PP Bullets in a Tube Magazine Rifle?

[Don McDowell]

Always curious about this "no bump up " stuff from smokeless.... why would a lower pressure from blackpowder bump a bullet up, but not higher pressure from smokeless???

[Kurt]

Don.

There was a article in Gun or reloaders digest don't remember for sure which it was about this subject of bump up with smokeless and jacketed loads. The finding was that the jacketed bullet does fill the void between the case mouth and the 45 degree chamber end. I have never looked at recovered jacketed looking for this, but they showed the bullets and it clearly showed the drag ring .

Kurt

[Kurt]

The lube would not be much of a problem. I would worry more about the rolled back patchwhen the round gets pushed off the ramp and at an angle into the chamber.
I loaded some dummy rounds for the .444 in my Marlin and ran them through the rifle and most of the patches where damaged.
Don't do this with live rounds. If you stick a bullet and the hammer drops on the next might not be the best for you and your rifle.

[Flash Pan Dan]

I just slugged the chamber mouth and lead and found there is hardly any lead at all. The chamber mouth measures .342, the lead is .09 long and measures .323 just before the 5 groove rifling. So I'm thinking I should get a mould that casts .318 slick since two wraps of my favorite paper adds .0055 to the diameter. I'm surprised by how short the lead is in this chamber it almost makes me want to try patching to bore size and giving it a try with black powder. But I am limited by the cartridge length since this is lever gun. I am most appreciative of all the help.

[bruce moulds]

don,
the bumpup problem is due to the progressive burning of smokeless.
black goes instantly to peak pressure probably before the bullet starts to move or just after.
the bullet goes further before peak pressure with smokeless and gas can start leaking while this is happening.
groove diameter bullets help here, as there is a quicker seal.
the issues here are several.
one is that the rifle is a repeater, complicating fouling control.
this not only requires plenty of lube, but the right lube, which might mean different lube for different seasons.
if using smokeless the fouling issue goes away. duplex could also be considered.
with smokeless, groove diameter bullets would help.
as mentioned feeding from the mag is a potential issue unless the patch is fully in the case.
you did no hear this from me, but a greaser would seem to be the obvious choice, even with duplex.
accurate makes some good designs in many calibres for this type if application, but not sure of this calibre.
single shots make life a lot simpler. you can wipe, blowtube, breech seat, seat bore diameter bullets way out in the rifling etc etc.
keep safe,
bruce.

[Don McDowell]

All I can say is shooting a 400 dia slick wrapped in 9 lb paper works fairly decent in my 405 Winchester using smokeless powder. Those bullets bump up enough to fill the grooves well enough to ring gongs etc out to 300 yds anyway..
I also contend that if smokeless didn't bump a bullet up shooting 38's in a 357 chamber would be a fruitless adventure , as would firing the "standard" .426 diameter 44-40 bullet thru .430 groove barrels.. the Ruger 22 interchangeable cylinder revolvers use the .225 diameter barrel for the 22 magnum...

[bruce moulds]

don, you are probably right, and have tested this more than I.
keep safe,
bruce.

[Don McDowell]

Don't know as it has anything to do with how much testing anyone has done, just a few hands on observations I've accumulated over the years.

[Don McDowell]

I just slugged the chamber mouth and lead and found there is hardly any lead at all. The chamber mouth measures .342, the lead is .09 long and measures .323 just before the 5 groove rifling. So I'm thinking I should get a mould that casts .318 slick since two wraps of my favorite paper adds .0055 to the diameter. I'm surprised by how short the lead is in this chamber it almost makes me want to try patching to bore size and giving it a try with black powder. But I am limited by the cartridge length since this is lever gun. I am most appreciative of all the help.

I would think that .318 slick would work just fine, especially if you resize the cases so the bullet has plenty of neck tension. A tapered bullet might really shine in this instance. Or a dual diameter bullet with the base at around 325 and the nose at 318 or slightly under. Keep the patch length short enough that it won't quite engauge the rifling when the round is chambered with either bullet.