shooting 6.5 Creedmoor out of a .308 barrel

[piaa1209]

All,
I have attach two pictures of a 6.5 CM that was shot out of 308. This happened the day before the start of our deer season here in pa. This was hornady factory ammo.

 

[Sandstorm]

Well thats a 6.5 NOmore

 

[DShortt]

 

[Ray123]

My 6.5 Creedmoor ammo will fire in my 308 rifle.

Then your 308 standard chamber is way put of print...can't get a .462 diameter shoulder down a .454 hole...the 308 tapers down faster also .016" to the 6.5 Creedmoor's .008" body taper...that's a problem...and no inprint 308 will chamber a 6.5 Creedmoor ...it's impossible. The 6.5 Creedmoor hould stop from chambering about 1/4" out of battery on an inprint chamber. Check the diameter of the .308 chamber reamer it's way back from the shoulder at .462" probably .4" ...the 308 longer distance to the shoulder allows the 6.5 cartridge to go only down about a 1/4" out of battery in a properly chambered in print 308. None of my 308s even come close to chambering a 6.5 Creedmoor bolts I've chambered or AR s chambered by Proof or Schilen....you need to have your 308 rechambered,... it's out of print.

 

[Dusty Stevens]

Then your 308 standard chamber is way put of print...can't get a .462 diameter shoulder down a .454 hole...the 308 tapers down faster also .016" to the 6.5 Creedmoor's .008" body taper...that's a problem...and no inprint 308 will chamber a 6.5 Creedmoor ...it's impossible. The 6.5 Creedmoor hould stop from chambering about 1/4" out of battery on an inprint chamber. Check the diameter of the .308 chamber reamer it's way back from the shoulder at .462" probably .4" ...the 308 longer distance to the shoulder allows the 6.5 cartridge to go only down about a 1/4" out of battery in a properly chambered in print 308. None of my 308s even come close to chambering a 6.5 Creedmoor bolts I've chambered or AR s chambered by Proof or Schilen....you need to have your 308 rechambered,... it's out of print.

No its not. I just put one in a brand new 308 match chamber. Your chamber becomes the sizing die. You should try it like these others have done

 

[Ray123]

No its not. I just put one in a brand new 308 match chamber. Your chamber becomes the sizing die. You should try it like these others have done

I have tried to chamber new unfired 6.5 Creedmoor brass, smallest available, in every 308 chamber I have, total of 6 different chambers some I've chambered some AR 10s are Proof and Schilen chambered. The 6.5 Creedmoor is a full 1/4" out of battery in each one. Not even close ... had to pound out the case with a cleaning rod. The only way is to have an oversize chamber in dia caused by runout at the shoulder neck junction, while finish reaming ...so it wouldn't matter if its a match reamer, runout will cause it to cut oversiz. in diameter as the pilot tries to follow the bore. You'd have to pound on the bolt hard inorder to use the chamber as a sizing die, and since it's not lubed...well ..it'd be stuck...just like not lubing a case before sizing it. So inconclusion any rifle chambered in 308 that the bolt closes on a 6.5 Creedmoor, has been incorrectly chambered, match chamber or standard....it's dimension constraints and mathematics...just the facts...
Or over polish a finished chamber, a lot.

 

[Dusty Stevens]

I have tried to chamber new unfired 6.5 Creedmoor brass, smallest available, in every 308 chamber I have, total of 6 different chambers some I've chambered some AR 10s are Proof and Schilen chambered. The 6.5 Creedmoor is a full 1/4" out of battery in each one. Not even close ... had to pound out the case with a cleaning rod. The only way is to have an oversize chamber in dia caused by runout at the shoulder neck junction, while finish reaming ...so it wouldn't matter if its a match reamer, runout will cause it to cut oversiz. in diameter as the pilot tries to follow the bore. You'd have to pound on the bolt hard inorder to use the chamber as a sizing die, and since it's not lubed...well ..it'd be stuck...just like not lubing a case before sizing it. So inconclusion any rifle chambered in 308 that the bolt closes on a 6.5 Creedmoor, has been incorrectly chambered, match chamber or standard....it's dimension constraints and mathematics...just the facts...
Or over polish a finished chamber, a lot.

