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Lyman manuals have me confused
hunter86004
Member Posts: 1,222 ✭✭✭✭✭
Brought this over from the cowboy action forum. Not much going on over there.
Ok, decided to reload a bunch of 45-70s for my trapdoor and looking at both the 46th and 49th editions, it suddenly became strange.
Using the same bullet mold, the 46th edition shows a bullet weight of 366gr. and the 49th edition has it at 385gr.
It got even better when I looked at the starting load for IMR3031 which I have quite a bit of. The 46th edition shows a start to max as 30-39 grains with a Dacron filler and the 49th edition shows a start to max of 40-44.5 grains with no filler.
Then, when I looked at the pressure for the max charge, in each book, the older book shows 17,000 cup with the lighter charge and 15,800 with the larger charge in the new book.
What is a fella to believe?
Ok, decided to reload a bunch of 45-70s for my trapdoor and looking at both the 46th and 49th editions, it suddenly became strange.
Using the same bullet mold, the 46th edition shows a bullet weight of 366gr. and the 49th edition has it at 385gr.
It got even better when I looked at the starting load for IMR3031 which I have quite a bit of. The 46th edition shows a start to max as 30-39 grains with a Dacron filler and the 49th edition shows a start to max of 40-44.5 grains with no filler.
Then, when I looked at the pressure for the max charge, in each book, the older book shows 17,000 cup with the lighter charge and 15,800 with the larger charge in the new book.
What is a fella to believe?
Comments
Powder's can/do change over time. Primer, case, and bullet type and weight make a difference. So does the manner of testing copper crusher or strain gage.
Lyman has varied the weight of bullets with the same mold #'s over the years. 20 grains in 400 is what 5%
Added: Looks like they cannot give any info to the general public for legal / liability reasons. That is the name of the game in today's world.
Does #46 say No 2 alloy? #49 does and that is a standard formulation.
When in doubt, I go to Ken Waters. He thought 38.5 gr IMR 3031 was right for a 383 gr cast .45-70. Note that this is on the high side for #46 and on the low end for #49. I would avoid non-gunpowder crap in my ammunition if I could.
Does #46 say No 2 alloy? #49 does and that is a standard formulation."
The bullet in the old book was sized to .457 and the new book it's .458, but, assuming the same size mold is used, sizing does not change the bullet weight. Both mold numbers are the same. No alloy is listed in either book, but both were tested on a universal receiver.
I guess my question is why a smaller diameter, and lighter, bullet over a lighter charge would create a greater pressure while a larger bullet over a larger charge would be less pressure. It doesn't sound right to me.
Good morning Don,
You should be using the most current load data for your application. Loads don?t stay the same over time, as even just 1 minor change to the recipe could completely change the results. We no longer recommend the use of ANY fillers for reloading. Please give us a call at 1-800-225-9626 if you need further assistance.
Best Regards,
Customer Service
From: Lyman [mailto:customerservice@lymanproducts.com]
Sent: Tuesday, May 09, 2017 1:04 AM
To: Customer Ticket Mailbox
Subject: Contact/Catalog Request Received