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TonyMang_89
12-05-2009, 12:15 PM
whats the difference in the 16" midlength and the m4 carbine ?

i have a complete lower and have heard nothing but good things and decided i want a bcm upper, one is 100 dollars more than the other so im missing something

till44
12-05-2009, 12:24 PM
Mainly due to this:
"Cold Hammer Forged Barrels: This process of manufacturing barrels has been used for European small arms for generations, and it is gaining popularity in the United States because of the increased barrel life and outstanding accuracy of a hammer forged barrel. The BCM BFH™ series of barrels are made right here in the USA! (Just like all the BCM products.)"

Price is from expense in the better barrel. I'd go middy, all around more reliable and a better feel in recoil. IMO.

aplinker
12-05-2009, 12:33 PM
Normally the answer would be the location of the gas port (shorter for carbine, longer for mid-length), but in this case there's more.

The mid-length has their new BFH (their "code" for cold hammer forged) barrel.

The carbine doesn't - it has a traditional button rifled barrel from a forged rod.

If they had the same barrel, the obvious answer is mid-length (the longer gas system is more reliable and less harsh).

The difference in performance by the BFH is CHF barrels are more durable.

If you're an avid shooter the BFH is a good deal. If you never shoot, then you likely won't see a real performance difference in the different barrels.

However, you will definitely have a more reliable set-up with the mid-length.

reidnez
12-05-2009, 12:39 PM
I would go with the middy, you're getting quite a bit for that extra $100.

Flogger23m
12-05-2009, 12:54 PM
M4 = M4 style gas port
Mid length = Gas port is further and hand guards are longer. Shorter than M16/rifle style.

The mid length is a good compromise. The M4 was designed for 11.5 and 14.5 barrels, and we can't get those without fixing something to make it at least 16".

So the mid length moves it up further. Apparently, it seems to make it more reliable and not wear the parts as quickly. I've heard it also reduces recoil a bit. Makes it look better with larger stocks to.

So unless you want the rifle to be really light weight or want an M4 clone, then the mid length is a better choice IMO.

Only problem is rails and whatnot seem to be harder to find for the mid lengths.


For a rough size comparison, check here:
http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=265
http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=266

TonyMang_89
12-05-2009, 12:57 PM
alright cool, ya the extra 100 seems well worth it for me since i'm trying to build a rock solid reliable rifle

aplinker
12-05-2009, 1:54 PM
Mid-length IIRC ends up slightly lighter, as it's profiled longer under the handguard - enough it makes up for the small addition in weight from the handguard. Everything else is the same.

Rails are easy to find for mid-lengths. Almost everything is now made as a mid.

(M4 = M4 style gas port
Mid length = Gas port is further and hand guards are longer. Shorter than M16/rifle style.

The mid length is a good compromise. The M4 was designed for 11.5 and 14.5 barrels, and we can't get those without fixing something to make it at least 16".

So the mid length moves it up further. Apparently, it seems to make it more reliable and not wear the parts as quickly. I've heard it also reduces recoil a bit. Makes it look better with larger stocks to.

So unless you want the rifle to be really light weight or want an M4 clone, then the mid length is a better choice IMO.

Only problem is rails and whatnot seem to be harder to find for the mid lengths.


For a rough size comparison, check here:
http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=265
http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=266

Flogger23m
12-05-2009, 2:37 PM
Mid lengths are lighter? I thought it was the other way.

Well, that is another plus to it then.

aplinker
12-05-2009, 3:21 PM
Mid lengths are lighter? I thought it was the other way.

Well, that is another plus to it then.

Only in the gov't profile - the barrel is profiled thinner under the handguard.

"mid-lengths are lighter" isn't a correct general statement. There is no general statement you can make about weight, but the difference will be negligible (within an oz or two either way) for a similarly profiled barrel.

Ravenslair
12-05-2009, 3:42 PM
I run a 12" rail on mine. The extra rail space is nice to have. Obviously, if you are going to run a fix front sight, this will not work for you.

8200rpm
12-05-2009, 4:36 PM
alright cool, ya the extra 100 seems well worth it for me since i'm trying to build a rock solid reliable rifle

You could save the $100 for beer and get the middy with a standard barrel (non-CHF)...

http://www.bravocompanyusa.com/BCM-16-Mid-Length-Upper-Receiver-Group-p/bcm-urg-mid-16.htm

CHF barrels don't improve reliability, only durability. CHF barrels will in theory wear out later than a button rifle barrel.

Unless you're shooting thousands of rounds per year (aka thousands of dollars in ammo), you probably won't notice the difference between the CHF and non-CHF. They're both chrome-lined so the theoretical increase in durability of the CHF barrel is pretty academic for most recreational shooters.

If you're shooting thousands of dollars worth of ammo, spending $100 more for a CHF barrel to shoot thousands of dollars more worth of ammo before replacing a measly $600 complete upper seems pretty irrelevant.