6.8spc vs. 6.5 Grendel - Page 3

Shawn Dodson · November 27, 2009, 01:34 PM

Interesting argument for adopting 6.5 Grendel as standard NATO small arms ammunition to replace both 5.56mm and 7.62mmm:

http://www.quarry.nildram.co.uk/btb.pdf

http://www.quarry.nildram.co.uk/btbjdw.pdf

Darth AkSarBen · November 27, 2009, 01:39 PM

For most deer shot, I read someplace that the average shot is 75 yards. Some more but some a lot less. In this range I would think the 6.8 in the 16" barrel would be quite sufficient.

Longdayjake · November 27, 2009, 02:39 PM

Tirod,
The only reason that the 6.8 beats the 6.5 from short barrels is because the 6.8 usually shoots much lighter bullets that require faster burning powders. Now, put a light bullet in the grendel like the 95 grain vmax and put a fast burning powder behind it and it will perform just as well as the 6.8 spc. Granted you lose the high bc but you still get the same performance as you would from a 6.8 with just a tiny bit higher BC.

You are wrong to think that the 6.5 needs to be long range to benefit from the high BC bullets. Think of it this way. If you take a ballistics calculator and compare the 115 grain 6.8 load with a BC of .325 shot at 2700 fps to a 123 grain 6.5 with a bc of .550 shot at 2500 fps (16" barrel velocities). Look at how soon the grendel surpasses the 6.8 in energy as early as 100 yards. And look at how the grendel is going faster at 180 yards. Thats not exactly long range.

6.5 grendel with a 123 grain bullet of .550 BC
Range Velocity Impact Drop ToF Energy Drift
00 2500 NaN 0 0 1707 0
10 2481 NaN 0.06 0.01 1681 0
20 2465 NaN 0.16 0.03 1660 0
30 2450 NaN 0.33 0.04 1639 0
40 2434 NaN 0.55 0.05 1618 0
50 2419 NaN 0.84 0.06 1598 0
60 2404 NaN 1.18 0.08 1578 0
70 2388 NaN 1.58 0.09 1558 0
80 2373 NaN 2.05 0.1 1538 0
90 2358 NaN 2.57 0.11 1519 0
100 2343 NaN 3.16 0.13 1499 0
110 2328 NaN 3.81 0.14 1480 0
120 2313 NaN 4.53 0.15 1461 0
130 2298 NaN 5.31 0.17 1442 0
140 2283 NaN 6.16 0.18 1424 0
150 2268 NaN 7.08 0.19 1405 0
160 2253 NaN 8.06 0.2 1386 0
170 2239 NaN 9.11 0.22 1369 0
180 2224 NaN 10.24 0.23 1351 0
190 2209 NaN 11.43 0.25 1333 0
200 2195 NaN 12.69 0.26 1316 0
210 2180 NaN 14.03 0.27 1298 0
220 2166 NaN 15.44 0.29 1281 0
230 2151 NaN 16.92 0.3 1264 0
240 2137 NaN 18.48 0.31 1247 0
250 2122 NaN 20.12 0.33 1230 0
260 2108 NaN 21.83 0.34 1214 0
270 2094 NaN 23.62 0.36 1198 0
280 2080 NaN 25.49 0.37 1182 0
290 2066 NaN 27.45 0.39 1166 0
300 2052 NaN 29.48 0.4 1150 0

6.8 shot at 2700 fps with a 115 grain bullet and a bc of .325

Range Velocity Impact Drop ToF Energy Drift
00 2700 NaN 0 0 1862 0
10 2666 NaN 0.05 0.01 1815 0
20 2638 NaN 0.14 0.03 1777 0
30 2610 NaN 0.29 0.04 1740 0
40 2583 NaN 0.49 0.05 1704 0
50 2556 NaN 0.73 0.06 1668 0
60 2528 NaN 1.04 0.07 1632 0
70 2502 NaN 1.39 0.08 1599 0
80 2475 NaN 1.81 0.1 1564 0
90 2448 NaN 2.28 0.11 1530 0
100 2422 NaN 2.8 0.12 1498 0
110 2396 NaN 3.39 0.13 1466 0
120 2370 NaN 4.04 0.15 1434 0
130 2344 NaN 4.75 0.16 1403 0
140 2319 NaN 5.52 0.17 1373 0
150 2293 NaN 6.36 0.18 1343 0
160 2268 NaN 7.27 0.2 1314 0
170 2243 NaN 8.24 0.21 1285 0
180 2218 NaN 9.28 0.22 1256 0
190 2193 NaN 10.39 0.24 1228 0
200 2168 NaN 11.58 0.25 1200 0
210 2144 NaN 12.84 0.26 1174 0
220 2119 NaN 14.17 0.28 1147 0
230 2095 NaN 15.59 0.29 1121 0
240 2071 NaN 17.08 0.31 1095 0
250 2047 NaN 18.65 0.32 1070 0
260 2023 NaN 20.31 0.34 1045 0
270 1999 NaN 22.05 0.35 1020 0
280 1976 NaN 23.88 0.37 997 0
290 1953 NaN 25.8 0.38 974 0
300 1929 NaN 27.81 0.4 950 0

