7.62NATO or 6.8SPC for a SPR type rifle?

[dlrflyer]

I've been wanting to buy an SPR/DMR-type rifle for awhile now, I'm just not sure I like my options. I'm wanting a rifle primarily for 300-500m, maybe stretch to 600, but no more, and to be honest, 0-300m is a lot more important than 500-600m. 5.56mm is out, I'm a civilian, so I'm not locked into what the military uses, while hits are no problem, it just doesn't have enough poop at those ranges to satify me. 6.5Grendel is out too. Too proprietary to be useful. This leaves 6.8SPC and 7.62N. Reliability and durability are important to me, and the stories of AR-10 type rifles being rather undependable are a bit too common for my taste. 6.8spc mags have been questionable at times, but the rest seems ok. I hate to add another caliber to my already too large collection of 5.56, 7.62N, 7.62x39, 30-06 and 30 carbine, but maybe at this point, it doesn't matter. I've looked at trajectory tables, surprisingly, 6.8spc is very similar to what 7.62Nato is, so that isn't really a factor. I do like the lighter weight of a 6.8spc setup, I don't feel as though it needs to be very heavy since it's not a full blown sniping setup. For optics, probably Leupold 2.5x8 MR/T, or a 5.5 or 6x ACOG for simplicity. If not for pending assault rifle crap here in Illinois, I'd just wait for a SCAR-H, but that might be too late.

So anyway, give me some thoughts, perhaps some of you have a better theories than me.

[30russkie]

i would say go with 7.62

i have a 6.5 grendel upper and it is a very good round. ammo is sort of cheap $11.99 a box for brass wolf gold. but it really needs to be hand loaded to shine--or you need the $25 a box special loadings to get to go full on. i was sort of bummed at the wolf only hitting 2450fps--my hand loads are much better.

6.8spc--another round i really like but don't have. i did get the chance to fire a few rounds of it while it was testing. ammo is expensive last time i checked it was $24 a box of 20. like the 6.5g it should hand load very well. the 6.8spc has had some development problems that has lead to it being downloaded when factory loaded. there are several chamber revisions and rifling/rate of twist changes that just happened at just the wrong time and hurt the project. if you have to have one get the latest chamber spec and something on the order of 11 to 1 twist rate--less is more with this round.

the 6.8spc and the 6.5 are about the limit of what you can do with the small AR

7.62x51 the old standard. much more push than either the 6.8 or 6.5 and with heavy bullets it can certainly do anything the 6.5 can for the same price or less. the only real downside is bigger rifle- and ammo and mags--more weight,report and muzzle flash--if these things arn't a problem--go 7.62 all the way.

[deltaARman]

I think the 308 is the way to go, between me and my dad we have (lets just say a small collection of ar 10's;) ) and we have never had any problems with are Armalites', or Rocks'. If you clean your weapon like your suppose to they feed flawlessly, these new and improved piston ar's are cool, I'll be the first to admit it, but unless your shooting suppressed fire, fully auto dumping beta mags, you just don't need it. Sorry I kinda rambled there for a bit, but back to the question at hand, if you are considering the weight factor in, then 6.8 isn't a bad round either, it kicks just like a 223 but you got the knock down power that you expect. It doesn't weigh anymore than a standard ar 15, but ballistic past 300-400 yards in my opinion I would rather have the 308. I can't help you on the price per box being we reload our own(6.8).

[FlyingHunter]

I own 2 6.8spc rifles and they are great. However, from what you described, I believe you would be better served by a 308. I have a DMR set up and SBR set up. My DMR is excellent to 300yds and thats about as far as I ever shoot. This part of the world doesn't offer much terrain that present shots longer than 300yds and the 6.8 kills deer just fine. Good luck.

[thmpr]

After shooting both platforms, recommend the 6.5 for the 4-600 meters distance. The reason I state this is due the consistent POI the 6.5 will give you at these distance especially on windy days. They are both great platforms and each has it's benefits but for consistent placement at longs distance, the Grendel wins. For 300 yards or less, the 6.8 will do. To each his own.

[Dave L.]

+1 6.8SPC

You can take an existing AR15, buy a Cardinal Armory barrel that will shoot sub MOA, new bolt, and mags. Apparently 6.8 only looses around 36fps in a 16" barrel when compared to a 20".
If you are target shooting out to 500 and beyond you should be fine. I wouldn't try to kill a deer at those ranges but I wont shoot deer beyond 400 even with a 7mm Mag(ethics).
For a good and reliable AR10/SPR type it's going to cost you a ton.
Like wise man on this sight says- "what are you going to use it for, and how much do you want to spend"?

[FromMyColdDeadHand]

What about using 5.56, with a 1x7-8 barrel with the 75gr+ bullets for long range, and lighter (and cheaper) surplus ammo for closer in. Out of a 14.5 or short barrel that might not get you out to 600, but I would think with an SPR/18inch barrel that would work, and if you are talking a DMR/20inch barrel that would work better.

