OK. So I have an opportunity to shoot a 1895 CB 45-50 longdistance. from 200 to 500 meters. The rifle has a lyman receiver sight and a globe front sight. It will be black powder and lead. Any recommendations? Bullet size?
Probably 95% of my shooting is with single shot Black Powder rifles and paper patch bullets.
Is this going to be a one-shot experience or a reoccurring event?
Are you going to load single rounds or feed through the action?
For what it is worth:
First step: slug the bore to determine its diameter. Once that is done, it will be easier to recommend the bullet diameter.
Believe that you will need a soft lead bullet either 1:20 or 1:30 alloy (that is, 1 lb. of tin to 20 or 30, or so lbs. of lead) to obturate, seal the bore and protect the base of the bullet from the gases.
A heavier bullet will "buck" the wind better.
A wad between the bullet and the powder will act as a gas cheque.
Black Powder does not need a magnum primer.
A Black Powder compatible lube is strongly recommended to keep the fouling soft and prevent leading.
When done shooting, decap the cases and wash the case out in warm soapy water. A short section of cleaning rod with a .45 calibre Nylon brush or the appropriate sized test tube cleaning brush works very well. Otherwise, the Black Powder residue will start to weaken the case. If you do not decap the case, chances are that the powder residue under the primer may not be neutralized.
Depending upon weather conditions, you may need to clean in between shots or after every 2-3 shots. If Black Powder fouling is not managed properly, the barrel will lead and accuracy will suffer.
My powder choice would be KIK; granulation of choice would be FFg.
With the thicker and therefore stronger modern cases, it is difficult to load a full 70 grains. A 24” drop tube will help settle the powder in the case. A powder compression die may also be helpful.