Bullet fit

[JKR]

I’ve watched very experienced and successful shooters who shoot muzzle loading rifles at our long range matches. Their PP bullets slide down the bore very easily. Practically from the weight of the loading rod. Their rifles shoot every bit as well as the best of our cartridge rifles.
This loose bullet fit is contrary to the way I learned. Do you believe the bullet should be a rather snug fit when the cartridge is chambered? Or, is loose better?
I can push my bullet wrapped in SC55W through the bore with one finger on the rod. The same bullet wrapped in my usual 9# paper requires a firm push. I’ll soon try the looser bullet on the target but thought I’d ask your opinions in advance.
Jim

[Kurt]

Jim,

I'm not a slug gun shooter but I have played with the patched round ball ML rifles using PP bullets and no mater how soft I cast those bullets they would just not bump up enough to fill the grooves. The round ball M/L have deeper grooves than what we use in our suppository rifles
But the M/L you're talking about have shallow grooves like what we use and also they have a faster twist. A loose fitting bullet that slides down with the weight of the rod will fill the grooves and make a seal. The advantage the M/L has over a cartridge rifle with a loose fitting projectile is it's held inking with the bore. A cartridge rifle if not loaded properly can endue with runout.
I have front loaded a sharps using the same case that is longer than what I use but I wanted to fit it tight into the throat to help the seal, de priming and cleaning it and recharging the case flush to the case mouth and pushing a bullet down on the case like some of the Schuetzen and bench rest shooters do to see if it improves the over all accuracy and it did but it's time consuming doing it.
It was good for the curiosity

Kurt

[Kurt]

I might add, when I load for hunting.
My first shot is a bore diameter PP bullet. If I need a followup shot the shell is loaded with a PP bullet .002" under bore diameter so I can chamber it in a fouled bore and it still will hold good accuracy but it's a soft hunting bullet that will fill the groove.

[Don McDowell]

I believe the difference in what works for X ring hunting with a muzzle loader and a cartridge gun is the throat of the cartridge chamber. A muzzle loader barrel only has the breech plug at the end of the rifling. That makes for the bullet to have a onetime expansion into the rifling the entire length of the bullet . Where a cartridge gun will expand the base of the bullet first then sewage it down to bore and groove.

[JKR]

How is a true paper patch chamber configured?

[Don McDowell]

I don’t know for sure if there really is a true paper patch chamber
The ODGs that muzzle loaded their cartridge rifle seated their bullets from the muzzle to a predetermined depth then chambered a charged case when ready to fire. The Creedmoor shooters details on that are slim, but the schuetzen shooters had a 1/16-1/8 in space between the wad in the case mouth and the bullet base.
David Menshall came up with some factory patched Creedmoor bullets preserved in a British museum wrapped in thin paper ,and the bullet diameter was .446

[Kurt]

Jim,

I have been fortuned enough to be able to look at chambers of the original Sharps and the Hepburns. I also have two chamber casts one .44-77 and the other was from a Hepburn that was actually used for the creedmoor matches complete with loading tools cases and patched bullets. This fellow asked me if I had some bullets and I said yes. I asked him if he could make a chamber cast because I would like to make a reamer of an original Remington Straight. I sent the cast to PT&G and Dave measured and sent me the specks. I had him make some changes on the neck diameter because it was closer to the .45 caliber than the .44's now used and the chamber end transition was a 4º funnel from the chamber wall to the lands.
All of the Sharps I have an opportunity to bore scope the transition had a funnel type taper and what looked like a very shallow groove.
I since have several reamers made for the rifles I have with the funnel transition from 4º to 7º.
Below is a .44-77 Sharps cast and this chamber and bore was rough but if you enlarge the photo you can see a very shallow transition. As near as I can measure it's a 3º very shallow. The cast on the carpet is a Remington straight cast.
I have added more reamers since I took this picture
I like to call this type of chamber a lead bullet chamber
But in all reality the new modern 45º transition what I call a chambered wall, this type of chamber transition also works, but I give the funnel transition the leading edge over the wall.

Kurt