Pre-'79 IMR-4350 & 8x57 ?

[kcofohio]

A guy I work with gave me 5 lbs. of IMR-4350, several 100 casings and 170 gr. bullets, and over 800 CCI 200 primers. They were his Father-in-laws', who had passed away in '79. With this came a '73 Hornady Vol. II and a '62 Speer No. 5 handbooks.
The Hornady listed the 170 gr. RN. at 49.3-56.0 gr.with a seating depth of .292". At 52.6 gr. the casing is topped off, even with lightly tapping the side to try and settle it down only gives me up to 53.0 gr.
The powder is dry, as when I poured it into the hopper, I could see dust rising from it.
My question is could the powder have dried out to where is lost some weight to it? Or do you have to compress with a dowel to get it up to 56 gr.?
BTW, I loaded up some rounds from 50.5-52.3 gr. and all fired well with no signs of over pressure. I'm quite new to rifle reloading and Varget is all that I have used before this.

 

[NCsmitty]

You first need to determine if the powder is viable to use. Does it still have an ether type odor, and is the container metal, and free of rust, and does the powder have any visual signs of deterioration? If not, it's probably safe to use. I would only try some minimum loads to start though.
Being new to reloading, you need to be cautious because you don't know the powder's true history.


NCsmitty

 

[kcofohio]

I did check for odors and the color of the powder. Containers are sealed with the tin plugs. The top of the one I used had light surface rust, from handling, and still smooth to the touch. It looks as though the top has a coating of OD green and the Lot# ink is quite clear. The bottom of the canister is bare tin with no rust. Inside is brand new shiny.
The powder is of the extruded type and the pellets show no signs of breaking down.
When fired, they had less felt recoil than the Varget loads, which were at the high side of a medium load per Hodgden data.

 

[Otto]

What's the lot number?

 

[kcofohio]

Ra3 6153 That is the one I opened. It is labeled IMR-4350 "Improved Military Rifle Powder".

The others are just labeled IMR-4350 and a lot P76MY07B 6296.

 

[Otto]

P76MY07B 6296 = May 7, 1976

 

[kcofohio]

Thank you Otto! The first one listed I'm guessing to be older.