Early trials with a Snider

[afmelo]

Indeed! I gave a look to the JBM site and was surprised with the handfull information contained therein! Will take time to absorb... Many thanks!

 

[fourfive8]

Most of the time I use the "Trajectory (Simplified)" program by JBM. Norma used to have a neat interactive program but IIRC quit supporting the best version of it a 3-4 years ago?

JBM - Calculations - Trajectory (Simplified)

www.jbmballistics.com

 

[fourfive8]

@afmelo,
Haven’t quit the project, still shooting and testing.

Baked these up last evening. Pan lubing some in SPG. I had cast some more 520 p Snider bullets at a slightly harder BHN of 10.5. Have been shooting very soft alloy recently, about 5 BHN. Logic says, especially with increasing smokeless pressures, the alloy hardness should go up to help prevent base cutting. We’ll see.

 

[fourfive8]

OK, I'm beginning to feel like this is not the "Early Trials" anymore
I have been going to the range the last couple weeks testing many loads and chronographing results.
Very slowly and incrementally, have reached my objective without excessive pressure of 1050 fps MV with the 520 gr ACC bullet with a smokeless load out of the 1872 Snider Short Rifle.

I have no recommendation for this recipe for any other Snider or shooter. Mine is a "Steel" marked 1872, purpose built Short Rifle.

14ga Magtech brass trimmed to 1.98" length for my chamber. .600" ACC 520 gr "P" bullet cast of 10.5 BHN alloy. Pan lubed with SPG. WW Large Pistol Magnum primer. 34 gr Accurate 5744 powder. 1 3/4" X 1 3/4" X 1/4" square Dacron over powder filler. .630" X .020" base wad punched from cereal box cardboard material. Bullet seated in contact with base wad with small compression of Dacron during seating. Bullet seated to middle of top drive band and lightly roll crimped. Bore swabbed with Hoppes followed by dry patch after each shot. Shot at 50 yards from bench rest. 6 o'clock fine bead hold on large bull.

The extremely low standard deviation of velocity, small group size and reaching my velocity objective of 1050 fps means I am likely finished experimenting with smokeless loads in this rifle.

Average muzzle velocity 1056 fps
Stand. Dev. (sample) < 5 fps
C-C group size @ 50yds = 1.25"

 

[afmelo]

Well done!
It's a shame that the sole MKIII "steel" that I own is a cavalry carbine and I do not expecte such short barrell to give good accuracy!
All my other Sniders are conversions with - maybe- an exception of an artillery carbine built by the Portuguse arsenal "FA" on 1878 with barrels imported from Beigium, but not marked "steel".
So I will instead follow your guidance on mixed charge - likely N110 + BP
In the meantime I produced an experimental lube for the bullets and impregnate wool felt for wads - 80% bees wax + 20% olive oil. Seems to work well!

 

[fourfive8]

Yes, looks good! Beeswax with vegetable oil mix works very well. Even better if you can get some carnauba wax or microcrystalline wax and mix a small amount in each batch. For years I made my own soft lube for cast bullets. I finally got lazy and use SPG now. Bought another pound a couple of weeks ago. Pan lubing, letting the lube congeal after cooling then pushing the bullet out by pushing on the nose is pretty easy process if the lube is relatively soft. But after awhile my thumb gets sore even with soft lube

Give the BP load of about 50-60 gr FF with 5-6 gr of smokeless on top of primer a try. The wad stack is the variable for taking up space between powder and bullet base. As with any BP load don't leave any air space between powder or wads and base of bullet. The wads need to be fairly stiff like dense felt or shot shell fiber wads. The lube soaked felt wad toward the bullet end of the stack also helps to keep the powder fouling soft in the bore so the next bullet fired isn't running over or being damaged by hard fouling. Not dangerous, but tends to hurt accuracy.