16” 6.5 Creedmoor barrel worth it?

[pointblank4445]

If using 123 grain or lighter projectiles I wonder if 6.5 CM is worth the bulk over 6.5 Grendel, especially if center of gravity is a motivating factor as one could get away with a somewhat longer barrel on the AR-15 action.

The 142 grain load is in another league however as in that weight the bullets eat up the limited Grendel case capacity.

RifleShooter.com shows 120 grain Creedmore trending toward about 2600 fps from a 16" barrel.



With an 18" Grendel barrel Andy Hobein averaged as much as 2534 fps with Federal ammunition. Other brands were slower.

Man I couldn't tell you jack about how those 120's compare to 123 Scenars...so I don't know.

I'll note that with that 130gr NORMA, I'm seeing 2885-2860fps out of a 24" (Chrono'd a new lot just yesterday in fact). A good baseline for numbers comparison, but not a perfect representation. I do love that resource though.

Again, it comes down to how much you willing to sacrifice?

You want a 120gr 2600+fps out of 16" in a hamstrung large frame?
or
you want 120gr maybe 2500 out of an 18" eeking out every thing you can from a small frame?


Then at what point do you stop and start looking at a 6mm?

[Hammer_Man]

Man I couldn't tell you jack about how those 120's compare to 123 Scenars...so I don't know.

I'll note that with that 130gr NORMA, I'm seeing 2885-2860fps out of a 24" (Chrono'd a new lot just yesterday in fact). A good baseline for numbers comparison, but not a perfect representation. I do love that resource though.

Again, it comes down to how much you willing to sacrifice?

You want a 120gr 2600+fps out of 16" in a hamstrung large frame?
or
you want 120gr maybe 2500 out of an 18" eeking out every thing you can from a small frame?


Then at what point do you stop and start looking at a 6mm?

It seems like 130 grain maintains similar velocities compared to the lighter loads starting from 22” down to 16”. In the end everything is a compromise. If you want higher velocities you need a longer barrel, but that compromises maneuverability, and vice versa. I’m willing to sacrifice velocity in the name of maneuverability, because In the end 6.5 Creedmoor still produces velocities similar to 308 when fired from a shorter barrel.

I’ve looked into 6mm ARC, and it seems like people are still ironing out a few bugs (magazines, and bcgs). On top of that factory Ammo is unobtainium where I live, but I see 6.5 Creedmoor at most stores.

[Failure2Stop]

A 16" 6.5 Creedmoor barrel significantly out-performs a 20" .308 barrel.
I have been shooting "short" 6.5 barrels for about 4 years now. I think that they shine in the 16" area and over 20".
All depends on your application.

[markm]

A 16" 6.5 Creedmoor barrel significantly out-performs a 20" .308 barrel.
I have been shooting "short" 6.5 barrels for about 4 years now. I think that they shine in the 16" area and over 20".
All depends on your application.

What's your bullet preference in this highly questionable endeavor? (just incase Pappabear gets wind of this insanity and I have to think about loading for it)

[Disciple]

I’ve looked into 6mm ARC, and it seems like people are still ironing out a few bugs (magazines, and bcgs).

What BCG problems have you heard of with the 6mm ARC?

[pointblank4445]

What BCG problems have you heard of with the 6mm ARC?

Sheared lugs, broken extractors and all the other fun stuff trying to trim off the meat to accept 220 Russian bases into an AR bolt.

[Hammer_Man]

A 16" 6.5 Creedmoor barrel significantly out-performs a 20" .308 barrel.
I have been shooting "short" 6.5 barrels for about 4 years now. I think that they shine in the 16" area and over 20".
All depends on your application.

Heck yeah!! Your input means a lot.

Sheared lugs, broken extractors and all the other fun stuff trying to trim off the meat to accept 220 Russian bases into an AR bolt.

Pretty much sums up what I’ve been reading. I’m sure they’ll figure it out, especially with big names like Geissele putting their weight behind it.

[MadAngler1]

A 16" 6.5 Creedmoor barrel significantly out-performs a 20" .308 barrel.
I have been shooting "short" 6.5 barrels for about 4 years now. I think that they shine in the 16" area and over 20".
All depends on your application.

What barrel life are you getting with KAC’s uppers? 16 or 20”? How does it compare with .308?

[1168]

Pretty much sums up what I’ve been reading. I’m sure they’ll figure it out, especially with big names like Geissele putting their weight behind it.

I hypothesize that the 6mm ARC has the same problems that other cartridges before it have suffered.
1) much hype, big fanfare
2) handloaders attempt to reproduce the hype, because without the advertised numbers, the cartridge doesn’t make much more sense than existing ones.
3) everyone discovers that physics still exist.

As an example of this, take a look at published loading data for Valk with 77gr ammo vs published 5.56 data with the same projectiles. Then flash back a few years and remember that it was talked about like a baby 22-250 Fast Twist at introduction due to its increased case capacity. Obviously, it can handle a longer projectile, which is cool.

[markm]

I hypothesize that the 6mm ARC has the same problems that other cartridges before it have suffered.
1) much hype, big fanfare
2) handloaders attempt to reproduce the hype, because without the advertised numbers, the cartridge doesn’t make much more sense than existing ones.
3) everyone discovers that physics still exist.

Outstanding post. Much more elegantly put than how I usually just call stupid cartridges "retarded".