Longdayjake · December 1, 2009, 12:51 PM

I just thought that I would add that both rounds offer a significant increase in lethality over the .223.

Darth AkSarBen · December 1, 2009, 01:18 PM

10-4 Longdayjake !! a 22 caliber bullet traveling very fast that had it's origins shooting at gophers.

That pdf article above entitled "Bite The Bullet" was so good I got permission and also host it on my links page of my web site. It really tells the tale of the .223 Remington, turned into the 5.56 X 45 NATO.

bedlamite · December 1, 2009, 04:10 PM

Setting aside logistics, 6.8 SPC has the advantage of 200-300fps faster using the same weight bullet from the same length barrel, and doesn't lose as much velocity from shorter barrels. 6.5 Grendel has the advantage of match bullets with a higher BC.

For Military use, any change from 5.56 will have to be shoved down the Army's throat. Ain't gonna happen.

For Hunting, a lighter gun you can carry all day favors a short barrel, and the higher BC match grade bullets are a terrible choice for hunting. When using bullets designed for hunting, both 6.5 and 6.8 fall below 1000 ft-lbs around 300 yards. Given those parameters, I'd choose a 16" barrel 6.8 spc for deer/hog sized game. Farther than 300 yards and you need more energy from a larger caliber like 308/30-06 to about 500 yards, and magnums beyond that. Just because you can hit something out that far doesn't mean it's an ethical shot for taking game.

For targets/competition, below 400 yards, it's a wash. The 6.5 has a higher BC, but the shorter TOF of the 6.8 negates that at short range. Medium range from 400-800 yards, the Grendel from a long heavy barrel is the winner here. Beyond 800 yards neither one is a good choice, I'd use the 6.5 bullets, but I'd shoot them from a 260 Remington.

Darth AkSarBen · December 1, 2009, 10:10 PM

"Beyond 800 yards neither one is a good choice, I'd use the 6.5 bullets, but I'd shoot them from a 260 Remington."

+10 I really like the performance of the .260 Remington as it is a .308 that has been neced down. Performs admirably for it's recoil and I am surprised that it has not been seen as more popular.

sailskidrive · December 1, 2009, 10:58 PM

Doesn't the 6.5mm Creedmoor outperform both the 6.5 Grendel and the 6.8 SPC?

~Sail

jglsprings · December 1, 2009, 11:06 PM

Quote:

If you're going 6.5....

--------------------------------------------------------------------------------

Doesn't the 6.5mm Creedmoor outperform both the 6.5 Grendel and the 6.8 SPC?

~Sail

The Creedmore takes a "308 Length" action the 6.5G and 6.8 work with the 5.56 length actions....

You just swap uppers and mags with your "regular" AR platform.

As I understand it...

sailskidrive · December 1, 2009, 11:25 PM

Oh right, I forgot.

I think I want one. :-) Maybe a Fulton Armory Titan.

~Sail

Darth AkSarBen · December 1, 2009, 11:26 PM

That is correct. If you wish to stay within the realms of the AR-15 platform and not get into the .308 class such as the AR-10 then you need to keep the OAL to around where the .223 Reminton is. Yes, the Creedmoor outperforms them as it has a lot more powder capacity, but, in the same light, the much older .260 Remington (a necked down .308 to 6.5mm bullets) has the ability to outperform even the 6.5 Creedmoor. It just has a longer OAL is all. You can get an AR in either the 6.5 Creedmoor or the 260 Remington from at least one well known AR maker.

