6mm ARC vs 6.5 Grendel

Mr. Whitely initially developed/promoted the 6mmAR.

Hornady swoops in, changes the name to 6mmAR'C' and the whole world drools at Mr. Whitely's concept because of the Hornady name. Hornady gives no credit to Mr. Whitely, just copies his concept and calls it their own.

Shame, shame on Hornady!

FYI...Mr. Whitely has actually improved on his 6mmAR concept...the 6mmAR Turbo 40° Improved. (Hopefully this can't be copied without being so obvious.)

I am pondering an AR upgrade...it's between these 2:

6.5 Grendel...cheapest to convert, and tons of info/support/factory ammo.
6mmAR 40° Improved...not as cheap to convert, but it has the better accuracy potential.
 
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The 6mm version is superior in my opinion. I have both. The 6mm does 2700 with 105s with AR Comp on a 20" barrel. My old 18" 6.5 barrel would only do 2580 with 107 TMKs and 2460 with 123s. Best load was 130 Bergers at 2390. Even adding 50ish FPS for the 2" longer barrel, the 6mm has about 200+ more FPS than the 6.5 with similar BC bullets. Also, shot a big bodied whitetail doe with the little 87 VLD at 2910 and dropped her instantly. My 6.5 now is a 16" gun with a 1-6 for 0-200 use.
 
Mr. Whitely initially developed/promoted the 6mmAR.

Hornady swoops in, changes the name to 6mmAR'C' and the whole world drools at Mr. Whitely's concept because of the Hornady name. Hornady gives no credit to Mr. Whitely, just copies his concept and calls it their own.

FYI...Mr. Whitely has actually improved on his 6mmAR concept...the 6mmAR Turbo 40° Improved.

I am pondering an AR upgrade...it's between these 2:

6.5 Grendel...cheapest to convert, and tons of info/support/factory ammo.
6mmAR 40° Improved...not as cheap to convert, but it has the better accuracy potential.
You are spot on! Perhaps it's asking too much, or there may be unknown factors, but IMO, if Hornady had any sense of dignity they would acknowledge the prior work of Whitely which was well established over a decade ago. My Whitely rifle and his supplied reloading accessories have performed even better then Whitely claimed. Easily fire-formed Lapua brass lasts for 30+ reloads. His upper with Hart barrel has delivered well in competition against bolt rifles....


107gr SMK@ 2775FPS,100 yards.
5B5FEC32-E58B-45A7-AF40-248C59009BDA.jpeg
 
The 6mm version is superior in my opinion. I have both. The 6mm does 2700 with 105s with AR Comp on a 20" barrel. My old 18" 6.5 barrel would only do 2580 with 107 TMKs and 2460 with 123s. Best load was 130 Bergers at 2390. Even adding 50ish FPS for the 2" longer barrel, the 6mm has about 200+ more FPS than the 6.5 with similar BC bullets. Also, shot a big bodied whitetail doe with the little 87 VLD at 2910 and dropped her instantly. My 6.5 now is a 16" gun with a 1-6 for 0-200 use.

There is a variation in attainable velocity for different barrels. Your Grendel barrel appears to be on the slow side. I have an 18" TC Encore barrel that yields about 2660 for the 107 gr and about 2500 for the 123 gr. It also gets over 2900 fps with 85 gr bullets.

NONETHELESS, If my shooting was centered the way yours is, I would go the same way, althouigh I wuuld stretch my Grendel use out to closer to 300 yards. This is in spite of the fact that a fair number of folks have reported kills on deer-class animals out a lot further.
 
There is a variation in attainable velocity for different barrels. Your Grendel barrel appears to be on the slow side. I have an 18" TC Encore barrel that yields about 2660 for the 107 gr and about 2500 for the 123 gr. It also gets over 2900 fps with 85 gr bullets.

NONETHELESS, If my shooting was centered the way yours is, I would go the same way, althouigh I wuuld stretch my Grendel use out to closer to 300 yards. This is in spite of the fact that a fair number of folks have reported kills on deer-class animals out a lot further.

No doubt about different barrels coming into play. My 6mm is a .243 LBC BHW barrel with 3p rifling, the 18" 6.5 was a 5R Xcaliber, and my 16" is a 5R Faxon melonite. The Faxon barrel is running considerably slower than expected. With the same lot of 123 ELDM, Same lot of AR Comp, Same lot of Fed 205MAR Primers, and the same hornady brass, it is running only 2340 at the same charge and OAL. I would be pretty disappointed except for the fact that it shoots this load consistently under .5 MOA with an SD of 6 and ES of 12 over the last 10 rounds I tested. This is with a 1-6 Scope at 100 yards.
 
I was not much on the Grendel when it appeared on the scene but after a while and shooting one I love the little cartridge and always thought it would be better in the 6 mm. Form Trust me 400 yards is as long as you ever want to shoot an animal with a Grandel the 6 mm would probably be the same this is in the hands of a good rifleman and yeah you can shoot it to any range you want I can shoot a 30-30 at a 1000 that doesn't mean that it is good I own 6 Grendels 3 bolt and 3 ARs I love to shoot them out 5 to 6 hundred yards they are fun guns to shoot and they are competitive at that range all are sub MOA next build will be 6mm arc over turbo 40 just because every thing is cheeped brass and reloading Equipment and a big factor is it is endorsed by DOD May even get surplus ammo eventually truth is you couldn't go wrong with either one just to have fun shooting
 

So is Hornady spewing or being truthful?
 
I thought the 6.8 SCP was endorsed by the DOD
It wasn't the 6.8 SPC that was adopted, it was Sigs 277 Fury. Same bullet, very different cartridge. That still doesn't mean the ARC can't be adopted by some branch(es) of the military. While the M9 was the military's official sidearm the Navy adopted the P226 for certain parts of it's branch as a sidearm. The same might be true of the ARC.
 
Well this thread has me thinking.

I basically designed my 24" 6.5 Grendel to be a long range steel shooter (600 yards is our longest shot). Shooting 107gr Sierra Match Kings BC G1 .455

The BC advantage of the 6mm bullets...95gr SMK BC G1 .515 or the Hornady 108 ELD-M BC G1 .536....

Would transforming my 24" Grendel to the 6mm ARC be as simple as a barrel swap?

They both use the same bolt?
 

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