Hodgdon vs IMR and data change???

[cloverleaf]

Shot a few of my tried and true loads for the 250 Savage a few weeks ago. 38 gr off 4350 over a 100 be BT. Groups opened up more than I thought they should and bolt lift was too stiff. Got to looking at my notes and Dad's and realize that he loaded Hogdon and I was using IMR. My manual indicates 1\2 grain less as max load with IMR. Don't assume!!! Got to looking a little more and when comparing loads with IMR 4064 his 1964 manual indicates max load of37 gr and my 1992 version is at. 34 gr max. Is it common for powders to change over time? If so, my data is in need of re evaluation. CL

 

[Paul Barnard]

Yes, it is very common. You'd be astounded if you compared Nosler's #4 manual to Nosler's #8. It's that way with all component manufacturers. In front of me I have a Ramshot loading pamphlet. The data in it is appreciably different from the data on Ramshot's website. There can be quite a bit of variation from one manufacturers manual to the next as well. Hornady my list a max of X powder for X bullet where Nosler may recommend more or less for the same powder and bullet.

 

[Guy Miner]

Yes - things change - which is why it's good to check current load data.

Also, when opening up a new canister of powder, it may be from a different lot number from previous canisters. Good call to drop back a bit on the powder charge and re-work that load.

One of the reasons I'm so fond of 8 pound powder canisters. Yes, they're expensive, but I don't have to stop and "adjust" my loads very often. I try to keep 8 pounders of Varget & H4350 on hand.

Guy