Longdayjake · December 2, 2009, 11:51 AM

Quote:

Setting aside logistics, 6.8 SPC has the advantage of 200-300fps faster using the same weight bullet from the same length barrel, and doesn't lose as much velocity from shorter barrels. 6.5 Grendel has the advantage of match bullets with a higher BC.

For Military use, any change from 5.56 will have to be shoved down the Army's throat. Ain't gonna happen.

For Hunting, a lighter gun you can carry all day favors a short barrel, and the higher BC match grade bullets are a terrible choice for hunting. When using bullets designed for hunting, both 6.5 and 6.8 fall below 1000 ft-lbs around 300 yards. Given those parameters, I'd choose a 16" barrel 6.8 spc for deer/hog sized game. Farther than 300 yards and you need more energy from a larger caliber like 308/30-06 to about 500 yards, and magnums beyond that. Just because you can hit something out that far doesn't mean it's an ethical shot for taking game.

Most everything you said here is just plain wrong. Lets start with the outright dream that 6.8 guys get 200-300 fps more from bullets of the same weight. First of all, there really aren't any bullets for both that shoot the same weight. Second, hardly anyone can get the velocities that the spc II claims is possible. And third, because of the high BC bullets in the 6.5 they usually pass up the 6.8 velocity wise at about 100 yards. In which case I would prefer the heavier bullets from the 6.5 any day.

Also, if you are wondering about high bc hunting bullets just look at the berger 130 grain. There are all kinds of folks shooting them with great results at about 2500 fps. That bullet has a BC of .552 and it doesn't drop below 1000 ft lbs until 450 yards. Or you can go with the 140 grain bullet at 2400 fps that doesn't drop below 1000 flbs until 480 yards. At that range the 115 grain 6.8 at 2900 fps is only doing about 700 ftlbs.

jglsprings · December 2, 2009, 12:05 PM

Quote:

I think I want one. :-) Maybe a Fulton Armory Titan.

Fulton Armory has one of EVERYTHING I want.

bedlamite · December 2, 2009, 04:55 PM

Quote:

First of all, there really aren't any bullets for both that shoot the same weight. Second, hardly anyone can get the velocities that the spc II claims is possible.

Where did you come up with that? I have had no problem getting 3050fps with the Barnes 85gr TSX and 2650fps with 110gr Nosler Accubond, both of which match the tactical load available from SSA (they only publish the commercial load for the SAAMI chambers that nobody except Model 1 Sales uses anymore), and 2450fps with the Sierra 130gr out of my 16" Ko-Tonics.

Quote:

There are all kinds of folks shooting them with great results at about 2500 fps.

You forgot to add "out of a 24" barrel". Thanks, but no thanks. I'd rather get the same velocity out of a 16" barrel with the 6.8, or a couple hundred fps more if you use the same length barrel.

It also helps to realize that the BC is not constant, and the vast majority of quoted G1 BC figures are for velocities over 2700 fps, and the farther below that you get, the lower the BC drops.

Darth AkSarBen · December 2, 2009, 09:40 PM

Thanks Bedofmice

I too think that the 6.8 with proper loading AND proper bullet weight will hold its own in shorter distances to the 6.5 Grendel. If you want to shoot match targets with the 6.5, there are other alternatives, such as the 6.5 Creedmoor and the .260 Remington. The latter may be actually the better of the two, but has not had the deserved recognition of what an interesting caliber it really is.

tirod · December 2, 2009, 10:40 PM

I just thought that I would add that both rounds offer a significant increase in lethality over the .223.

It's nice to see that wasn't disputed. Things have changed.

I wouldn't take any points here as steadfast opposition to the 6.5 Grendel. The entire point of debating the two calibers - as diametrically opposed in the design phase as they were - is they are significant choices vis a vis the 5.56. They didn't exist 10 years ago, and they certainly ramp up the performance of the AR to medium game rifle as opposed to poodleshooter.

And you can have them both, same lower and trigger. Hunt whitetails in the bottoms and woodlands with the 6.8, switch to 6.5 in open fields or for antelope. Prairie dogs, back to 5.56. You can have your cake and eat it, too.

Can't do that with any old bolt action.

bedlamite · December 3, 2009, 07:32 AM

Quote:

And you can have them both, same lower and trigger. Hunt whitetails in the bottoms and woodlands with the 6.8, switch to 6.5 in open fields or for antelope. Prairie dogs, back to 5.56. You can have your cake and eat it, too.

