ROT 4570 bbl.

[D. Taylor Sapergia]

I have a new rifle coming from Shiloh in 4570. I'd like to get ahead of the game a bit, and order a new paper patch bullet mold. Can anyone tell me what I can expect in Rate Of Twist, and possibly recommend a cast bullet diameter?

[BFD]

Your barrel will be 18" twist unless you special ordered something else like a 16" twist.

Either way, this is your mould https://www.buffaloarms.com/443-530-ell ... jim443530e

[Lumpy Grits]

Yes, 1/18 ROT.
They really like heavy(500+gn)bullets.
You want .4585"-.459" dia.
Shiloh makes about the very best barrels out there.
If you don't cast yet. He's a good outfit to deal with.
https://www.montanabulletworks.com/
Don't know what the issue is getting them into Canada.....
Gary

[Kurt]

I shoot that bullet Brent gave you a link for. I use it in the 18 ROT and 16 ROT and I don't think that there is a better choice for a PP in the 16 or 18 twist.

[mdeland]

Some guys are going to the 16 twist for bullets over 550 grains. I have two 45-70's in both twists and can't tell a lick of difference in accuracy in the bullets I shoot up the 530 PJ Creedmoor .
I do have a 620 grain NASA bullet I have yet to try in the 16 pitch.

[Call Turner]

According to what Kirk told me, order a mould that casts a .442 bullet, use 2 wraps of .002 paper. and use 2 wads of .025 cardboard. Your lube cookie will be 2 lbs beeswax to 1 lb jojoba oil . He recommended Brooks mould , I found most everything I needed at Buffalo arms.

[D. Taylor Sapergia]

Thank you lads! I ordered and received today my BACo 492500 pp bullet mould for my .50 cal barrelled Sharps. I now have three BACo moulds and they are truly splendid. I'm surprised someone hasn't recommended an adjustable mould, perhaps from KAL. There is no issue shipping moulds to the Great White North, though it is a spendy project. I like to buy high quality so that the quality remains long after the price is forgotten.
I have an adjustable .448" top pour pp mould already, but I'd be wrapping to groove dia. with that one. I'm pretty sure I need a bullet at bore dia. so I can seat it out and get max. powder capacity in the short 45-70 case.

[D. Taylor Sapergia]

The mould you suggested is now ordered! Thanks guys.

[BFD]

I'm surprised someone hasn't recommended an adjustable mould, perhaps from KAL.

The problem with adjustables is that they are all flatnosed by necessity. Not optimal for lots of things. Great for hunting though.

[mdeland]

My old shooting pard Bob Engelbach, who moved to Wyoming, would cast his pp bullet cores and then swage them to final shape in a punch die, before wrapping the patches on. It makes for a void fee bullet very consistent of weight and shape.
This was common practice in days gone by, usually accomplished by hammer swaging.

[Don McDowell]

I'm surprised someone hasn't recommended an adjustable mould, perhaps from KAL.

KAL makes some darn nice moulds. I've found the straight sided bullets out of his blocks to shoot better than the tapered. But what ever you do you absolutely need to stock every block you have with a set of his handles.

[SchuetzenDave]

Gyroscopic Stability factor (Sg) for BACO 45 caliber bullets for 18:1 and 20:1 twist:

BACO Sg@18:1 Sg@20:1
JIM459450M1 2.88 2.33
JIM459470S1 2.82 2.28
JIM459475 3.68 2.98
JIM459510C1 2.92 2.36
JIM459510C2 2.92 2.36
JIM459520M1 2.27 1.84
JIM459520M2 2.27 1.84
JIM459525M1 2.29 1.86
JIM459525M3 2.27 1.84
JIM459525M4 2.29 1.86
JIM459530 2.32 1.88
JIM459530M5 2.32 1.88
JIM459535C1 2.58 2.09
JIM459535C2 2.53 2.05
JIM459535M1 2.31 1.87
JIM459535M2 2.34 1.89
JIM459535M3 2.31 1.87
JIM459535P1 2.55 2.07
JIM459535P3 2.43 1.99
JIM459537M3 2.35 1.90
JIM459540M1 2.18 1.77
JIM459540M3 2.34 1.93
JIM459541M3 2.34 1.93
JIM459545C1 2.48 2.01
JIM459545C2 2.48 2.01
JIM459545C4 2.48 2.01
JIM459545M2 2.27 1.84
JIM459545M3 2.27 1.84
JIM459547C1 2.28 1.84
JIM459555C1 2.29 1.85
JIM459560M1 2.14 1.73
JIM459560M2 2.14 1.73
JIM459560M3 2.14 1.73

[D. Taylor Sapergia]

Wow! So what Sg should I be looking for in a 1:18" twist?