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View Full Version : Mid-Length or M4 upper?


Gunfighter01
02-16-2006, 5:42 PM
I'm going to change out my upper on my 20" and is wondering what all the hoop-la is about on the Mid Length over the M4. I always heard the M4 is lighter, quicker, and better balanced than say a Mid-Length. I like the M4 personally, but my only concern is,,,, is there room to mount a Harris Bi-
pod and still have room to fully grip your forearm. The Bi-Pod is a neccessity i would rather not live without. OPINIONS PLEASE!

BigAL
02-16-2006, 5:50 PM
The mid length is all the rage now. It has a gas system between the rifle and carbine length. This allows the chamber pressures to drop (compared to the M4) more before extraction. This creates a "smoother" recoil and less wear and tear on parts. You can really start to run into function issues as the direct gas system gets real short like on 10.5 barrels or even 7.5" ones. This is why you see a lot of things in the aftermarket designed to make extraction more forceful like o-ring inserts and extra strength springs. What I like about the M4 carbine length is it is a military standard and parts for it are everywhere whereas midlength is more of a civilian thing. But how often are you going to replace a gas tube? Probably never.

shopkeep
02-16-2006, 5:52 PM
I like the M4 personally, but my only concern is,,,, is there room to mount a Harris Bi-
pod and still have room to fully grip your forearm. The Bi-Pod is a neccessity i would rather not live without. OPINIONS PLEASE!

You could always try a dissipator version of the 16" rifle (http://www.bushmaster.com/shopping/uppers/post-ban/pura2b16d.asp this one is made by Bushmaster). One that has the longer forearm but a shorter barrel. Then just install a rail system over the forearm and you'd have a dissipator with a bi-pod.

I've also seen M4 rifles with bi-pods but there's not really room for a forward pistol grip or much hand room when the bipod is folded.

BigAL
02-16-2006, 5:56 PM
You could always try a dissipator version of the 16" rifle (http://www.bushmaster.com/shopping/uppers/post-ban/pura2b16d.asp this one is made by Bushmaster). One that has the longer forearm but a shorter barrel. Then just install a rail system over the forearm and you'd have a dissipator with a bi-pod.

I've also seen M4 rifles with bi-pods but there's not really room for a forward pistol grip or much hand room when the bipod is folded.

I'm pretty sure the thing about these guns is that they are not "true" dissipators. In other words, there is actually a gas block under the handguards in the standard carbine position and the one under the front sight does nothing. It gives you the longer sight radius but kinds defeats the purpose by using the carbine gas system. I'm not 100% sure that this is what Bushy uses (had a few beers), but i'm pretty sure.

rkt88edmo
02-16-2006, 6:10 PM
As you move from M4-carbine to midlength to 20" A2 you:
Increase weight
Increase bulk
Increase Accuracy with iron sghts due to increased distance between FS & RS
Reduce recoil
Increase velocity (important for round fragmentation)

The 18" midlength is felt by some to capture the best "all around" performance aspects of the AR in the handiest package based on the above criteria.