The only problem with that is you will eventually end up buying 3 lowers

jglsprings · December 3, 2009, 08:50 AM

Quote:

The only problem with that is you will eventually end up buying 3 lowers

Oh, you just need to get around that anyway... one for your NM, one for your M4 Carbine set up, one for the varmint uppers.... it goes on and on!!

LOL!

tirod · December 3, 2009, 09:27 PM

Whoops, obviously manifested a symptom of EBR there - denial of the actual outcomes.

No, really, I'm just building the one. It'll be everything I need. Extra uppers are something those other guys talk about on forums.

hknut · June 28, 2010, 03:51 AM

I know it has been said that any thing over 18" is a waste for the 6.8. Would a 20 or 22" barrel make a differance with the new chamber (SPC II) of the 6.8?

Darth AkSarBen · June 28, 2010, 07:02 AM

"I know it has been said that any thing over 18" is a waste for the 6.8. Would a 20 or 22" barrel make a difference with the new chamber (SPC II) of the 6.8? "

No. Simple answer. At 16" barrel it is at 98% of it's attainable velocity. At 18" you gain maybe an extra 30-50 fps. And with a 20" you might gain another 30fps over the 18" barrel. There was even a study done with the Bravo 51 .308 sniper rifle and it's velocity when cutting down the barrel. At 20" they started to notice a slight reduction in the velocity, but were still able to keep 1/4" groups at 100 yards.

The whole beauty of the 6.8 SPC II is that it does extremely well in shorter barrels. 16" and 18" are very nice, as they are not overly long, especially in a combat situation. The 6.8 SPC II really shines in short barrel 14.5" barrels used in a M4 configuration. Where the 5.56 looses a LOT of velocity in such a short barrel, the 6.8 SPC II, because of it's bore dia. to powder case configuration looses very little velocity even at 14.5 inches. It's all about the bore diameter as it relates to case size and efficiency. They really either lucked out or were very smart when they came up with the case/bullet combination on that cartridge.

Darth AkSarBen · June 28, 2010, 07:09 AM

Let me go on to explain something else regarding the 6.8 SPC and the improved SPC II chamber. The 6.8 SPC II chamber is more like the original idea that the developers had when they came up with the 6.8 SPC. All that is different in the II chamber is that is has a freebore (leade) of 0.100" instead of 0.050" of the regulare 6.8 SPC. It also has better slope for the bullet engaging the rifling. That little extra bit allows the bullet some room to engage the rifling before creating a large pressure spike from the onset. It reduced pressure some 2000 psi. This alllowed the reloader to adjust the grain used up a bit to keep within the safe operating pressure and gave an increase of velocity. More velocity, but with same pressure. Before if you added the extra grains of powder you moved over the accepted pressure level and the cases showed it.

thesheepdog · June 28, 2010, 08:19 AM

6.5 is the way to go. The 6.8 falls short at 600 yards. Both have the same damage at 600 yards and under. The Grendel ammo is harder to find, but is becoming more available-i just got some boxes from Cabelas not to long ago.

Darth AkSarBen · June 28, 2010, 09:01 AM

Realistically, if you are hunting deer , the average shot to kill a deer is 75 yards. Most are less and just a few longer. My property is 10 acres, 1330 feet long. 400 yards is 1200 feeet. shooting at a deer at 400 yards is not necessary. If you have a gun that shoots 1 moa, appx 1" groups at 100 yards, that is 2" at 200 and at 400 that is 4 moa at best. will probably be more like 6 moa at that distance. You know you'll have some bullet drop. Each 50 yards makes a difference in how much to adjust. MOST hunters don't have rangefinder optics such as laser binoculars with them when shooting deer. Guessing at 400 yards when it's only 300 will make you shoot over the deer. If you guess at 400 yards and it's actualy 500 yards, you wiill under shoot.

Long distance shooting is a good way to miss or seriously wound a deer.

thesheepdog · June 28, 2010, 09:13 AM

Quote:

If you have a gun that shoots 1 moa, appx 1" groups at 100 yards, that is 2" at 200 and at 400 that is 4 moa at best. will probably be more like 6 moa at that distance

1 MOA is 1 MOA. 4 MOA at 400 yards is 16 inches. If you can shoot 1 MOA at 100 yards, then you can shoot 1 MOA at 400 yards.

