My rifle arrived today. I quickly found that the cases I made from 303 B will definitely have to be neck turned. Even with bullets sized to .408" they will not chamber.  The sized brass chambers fine without a bullet seated.
I tried my old Forester turner but the pilot is too long and only allows turning about half the neck length that needs turned.
I thought I still had it covered with a Hornady neck turner but found they only make pilots up to 35 caliber.
I have a pair of old RCBS trim pro's but no neck turning attachment.  I can find those on line but I can not find any neck turning pilots for it. Very frustrated !
The rifle looks great. I tapped a .410" diameter two drive bands into the muzzle and turning that portion of the bullet in a mic I get .403" at the low end and .409" at the high end.  If I can get cases with a .408" bullet to chamber I will be happy. 
  I think if I shorten the stud end of my Forester pilot it will seat deeper into the cutter shaft and that might solve the problem with the Forester neck turner not turning enough case neck length.  We shall see.
OH BTW I did shoot it once.  I seated a soft .408" bullet then sized the neck in a 41 mag die. That worked a charm for chambering but I imagine the bullet was squished pretty skinny.

What I have so far discovered with this rifle is that with a .408" bullet seated in a case the case neck diameter can not exceed .433" for the round to chamber.   Cases that have not been turned having a .408" bullet seated measure .440" at the location of the bullet base in the case. So for this rifle with the 303 brass I used (PPU) and using a .408" bullet diameter case necks have to be reduced in diameter .007" to chamber.
I push a slug all the way through the barrel and turning that slug in a mic I get .403" x .408" so it looks like a .408" groove barrel.
   Since my neck turning tools did not work for this case I fudged a method of getting it done.    What I did was to fully seat a long .408" bullet in the case then chuck the bullet nose in a power drill and turn the necks into a file until neck diameter to the base of the seated bullet is .433".  Then the bullet used as a mandrel is pulled the case is re-sized , primed, charged and a new bullet seated.  That method is working fine but I wouldn't want to do a large volume that way.  I made 15 cases and that is enough to get started with until I can get my neck turning tools in order.
   

I am still working on a more precise method of turning cases for the 40-50 SS. Maybe I have a particularly tight chambered rifle but with the PPI 303 B brass I used the cases have to be turned nearly full length to chamber without resistance with a .408" diameter bullet seated.
When I bought the rifle I thought from the angle of the hammer that it was a post 1901 smokeless action but the last patent date on the tang is 1887 so I guess it it a black powder action.  So I will limit its use to black powder.
  I tried it today with some bullet I cast using an old Winchester wish bone mold that is stamped 40-82.   It drops a 265 gn flat nose plain base bullet at .408" diameter. Lubed with our NASA BP lube I loaded some with somewhere around 40gn of GOEX FG powder and those shot good blowing three long puffs down the barrel between shots. 
   I tried a smokeless kicker under the black but this darn thing shot best with straight black.  Maybe the duplex load kicked the pressure up too high for the BHN-8 alloy used. Dont know for sure but I will listen to the rifle and go with straight black.
  Tomorrow Lord willing I might cast some in a Ballard mold I have had for a long time. I knew Tom Ballard, he lived about 120 miles north of me . I bought the mold from Tom at a gun show in Wisdom MT about 40 years ago. It is adjustable for weight so I will adjust it down to about 250 grain. That will make most of the bullet length a bore ride nose with very little full bore diameter to take up powder space in the case.  Maybe that way I will get closer to the 50gn volume the case originally held.

bullshop wrote yesterday at 6:16pm:


Both of my Rolling Blocks in .40-50SS are BP era actions, and I shoot nothing but smokeless in them. I think the .40-50SS is a much better cartridge with smokeless than it ever can be or was with BP. I also use a heavier bullet and it works better at further distances with a heavy bullet.

marlinguy wrote Today at 12:40pm:

My rifle is something of a bastard too short to be a rifle and too long at 26" barrel to be a carbine.   Maybe long range is not in the game for this one.
  It does seem to have plenty of twist for heavier bullet though. Just going by eye looking into the barrel it seems to make slightly more than two turns in its 26" length.
I did mount a tang peep sight today just to help see what kind of accuracy I can juggle my loads into.   

Thank you Dellet.  I will now be on the hunt for some Hornady 30/40 brass. 
Not much to go on just firing one three shot group today with the tang sight mounted but those three loaded with the Winchester 40-82 bullet and about 40gn FG black powder went into right about 1" from 50 yards. Encouraging ! 
   I gave four long breaths down the barrel between shots.  That and our NASA lube is keeping the fouling soft and it is hot and dry here right now.
   The duplex load with the smokeless kicker left visibly less fouling in the barrel but what fouling was left seemed much harder. 
   Smokeless powder makes things easier for sure but I am afraid regular use may loosen this old BP action and with the beautiful re-cased receiver someone had done the thought terrifies me. Both the receiver and butt plate have been tastefully re-cased. Its a handsome little rifle.   
  I am seeing it as more of a just for fun and small game shooter than any kind of target rifle. Should be dandy for calling in coyotes too. Using a BPC just adds a twist