6mmARC barrel, short and light or long and heavy

[troy fairweather]

Looking to get a 6mm arc barrel for a build, kinda of a all around gun so some bench work some hunting deer and varmint. But don't think to much deer hunting just pop a few with it.

There are a few barrels out now, most are $200-$280 most are heavy and some are dmr and spr contours. But I can't decide if I want a 18-20 or a 22-24. Inch barrel.

I'm think I'd get the 24" to get its full potential .what do you think.

 

[cdb1]

24” with the admission I prefer 24-26” barrels on just about anything bolt action centerfire.

 

[troy fairweather]

24” with the admission I prefer 24-26” barrels on just about anything bolt action centerfire.

Better chance getting a good node to. The pressure is set at 52k so the longer barrel should help keep the velocity up.

 

[LoonWulf]

AR, 20" heavy
Mini bolt, 24" light
Regular bolt, 24 sporter.

 

[troy fairweather]

AR, 20" heavy
Mini bolt, 24" light
Regular bolt, 24 sporter.

Things are quickly getting into 527 varmint range.

 

[LoonWulf]

Things are quickly getting into 527 varmint range.

Yes......

 

[troy fairweather]

Yes......

25.6 barrel should get pretty good fps.

 

[LoonWulf]

I wonder what the loss/add in velocity per inch is.

 

[troy fairweather]

I wonder what the loss/add in velocity per inch is.

The 6 arc from what I've seen is very little loss when shorter. Read a guy had a 10.5 and it did not even loose 200 fps from 20"

the 6.5 grendel is good to. The 25.6 barrel on the cz loaded up may get into creedmoor territory.

 

[Texas10mm]

The 6 arc from what I've seen is very little loss when shorter. Read a guy had a 10.5 and it did not even loose 200 fps from 20"

the 6.5 grendel is good to. The 25.6 barrel on the cz loaded up may get into creedmoor territory.

I find that EXTREMELY hard to believe. I suspect a bad chronograph.

 

[horsemen61]

I’d do 20 myself I think it’s a good balance if CZ puts it in the 527 I’ll get one I’m getting to where I prefer the bolt action more and more

 

[troy fairweather]

I find that EXTREMELY hard to believe. I suspect a bad chronograph.

See if I can find the video,

 

[gotboostvr]

I'd really like to see a 18-20" Ruger American

 

[Legionnaire]

22-24" in a bolt action hunting rifle. 26" for a heavy barrel varmint rig.

 

[troy fairweather]

The 20" ballistics advantage looks about perfect to me.
dmr profile barrel 1-7 stainless rifle length.750 gb just over $250 but out of stock.

The 20" faxon looks good to. 1 -8 5r rifle.750gb black nitrite stainless.$215

 

[Coal Dragger]

For that cartridge if it won’t hit advertised velocity out of an 18”-20” barrel on a gas gun it’s pointless and stupid. Preferably do it out of a 16” barrel with a 14.5” not losing too much, otherwise it’s not an attractive proposition to me. So 18”-20” acceptable, 16”-14.5” preferred.

As far as the barrel contour on a carbine give me a light to medium contour CMV 4150 cold hammer forged chrome lined barrel. I have enough experience with those in 5.56 to know most will hold around 1-1.2 MOA for 5 shots and that’s better than most low power variables I would use are going to be able to resolve beyond 100 yards anyway. That gives you acceptable mechanical precision to put rounds into vitals well beyond 600 yards on medium to large game, or the two legged Homo Sapiens Felonious.

 

[Varminterror]

Some data reported by Steve Lockwood, captured during the pre-release development phase of the 6 ARC ammo from Hornady.

 

[Varminterror]

Personally, I have a 24” 243LBC meant for long range shooting - and inevitably some hunting, but which will be rebarreled for 6 ARC soon as this barrel wears out, and I have a 16” upper in 6 ARC planned for my son’s AR, for the lighter weight - meant for deer hunting and plinking.

So “horses for courses,” in this case - if you primarily want to shoot long, get the long and heavy barrel. If you’re primarily hunting, you’ll still be able to reach 1,000 better than any other AR-15 SAAMI cartridge, but will have substantially more punch on game than 5.56.

 

[horsemen61]

^^ I agree with the above couldn’t have said it better myself

 

[Texas10mm]

Some data reported by Steve Lockwood, captured during the pre-release development phase of the 6 ARC ammo from Hornady.

View attachment 934669

Without knowing the SD of that ammo used that chart is pretty meaningless.

Take the 15", 14.5", and 14" numbers. The first half inch takes 5 fps off, the second half inch takes 27 fps off.

There's 305 fps between 18" and 11.5". Expect another 50 fps or so for the drop from 11.5" to 10" and it's quite a ways from the claimed 200 fps.

Again, shooting single shots, without knowing the SD is meaningless.

Ideally one would shoot 10-30 rounds at each barrel length and give the average and the SD.

 

[Varminterror]

God help you if you can’t accept any data, even from the folks working directly with the manufacturer to develop the ammunition.

 

[Dustbowl]

I’ve got everything but a barrel for my 6mm arc build and want to go with a 18” but I’ve heard bad things about Faxon so I’m waiting on ballistic advantage to become available again

 

[troy fairweather]

I’ve got everything but a barrel for my 6mm arc build and want to go with a 18” but I’ve heard bad things about Faxon so I’m waiting on ballistic advantage to become available again

Ya think I'd get the ba barrel.

 

[Goosey]

Without knowing the SD of that ammo used that chart is pretty meaningless.

Take the 15", 14.5", and 14" numbers. The first half inch takes 5 fps off, the second half inch takes 27 fps off.

There's 305 fps between 18" and 11.5". Expect another 50 fps or so for the drop from 11.5" to 10" and it's quite a ways from the claimed 200 fps.

Again, shooting single shots, without knowing the SD is meaningless.

Ideally one would shoot 10-30 rounds at each barrel length and give the average and the SD.

You can always plot it out:


Judging from the plotting of that set of chronographed shots, extending the barrel to 20" would result in about 2650 fps, 22" would be around 2700 fps, and a 24" would go 2735 fps. A 28" barrel would get around 2800 fps.

Hornady says 2750 fps from a 24" test barrel.