Home Forums Hunting & Shooting BPCR The 8mm Danish roller - chamber is cavernous

1st, a shout out to crossfire for the pm's contributing to my knowledge on the topics of rollers and loading. I can't express how good advice saves time, trial, and error.

Same for DigDan.

On his links, I have done a hammer cas of this swede in 8 mm Danish in hopes of evaluating bullet, powder, paper patch(?) better.

Here it is:

The near inch from the case ledge to the final rifled dimension is a hell of a gap. Almost half inch free.

And the case length is longer than saami by a bit.

Help me out interpreting the 2 dims. that are "stacked"

Case Mouth ID and at the end of the freebore.

What exactly are we looking at there ?

GTC

Looking more and more like a great candidate for a rebore/rebarrel.

The first set of stacks, 368 is the chamber neck diameter and 350 is the start of the bore.

The second set reflects bore/groove

No. If for no other reason than to prove you in error.

Yes, I know, which makes the eventual all the more sweet.

I'll get it shooting if if have to lube the bullets with virgin pixie blood.

You dwarves could probably arrange that.

Not saying it won't shoot. Just that it's shoot better, longer, further, and more efficiently and effectively rebored or re-barreled to .45" and on a -70, -90, or -110 case. You know this to be true as well.

Jeez,...

That seems awful shallow

Do you have the Bore / Groove Dims at the muzzle ?

GTC

Should read .323/.310 .

That's at the muzzle as well

So, what degree error in measurement was that?

OK,...that sounds more typical.

That big old freebore is going to be tough to work around, a .3245" slug being about the top end for a softer alloy greaser.

Head scratchin' here....

GTC

What's the neck thickness on the brass ?

GTC

Neck thickness on the resized 45-70 brass is 0.010

Well, scratchin' around a bit,.... I'm coming up with .0235" of "Rattle" in a FF, unsized case, and a properly sized CB.

...that throat's a problem, Se�or.

GTC

Better off to form cases from either the 762x54, or the 8mm Hungarian rimmed and other variants.

He knows there's a fix to that, too, and a good one.

Reminds me of that really fine old Stier Kropatschek I had years ago, ...same kind of military chamber weirdness.

Yeah, I finally got the thing shooting reasonably well, but can also advise that 8MM is NOT a very practical BP bore size.

The fella' that traded me out of that old pelter was going to build a .45-90 on it.

This particular Swede ?

Given the softness of alloy that's gonna' be required to get the slug bumped up and than swadged back down, I don't want to even THINK about trying to run smokeless.

GTC

He is starting to see the light.

It appears the barrel is too skinny to rebore to .458".

Any recommendations as to what might be a good rebore keeping with a BP cartridge that would clean up that chamber?