I never said you didnt have to beat the bolt closed. Brass is pretty resilient and its not an issue at all if you have the will to make it happen. I dont care what a print says

 

[Dusty Stevens]

Just measure the shoulder on the leftover rounds that were fired in the 308 and they are .4565 to .467 right out of federal’s factory. Cant always go by a reamer print. My custom whidden die leaves new lapua brass at .456 sized and ready to fire

 

[piaa1209]

by the way, case was nocked out with a cleaning rod

 

[Dusty Stevens]

Well thats a 6.5 NOmore

Short neck 308. Less friction on the bullet

 

[Ray123]

Just measure the shoulder on the leftover rounds that were fired in the 308 and they are .4565 to .467 right out of federal’s factory. Cant always go by a reamer print. My custom whidden die leaves new lapua brass at .456 sized and ready to fire

I measured the reamer ...not a print .
My brass follows my reamer very closely...my fired brass measures .4545" at the shoulder...the Wilson die sizes it back to .4534" .
New LC military is .450" at the shoulder. New Lapua Palma brass measures .449" at the shoulder.
When measured on a "new "308 Lapua case .457" goes over a 1/2" up from its new .449" shoulder .46850" is the case head diameter! .467" at the shoulder on some of your brass ...sure that's not .457"! That .467" is almost new lapua case head diameter at .4685"!
No wonder a 6.5 Creedmoor will chamber in your 308 chamber ....it's oversized ...put a new 308 Lapua case in there and listen to it rattle around when you shake the rifle, if your measurements are correct. There is ..010" difference between new 308 brass and new 6.5 Creedmoor brass unfired. Sufficient to stop the new .459" unfired Creedmoor a full 1/4" out of battery from chambering in a correctly chambered 308...it's a hard stop in all 6 308's I own...no way its gonna chamber.

 

[Dusty Stevens]

I measured the reamer ...not a print .
My brass follows my reamer very closely...my fired brass measures .4545" at the shoulder...the Wilson die sizes it back to .4534" .
New LC military is .450" at the shoulder. New Lapua Palma brass measures .449" at the shoulder.
When measured on a "new "308 Lapua case .457" goes over a 1/2" up from its new .449" shoulder .46850" is the case head diameter! .467" at the shoulder on some of your brass ...sure that's not .457"! That .467" is almost new lapua case head diameter at .4685"!
No wonder a 6.5 Creedmoor will chamber in your 308 chamber ....it's oversized ...put a new 308 Lapua case in there and listen to it rattle around when you shake the rifle, if your measurements are correct. There is ..010" difference between new 308 brass and new 6.5 Creedmoor brass unfired. Sufficient to stop the new .459" unfired Creedmoor a full 1/4" out of battery from chambering in a correctly chambered 308...it's a hard stop in all 6 308's I own...no way its gonna chamber.

Hit it hard forward. I assure you itll go in. Too many have actually done it

 

[Ray123]

Hit it hard forward. I assure you itll go in. Too many have actually done it

I did earlier, on one of the bolt guns, ...and it would not go ... so I tried to pound on the bolt with the my hand a few times..it didn't budge .... still way out of battery...but I was rewarded with having to take a cleaning rod to pound the 6.5 case out,...it was really stuck in the chamber...like oops no lube on the case when it was pushed into the die, stuck.

 

[Catfur]

A controlled explosion is firing the correct cartridge in the correct barrel.

An uncontrolled explosion is what you are describing. These are also called bombs.

It's actually the opposite, really. Unconfined, smokeless powder burns less rapidly then when confined. With a bore much larger than the bullet, the pressure never rises high enough to cause problems.

You can get obstructed bore problems which would cause problems the next shot you fired.

Just check out the bore to make sure there is not obvious damage.

 

[Sniperhandle]

It was a John Deere.

"She sent me a John Deere Letter"

 

[Edd]

Look at the SAAMI spec drawings.

The diameter specs for a 6.5 Creedmoor cartridge at 1.4901" from the bolt face is .4540" - .4620".

The diameter specs for a 308 Winchester chamber at that same distance is .4559 - .4579".

 

[dellet]

First time reading this thread this morning and had to read it all the way through just to make sure this wasn’t a duplicate post.

I have not seen a single person question or ask if there was any of the questionable ammo left unfired that could be checked. Even the box to compare lot numbers with someone who might have the same lot.

All caught up in arguing over how it can’t happen, to figure out if it actually did happen, why.

Ammo can be out of spec too.

The photos in post #81 by @piaa1209 show excessive headspace by the primer backed out, so clearly the bolt was not hammered home.

 

[Owens85]

It's actually the opposite, really. Unconfined, smokeless powder burns less rapidly then when confined. With a bore much larger than the bullet, the pressure never rises high enough to cause problems.

You can get obstructed bore problems which would cause problems the next shot you fired.

Just check out the bore to make sure there is not obvious damage.

Yep, I fire form my 6 ppc brass with a 22 cal. Bullet down a 6 mm barrel. (Old barrel)

 

[DukeDuke]

I have fired a 6BRX in my 308. It took me a minute to figure what happened after I opened the bolt.

 

[DukeDuke]

I just tried to chamber a 6.5C in my 308. Guess what?