223 vs 6.5 Grendel

Ganderite

Ganderite

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Looking to see if I could shoot an AR 15 at the short range F class matches - say to 600 yrds.

I see I can buy quality heavy drop in barrels in 224, 300 Blckout, 6.5 Grendel and 6.8.

No doubt all can be accurate at short rnage. Am I correct in assuming that by single loading 223 ammo with the Sierra 80 the 223 would be the best choice?

I have a real F Class rifle in 260 Ackley, but looking to amuse myself with something different.
 
I only have experience with the 223/556, but I know that a 75 A-max or 80 Sierra/Nosler can be driven at 2825+ if single loaded in a Wylde chamber. Probably a little more in a 556 chamber. The 82 Berger should work as well but I've never tried it.

Plug a ~0.22 G7 at 2825 fps into JBM and compare.
 
Because the 223 keeps you in FTR, it would be the best chance to stay competitive.

Depending on the twist, single feeding lets you use anything from 80 to 90gr. I would suggest an adjustable gas block so you can keep the cyclic forces as low as possible but muzzle velocity up.

Free floating handguard, could be very interesting.

Let us know how you make out.

If you are looking for match barrels, let me know

Jerry
 
rgv said:
I only have experience with the 223/556, but I know that a 75 A-max or 80 Sierra/Nosler can be driven at 2825+ if single loaded in a Wylde chamber. Probably a little more in a 556 chamber. The 82 Berger should work as well but I've never tried it.

Plug a ~0.22 G7 at 2825 fps into JBM and compare.
Click to expand...

Are you confirming that 223 is the way to go, instead of 6.5G or 6.8?

Logic suggests that to me, but I am looking for some support or direction.
 
Mystic Precision said:
Because the 223 keeps you in FTR, it would be the best chance to stay competitive.

Depending on the twist, single feeding lets you use anything from 80 to 90gr. I would suggest an adjustable gas block so you can keep the cyclic forces as low as possible but muzzle velocity up.

Free floating handguard, could be very interesting.

Let us know how you make out.

If you are looking for match barrels, let me know

Jerry
Click to expand...

had not thought of the gas issue. A case full of RL15 under a 80 would probably have a lot of port pressure. Was not aware there was an adjustable gas port. Thanks.
 
Ganderite said:
Are you confirming that 223 is the way to go, instead of 6.5G or 6.8?

Logic suggests that to me, but I am looking for some support or direction.
Click to expand...

Can't confirm anything as I've not shot the other cartridges you list, just throwing out a benchmark number that a 20" AR can do without going to a 1:6.5" barrel.

I can see the Grendel being up there but not the 6.8. That 224/80 amax is like a #2 pencil. If you loaded it to the same pressures we run 77's at magazine length, high 2800's is possible.

A drop in carrier weight with the tungsten insert is all I've ever used to slow things down.
 
rgv said:
Can't confirm anything as I've not shot the other cartridges you list, just throwing out a benchmark number that a 20" AR can do without going to a 1:6.5" barrel.

I can see the Grendel being up there but not the 6.8. That 224/80 amax is like a #2 pencil. If you loaded it to the same pressures we run 77's at magazine length, high 2800's is possible.

A drop in carrier weight with the tungsten insert is all I've ever used to slow things down.
Click to expand...

??? Don't you mean you switched to a heavier buffer?
 
rgv said:
Can't confirm anything as I've not shot the other cartridges you list, just throwing out a benchmark number that a 20" AR can do without going to a 1:6.5" barrel.

I can see the Grendel being up there but not the 6.8. That 224/80 amax is like a #2 pencil. If you loaded it to the same pressures we run 77's at magazine length, high 2800's is possible.
Click to expand...

All within SAMMI specs right?
 
The Berger 70 gr. VLD has the same BC as the 77 gr. SMK, but you can launch it at 69 SMK velocities. No other bullet can match it ballistically loaded to mag length.

Bolivar said:
All within SAMMI specs right?
Click to expand...

Hornady manual lists 5.56 SR specific loads for 75gr. bullets up to 2900 fps. and 80 gr. bullets up to 2800 fps. Will be valid for a Wylde chamber as well.
 
kombayotch said:
The Berger 70 gr. VLD has the same BC as the 77 gr. SMK, but you can launch it at 69 SMK velocities. No other bullet can match it ballistically loaded to mag length.



Hornady manual lists 5.56 SR specific loads for 75gr. bullets up to 2900 fps. and 80 gr. bullets up to 2800 fps. Will be valid for a Wylde chamber as well.
Click to expand...

Thanks. Was not aware of the 70 VLD. I assume it is loaded into the rifling?

If I opt for a heavy 223/5.56 barrel (I have my own JGS Wylde reamer) I will test the Berger 70, Hornady 75, Sierra 77 and Sierra 80. I have a few thousand 75s, 77s and 80s. I will ask Berger for a sample box of 70s.

For powder I will try N150 and RL15, since I happen to have those on hand, and they used to work well in my bolt rifles.
 
With a bull barrel, and a lighter trigger, I'm sure it could be more accurate. I turned the barrel down to 0.7" before the gas block and 0.8" under the handguard because it was impractical to shoot off-hand otherwise. Prior to that, it was something like 0.9" before the gas block and 1.1" under the handguard.

They were more like 60+ thou off the lands.
 
As you know F/Open is where the 6.5 Grendel and 6.8 SPC would put you. It is the land of 1/4 -1/3 MOA and I cant see an AR working for you in that atmosphere. A choice of .223 puts you in F/TR where 1/2 MOA is more common - now that is still a stretch for an AR but you might beat a few of the guys who are having bad days :)

Good luck.
 
kombayotch said:
Not even close!

This is what I got in the barrel that came with the rifle (had a Wylde chamber):



Not bad for a 6 lbs. trigger and a turned-down barrel...
Click to expand...

Is that magazine length? How fast is it with that ARComp load?

Looks good.
 
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