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Seems the minimum SAAMI COL is 2.750"...

Brilliant thank you and thanks for the link.

Thing is though, Dave, Vhit load data with 139gn bullets, gives a COL of 3.071" for one of the bullets and 3.150" for the other two. COLs under 2.850" are listed, but with 85 and 100gn bullets.

http://www.vihtavuori.com/en/reloading- ... auser.html

Thing is though, Dave, Vhit load data with 139gn bullets, gives a COL of 3.071" for one of the bullets and 3.150" for the other two. COLs under 2.850" are listed, but with 85 and 100gn bullets.

Yes I know that's my point if I build to 3.071 or 3.150 with a 139grain bullet its impossible to close the bolt.

Second hand rifle? Could it be that it was built purely for the lighter bullets? People do all manner of things which make sense to themselves. Having a rifle chambered to a specific bullet is not uncommon. Pain in the arse if you don't know that when you buy it....

Use the method I described to find the actual max COAL for the bullet you're wanting to use, knock off 5 thou" and go from there, don't immediately drop to 2.75" that will be based on a particular type of bullet.

As an example, COAL's for my 6.5 Creedmoor, with 140gr Nosler CC FMJ it's 2.75", using Hornady 140gr A-Max it's 2.80", although there's 50thou" difference in COAL in reality due to the slightly different shape of each bullet it means they are both seated at 15 thou" from the lands on my chamber.

For my 308Win Steyr I have a COAL with Nosler 168gr CC FMJ of 2.81", using 165gr round nose cast for sub-sonic loads it's a COAL of 2.5", again both are at the same distance from the lands.

COAL isn't the only thing that could be causing your problem.

You said originally that the rifle has a tightly chambered barrel. It sound to me like there may not be enough enough neck space for the case to expand and release the bullet when the round is fired. That would account for the difficulty in closing the bolt and the other symptoms you describe.

To check, measure the case neck width of cases fired in your rifle and of your reloads. The unfired round needs to be at least 3 or 4 thou smaller.

Triffid

Tight chambers will almost always require the case necks to be turned to a pre determined size to allow to fit

If the rifle is secondhand try and get the information off the previous owner or if the smith is known then give him a call and ask his advice against the reamer he would have used

Also brass manufacturer may have an impact on your problem

Really sounds to me like you need to turn the necks down

Duey - if it has a 'tight neck' it will be stamped onto the barrel next to the proof mark.

The easy test - try chambering a brand-new empty case. I bet it'll fly in.

I know that
Still may have been overlooked

It has stampings next to the proof mark but they mean nothing to me. I tried a new case no it does not fly in there is resistance on bolt close slightly but it is there.
Any way I have the thing in bits I got the answer to my question what's the minimum over all length I can go to. I have dismantled all my 6.5 ammo and I intend to spend to day getting to the bottom of it.
Thanks for all your input.