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

40/90 SBN

Made that recommendation to him, among a list of others. A 450/400 NE might work, too.

Rebore / re-chamber ?

you boys are missing a rather subtle little machining problem inherent in this stunt.

If I owned a fresh sharp .40-90 SBN reamer, or had rented one for the job,.... I would be EXTREMELY concerned about sticking the thing into the INTERRUPTED CUT that the existing extractor recess would dictate.
Pretty near guarantees hanging up a flute and trashing both the reamer and the barrel.

The Swede roller conversions are a very peculiar style of extractor cut, and were originally put in with a clapper box shaper,...
They can be done on a mill, ...backed up by LOTS of hand filing and die sinker style Foredom work.

....I have to do one today,... there'll probably be photos posted over on that other roller thread.

GTC

Rebarrel, then?

That or figure out a LONG case adaptation, and go through an incredibly contorted series of custom case forming operations so's to have that one shooting.

It's an old converted military rifle musket. "Re-heat treated", etc, etc.

Were it a really valuable top line sporter or double rifle, it would probably be worth it.

The Swedes are a decent piece of raw material to build on,...I actually prefer the Christianna Arsenal actions,and the chambers in some of those are pretty decent....IIRC the one discussed here is a Remington,....hence very EARLY in the line of conversions, ....

Bored to the .400 cals proposed, that rifle, ( already pretty light and svelte) becomes a guaranteed flinch inducing recoil monster. LOOK at the drop at the heel, and the scant STEEL butt cap.

GTC

Oh, that should be fun!

I also suggested the .360 Nitro Express No. 2. Why? Well, because dies and brass for the 8mm just aren't pricey enough.

The ECONOMY solution to all of this would have been to measure alla' the parameters UP FRONT,....prior to buying or ordering ANYTHING.

As it sits, one could breech seat a tapered greaser or PP, and than load scheutzen style, ....duplexed BP with card wads, drop tubed into a cobbled up die that left the face of the wad right at the case mouth, and than contacting the bullet's base.

Don't ask how one hunts with something like that, though.

GTC

yep Remington action - Swedish Arsenal rebuild.

how far is the extractor cut along the barrel? Given the unholy amount of freebore, can it be set back and rethreaded to avoid a chamber reamer hanging up - new extractor cut to be put in after?

But finding a new cartridge in 8mm would be fun. I suspect reamers in the 8Danish are few and far between. You'd have to cut off almost an 1-3/4" to get an 8x72r Sauer to clean up the leftover Danish. Similar amount for 32 Winchester. 8mm Lebel?

Gosh I hate being beaten, but a rebarrel to something off the 45-70 family seems to be the most unstubborn thing I could do. This would require the least amount of action work regarding the extractor.

Then I could take the beautiful 33 inch 8mm barrel and slap it on some Frankensteined single shot after making a 32 Win out of it.

The beauty of the internet buying.

Won't be my last screw up I assure you.

Short of offering up the dies, I guess I should just work up a few conservative loads and shoot the damn thing.

You have the rifle in front of you, and are better set to measure the somewhat SCANT octagon section just forward of the frame barrel juncture. Single point tooling, and "picking up" the 12 square threads, extending them proportionate to the set back, is not a first year machining class exercise.

Doable ?...yeah, but (outside of STOUT shop fees) I'll pass on the opportunity to prove that, thanks.

The extractor cuts are typically the LAST operation performed on most all single shot BP rigs. One CAN do follow up chamber work with sharp boring bars in play at the interrupted areas,...and superlative metrology in play.

Fine and dandy if one owns his own tooling, and has lotsa' time.

Cost effective ?

....in yer' dreams.

GTC

Rebarrel to something in the .38-55 class?

I've got a Badger #1 Heavy Sharps barrel, .368 / .377, sitting in the corner I fitted it to a Shilo with some killer heavy wood,... and it would not make the 12 lb. 2 oz. BPCR weight rule.

That would work.

I'd go with the .38-50 Rem. Hepburn,....more oomph.

WAY more.

GTC

If one was going to keep that adequate , but in no way particularly special wood that the roller conversions typically sport,..., I'd be more inclined to go with something like a .303 Brit or .30-40 Krag.

.....now we're concerned with pressures and bushing firing pins for modern primers, etc.

The original firing pin, and it's incompatability with modern primers hasn't come up, in discussing this one, has it ?

GTC

Nope, that hasn't been mentioned at all.

Sounds like another "aw crap" moment coming up for RWE.

I can almost hear wee digits slapping a face palm.

The re-bush of one of these is pictured over on the other thread.

Suffice it to say that it's a SMART mod to make on a design that handles gas very poorly from the get go.

GTC

I figure RWE can handle that. He's bushed pins before on the double he built.

The LATE conversions were fitted with smaller dia' firing pins, as were a lot of those Swede sporting RBs.

Hey, they were figuring it out as they went along, eh ?

GTC

I bushed a set on the 30-30 SxS build - you know, the one I blew up the stock on before I bushed the strikers...

But that was by hand, and strictly another example of "I'm too stubborn to be economical" and afterwards it it hit the official "Don't want to do that again without power tools" list.

It's an adequate but ugly job

Like most of us, right?

I've known a bunch of Swedes and dated a few. Figuring it out as you went along with them was always worth the effort, and generally ended up with great results.

Didn't know about the detonation.

Scratch that idea.

Sell the roller down the road, cut your losses, and move on?