I agree that 7.62 would be the way to go, and after Barak gets us out of Iraq, there should be plenty of surplus ammo :D , but the economics of the cheaper 5.56 ammo, cheaper rifles, cheaper mags, smaller rifles/more cool stuff have made me think I'll go 5.56 type ARs.

[TurretGunner]

I would take a serious look at .260 as a AR platform. I know DPMS makes a very good black rifle in this caliber. Its much more recoil/wear and tear forgiving and shoots flatter then the .308. There are also .243 stoners that are nothing to snivel at out to the 1k yard line.


Of corse the benifit to both of these is they can be picked up at any sporting good store worth a shit. Long when 6.5 and 6.8 go the way of the dodo bird, they will still be around.

[Buckaroo]

I would take a serious look at .260 as a AR platform. I know DPMS makes a very good black rifle in this caliber. Its much more recoil/wear and tear forgiving and shoots flatter then the .308. There are also .243 stoners that are nothing to snivel at out to the 1k yard line.


Of course the benefit to both of these is they can be picked up at any sporting good store worth a shit. Long when 6.5 and 6.8 go the way of the dodo bird, they will still be around.

Sounds like the .243 Stoner (KAC 6x35 PDW) uses a shortened case?

http://www.sofmag.com/news/permalink1/2006/11/7/2318133612237.html

6x35mm PDW

Designed entirely around a brand new short .243 caliber cartridge made by Hornady exclusively for KAC, the receiver/magazine-well section of the KAC/PDW is 1/3-inch shorter than those elements of the M4 and that includes the magazine. This because the overall length (OAL) of the KAC/ PDW 6x35mm cartridge is .32-inch shorter than that of the 5.56x45mm NATO cartridge.

http://www.knightarmco.com/images/pdw1.html

I would be interested to see a .243 Black Rifle but my google fu did not reveal any...

[TurretGunner]

I googles " ar15 .243" and these popped up on the first page:

http://www.ar15performance.com/

http://www.dpmsinc.com/firearms/category.aspx?id=7

http://www.olyarms.com/index.php?page=shop.browse&category_id=12&option=com_virtuemart&Itemid=37&vmcchk=1&Itemid=37

Althought the last one is WSSM and is Oly which I would not recomend.

[Buckaroo]

I googles " ar15 .243" and these popped up on the first page:

http://www.ar15performance.com/

http://www.dpmsinc.com/firearms/category.aspx?id=7

http://www.olyarms.com/index.php?page=shop.browse&category_id=12&option=com_virtuemart&Itemid=37&vmcchk=1&Itemid=37

Althought the last one is WSSM and is Oly which I would not recomend.

Well, I stand corrected! (I googled .243 stoner....)

Thanks

Buckaroo

[ccoker]

the 243 is built on an AR10 platform

I have a 6.8, I got it because it's a lot lighter than an AR10 and I want it for stalk hunting... mine is sub MOA with all factory loads and even better with handloads.
I also have a 308 bolt action, a 243 and 270

there's a good post on the 68forums with a two guys shooting a bolt action 308 and a 6.8 AR out to 600 yards, suffice it to say the groups show the 6.8 clearly holds it's own...

not trying to push the 6.8 but this "300 yard limit" is nonsense

[KellyTTE]

My vote is for a Sabre Defence 6.5 Grendel with an 18" barrel. Can be maneuvered fairly well, and hits hard at intermediate ranges.

[at4rxj]

I vote for the 6.8, simply for the fact that you can use the ar15 platform instead of the ar10. For the same price as the 308 build you can build a NICE 6.8, and get an extra complete 5.56 upper to plink with.

As you said, the 6.8 and .308 have similar trajectories. The .308 will honestly probably be better at long distances, but as you said, 0-300 is typically what most ppl should focus on. Realistically, how much of your shooting with this would be over 300yds? The 6.8 is a great round... that's what I would do (actually what I DID :) )

[BSHNT2015]

With what you are designing this rifle for, 0-300 range. If it's a practical/tactical rifle with real world application, the sh** has hit the fan. An AR base weapon system is robust and simple enough to use, the 6.8mm can be switched out over the 556/223. 6.8mm reloading is available. Military 308 surplus is reasonable. You can still train/shoot 556/223 and switch out to 6.8mm.

For typical urban setting, picture yourself carrying 5-6 20 rd mags of 308 vs 5-6 25 rd mags of 6.8mm. Considering that major AR makers are now building 6.8mm. One would consider a 6.8mm over the 308. This is an opinion, nothing more. I'm no Spec-op guy, so my opinion is based on practical needs learnt from spec-ops and LEO. What do I have, 556/223 AR with an 6.8mm upper. It made sense to me. Good luck. See attached link.

http://cardinalarmory.com/cardarm-pcart/pc/viewContent.asp?idpage=4