Powder differences

[dsmjon]

Trying not to be a hard head here..

What's the difference b/w Win 748 and Win 760 powders? I bought a pound a while back, to use up some LR Magnum primers I was accidentally sold (w/ no return/exchange policy).

I'm trying to go ahead and burn this stuff up, both powder and primers.

Using a 425gr slug in a 45-70, does anyone know of a load using such a powder/primer combo?

I loaded 1/2 dozen tonight with 52gr 4654 w/ std LRP's. Only other 'rifle' powder I have is 4350. Any load data for that powder would be appreciated as well.

I have learned quickley, being on this site, what the most popular powders are! Next time it'll be RE-7 and 3130 (or was that 3031?) :)

TIA if anyone can humor me with the above questions.

[SierraWhiskeyMC]

What are you shooting in .45-70?
Trapdoor Springfields need pretty light loads.
Lever actions like Win 1886 can use somewhat heavier loads.
Modern rifles can use pretty heavy loads.

Depending on what rifle(s) you have, you may or may not be able to use those components.

[madsenshooter]

748 has a burn rate near IMR 4895 wheras 760 has a burn rate a trifle faster that IMR 4350. In 30/06 I always had to use magnum primers to get a complete burn with 760. I can't offer anything in the way of data without knowing the gun. Hornady has data for modern rifles like the Ruger, with 500 grain bullets, starting at 47.8 of IMR 4895 @ 1500fps, if we're talking about a Ruger, then that'd be a good point to work up from with the 748 and the boolit and primer you have.

[Rocky Raab]

I'm unclear from your post what you bought. A pound of 748? A pound of 760? A pound of each?

[dsmjon]

Sorry, no more late night posting for Jon!

It's a 1895G Marlin .45-70.

I have 1lb of 760.

[SierraWhiskeyMC]

Well, both 760 and 4350 are a bit too slow for use with a straight-walled cartridge case like the 45-70. Those powders are really meant more for .30-06 and other necked cartridges with heavy J-word bullets.

Although the initial chamber pressure would be low, you might wind up with some really high secondary peak chamber pressures that could disassemble your rifle.

IMR 3031 is a great powder, but can be a booger to meter due to it's strong tendency to bridge.

Look at using 2400 or IMR 4198 instead. You won't get quite the velocity as with 3031, but they're more economical and a lot easier to meter.

Meanwhile, I use IMR 4350 primarily for long range target shooting with .30-06. You can push a 172gr HPBT a long ways with 56gr of it; and even with that cartridge it's a compressed load.

[dsmjon]

So with the listed powders, I'm fairly SOL without buying more? I will be getting some 3031 and/or Re-7 based upon what I've read, but I'm hoping to shoot a few rounds before I'll have a chance to go get the powders.

I did load a few rounds last night using a Hornady (?) data book, 52gr of 4064 under a 425gr GC'd boolit.

I'll be trying a few loads with Unique, just didn't want to mess with fillers in the case.

I see folks talking about burning rate charts to sample "xx" load, based up it's burning rate compared to "yy". At the risk of going to another topic, how does one use such data? Could suck information be used to determine a load one could try using with a Magnum LR primer?

[Rocky Raab]

You can't really use a burn rate chart that way - they're good only for broadly generalizing powders. You should really be using published and tested load data only. There is no excuse not to, as so much of it is online now. Check the manufacturers' websites first.

If you begin with Start loads (as you always should), you can safely use those magnum primers with any powder. Just be sure to stop working up when you get close to the velocity predicted by "book" maximums, even if you are using less powder than the "book" load.

Save that 760 for when you buy a 30-06.

[c3d4b2]

Very good advice


You can't really use a burn rate chart that way - they're good only for broadly generalizing powders. You should really be using published and tested load data only. There is no excuse not to, as so much of it is online now. Check the manufacturers' websites first.

[dsmjon]

Rocky, that's exactly the way I do it, and the 760 is only used in the ought6 ;)

I wasn't sure what people did with burn rate data, now I know. From reading various posts about using such data, I was surmising there was a way to deduce a start point for using a load combo which is otherwise not published somewhere.

[madsenshooter]

I really like Hodgdon's site. Pressures are given for the starting loads and most other sites don't mess with it. That comes in handy for me, as the .308 and 30/40 have similar capacities and some of the/308 starting loads are within the Krags pressure limits. They don't show any loads for a boolit as heavy as what you're using in your 45/70, but they do go up to 400 grains and from that you can get an idea on your 4064 load. <30,000CUP and <1800fps.

[SierraWhiskeyMC]

I like Hodgdon's site too, but...
I wish they listed loads for heavier bullets and boolits than they do.

I sure wish they gave more specifics along with the data, for instance what primers were used, what was the length and twist rate of the barrel they used to test the load in.

Going from 400gr data to 425gr estimation is not a big stretch; that's just a 6.25% increase in boolit weight.

But unfortunately, they don't have ANY data online for lead boolits in .45-70 for lever action rifles; and trying to use J-word bullet data for lead boolits can get you into big trouble.

[smith52]

I sure wish they gave more specifics along with the data, for instance what primers were used, what was the length and twist rate of the barrel they used to test the load in.

SierraWhiskeyMC,
Hodgdon's site does give the primer, twist rate, and barrel lenght they used for their data but, only when you click on Hodgdon's "PRINT" icon. The info is at the top of the printable page. I use the site alot myself.