Author Topic: 45/70 cast bullet diameter question (Read 820 times)

lookin back charlie · « **on:** August 07, 2003, 01:30:46 PM »

I am in the process of prepping cases for a 45/70 that is on the way....The bullets that I have accumulated for this round all mike out at .455 to .457..is this the case for this round? Do they obdurate to fill out, are these undersize?......What would be a good starting load for 300 gr slugs to move out at around 1200-1400 fps?...

charlie...

are they gaining on me? I keep looking back to see....

Cat Whisperer · « **Reply #1 on:** August 07, 2003, 02:54:29 PM »

Typically one launches cast boolets at bore size or .001 to .002 over bore size. This means you need to wait. Soft boolets will obdurate better, and there are innumerable things to put in under the boolet to help this - fillers, wax et al.

Starting loads - there will be several others that will suggest specific loads, I just grab the manual and pick a powder I like and start working it up. It will depend on what you are shooting - the loads I use for the trapdoor springfield are MUCH milder than for the H&R or the Ruger #1.

Kragman71 · « **Reply #2 on:** August 08, 2003, 03:52:23 PM »

Charlie,
I have three Trapdoors,that I shoot;two of them regularly.
I find the .457 diameter a little too small. I find little difference with accuracy between .458 and .459 diameter bullets.
Most of my shooting is in the 1200-1500 FPS velocity range.
I like IMR#4198 and Alliant #7 powders.
I always use fillers with 4198 and sometimes with Rel#7
Frank

Sheriff Bart · « **Reply #3 on:** October 31, 2003, 10:49:32 AM »

The diameter of the bullet is dependant on the size of the bore. The old rifles Trapdoors and Sharps have grooves running from .457 to .463. This wasn't a problem with black powder as a .457 bullet had a hollow base and thew force of the elploding powder bumped the bullets up to size. In addition as the bullets of SOFT lead slugged up in the bore they tended to wipe out the black powder fouling. Smokless powder does not bump up the bullets like black does and so you need to be a lot more picky in choosing bullet diameters. If I load smokless in my trapdoor I use a .459 bullet and in my sharps I use a .457. For my best friends Sharps we have to use a .460. I am lucky as I have a lathe and make my own sizing dies in the diameters I need. I think LEE will supliy odd sizes if needed. For Black powder I use copies of/or Oirginal moulds with the old hollow base design and use 1-20 lead at the HARDEST and have no problem getting under 4" at 100 with military Iron sights.

Lead pot · « **Reply #4 on:** October 31, 2003, 01:09:02 PM »

Charlie.

I dont shoot jacketed bullets or smokless powder in my sharps or trap doors.You should slug the barrel and fit the bullet to it.

I cast my bullets .001-.002 smaler on the ogive or bore,and fit the groove.
take my Shiloh it mesures .400 bore.408 groove.my mould is cut .398-.408.
Like Krag man said the old trapdoors run a little large,I have found them at .462.With a .457 bullet in that barel you will get gas cuts even with a jacked bullet.
I would stay with black powder in those old rifles I think you will find they shoot better with it,and the rifle cleans better with it.I can get my powder rifles clean faster then I can smokless with jacketed bullets.
And yes the jacket should be larger then the bore.But regardless what is said at times,the smokless load will slug up a jacketed bullet some.

Lp.

The Shrink · « **Reply #5 on:** November 03, 2003, 01:52:42 AM »

Contact your berrel maker, or the gun maker. They should tell you the exact bore and groove diameters of you barrel.

Go with the above advise from there.

Wayne the Shrink