shooting 6.5 Creedmoor out of a .308 barrel

[chuckt]

I ain't convinced....
Your loaded 308 cartridge brass has uneven shoulder, and a dented in too much lube on shoulder?... reject grage sale ammo comes to mind...surprisingly the 308 ammo fit the 308 chamber!
The fireformed brass has less then filled out shoulder with a full load...plus holes and lube dents in the shoulder. Weird...
And you just happened to have do your firing mixup just in time to post about it...
Strange coincidences.

I wasn’t trying to convince you. I did not post my experience in order to argue, testify, make a case, or convince anybody whether or not it happened. I was sharing my experience in order to try and give some insight and information to the other people that made my same stupid mistake of firing a 6.5 CM in a .308 chamber.

 

[Ray123]

Worn out reamer makes a smaller chamber, think about it.

Depends on the type reamer and the material being cut...normally that is true if worn in size slightly but still fairly sharp ...if dull it can and often does cut oversize galling and tearing metal ...depending on a bunch of factors, the metal, depth of cut, coolent or lubrication qualities of cutting oil. It will dull first usually on the leading edge with the trailing edge still cutting to size ..for a little while.
Then your gunsmith polishes it to get the chamber to look better so it becomes oversize even more after galling...another way is a nice sharp reamer starts straight...but is knocked out of true or barrel indicated incorrectly then a slight runout begins wobble the reamer...it cuts oversize...and so will a slightly dull reamer in this case.
There is some a lot of poor quality from supposedly good manufacturers today...I had a brand name 9mm barrel that would chamber bullets over .355" .3554" wouldn't chamber had to be .3550" or less...bought a reamer from Brownells and fixed it.
Another had a big step in the throat from runout...scrapped it out. ...don't even bother telling the manufacturer, as this was a cheap barrel not like the more expensive barrels, try to send them back and all they do is argue with you, until you send a picture of their match grade barrel.. that ain't match grade...then they almost run out the 30 days getting you a shipping label...companies are desperate for employees and a lot of them just shows up, not concerned about the quality...if they show up. Saw an employee cry at Starbucks because they were short handed and the poor little fellow had to work ...8 hours!.. In one Day!
I actually breakout in laughter at some of the poor quality being sent out by today's big name manufacturers, yep they will send out brand new out of print chambers, bad match grade barrels
numerous pits one pit from land to land long. Revolvers with excessive head space...autos that won't function with any ammo...but you must use the premium ammo...but it still doesn't function.
By the hundreds thousands we are getting inferior products..A brand name is only good, if it produces quality!

 

[Ray123]

I wasn’t trying to convince you. I did not post my experience in order to argue, testify, make a case, or convince anybody whether or not it happened. I was sharing my experience in order to try and give some insight and information to the other people that made my same stupid mistake of firing a 6.5 CM in a .308 chamber.

I am definitely not convinced...and not concerned ...I don't have to worry about it...I already tried it.
I have 7 308s and 2 6.5 Creedmoors ...and none of the 6 5 Creedmoor cases will come close to chambering in my properly chambered 308s ...they are a full 1/4 " out from chambering...you cant even force it I tried, it didn't budge and had to pound the case out with a cleaning rod. ..even the 308 Proof and Schlein AR 10 barrels will not chamber a 6.5 Creedmoor case in New factory ...which is its smallest dimensional form. And I didn't do the chambering on those...In properly chambered 308, it can't happen...Tested ...with several different 308 chamber reamers...

 

[johnfred1965]

Is the Steyr a European firearm? Would the CIP have different domensions for 308 or 7.62 nato? Is it a military derived weapon, with looser tolerances that they like to keep things running? And who is to say that virgin Lapua brass is the same size as loaded Hornady cartridges? Don't compare max to max or min to min, compare max chamber to min ammo standards and see how close you are. And then jam it in there, with authority like a sniper would do. Another consideration for the creed fitting in a 308 is the shoulder is about 3mm shorter tham the 308, so you shouldn't be comparing shoulder to shoulder diameters anyway.

There are probably many more explainations to this experience, but I know anyone who deals in absolutes is usually wrong.