the free float handguard, etc, etc.

Just as I was about to start buying all the parts and tools, I found a complete upper on sale for a couple hundred bucks and just bought that.

[kcheung2]

You don't need to change the bcg, nor the rear buffer. You will need a new midlength gas tube.

If you got a new complete upper (sans bcg) you won't necessarily need to get a new bcg. Like the situation above, you can reuse your existing bcg. While it's not the recommended situation, it's not hard to swap out bcgs between 2 uppers. Takes less time than loading 10 rds in a mag, actually. Or don't cheap out and just buy another bcg, they're not that expensive. Esp now when Classic has sales on Toolcraft ones for $70,

https://www.classicfirearms.com/tool...556-9310-bolt/)

or PSA sells nitrided ones all day for $60.

[MrFeetZ]

Ya, that sounds just like me. I rushed to get rid of the front site post and put a quad rail on my colt because:..... Im impatient! Well, now that Ive used it, I dont find it all that comfortable and my wife hates it. So, much so that I ended up getting a second AR for her and went with a complete Odin upper. I have a friend who has the Centurion CMR rail and I find it really comfortable. Just not many places that sell uppers with that handguard

I did something similar with an M4 type upper that has plastic handguards, front sight post, etc. I would have to remove the sight post, install a gas block, remove barrel nut, install a new barrel nut that goes with the free float handguard, etc, etc.

Just as I was about to start buying all the parts and tools, I found a complete upper on sale for a couple hundred bucks and just bought that.

[MrFeetZ]

thanks a bunch for that link! Funny, I picked that exact BCG but your place is $10 cheaper than what I found.

You don't need to change the bcg, nor the rear buffer. You will need a new midlength gas tube.

If you got a new complete upper (sans bcg) you won't necessarily need to get a new bcg. Like the situation above, you can reuse your existing bcg. While it's not the recommended situation, it's not hard to swap out bcgs between 2 uppers. Takes less time than loading 10 rds in a mag, actually. Or don't cheap out and just buy another bcg, they're not that expensive. Esp now when Classic has sales on Toolcraft ones for $70,

https://www.classicfirearms.com/tool...556-9310-bolt/)

or PSA sells nitrided ones all day for $60.

[ar15barrels]

I am thinking of changing out the barrel and handguard on my AR. I currently have a colt 6920 with stock 16" 5.56 barrel with a 1:7 twist and a Fortis Rev handguard. I am looking to change to a Faxon Match Series 16" .223 Wylde w/ 1:8 twist and a Centurion HG.

I have the tools, but hardly any experience and I'm happy to try the work myself.

I am wondering if I need to change the bcg (or bolt) when going to this new barrel? Existing bcg does not have very many rounds thru, certainly less than a thousand or so if that makes any difference.

Also, would I need to change buffer? The colt has a carbine length gas system and the new barrel is a mid length.

Come to think of it, I guess I would also need a new gas tube.

Maybe I should get a new, second upper receiver and just have a completely second upper assembly. But then I would need new BCG, charging handle and optic. Boy... this is getting expensive.....

Seriously, please let me know if new bcg or bolt would be needed if I changed barrel as described above. I suppose the big thing driving this change is my desire to change handguard. I'm not really digging a rail at both 12 and 6 o'clock and like the more narrow diameter of the centurion cmr. I'm ok with the existing barrel but thought I may as well change it while I'm there.

You can re-use your old bolt carrier group.
Just check headspace with the new barrel.

You can re-use your carbine buffer and spring.

You could simply change your handguard to start and then decide later if you want a different barrel too.

[MrFeetZ]

I think I will start at just handguard. However, the barrel I'm looking at is on sale now!

[ar15barrels]

I think I will start at just handguard. However, the barrel I'm looking at is on sale now!

And it probably will be on a BETTER sale on Black Friday.

[Dave Hoback]