6 ARC vs 6.5 Grendel Pistol

[Bee3440]

About to rebarrel my AR pistol and I am flipping between a 12.5” 6 ARC and 6.5 Grendel. Will mostly be used as a light weight coyote rig when I don’t want to carry my 6 Creedmoor AR.

 

[Bee3440]

Would also consider a 6mmAR if the advantages outweigh the reloading disadvantages.

 

[rcook10]

Cartridges with proportionately larger neck diameters to powder charge/column are less sensitive to barrel length related velocity loss. Think about a 16" 308 vs 16" 6.5cm. The CM looses significantly more velocity per inch compared to the 308. The same can be said for the 6.5 grendel and arc. The arc really only shines when maximum velocity is attained, if you're looking at balanced killing characteristics the grendel is the way to go. If you are loading a lot of 6mm bullets sure the arc may suit you better but I would pick the grendel. It is also a fabulous short mid range deer round and I have handily killed elk with it to 300 yards.

 

[Mark M.]

Grendel

 

[ormandj]

Per-shot data on my 10.5" Bartlein 6mm ARC, measured by Labradar, factory 108gr ELD-M match ammunition. The barrel was brand new (the first 20 rounds, I fouled it then shot the following). The rifle is suppressed, and running adjustable gas nearly wide-open in bleed-off mode.

2343
2319
2313
2335
2312
2336
2287
2329
2301
2318
2322
2327
2318

AVG: 2320
SD: 15.0443788

It's no slouch in the SBR realm, and it's plenty for hunting light to medium game out to 200-300, and steel out to 800. The Grendel is probably a slightly better hunting cartridge, but the difference isn't terribly significant at the distances you'd be shooting either one at game with the right construction bullets, out of a SBR. It definitely won't matter on a coyote.

 

[Mark M.]

You're splitting hairs, go what's more established and less expensive

 

[LCazador]

I have a 6,5X47 lapua XP100 and a Xp100 6PPC pistol. Both kill coyotes like a laser. Used both on Texas white tails both killed deer DRT within 100 yards of my blind, one shot one kill. So are you looking for a quick accurate follow up shot in case several coyotes show up? If that's the case get a shotgun!! I have both ready!

 

[lb-ft]

My 6x45 (223 necked up to 6mm) shoots 80 gr bullets slightly faster than 68 gr bullets out of my 223. Both barrels are 16”.

The 6mm 80 hits considerably harder 400 yards and in.

Force = area x pressure. Bigger diameter bullet (greater area) harnesses power better than smaller diameter bullet, even when pressures are equal.

I’d go 6.5 Grendel in a heartbeat for what you want. Compared with 6ARC, it will hit considerably harder at the ranges you’re planning.

 

[Gtscotty]

Per-shot data on my 10.5" Bartlein 6mm ARC, measured by Labradar, factory 108gr ELD-M match ammunition. The barrel was brand new (the first 20 rounds, I fouled it then shot the following). The rifle is suppressed, and running adjustable gas nearly wide-open in bleed-off mode.

2343
2319
2313
2335
2312
2336
2287
2329
2301
2318
2322
2327
2318

AVG: 2320
SD: 15.0443788

It's no slouch in the SBR realm, and it's plenty for hunting light to medium game out to 200-300, and steel out to 800. The Grendel is probably a slightly better hunting cartridge, but the difference isn't terribly significant at the distances you'd be shooting either one at game with the right construction bullets, out of a SBR. It definitely won't matter on a coyote.

That's pretty impressive for a 10.5" ARC, I only get about 100 fps more with my 16" Grendel shooting 123gr.

If the OP were to go with a 12.5" ARC and use varmint bullets on the lighter end (70gr TNT, 58gr or 65gr V-Max), seems like he'd probably be able to get decent velocities for coyote thumping. Although the same thing could probably be said for a stubby Grendel if you can light enough varmint bullets, it looks like the V-Max and TNT only go down to 90gr-95gr.

