6.5 barrel burners

[alf]

H-1000

 

[Pawnee Bill]

Then there is the venerable 264 Win Mag.

 

[Bart B.]

Then there is the venerable 264 Win Mag.

My long range match rifle barrel so chambered died at 640 rounds. Case mouths gripped bullets with 1/16th inch of the neck. Went from sub MOA at 600 yards to near 4 MOA over 4 shots in a match. 72 grains of H870 under 139 grain FMJBT nickel plated Norma match bullets.

Almost exactly what my barrel life formula predicted.

 

[Ray in Houston]

Is anyone shooting the 6.5 SUPER round...????

 

[Bart B.]

Is anyone shooting the 6.5 SUPER round...????

It's about the same as the 260 Rem and barrel life about 2000 rounds best accuracy.

 

[Scotts556]

269 AI isn't bad if kept bellow 2900. I'm trying to get the 147 ELD bullets up to 2900 maybe even 2950. But nothing more. But one of the guys I shoot with run 147's at 3010. And boy......... barrels go quick. I'm also not a big PRS guy. I don't run my guns fast and hard, slow and steady is fine for me.

Scott

 

[Timinator]

.264 Win Mag doesn't burn barrels any faster than anything else. My buddies and I have never had one go less than 4000 rounds before they open up. With 300 fps speeds faster than a 6.5 CM with the same powder and bullets, it's a no brainer.

 

[Bart B.]

.264 Win Mag doesn't burn barrels any faster than anything else. My buddies and I have never had one go less than 4000 rounds before they open up. With 300 fps speeds faster than a 6.5 CM with the same powder and bullets, it's a no brainer.

I'm referring to match barrel accuracy.

Did any of them you're referencing start out sub MOA at 1000, about half MOA at 600 or 1/4 MOA at 100 for 20 shot groups?

Why do top ranked competitors shooting 6.5x284 ammo rebarrel before 1000 rounds using less powder per bullet weight than 264 Winnie Maggie rounds?

This is a better "no brainer" to figure out as it states conditions and standards. Yours didn't. I used to think like you then I became a friend of someone whose job was testing bullets for accuracy wearing out all different barrels chambered for different cartridges. He and I shot a lot of matches together. He knew well the more powder burned for a given caliber, the shorter the barrel life is.

 

[Timinator]

Yea you may be right punching paper at 1000 yards, but that's not something I do. I shoot prairie dogs, ground hogs and coyotes out real far. But, as far accuracy, the barrels shoot one hole at 200 yards for pretty much the life of the barrel, and that's good enough for me and most people. Holding energy out far enough to dump what I'm aiming at is what at .264 does better than most.

 

[Bart B.]

But, as far accuracy, the barrels shoot one hole at 200 yards for pretty much the life of the barrel, and that's good enough for me and most people.

That makes sense. The general perception of a 1 hole group is twice the bullet diameter. .528" groups at 200 yards all the time over near 4000 rounds is pretty good. First time I've heard of such phenominal accuracy.

How many shots per group?

 

[Exercion]

That makes sense. The general perception of a 1 hole group is twice the bullet diameter. .528" groups at 200 yards all the time over near 4000 rounds is pretty good. First time I've heard of such phenominal accuracy.

How many shots per group?

Well played, sir. Game, set, and match.

 

[Timinator]

Like I said, I don't punch paper that much unless I'm trying out a new load or scope. But after I dial either of them in, I shoot 3 or 4 shots at 200 yard and sight in 2" high at 200. With a custom barrel and the same amount of powder using the same bullet a .264 is up to 300ft faster than a 6.5 CM across the board. Something CM shooters would strive for if it was an option. When my buddies with CM's start dumping PD's out further than me, I'll take a second look at one, but there's no need to fix something that ain't broke.

 

[Rust]

Like I said, I don't punch paper that much unless I'm trying out a new load or scope. But after I dial either of them in, I shoot 3 or 4 shots at 200 yard and sight in 2" high at 200. With a custom barrel and the same amount of powder using the same bullet a .264 is up to 300ft faster than a 6.5 CM across the board. Something CM shooters would strive for if it was an option. When my buddies with CM's start dumping PD's out further than me, I'll take a second look at one, but there's no need to fix something that ain't broke.

