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Old January 22, 2009, 10:30 AM   #1
Magnum Wheel Man
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.6.8 Remington SPC... who shoots it, barrel lengths, reloading, results...

I'm considering the 6.8 SPC for a Thompson Contender carbine... for 300 yard target shooting... understand in a normal rifle there are better calibers to choose from, for that purpose...but in the limited pressure action of the Contender, it seems like a natural...

my understanding, is that the cartridge was developed for short barreled CQB rifles... & the standard Contender rifle barrels are 1 in 10" twist, & 23" long... with current load receipes available,

1st... do you think there is much advantage to that additional barrel length over a 16" or so barrel ( I could shorten the barrel to 16" & do something with the additional 7" of barrel... maybe a short 270 Ren barrel or ??? )

2nd... I see "everyone" is coming out with load components, ( brass dies, etc. ) anyone that is currently loading for the cartridge care to share some favorite loads / velocities per barrel length, components, etc...

....links ??? seems the cartridge is still "new" enough that there isn't that much internet data... any load books that have load data for the 6.8 ???
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Old January 22, 2009, 01:00 PM   #2
Shawn Dodson
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I converted a Colt AR15A2 Sporter from 5.56 to 6.8 by installing a new 20" HBAR, a new bolt and new magazines.

I started handloading the cartridge and was working up a standard load until I transferred to FL a year ago. I'm just now getting my reloading gear together to resume reloading.

There is no velocity advantage with a barrel longer than 16". By that I mean you'll see trivial increase in velocity with a longer barrel.

If you have a .270 barrel already then I suggest you just stick with it instead of acquiring 6.8. You'll have greater flexibilty in load development with .270 versus 6.8.

As for handloading data for 6.8 the 7th edition Hornady manual has some as well as the Hodgdon web site - http://www.hodgdon.com .

Suggest you visit http://www.68forums.com/

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Old January 22, 2009, 01:01 PM   #3
bedlamite
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First, everything you seek can be found at http://68forums.com

The 6.8 doesn't lose much when you use short barrels, there are people using it in SBR's as short at 12" still producing decent velocity.

Rifle twist ion the 6.8 has more of an effect on pressure than many other cartridges, slower twist helps lower the pressure. It's generally accepted that 1/11 or 1/12 twist is ideal in an AR, but with a Contender you can use the longer, heavier bullets so a 1/10 twist might be useful. You also want to have a DMR or SPC2 chamber; Remington really screwed up when they submitted it to SAAMI. The DMR chamber is very close to the original chamber Murray used when designing the cartridge, and the SPC2 chamber has a longer leade than the SAAMI chamber. Having a SAAMI chamber is a handicap of 100-200 fps, although it can be reamed out to SPC2.

For loads, I use either a 110 gr Sierra Pro Hunter or a 110gr Hornady Vmax on 29 grains of H322 for 2550/2600fps from a 16" barrel, but that is probably a little too hot for a SAAMI 1/10 gun. SSA has a Barnes 85 gr TSX loaded to 3000 fps.
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Old January 22, 2009, 04:25 PM   #4
Magnum Wheel Man
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Thanks for the info guys...

Shawn... the Contender can not shoot the regular 270 Winchester ( the Encores can, but the Contenders are like the little brother ) pressures like found in the 6.8 are about maximum for the Contender action...

I'm currently building a "faster twist" 16" 223 barrel for my action to handle some of the heavier 223 bullets, so I'm thinking a 16" 6.8 to match might be cool... I didn't think there was much to gain with current loadings from the dditional barrel length found in the standard TC barrel

IMO, the cartridge doesn't offer much over the 6mm, 6.5mm, or 7mm TCU cartridges, which I already shoot in handgun length barrels, just reforming the 223 cases is a pain... commercial brass for the 6.8 would be a big plus... I see Hornady brass is expected in at Midway anyday... I also saw a brand I was unfamiliar with ( maybe they developed the cartridge ??? )... what are you guys using for brass ??? ( sorry... it might be in the load data, but I haven't had the time to go through it yet )


EDIT... ah.... Silver State Armory... there is the brass I'd never seen before, & I see the load data lists the case manufacturer

SSA brass... how does it compare to the other major suppliers ??? anyone know who makes it for them ???
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Last edited by Magnum Wheel Man; January 22, 2009 at 04:48 PM.
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Old January 22, 2009, 08:51 PM   #5
bedlamite
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Quote:
IMO, the cartridge doesn't offer much over the 6mm, 6.5mm, or 7mm TCU cartridges
300-800 fps for the same weight bullet isn't enough?

SSA brass is made in their own factory and is on par with Hornady. Remington offers 6.8 brass too. SSA and Hornady have both switched to small primers, Remington still uses large rifle primers. I use Remington mainly because I came across it at a price I couldn't refuse.
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Old January 22, 2009, 09:49 PM   #6
hodaka
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16 inch 10 twist barrel AR. Off a bench with a 16X Tasco on an A2 handle mount. I love this cartridge. SSA brass lasts forever and is easy to load.
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Old January 23, 2009, 07:42 AM   #7
Magnum Wheel Man
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thanks again for the info... I'm starting to lean towards the 6.8 for my next Contender barrel...

BTW... HODAKA... nice group...
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