 

[Gtscotty]

Just playing with a few numbers in Quickload assuming 12.5" barrels, it looks like in the ARC you might be able to get a little over 3,000 fps with 58gr, 2,950 fps with 65gr, and 2,750 fps with 75gr. With the Grendel, QL predicts closer to 2,650 with 90gr to 95gr. With bigger game, the Grendel certainly has an edge, but the lightest 6.5mm bullets are quite a bit heavier than the light end of 6mm bullets, given that the OP is just looking for a short, light coyote rig, the ARC looks like a pretty sweet option.

 

[Bee3440]

Little update for everyone, I went 6 ARC and got a custom 12.5” barrel from Compass Lake Engineering. Got it out today to get the gas set and a rough sight in. Safe to say I was pleasantly surprised at 100 yds.

 

[bowfisher]

Keep us posted on your final load development please.

 

[EOD Rob]

You're splitting hairs, go what's more established and less expensive

I agree with Mark, I dont think you would have any issues with either one. The only thing that you said that might send me one way or the other was coyotes. That would lead me more down the 6 ARC road, just for saving the fur. There are plenty of really good bullets out there for taking smaller game without over kill. However, I could say the same for both calibers.
The only other thing to keep in mind, if you go grendel, velocity should be higher with the same grain bullet vs the ARC. Surface area is a real thing. Just look at the 223 vs 6x45mm.

Rob

 

[EOD Rob]

The little data I can find for the 6ARC, 87gr A-Max are running on average at 2750fps vs the 6.5 Grendel with an 85gr running on average at 2900fps.
Something to think about. Your not getting that out of a 12.5" barrel, but it will all translate.

 

[EOD Rob]

Also, I cant vote on this one! I have both and will keep it that way! I love both!

 

[Gtscotty]

The little data I can find for the 6ARC, 87gr A-Max are running on average at 2750fps vs the 6.5 Grendel with an 85gr running on average at 2900fps.
Something to think about. Your not getting that out of a 12.5" barrel, but it will all translate.

What barrel length are you getting that 87gr velocity from? Hornady data shows a max of 2,850 fps with LVR and 87gr V-Max from an 18" barrel. Hodgdon data shows a max of 2,993 fps with CFE223 under Berger 88gr out of a 24" barrel.

I'm going to try load development for my 21" barrel first with 105gr Barnes and 85gr Sierras. From the data above, I'm hoping for low to mid 2,900 fps with the lighter bullet weight.

 

[EOD Rob]

What barrel length are you getting that 87gr velocity from? Hornady data shows a max of 2,850 fps with LVR and 87gr V-Max from an 18" barrel. Hodgdon data shows a max of 2,993 fps with CFE223 under Berger 88gr out of a 24" barrel.

I'm going to try load development for my 21" barrel first with 105gr Barnes and 85gr Sierras. From the data above, I'm hoping for low to mid 2,900 fps with the lighter bullet weight.

That was an average from Hodgdon. Not Max, not min.

 

[EOD Rob]

That was an average from Hodgdon. Not Max, not min.

Correction, the ARC data was from Hornady only. Thanks to you, I now know that Hodgdon has ARC data.

 

[Gtscotty]

Correction, the ARC data was from Hornady only. Thanks to you, I now know that Hodgdon has ARC data.

It came out with their most recent quarterly online load data updates. There is some significant discrepancy between maxes for LVR between Hornady and Hodgdon, I went with the Hornady this first go round, but we'll see.

 

[EOD Rob]

It came out with their most quarterly online load data updates. There is some significant discrepancy between maxes for LVR between Hornady and Hodgdon, I went with the Hornady this first go round, but we'll see.

Please post your finding good sir! I would be interested in hearing what you have to say!!!
What is your plan for loads?
I'm thinking of running SMK 107grs. That is what I run in the 6 Creed and wanted to stay in the same ball park with the ARC.