You must mean "4 inches at 400 yards?

November 27, 2009, 01:39 PM	#52
Darth AkSarBen Member Join Date: September 9, 2008 Location: Near Fennville, MI USA Posts: 82	For most deer shot, I read someplace that the average shot is 75 yards. Some more but some a lot less. In this range I would think the 6.8 in the 16" barrel would be quite sufficient. __________________ Vern Sic Semper Tyrannis http://Taurus45ACP.com Sig Sauer 522 "Classic" AR Performance 16" 5R 1:11.25 twist barrel in 6.8 SPC, 80% lower, along with LOTS of other things.

November 27, 2009, 02:39 PM	#53
Longdayjake Senior Member Join Date: August 11, 2009 Posts: 619	Tirod, The only reason that the 6.8 beats the 6.5 from short barrels is because the 6.8 usually shoots much lighter bullets that require faster burning powders. Now, put a light bullet in the grendel like the 95 grain vmax and put a fast burning powder behind it and it will perform just as well as the 6.8 spc. Granted you lose the high bc but you still get the same performance as you would from a 6.8 with just a tiny bit higher BC. You are wrong to think that the 6.5 needs to be long range to benefit from the high BC bullets. Think of it this way. If you take a ballistics calculator and compare the 115 grain 6.8 load with a BC of .325 shot at 2700 fps to a 123 grain 6.5 with a bc of .550 shot at 2500 fps (16" barrel velocities). Look at how soon the grendel surpasses the 6.8 in energy as early as 100 yards. And look at how the grendel is going faster at 180 yards. Thats not exactly long range. 6.5 grendel with a 123 grain bullet of .550 BC Range Velocity Impact Drop ToF Energy Drift 00 2500 NaN 0 0 1707 0 10 2481 NaN 0.06 0.01 1681 0 20 2465 NaN 0.16 0.03 1660 0 30 2450 NaN 0.33 0.04 1639 0 40 2434 NaN 0.55 0.05 1618 0 50 2419 NaN 0.84 0.06 1598 0 60 2404 NaN 1.18 0.08 1578 0 70 2388 NaN 1.58 0.09 1558 0 80 2373 NaN 2.05 0.1 1538 0 90 2358 NaN 2.57 0.11 1519 0 100 2343 NaN 3.16 0.13 1499 0 110 2328 NaN 3.81 0.14 1480 0 120 2313 NaN 4.53 0.15 1461 0 130 2298 NaN 5.31 0.17 1442 0 140 2283 NaN 6.16 0.18 1424 0 150 2268 NaN 7.08 0.19 1405 0 160 2253 NaN 8.06 0.2 1386 0 170 2239 NaN 9.11 0.22 1369 0 180 2224 NaN 10.24 0.23 1351 0 190 2209 NaN 11.43 0.25 1333 0 200 2195 NaN 12.69 0.26 1316 0 210 2180 NaN 14.03 0.27 1298 0 220 2166 NaN 15.44 0.29 1281 0 230 2151 NaN 16.92 0.3 1264 0 240 2137 NaN 18.48 0.31 1247 0 250 2122 NaN 20.12 0.33 1230 0 260 2108 NaN 21.83 0.34 1214 0 270 2094 NaN 23.62 0.36 1198 0 280 2080 NaN 25.49 0.37 1182 0 290 2066 NaN 27.45 0.39 1166 0 300 2052 NaN 29.48 0.4 1150 0 6.8 shot at 2700 fps with a 115 grain bullet and a bc of .325 Range Velocity Impact Drop ToF Energy Drift 00 2700 NaN 0 0 1862 0 10 2666 NaN 0.05 0.01 1815 0 20 2638 NaN 0.14 0.03 1777 0 30 2610 NaN 0.29 0.04 1740 0 40 2583 NaN 0.49 0.05 1704 0 50 2556 NaN 0.73 0.06 1668 0 60 2528 NaN 1.04 0.07 1632 0 70 2502 NaN 1.39 0.08 1599 0 80 2475 NaN 1.81 0.1 1564 0 90 2448 NaN 2.28 0.11 1530 0 100 2422 NaN 2.8 0.12 1498 0 110 2396 NaN 3.39 0.13 1466 0 120 2370 NaN 4.04 0.15 1434 0 130 2344 NaN 4.75 0.16 1403 0 140 2319 NaN 5.52 0.17 1373 0 150 2293 NaN 6.36 0.18 1343 0 160 2268 NaN 7.27 0.2 1314 0 170 2243 NaN 8.24 0.21 1285 0 180 2218 NaN 9.28 0.22 1256 0 190 2193 NaN 10.39 0.24 1228 0 200 2168 NaN 11.58 0.25 1200 0 210 2144 NaN 12.84 0.26 1174 0 220 2119 NaN 14.17 0.28 1147 0 230 2095 NaN 15.59 0.29 1121 0 240 2071 NaN 17.08 0.31 1095 0 250 2047 NaN 18.65 0.32 1070 0 260 2023 NaN 20.31 0.34 1045 0 270 1999 NaN 22.05 0.35 1020 0 280 1976 NaN 23.88 0.37 997 0 290 1953 NaN 25.8 0.38 974 0 300 1929 NaN 27.81 0.4 950 0 __________________ If you need bullets for reloading give my website a look. www.rmrbullets.com Last edited by Longdayjake; November 27, 2009 at 02:48 PM.

