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Phillip Allen
10-03-2009, 08:08 PM
as mentioned in another thread...my .22 with bulk ammo had an unacceptable variation in velocity

the same day I shot a 45-70 (26" bbl)
smokless powder with cast bullet of 345g (plain base)
the standard deviation came to about 100fps with average speed at 1550fps

a .45 Colt (8" bbl)
smokless powder with 251g cast bullet
SD was about 75fps with average velocity at about 900fps

and a .44 Cap and ball revolver (8" bbl)
black powder with round ball
SD of 6fps and average velocity of about 1050fps

black powder looks better and better...6fps SD!

bullets were sorted by weight
charges were carefully weighed
cases matched

next time maybe I"ll write the numbes down and not have to rely on memory...still...WOW!

BrianW
10-03-2009, 09:05 PM
next time maybe I"ll write the numbes down and not have to rely on memory...still...WOW!

Or buy one of the chronographs that prints out the numbers.

Phillip Allen
10-04-2009, 10:36 AM
is no one suprised by the inconsistancy of smokless powder (at least in this aplication)?

BrianW
10-04-2009, 09:17 PM
What kind of smokeless powder were you using?

Check out this old website I did years ago...

The 416Taylor Webpage (http://www.geocities.com/bw_99835/)

...under the reloading data. I wasn't testing for speed deviation, but did write down some fps readings for different loads. Fairly small spread with most of mine, even increasing powder weights.

Both the cartridges you list, the 45-70 and 45 colt, were originally black powder cartridges, IIRC. Might be something there?

Phillip Allen
10-04-2009, 09:52 PM
I was using IMR powder for one and Unique for the other...(and Swiss 1 1/2 Fg for the black powder stuff)

oh yeah, Federal primers except in the case of the cap and ball revolver in which I used CCI caps

the same lube for all...

purri
10-04-2009, 09:56 PM
How old was the smokeless powder and load density vs case capacity?

I think 45-70 prefers abt IMR 4320, maybe faster.

Phillip Allen
10-04-2009, 09:56 PM
I have loaded up some black powder for the 45-70 and two smokeless loads (different IMR powder) for the same cartridge...next trip to the range and we'll see if there's a difference

Phillip Allen
10-04-2009, 09:58 PM
How old was the smokeless powder and load density vs case capacity?

I think 45-70 prefers abt IMR 4320, maybe faster.

40 some odd grains of IMR 3031...the fluffiest load I could come up with
the powder is brand new...using the Lyman 49th edition

purri
10-04-2009, 10:15 PM
I think the conversion factor of Nitro (cordite) for black loads runs as follows: the original black was 70 grains then multiply by 0.61.
But it depends what action and powder you're using.

Graeme Wright's"Shooting the British Double Rifle" has some good info.

BrianW
10-04-2009, 10:15 PM
I don't load for the 45-70, but I see that your IMR 3031 is fairly popular. Also saw some recommendations of H322 from some folks I trust. That should be a ball powder, and easy to throw.

H4895 was mentioned a few times, which is what I prefer in my 416 Taylor.

Phillip Allen
10-04-2009, 10:24 PM
I've got to use the powder on hand for now...they're still pretty much out of powder at the local shops

purri
10-04-2009, 10:40 PM
If you can use Hogdon/Varget. It's made and sold here in OZ as Mulwex. You can access their reloading charts and burn rate comparisons online.

It's an extruded short grain powder that is wholly temperature resistant.