600 YD Target

quote:

Originally posted by old rugged cross:
600 YD Target

Weshowe posted that target last summer, stating it was at 100 yards. Great results.

I don't recall seeing any results at 600 yards.

Gents,

No 600 yard target to show. It was electronic and I had no way to capture it. It was about three inches for 5 rounds using my beforementioned load. The darn things shoot well out of my bolt gun...

Still need to test them out of my Kreiger barreled M-14 DMR. THAT will be a different load in order to meet the OAL mag length (2.83").

The bullet shows promise so far, but I'm not ready to switch from my 175 gr. SMK's as my "go to" load.

Will have more data this month.

Wes

quote:

Originally posted by Voshterkoff:

quote:

Originally posted by fritz:
6.5 Creedmoor advantages:
- Noticeable reduction in recoil. Depending on load, 1/4 to 1/3 less than 308.

This is the thing that interests me the most. Given a close range unsupported shot, can you get off 3 hits instead of 2 with 308? 2 instead of 1?

Good question. It requires similar 6.5 and 308 ARs, and a timer. Plus some accuracy standards. I don't have comparable AR10s.

However, I do have almost identical bolt actions in multiple calibers. Not the same drill, but from somewhat unstable positions.
*****

Going back to recoil, rifle tables list 8-ish pound rifles with these recoil figures in foot pounds:
308 Win @ 16-18 foot pounds
6.5CM @ 10-13
6CM @ 8-11
223 Remy @ 3-4
My rifles weigh more than 8 pounds and I use suppressors. Thus my recoil forces are less, but they remain relative among the calibers.

Here's my 308 bolt action from some of my training barriers. The spool is quite stable. The cheesy tank trap is relatively stable, as long as I use a good bag. The pallet on end, "supported" with steel T-posts inside the pallet -- well, it wobbles a lot. I can put a little forward pressure to take up some slack, but with very much pressure the T-posts start flexing. Add a rifle's recoil to that, and the sight picture can swing wildly while firing. So...I've found the best method is to lightly press down on the scope turret and shoot free recoil -- with my shoulder just lightly touching the buttstock. With a good trigger press and other fundamentals, my accuracy is pretty high.



JBM says bullet flight time to 300 yards varies from .32 seconds with my 6CM to .37 seconds with my 308. My 6.5CM and 223 are in between. Call it 1/3 second from bang to ting on steel targets. From a prone position (bipod & rear bag) with any of these rifles, I am stable enough that the reticle stays on POA and I see the bullet impact the steel. By that I mean that I actually watch the bullet splash and the white paint strip away. Not "Oh yeah, after the gun stopped moving, I see where I hit."

From the pallet barrier, the 308 jumps so much from recoil that the reticle is almost always completely off a 12" plate. Once I re-acquire a sight picture, I can see the impact location. Or not, it I miss.

With the 6.5 CM from the pallet, I'm almost 50/50 in spotting my own impacts at the time of impact. But the reticle still moves a fair bit -- at least to the top of the plate.

With the 6 CM from the pallet, I'm a little better than 50/50 in spotting impacts. The reticle remains somewhere in the plate.

With my 223, there's not much reticle movement. I can spot all my hits. Definitely not as stable as prone or the other barriers, but pretty easy to deal with.

******
FWIW. Maybe useful, maybe not.

It is helpful. If anything, I’ll make another upper in 6.5cm and give it a whirl. I’m already planning two different barrel lengths for .308 anyways. The real difficulty is finding a barrel you like that hopefully works for your setup.

Can a CM upper be used on a std lower with different mags?

quote:

Originally posted by old rugged cross:
Can a CM upper be used on a std lower with different mags?

6 and 6.5 Creedmoor upper receivers are the same size as 308 upper receivers, so they are completely compatible. Lower receivers are also the same size.

Standard AR10 magazines hold 308, 6.5CM, and 6CM rounds equally well. There is no need to use different mags for different calibers. Well, other than to avoid loading the wrong caliber in a given rifle -- for those who have similar rifles in different calibers.

If you are going 308, today is a good day.
It's "happy 3-08 day" everywhere with sales all over.
Get some.