December 1, 2009, 12:51 PM	#54
Longdayjake Senior Member Join Date: August 11, 2009 Posts: 619	I just thought that I would add that both rounds offer a significant increase in lethality over the .223. __________________ If you need bullets for reloading give my website a look. www.rmrbullets.com

December 1, 2009, 01:18 PM	#55
Darth AkSarBen Member Join Date: September 9, 2008 Location: Near Fennville, MI USA Posts: 82	10-4 Longdayjake !! a 22 caliber bullet traveling very fast that had it's origins shooting at gophers. That pdf article above entitled "Bite The Bullet" was so good I got permission and also host it on my links page of my web site. It really tells the tale of the .223 Remington, turned into the 5.56 X 45 NATO. __________________ Vern Sic Semper Tyrannis http://Taurus45ACP.com Sig Sauer 522 "Classic" AR Performance 16" 5R 1:11.25 twist barrel in 6.8 SPC, 80% lower, along with LOTS of other things. Last edited by Darth AkSarBen; December 1, 2009 at 01:20 PM. Reason: Addendum:

December 1, 2009, 04:10 PM	#56
bedlamite Senior Member Join Date: August 10, 2000 Location: WI Posts: 1,395	Wow. This thread has more BS than the local stockyard. Setting aside logistics, 6.8 SPC has the advantage of 200-300fps faster using the same weight bullet from the same length barrel, and doesn't lose as much velocity from shorter barrels. 6.5 Grendel has the advantage of match bullets with a higher BC. For Military use, any change from 5.56 will have to be shoved down the Army's throat. Ain't gonna happen. For Hunting, a lighter gun you can carry all day favors a short barrel, and the higher BC match grade bullets are a terrible choice for hunting. When using bullets designed for hunting, both 6.5 and 6.8 fall below 1000 ft-lbs around 300 yards. Given those parameters, I'd choose a 16" barrel 6.8 spc for deer/hog sized game. Farther than 300 yards and you need more energy from a larger caliber like 308/30-06 to about 500 yards, and magnums beyond that. Just because you can hit something out that far doesn't mean it's an ethical shot for taking game. For targets/competition, below 400 yards, it's a wash. The 6.5 has a higher BC, but the shorter TOF of the 6.8 negates that at short range. Medium range from 400-800 yards, the Grendel from a long heavy barrel is the winner here. Beyond 800 yards neither one is a good choice, I'd use the 6.5 bullets, but I'd shoot them from a 260 Remington. __________________ A plan is just a list of things that doesn't happen.

November 27, 2009, 01:34 PM	#51
Shawn Dodson Junior member Join Date: December 16, 1998 Location: Titusville, FL, USA Posts: 1,030	Interesting argument for adopting 6.5 Grendel as standard NATO small arms ammunition to replace both 5.56mm and 7.62mmm: http://www.quarry.nildram.co.uk/btb.pdf http://www.quarry.nildram.co.uk/btbjdw.pdf

December 1, 2009, 10:10 PM	#57
Darth AkSarBen Member Join Date: September 9, 2008 Location: Near Fennville, MI USA Posts: 82	"Beyond 800 yards neither one is a good choice, I'd use the 6.5 bullets, but I'd shoot them from a 260 Remington." +10 I really like the performance of the .260 Remington as it is a .308 that has been neced down. Performs admirably for it's recoil and I am surprised that it has not been seen as more popular. __________________ Vern Sic Semper Tyrannis http://Taurus45ACP.com Sig Sauer 522 "Classic" AR Performance 16" 5R 1:11.25 twist barrel in 6.8 SPC, 80% lower, along with LOTS of other things.

