300 Savage cases formed from 308 Win

Anybody worked much with cases made from 308 Winchester. I have been working with a small (6 cases) lot of Hornady cases. I am getting inconsistent results even to the point of a stuck case a moderate charge (39 gr.) of Varget and 150 gr. bullet. Easily tapped the case out with a cleaning rod. Cases are sized, and all trimmed to same length. I have weighed them and they are pretty much the same weight. After annealing and loading I again got a hard to extract (not stuck) on another case.
I do believe the chamber in my rifle is on the tight side. A maximum length (1.871" per Lyman manual) does not easily chamber. Also cases will not chamber unless they match the minimum data point in a Wilson case gauge. I have a few Remington 300 Savage cases and when sized and trimmed they load with no trouble.
I am beginning to think these cases are more trouble than they are worth.

Could try a small base .308 die first, if the body is the problem.

It's a pain in the azz !! I was forming the 250/3000 cases from Lake City brass.
Moving that much body taper is the problem. I ended up using a series of straight
wall dies to create a series of steps half way down the case, then a final push in the
FL die. Since the 308 case is a bit longer, a good anneal below the neck/shoulder
junction helps plus some good Imperial die wax. Fire forming will finish the job.

I too thought about the small base die, but no luck finding one. I do believe it would help. I am using Imperial for my forming.

I would do this https://www.go2gbo.com/threads/fs-sc...ss-nib.430543/

Are you starting with brand new brass? Fired brass could have the web area all out of kilter, especially if they were used in a semi-auto. If so, you'll need a small base sizing die to correct it.

I have a .300 Savage in a 24" Contender barrel, and it has very tight tolerances. But I have formed quite a few cases from new .308 (and a few 7-08) brass with zero issues. I simply run them into the die, trim, chamfer, deburr and load.