AR-10 - Work OK with Small Primer Brass?

[Phil3]

I wish to use the 6.5 x 47 Lapua cartridge in the Armalite AR-10(b) I am building.  However, that cartridge only comes with a small primer, not "large".  Will this present any problems with the AR-10?  For those who use the 6.5 Creedmoor with small primers (available in small or large), have you had any issues?  

Thanks,

Phil

Edited April 10, 2019 by Phil3
Typo

[sketch]

6.5 cm large primers here . results may varry? shooter is A#1 variable. realoader is ground 0. picks!

[98Z5V]

I would say - If other 6.5 x 47 Lapua guys aren't having an issue, then it's gonna be alright.  That's a pretty established cartridge, now, and Lapua put their name on it.  There's no way it doesn't function, as a developed load/cartridge, by Lapua. 

Here's good info on "the 3,"  6.5 x 47 Lapua vs. 6.5 Creedmoor vs. .260 Rem.

http://demigodllc.com/articles/6.5-shootout-260-6.5x47-6.5-creedmoor/?p=3

If it was me - I'd build a .260 Remington.  I can make the brass out of .308 Win brass, and I reload.  That's what seals the deal for me.

6.5 Creedmoor is based from the .30 TC brass - and finding that is hard, if I wanna convert it, or I buy it (Hornady brass a a buck a round).

6.5 x 47 Lapua is not gonna give you a "parent-case" brass choice - because that's it.  You pay buck-30 per round, new brass?  That's not bad.  My new Hornady Grendel brass is $40-per-50 pieces.  All new brass is expensive, Lapua being a little more.

Even though the 6.5x 47 :Lapua will go 1000 yards - that's not what it was designed for.  This is a quote from the article I linked above:

Because this cartridge was designed from the ground up for European long-range competition (in this case only 300 meter),

There's alot to think about before getting into this cartridge...  

[98Z5V]

Small RIfle Magnum primers, only, though...   That's what I picked up about this cartridge.  CCI-450s, CCI-41s, other small rifle magnum primers.  Something worth trying, if you go this route, would be the new-ish Federal Premium "AR Small RIfle Match" primers.  Federal's part number is GM205MAR.  I have a pile of these that I haven't tried yet, for the 5.56 guns. 

[Phil3]

I have considered the use of the 6.5 x 47 vs 6.5 CM in both my bolt gun build, and for this AR-10.  I think the 6.5 CM is an excellent round, but a number of things, however minor, once all added up steered me toward the 6.5 x 47.  It does have some negatives, as does most any cartridge.  I can share the pros/cons if people want, but not here to cheer lead for the 6.5 x 47.

The 6.5 x 47 brass can be had for as little as $1.03 a case, up to around $1.20, from what I saw today.  

Thanks for the article.  I have read that multiple times.  

Perhaps my biggest challenge will be building the AR-10 in an acceptable way that still meets California restrictions.  My biggest issues are the pistol grip and stock.  More on that in another post.  

Phil

Edited April 12, 2019 by Phil3

[98Z5V]

20 minutes ago, Phil3 said:

 I can share the pros/cons if people want, but not here to cheer lead for the 6.5 x 47.

I'm all about it, Phil, let it rip, man.  I went .260 over 6.5C, and I'll never look back.  However, I'm always interested in the "other side" of any of these cartridges. Go after it, at your leisure - it won't be bad info, that's for sure.   

[Phil3]

Hi,

I am definitely biased toward the 6.5 x 47, and while I have some specific technical reasons why, I would not be honest if I did not say, I just like the round, and find myself rooting for something different.  The 6.5 x 47 is that in the semi-auto world.  I built an AR-15 shooting 223 just to see how accurate I could make a semi-auto, and it was fun to out-shoot some bolt guys with regular 5 shot groups under 1/2 MOA at 100 yards, off a bipod.  

I want to see what I can do with the AR-10, and this time, using a cartridge not often seen in semi-autos.  I will be leaning on you guys to steer me in this build.  I have some good components already in, but have important decisions to make on other parts.  

Phil

[Sisco]

I have given some thought to chambering my AR10 B standard rifle in 260 Remington. From what I understand the biggest roadblock is fine tuning the gas port. 98 has already been through that however, and has me thinking about it when I get an extra $700 for a barrel.

[98Z5V]

My barrel was way less than that, brother - WAY LESS.  Wilson Combat Tactical Hunter 20" barrel, standard retail $335.  I nailed it on a sale for $280.

The .260 blows away every gun I have (minus one), at my standard target distance of 850 yards.  My 18" Grendel is getting that done with 9.0 mils of drop.  The .260 does it with 6.5 meals of drop.  (had to throw that in there...). 

The only other gun I have that beats it at that distance is the .300 Win Mag bolt gun, with 5.7 mils of drop, loaded with 195gr Hornady HPBTs cruising 2900 fps.  And the .260 does it with a hell of alot less recoil. The .260 is rolling along at a modest 2650fps...  

Edited April 16, 2019 by 98Z5V

[jtallen83]

6 hours ago, 98Z5V said:

The only other gun I have that beats it at that distance is the .300 Win Mag bolt gun, with 5.7 mils of drop, loaded with 195gr Hornady HPBTs cruising 2900 fps.  And the .260 does it with a hell of alot less recoil. The .260 is rolling along at a modest 2650fps..

The only thing slowing me down from adding a new cartridge is indecision. I've had Grendel barrels in the cart but then thought about the 260......odds are I will end up with both. The 260 may be first since I have piles of brass I could make work.