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-   -   The 7.5 lb. A2 (http://forums.thecmp.org/showthread.php?t=240250)

Talyn1 01-24-2019 04:54 PM

The 7.5 lb. A2
 
For those that like shooting the A2, and are interested in using that configuration to meet the new Class A weight limit, my build comes in right at 7.5 lbs. The completed rifle was weighed on a digital scale.

It's built as follows;
  1. RRA NM A2 upper w/standard CH,
  2. Anderson Manufacturing lower,
  3. Windham Weaponry 20" govt.-profile barrel w/FH, A2 ribbed handguards w/heatshields, A2 FSB, and associated barrel/GS parts,
  4. FailZero EXO "standard-mass" NiB BCG,
  5. LaRue MBT-2S trigger (4.5 lbs),
  6. A2 fixed stock and associated standard A2 buffer & spring.
  7. BAD LW ambidextrous safety,
  8. KNS non-rotation trigger/hammer pins, and
  9. A2 grip.

No other light-weight parts were used, like Ti parts.

So it's possible to meet this Class A requirement but there's no room for anything else, like a full-mass BCG and/or any extra stock weight for balance.

My .02

ceresco 01-24-2019 09:19 PM

Well....I have a complete (partially assembled) A2 resting on my scale and also at exactly 7lbs 7oz. No flash hider and still a few small details to finish. I used a White Oaks (pinned) A2 upper receiver, A2 20" military barrel from Bear Creek Arsenal, common A2 buttstock/lower, standard BCG, M16 front sight, and a rather heavy aluminum 12 inch tube free float HG. There are many ways to reduce the weight further if necessary. So, yes it can be done, and with no unusual cost or effort. I will test this rifle for accuracy in the next few days, expecting it to shoot very well out to 200yds. I would be less confident regarding the accuracy if it had standard handguards. BTW--Weighed my (GI birch stock) SA Inc M1A: exactly 9lbs including the charger guide.... Good Shooting. ....

HighpowerRifleBrony 01-25-2019 12:32 AM

So FailZero's "standard" mass is a semi carrier?


Shouldn't need rear balancing weight without a FF tube and HBAR.

Talyn1 01-25-2019 12:28 PM

Quote:

Originally Posted by HighpowerRifleBrony (Post 1796385)
So FailZero's "standard" mass is a semi carrier?


Shouldn't need rear balancing weight without a FF tube and HBAR.

According to FailZero's narrative, yes.

http://www.failzero.com/products/bol...er-detail.html

I mentioned that since manufacturers offer carriers with varied descriptors of weights such as LW, semi-auto, M16, full-auto, enhanced and full-mass.

I have a DSG enhanced Gen 2 full-mass carrier in my SR, and they state they make that one with extra weight compared to their standard even though their standard is a M16-type carrier.

https://dsgarms.com/dsg-4101-0004

Considering the basic/classic A2 is still a bit front heavy some may want to balance things. I mentioned that just in case & due to my build being right on the weight limit. I put 1/2 lb. of bagged split-shot in the compartment of the UBR stock on my SR.

GarandThumb21 01-26-2019 01:45 PM

I am at 7 lbs 9.7 oz with my Windham govt profile A4 upper and my RRA lower, according to my digital postal scale. I have a RRA chrome BCG. The RRA lower has the standard A2 stock and grip. Without more extreme measures such as swapping out the buffer tube etc, I could acquire a lighter BCG, or possibly remove the nuts on my A4 carrying handle in order to make weight. Any practical experience with the latter?

Talyn1 01-26-2019 02:34 PM

Quote:

Originally Posted by GarandThumb21 (Post 1796852)
I am at 7 lbs 9.7 oz with my Windham govt profile A4 upper and my RRA lower, according to my digital postal scale. I have a RRA chrome BCG. The RRA lower has the standard A2 stock and grip. Without more extreme measures such as swapping out the buffer tube etc, I could acquire a lighter BCG, or possibly remove the nuts on my A4 carrying handle in order to make weight. Any practical experience with the latter?

Ti is 50% of the weight of steel. So you don't have to shave off much to make weight.

Since the nuts are big and likely weigh a lot I wonder if you could find titanium nuts that would work with the steel cross bolts?

Does anyone know what thread the cross bolts are?

https://www.probolt-usa.com/titanium/titanium-nuts.html

Even Amazon sells Ti nuts such as these as an example. https://www.amazon.com/Allied-Titani...20713177&psc=1

If you have the coin you could contact V Seven and talk to them about a couple custom nuts.

Also, the side plate is steel and you really only need two shorter ones for each nut/bolt combo so one could save some weight if; #1 - if you find/have a spare cut the middle out, or #2 - if a Al or Ti substitute could be found.

V Seven has a slew of LW (Al, Mg & Ti) AR parts that could help shave off a couple oz. https://www.vsevenweaponsystems.com/gun-parts/?cat=91

GarandThumb21 01-26-2019 03:53 PM

On second thought, the easiest thing to do may be to swap out the standard buffer for a low mass rifle length buffer like this one:

https://www.brownells.com/rifle-part...prod27116.aspx

Perhaps not the cheapest solution, but certainly easy to do, and it would cut the necessary weight.

Talyn1 01-26-2019 04:15 PM

Quote:

Originally Posted by GarandThumb21 (Post 1796908)
On second thought, the easiest thing to do may be to swap out the standard buffer for a low mass rifle length buffer like this one:

https://www.brownells.com/rifle-part...prod27116.aspx

Perhaps not the cheapest solution, but certainly easy to do, and it would cut the necessary weight.



Good idea. That will save you 2.4 oz. over a standard one.

I didn't know they made a lighter weight rifle-length buffer. I've always just worked with carbine buffers of different weight vs. fiddling with different springs since when I did that once I had nothing but problems with functioning.

ceresco 01-26-2019 11:38 PM

Flash hider weighs about two oz. An ajustable buttstock will be much lighter than an A2. Many handguard possibilities... Don't make it difficult. Good Shooting. ...

GarandThumb21 01-27-2019 06:21 PM

I should’ve mentioned that I have a crowned barrel, so no opportunity to save weight with a specific flash hider. I’d prefer not to swap out the rifle length buffer tube and stock for a carbine length setup. If I can find another A2 or A1 stock that’s lighter than what I have, then that’s certainly an option. Even though my handguards are pretty light at 4.8 oz. apiece, I may be able to find some lighter ones so I'll keep looking at this as well.


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