The .264 has a bit more than 30% more case capacity of a CM. For a 140 gr bullet the minimum charge of powder for a .264 is greater than the maximum charge for a CM. True for all other powder and bullet combinations. Max CM powder charges with a 140 run about 39-43 gr depending on powder which would be way light loaded for a .264. Running the same bullet, powder and charge in a .264 would result in a lower velocity because it would generate less pressure in the big magnum case. Sorry Charley, not good enough for Starkist.

 

[Timinator]

That's just not true. Same amount or the same powder and same bullet is faster by as much as 300fps in a .264 vs. CM. Try it. No math needed.

 

[jr600yd]

I dount see how? Rust has a good point. Your talking two different size cases with two different case volumes. Even if the powder charge was safe in both the 264 case has more boiler room. That means less pressure and lower velocity.

 

[jr600yd]

What is needed is to load both to the same pressure. That means more powder in the 264

 

[Timinator]

http://sportingclassicsdaily.com/264-win-mag/

Snipers Hide "I personally just re did my buddys model 70 winchester in .264WM that was his grandpa's from the 60s. Now this was a hunting rig with a sporter barrel and I put a B&C stock on it scrubbed the HELL out of the barrel (jb bore paste, hoppes #9) then re crowned the muzzle... then I did a 300 yard ladder test with SWIFT bullets this 50 year old gun held sub moa out to 600yd with a barrel that has well over 2000 rounds threw it.. It opened my eyes to that round for sure being a 6.5CM shooter myself. The only issue is finding brass to reload I had issues well till his grandpa found a trash bag full of spent brass he had been saving for 20 years 600 pieces... Old timers! haha!"

"I've been shooting the 264 since 1982 and my father shot the same rifle since 1967 and have yet to burn the barrel out. It still groups 3 rounds in at 300 yds within an inch. I've used it to shoot coyotes antelope deer moose elk and bear. I have since bought my son one as well, it is a smokin hot cartridge that just shoots where you point it. My furthest single shot kill was well over 600 yds on a whitetail and well that is not a normal shot sighted in at 300 you just put the cross hairs where you want to hit and it does from 25 yds to 400 yds I would recommend the cartridge to anyone. My conservative estimate between Dad and I we have run 8000 rds through this rifle over the last 47 years because for a long while we both used it as our primary rifles and shot a lot on the farm"

RifleShooter Ballistic Article
http://www.rifleshootermag.com/ballistics/the-truth-about-ballistic-efficiency/

"The advantage of a larger case is that it works better with heavier bullets. Over-bored cartridges shooting lighter bullets are inefficient, and he pointed to the example of the .264 Win. Mag. versus the 6.5 Creedmoor. The larger .264 Win. Mag. requires a long barrel and careful powder selection and produces higher muzzle energy.

In addition, lighter calibers are more shootable and are less likely to spew unburnt (read: wasted) powder from the muzzle.

According to Nosler reloading data, the 6.5 Creedmoor will drive a 140-grain .264-inch bullet at 2,672 fps when using a max load of W760 powder. The .264 Win. Mag., using the same bullet and 54.5 grains of the same powder (also a max load), achieves a muzzle velocity of 2,942 fps. The 6.5 Creedmoor is averaging just under 66 fps per grain of powder while the .264 Win. Mag. is making just under 54 fps with a grain of powder. The .264 Win. Mag. load requires 25 percent more powder to achieve a nine percent increase in velocity over the Creedmoor, and the .264 Win. Mag. requires a longer, heavier barrel to do so."

I was just perusing while watching the F1 race and found these. Evidently, I'm not the only one who's figured it out. In the last case they were both using max loads though.

 

[Bart B.]

The .264 Win. Mag. load requires 25 percent more powder to achieve a nine percent increase in velocity over the Creedmoor, and the .264 Win. Mag. requires a longer, heavier barrel to do so."

Both cartridges in Nosler data use 24 inch barrels and the 264 has around 300 fps faster speeds. Pressures can be assumed equal. Barrel weight doesn't make any difference in velocities.

 

[Bart B.]

Over-bored cartridges shooting lighter bullets are inefficient, and he pointed to the example of the .264 Win. Mag. versus the 6.5 Creedmoor.

What's the established criteria for a cartridge to be "over bore?"

Or "inefficient?"

 

[270WinDude]

Both cartridges in Nosler data use 24 inch barrels and the 264 has around 300 fps faster speeds. Pressures can be assumed equal. Barrel weight doesn't make any difference in velocities.

Do they have equal throat length? I've seen reports of 270wby mags shooting at some ridiculous speeds, faster then a 270-300WM and in large part due to throat.