December 1, 2009, 10:58 PM	#58
sailskidrive Senior Member Join Date: October 26, 2008 Posts: 726	If you're going 6.5.... Doesn't the 6.5mm Creedmoor outperform both the 6.5 Grendel and the 6.8 SPC? ~Sail

December 1, 2009, 11:25 PM	#60
sailskidrive Senior Member Join Date: October 26, 2008 Posts: 726	oh... Oh right, I forgot. I think I want one. :-) Maybe a Fulton Armory Titan. ~Sail

December 1, 2009, 11:26 PM	#61
Darth AkSarBen Member Join Date: September 9, 2008 Location: Near Fennville, MI USA Posts: 82	That is correct. If you wish to stay within the realms of the AR-15 platform and not get into the .308 class such as the AR-10 then you need to keep the OAL to around where the .223 Reminton is. Yes, the Creedmoor outperforms them as it has a lot more powder capacity, but, in the same light, the much older .260 Remington (a necked down .308 to 6.5mm bullets) has the ability to outperform even the 6.5 Creedmoor. It just has a longer OAL is all. You can get an AR in either the 6.5 Creedmoor or the 260 Remington from at least one well known AR maker. __________________ Vern Sic Semper Tyrannis http://Taurus45ACP.com Sig Sauer 522 "Classic" AR Performance 16" 5R 1:11.25 twist barrel in 6.8 SPC, 80% lower, along with LOTS of other things.

December 2, 2009, 09:40 PM	#65
Darth AkSarBen Member Join Date: September 9, 2008 Location: Near Fennville, MI USA Posts: 82	Very Impressive!! Thanks Bedofmice I too think that the 6.8 with proper loading AND proper bullet weight will hold its own in shorter distances to the 6.5 Grendel. If you want to shoot match targets with the 6.5, there are other alternatives, such as the 6.5 Creedmoor and the .260 Remington. The latter may be actually the better of the two, but has not had the deserved recognition of what an interesting caliber it really is. __________________ Vern Sic Semper Tyrannis http://Taurus45ACP.com Sig Sauer 522 "Classic" AR Performance 16" 5R 1:11.25 twist barrel in 6.8 SPC, 80% lower, along with LOTS of other things.

December 2, 2009, 10:40 PM	#66
tirod Junior member Join Date: January 21, 2009 Posts: 1,672	I just thought that I would add that both rounds offer a significant increase in lethality over the .223. It's nice to see that wasn't disputed. Things have changed. I wouldn't take any points here as steadfast opposition to the 6.5 Grendel. The entire point of debating the two calibers - as diametrically opposed in the design phase as they were - is they are significant choices vis a vis the 5.56. They didn't exist 10 years ago, and they certainly ramp up the performance of the AR to medium game rifle as opposed to poodleshooter. And you can have them both, same lower and trigger. Hunt whitetails in the bottoms and woodlands with the 6.8, switch to 6.5 in open fields or for antelope. Prairie dogs, back to 5.56. You can have your cake and eat it, too. Can't do that with any old bolt action.

December 3, 2009, 09:27 PM	#69
tirod Junior member Join Date: January 21, 2009 Posts: 1,672	Whoops, obviously manifested a symptom of EBR there - denial of the actual outcomes. No, really, I'm just building the one. It'll be everything I need. Extra uppers are something those other guys talk about on forums.

June 28, 2010, 03:51 AM	#70
hknut Senior Member Join Date: March 2, 2005 Location: Olympia, Wa. Posts: 535	I know it has been said that any thing over 18" is a waste for the 6.8. Would a 20 or 22" barrel make a differance with the new chamber (SPC II) of the 6.8? __________________ "Gun control is like trying to reduce Drunk Driving by making it tougher for sober people to own cars" Walk softly and carry a big SIG.

