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Posted: 9/16/2004 8:39:44 AM EST
Looking at getting a RRA mid-length flat top upper.
Upper will be going on a lower with a 6-pos stock.
My question is, for weight and balance is it worth it to have it countoured under
the handguards?
Eventually I would like to put something like a YHM lightweight railed FF tube on it.
With the lightweight stock, does having weight removed under the hand guards put too much
weight forward, or will it even be very noticable as far as balance.
Just trying to decide is it's even worth the extra cost, or should I just leave the barrel as is.

Any advice from mid-length shooters is appreciated.
Link Posted: 9/16/2004 8:55:30 AM EST
Here's my middy:



This has a gov't profile barrel under the PRI tube and I like the balance of it alot. If it were a HBAR, balance would not be as good. If it has a YHM lightweight (heavier than the PRI, IIRC), balance would not be as good. If it were an HBAR and YHM, it would be bad.

If I could change one thing on this, I would change the PRI for a DD 9.0 or LaRue midlength (if they ever come out with a midlength tube). Both are extremely light and would only help the overall balance of the rifle.
Link Posted: 9/16/2004 8:59:45 AM EST
Yes, it is absolutely worth having the material removed. Look at it this way, a regular 16" HBAR barrel weighs as much as a 20" that is thinner under the handguards. The midlength has more area under the handguards so an HBAR midlength will weigh even more.
Link Posted: 9/16/2004 9:33:17 AM EST
MS-

I just did exactly what you are asking about.

A while back, I bought a "post ban" 16" mid-length stainless bbl with A2 FST from Rock River. My girlfriend and I shot it this way for like 6 months. It's really thick under the handguards - like 0.900" or larger.

I just had a gunsmith turn down the barrel profile to 0.700" from FST to muzzle, and closer to 0.75" for most of the length under the handguards (thicker closer to breech).

The difference in weight is dramatic, and the $$ spent on the lathe work was totally worth it.

-z
Link Posted: 9/16/2004 11:24:56 AM EST
+4
Link Posted: 9/16/2004 1:22:22 PM EST
+5

Yes, do it! You will absolutely regret it if you don't.

I have that exact barrel and had it contoured by ADCO to the A2 profile and have it mounted in a A2 upper and my carbine has a C1(A1 length) fixed stock. The balance is very good but still a little front heavy. I would have to imagine an HBAR contour barrel and with a collapsible stock would be a very unbalanced gun. Plus who needs the extra weight?
Link Posted: 9/16/2004 6:24:30 PM EST
its always a must to gov. profile a barrel
Link Posted: 9/16/2004 7:07:28 PM EST
Thanks for the input.

Hopefully giffman's group buy on the 1/7 goes through, then I can send it over to ADCO for contouring, I'm convinced.
Maybe by then I'll have decided on a FF tube, and saved the cash for my first upper build. Been waiting a year for the AWB to end, guess I can wait a little longer for perfection.

mongo001, very nice rifle... what kind of FH/brake is on the end of that beauty?
Link Posted: 9/16/2004 10:30:59 PM EST
An Armalite midlength barrel is reduced under the handguards, not all the way like a govt. profile, but definitely less than HBAR
Link Posted: 9/17/2004 2:46:11 AM EST

Originally Posted By MightySwede:
Thanks for the input.

Hopefully giffman's group buy on the 1/7 goes through, then I can send it over to ADCO for contouring, I'm convinced.
Maybe by then I'll have decided on a FF tube, and saved the cash for my first upper build. Been waiting a year for the AWB to end, guess I can wait a little longer for perfection.

mongo001, very nice rifle... what kind of FH/brake is on the end of that beauty?



I'm just curious, does a 1/7 twist mean that much to you? Have often do you realistically shoot 77gr ammo? Don't get me wrong, given the choice I would prefer a 1/7 over a 1/9 twist too but not enough to spend an extra $25 minimum + wait at least an additional 10-12 weeks.
Link Posted: 9/17/2004 3:32:51 AM EST

Originally Posted By Quake_Guy:
An Armalite midlength barrel is reduced under the handguards, not all the way like a govt. profile, but definitely less than HBAR




Quake is correct, but I took a Armalite Mid-Length barrel and had it taken down to A2 / govt. profile and put a Daniel Defense 9.0 free-floated rail system on the gun and the loss in weight is definately worth the cost of having the barrel lightened:






Semper Fi
Jeff
Link Posted: 9/17/2004 7:50:23 AM EST
1/7 isn't a neccessity, but it would be nice to see a group barrel buy happen, so I'll wait and see.
If not the 1/9 would be just fine, I usually shoot 55 or 62gr. Definitely want chrome lined though, and the wait isn't an issue. As much as I would love the instant gratification, it will take me a few more months of play money to get the other parts. The DD 9.0 looks pretty sweet.

If I decide to change out the FSB, any one that will fit the barrel diameter will work on a mid-length right?
The FSB and standard gas tubes are all the same diameter, or is there anything else to worry about on a mid-length?
Link Posted: 9/17/2004 8:10:18 AM EST
These are my two 16" carbines.

Green one has an older Aimpoint Comp M XD, ARMS M68 mount, #40 rear site and a 16" BM M4 barrel.

Coyote one has an ADCO lightened midlength barrel with a new Aimpoint M2, LaRue mount and BUIS.

Lowers are identical except for color.

The midlength is 4 ounces heavier but I can't tell you what makes up the weight difference since I didn't weigh individual parts.

Link Posted: 9/17/2004 8:51:21 AM EST

Originally Posted By MightySwede:
mongo001, very nice rifle... what kind of FH/brake is on the end of that beauty?



That's an Advanced Armament "flash compensator". It is threaded to accept the Advanced Armament M4-2000 supressor. I can't own a supressor, but I like odd/custom/different muzzle devices and this one tops of my middy very nicely.
Link Posted: 10/1/2004 8:44:09 AM EST
What type of accuracy are you guys getting out of your free-floated, mid-length, Gov't profile carbines? Especially ACOG/scope mounted versions.
Link Posted: 10/1/2004 8:25:35 PM EST
A RRA mid-length HBAR felt REALLY heavy to me. I bought one and immediately sent it to KKF for fluting. It was lighter, but then I saw ADCO's profiled ones, so I bought one of those. Now THAT's light. I'm thinking about having mine shortened to 14.5" with perm. flash suppressor for that last bit of "lighter".
Link Posted: 10/1/2004 9:52:29 PM EST
Having just held a 16" HBAR and a 14.5" gov-profile side by (Identical in all other regards) I can definately say you will notice the weight difference. It made me want to send my own 16" HBAR back to ADCO immediately to get it turned down.
Link Posted: 10/2/2004 9:47:14 AM EST
You should deffinitely go light.

My KISS HBAR middy is heavier than my M4 dissy which has a full lenghth rail system, VFG, front and rear BUIS and ML2/#22M68.
Link Posted: 10/2/2004 11:16:19 AM EST
I have not used a turned-down Middy, but I have an HBAR from RRA. It is quite heavy, but it's not too much of a problem. I would like to try it next time with a lighter barrel, just b/c this one is heavy and I'd be interested in seeing which way I like it better.
Link Posted: 10/4/2004 4:03:04 AM EST
Get it turned down. My midlenth was too heavy. Now it balances perfectly with a Cav Arms lower. The extra weight out front is great.
Link Posted: 10/6/2004 8:31:50 PM EST
[ link to LARGER image ]

This was turned down from full Hbar under the handguards.
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