H4350 Powder Specs

[Gil Martin]

I would refer to a current reloading manual. The load you mentioned appears to be a bit over maximum. The link below will provide useful reloading data. My recommendation would be to pull the bullets, save the powder and find a suitable load. You are correct, some reloading manuals have reduced powder charges over the years. Not sure why, but I follow their load data. All the best...
Gil





http://hodgdon.com/

[fishdoggydog]

I have both IMR and H4350 powders, what is strange to me is how a load listed 35 years ago is now considered unsafe. Yes I am going to pull the bullets, I fired one round today and I could see a case crack, and the primer was popped on ejection. The link to the Hodgdon site is where I went for the latest info. Thanks you guys.

[Jack]

Powders change over 40 years, just like people do.
So do methods of measuring pressure - some of the old manuals estimated pressure by looking at primer flatness and maybe miking expansions rings. Neither method is anything like precise. Then came the copper crusher method, which was better, but not perfect. Copper crusher could only be done in test barrels, too - not possible to use the method in a real world rifle.
Now the ballistic labs use much more accurate equipment - usually a strain gauge set up that measures in PSI, and can be used on the same model rifles that people can buy over the counter.
Some loads have been lightened over the years, and people claim it's "because of the lawyers". Nuh uh. Powder changes (and bullet and brass changes, too) and more accurate measuring capability now give us much better info on what's a safe load.
Fish, your old load might be fine, with the components you used at the time. If you have some left, they should be safe to use.
On the other hand, if you're going to do some loading now with new components and powder, use current data.

[skeet]

What Jack said. Pressure measuring is MUCH better these days. Doubt the 100 gr load is an overload though