Carbine vs Mid-Length Upper Question

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[ARCHIVED THREAD] - Carbine vs Mid-Length Upper Question

Posted: 10/22/2004 11:47:41 PM EDT

basic setup - 16" a3 chrome lined 1:9 heavy barrel kit from m&a, rra lpk, rra m4 stock, ameetec lower, arms 40l, maybe ff. iron sights first, then i will probably throw some kind of optic on it later, but primarily iron sights. primary uses - m193 ammo, range, desert plinking and home defense as i like rifles more than pistols, pistol is for road trips.

i have read all the post i can find about this but it seems there is no definate answer. i have read that people can feel a difference in recoil others say no, same with reliability. i understand that the 5.56 doesn't have much recoil and most don't notice it, but say you do. what type of difference would the longer gas system make? i am assuming the amount of recoil would be the same, but would it be slower? also, sight radius, does it make that much of a difference @ 100yds? 200yds? i am not to worried about the bayonet setup as i will not use it.

can you also post pics of your 16" with a mid-length setup :)

Posted: 10/23/2004 12:18:46 AM EDT

[#1]

Mid length ought to jump less. Muzzle jump is an issue. Also, sight radius is an issue at even under 100m. Not a serious one at that distance, but if you're going to get a 16inch barrel midlength has no real disadvantages.

Posted: 10/23/2004 8:31:06 AM EDT

[#2]

Quoted:
Mid length ought to jump less. Muzzle jump is an issue. Also, sight radius is an issue at even under 100m. Not a serious one at that distance, but if you're going to get a 16inch barrel midlength has no real disadvantages.

+1. AFAIC, the carbine has NO advantage over the midlength. The midlength is just a better mousetrap all the way around.

Can you tell I like mine?

Posted: 10/23/2004 2:34:41 PM EDT

[#3]

The RRA chrome lined 16" mid-length is a nice set up, I got the one from ADCO that is turned down to a lightweight contour (.610") under the handguards. Makes for a nicely balanced piece.

Posted: 10/23/2004 8:43:31 PM EDT

[#4]

thanks for the info

Posted: 10/23/2004 9:16:29 PM EDT

[#5]

I am a newby to much of the techinical info. What are the different lengths available and what are the length differences in relation to one another?

Posted: 10/25/2004 9:10:36 AM EDT

[#6]

There are 3 basic lengths available: carbine, midlength, and rifle. You can have custom made gas tubes and barrels to get something in between, but that's another story.
Carbine length = 7"
Midlength = 9"
Rifle Length = 12"

Carbine is the "standard" on 16" and occasionally 14.5" barrels
Rifle length is almost always used on 18" barrels and longer
Midlength is an option for 16" barrels (and 14.5" but I don't think I've ever seen it done)
Rifle length on a 16" barrel = Dissipator (see Bushmaster for that one)

The length has little to do with handguard length on a free floating barreled AR except that your handguards should cover your entire gas tube. For example, you can put a rifle length handguard on a 14.5" carbine gas system rifle and only have about 2" of barrel sticking out past your handguards. You just have to use a low profile gas block.

Posted: 10/25/2004 5:35:14 PM EDT

[#7]

The only downside of midlength that I have found is weight. If you don't do much training, then weight might not be an issue. After experimenting with the YHM midlength system, I went to a ff aluminum carbine tube and the weight savings is very noticable.

Edited to add that I did not notice any difference in recoil between the two.

Posted: 10/25/2004 6:01:27 PM EDT

[#8]

In my opinion, there is no downside to a mid-length setup, only advantages. There is no weight difference either. Both systems use a 16" barrel with whatever profile you select. I recommend the ADCO\RRA\Wilson chrome lined barrel profile to the A2 dimensions. I have not held a better balancing AR (I use a CavArms C1 (A1 length) butt stock on mine.

Mid length Advantages:
longer sight radius
Better gas pulse which:
Smooths out the operation
Tends to be more reliably
More room on the hand guards for either more mounting options or hand position
Can use a standard bayonet (I know that's important!

)
Disadvantages:
None that I'm aware of

Check it out...

Posted: 10/25/2004 8:22:46 PM EDT

[#9]

My point on the weight was with a rail system. If you are stick with plastic handguards then the weight is not a factor.

Posted: 10/25/2004 8:44:00 PM EDT

[#10]

Thanks for the info. So, I take it that midlength handguards are part of the midlength gas system placement option, by the picture. I think that it looks very nice. It looks like the amount of barrel protrusion from the handguard is the same that the 14.5 inch barrel has in the carbine setup. The proportions just look right. The 16 inch barrel in the carbine setup just always looks disproportionate to me.

I do, however, also like the dissipator appearance for the 16 inch barrel. It seems that one could easily make a dissipator setup by replacing an existing gas system with a low profile block and moving the front sight further down the barrel.

