I'm going to use smokeless powder in my new 45-90 and I don't care what anyone thinks. Sooooooo.......there! (You need to Login or Register to view media files and links)



            Joe.

Mick - those are similar, though about 30-50fps slower then my results with Goex & Swiss. With Swiss my spread is 8-10fps. 1.5" is ~1.5MOA at 100yd/m, which is competitive for BPCR & BPTR shooting. A Schuetzen cartridge it is not, though I may shoot a match with mine in April just for fun. 

And, don't pay any attention to those anti-luddites and their new fangled ideas, like smokeless powder (though 17gr of 4227 works pretty well pushing a 279gr bullet in mine).

Except for the lone 45-70, most of my BP shooting is in BN's.  The favourite being the 500/450 no.2 Musket.
Lots of people tell bad things about BN cartridges, most of them never tried one.
Yes, it is a different animal, and listents to different rules than a straight case - but I would never go back to straight cases again.  Finicky to develop loads for?  My very 1st load in my no.2 Musket (with a mix of leftover powder) won me a match...  And let me tell you, you can get even the Brit Martini-Henry 577-450 to perform quite well.  You just need to think outside the box.  My 45-70 now is my PP rifle.  Still shoots pretty well, but the heart is with the BN cartridges.  Tried and tested?  not today, but most BP cartridges of the day actually were BN's (yes, the US were a bit of an exception).  We just need to relearn what the oldtimers knew...

In a nutshell:  Less compression, nothing beneath the neck, coarser powder granulation for a same calibre.  Fg or 1 1/2Fg works very well.  And make sure you have a good chamber configuration...  There are a few weird reamer configurations out there  which do nothing for accuracy.
Some thing remain identical: initial bullet resistance required (either neck tension or bullet seated into the rifling), good primers.
Heavy bullets will perform best - if the rifling twist will allow it, and will also reduce fouling.  And IME, the more powder, the better the round will shoot (light to moderate compression will work).
The no.2 Musket is now at about 90 grs of  1 1/2Fg and somewhere between 1300 - 1350 fps with a 530gr bullet.

I shoot a 44-77 in BPCR rifle sil. competition.  It is extremely accurate.   The tricks that I have learned to loading this caliber are:  1.  use a coarse powder such as 1 1/2F .   2.  Drop tube the powder, but do not compress it.  3.  Make sure that the powder fills at least part of cartridge neck.  4.  One wet patch between shots (AZ is very dry).

Shoot straight!

I remember reading somewhere that the bottleneck cartridges yield more (perceived?) recoil for a given powder/bullet combination.  Possibly because burn rate of the charge is greater due to shorter, wider charge shape(??)

sss  about 72   72.5 grains of 1.5  swiss will give you about .020 comp.   art