June 28, 2010, 07:02 AM	#71
Darth AkSarBen Member Join Date: September 9, 2008 Location: Near Fennville, MI USA Posts: 82	"I know it has been said that any thing over 18" is a waste for the 6.8. Would a 20 or 22" barrel make a difference with the new chamber (SPC II) of the 6.8? " No. Simple answer. At 16" barrel it is at 98% of it's attainable velocity. At 18" you gain maybe an extra 30-50 fps. And with a 20" you might gain another 30fps over the 18" barrel. There was even a study done with the Bravo 51 .308 sniper rifle and it's velocity when cutting down the barrel. At 20" they started to notice a slight reduction in the velocity, but were still able to keep 1/4" groups at 100 yards. The whole beauty of the 6.8 SPC II is that it does extremely well in shorter barrels. 16" and 18" are very nice, as they are not overly long, especially in a combat situation. The 6.8 SPC II really shines in short barrel 14.5" barrels used in a M4 configuration. Where the 5.56 looses a LOT of velocity in such a short barrel, the 6.8 SPC II, because of it's bore dia. to powder case configuration looses very little velocity even at 14.5 inches. It's all about the bore diameter as it relates to case size and efficiency. They really either lucked out or were very smart when they came up with the case/bullet combination on that cartridge. __________________ Vern Sic Semper Tyrannis http://Taurus45ACP.com Sig Sauer 522 "Classic" AR Performance 16" 5R 1:11.25 twist barrel in 6.8 SPC, 80% lower, along with LOTS of other things.

June 28, 2010, 07:09 AM	#72
Darth AkSarBen Member Join Date: September 9, 2008 Location: Near Fennville, MI USA Posts: 82	Let me go on to explain something else regarding the 6.8 SPC and the improved SPC II chamber. The 6.8 SPC II chamber is more like the original idea that the developers had when they came up with the 6.8 SPC. All that is different in the II chamber is that is has a freebore (leade) of 0.100" instead of 0.050" of the regulare 6.8 SPC. It also has better slope for the bullet engaging the rifling. That little extra bit allows the bullet some room to engage the rifling before creating a large pressure spike from the onset. It reduced pressure some 2000 psi. This alllowed the reloader to adjust the grain used up a bit to keep within the safe operating pressure and gave an increase of velocity. More velocity, but with same pressure. Before if you added the extra grains of powder you moved over the accepted pressure level and the cases showed it. __________________ Vern Sic Semper Tyrannis http://Taurus45ACP.com Sig Sauer 522 "Classic" AR Performance 16" 5R 1:11.25 twist barrel in 6.8 SPC, 80% lower, along with LOTS of other things.

June 28, 2010, 08:19 AM	#73
thesheepdog Senior Member Join Date: May 12, 2010 Location: DFW Texas Posts: 1,996	6.5 is the way to go. The 6.8 falls short at 600 yards. Both have the same damage at 600 yards and under. The Grendel ammo is harder to find, but is becoming more available-i just got some boxes from Cabelas not to long ago. __________________ Krav Maga/Judo Qualified Rifleman/Marksmanship Instructor/Lic. Medic "There is therefore now no condemnation to those who are in Christ Jesus, who do not walk according to the flesh, but according to the Spirit" Romans 8:1

June 28, 2010, 09:01 AM	#74
Darth AkSarBen Member Join Date: September 9, 2008 Location: Near Fennville, MI USA Posts: 82	Realistically, if you are hunting deer , the average shot to kill a deer is 75 yards. Most are less and just a few longer. My property is 10 acres, 1330 feet long. 400 yards is 1200 feeet. shooting at a deer at 400 yards is not necessary. If you have a gun that shoots 1 moa, appx 1" groups at 100 yards, that is 2" at 200 and at 400 that is 4 moa at best. will probably be more like 6 moa at that distance. You know you'll have some bullet drop. Each 50 yards makes a difference in how much to adjust. MOST hunters don't have rangefinder optics such as laser binoculars with them when shooting deer. Guessing at 400 yards when it's only 300 will make you shoot over the deer. If you guess at 400 yards and it's actualy 500 yards, you wiill under shoot. Long distance shooting is a good way to miss or seriously wound a deer. __________________ Vern Sic Semper Tyrannis http://Taurus45ACP.com Sig Sauer 522 "Classic" AR Performance 16" 5R 1:11.25 twist barrel in 6.8 SPC, 80% lower, along with LOTS of other things.