Has anyone used the LMT enhanced bolt on a midlength setup? I wonder if it would work okay.

Posted: 10/26/2004 3:32:59 AM EDT

[#11]

Quoted:
Thanks for the info. So, I take it that midlength handguards are part of the midlength gas system placement option, by the picture. I think that it looks very nice. It looks like the amount of barrel protrusion from the handguard is the same that the 14.5 inch barrel has in the carbine setup. The proportions just look right. The 16 inch barrel in the carbine setup just always looks disproportionate to me.

Yes, a 20" rifle, a 16" mid length and a 14.5" carbine all have the same amount of barrel protrusion. That is why they will all accept a standard bayonet. I sure someone here will correct me if I am wrong but, a 16" carbine is just a 14.5" carbine stretched out to make it civilian legal.

I do, however, also like the dissipator appearance for the 16 inch barrel. It seems that one could easily make a dissipator setup by replacing an existing gas system with a low profile block and moving the front sight further down the barrel.

I think this is what you are looking for then...

it was built and "designed" by forum member "underdog75" and he refers to it as a "Dissergy". Read this THREAD for his latest range report.

Has anyone used the LMT enhanced bolt on a midlength setup? I wonder if it would work okay.

I'm sure someone has but my advice would be to save your money. It has yet to be proven that these "enhanced" bolts provide any reason world advantages but more than a few have been sent back for not functioning correctly (they seem to be ammo sensitive) or for early failure.

Posted: 10/26/2004 6:27:23 AM EDT

[#12]

Is a 16" carbine a 14.5" stretched out to make it legal? I guess you could put it that way. All it is, it's a longer barrel with the same gas system length. If you're using an M4 barrel though, it isn't literally stretched out because the cut for the grenade launcher is the same and in the same location.

The LMT "Enhanced" BCGs were designed for the 14.5 barrels with a carbine length gas system. The only thing I find really appealing about them is their dual extractor springs, although I think my $1.50 Wolff spring does the trick just as well. So unless you're using a 14.5" barrel and are having jams (especially when firing on full auto), then go ahead and replace your bolt carrier group. If it ain't broke, don't fix it.

Posted: 10/26/2004 8:20:47 AM EDT

[#13]

Quoted:
The LMT "Enhanced" BCGs ...The only thing I find really appealing about them is their dual extractor springs, although I think my $1.50 Wolff spring does the trick just as well.

It is those dual extractor spings that seemed like it was going to be a large improvement as it was supposed to help extraction and greatly improve service life. Problem is there have been a couple of people who have needed spring replacements within 7000-8000 rounds. Not good, especially considering these require a special spring.

Posted: 10/26/2004 11:32:44 AM EDT

[#14]

Midlengths look good with an A2 stock, but with a collapsable they look front heavy. I wanted a collapsable so I got a carbine/M4.

Posted: 10/26/2004 12:43:46 PM EDT

[#15]

cvg69, were we separated at birth?

Posted: 10/26/2004 1:39:45 PM EDT

[#16]

I'll tell you what, you guys have some really nice looking carbines. I think that I will build a midlength in the coming year, soley on what I have seen on this thread. I may also change the carbine that I am building at present into a dissipator setup. Man this forum is going to cost me a lot of money, but ain't it fun?

Posted: 10/26/2004 1:45:42 PM EDT

[#17]

I can barely tell these apart.

Same bolts, carriers and the lowers are identical with "H" buffers.

Posted: 10/26/2004 1:56:32 PM EDT

[#18]

innocent_bystandard, who made your lightweight midlength upper or is it a custom build?

Posted: 10/26/2004 2:00:55 PM EDT

[#19]

Barrel is a RRA/Wilson 1x9 chrome lined that was contoured by ADCO.

www.adcofirearms.com/rockriver/rockriverbbls.cfm?page=rra

Don't forget the group buy going on for 1/7 midweight midlength barrels.

Posted: 10/26/2004 5:40:37 PM EDT

[#20]

Quoted:
cvg69, were we separated at birth?

Posted: 10/26/2004 8:40:20 PM EDT

[#21]

oops

Posted: 10/26/2004 8:41:59 PM EDT

[#22]

Quoted:
I can barely tell these apart.

Same bolts, carriers and the lowers are identical with "H" buffers.

what exactly is a "H" buffer. thanks for the pics :)

Posted: 10/27/2004 7:56:16 AM EDT

[#23]

Uh, oh...

Looks like you're going to have company cvg69 and Snake45...

As soon as my 16" midlength barrel comes in from the Group Buy, I'll be putting together a carbine complete with A1 butstock and a detachable A2 carry handle/sight.

That set-up just seems so perfect. Compact, symetrical, and balanced....

I don't know why the military isn't looking at this configuration to satisfy their desire for a shorter over-all M16 (well, maybe with a collapsible stock). Seems like a perfect fit to me.