Looking for corroboration of 1969 7 mm mag loads using 4831

[Bmi48219]

I was cleaning out my misc ammo storage locker and came across 9 boxes of dad’s 7 mm Rem Mag reloads. Some of the brass is well tarnished and some not to bad. There are two different loads, both used H4831 powder.

One was a 154 grain Hornady jacketed bullet overtop 69 grains of 4831.
Other was a 175 grain Hornady jacketed bullet over 64.5 grains of4831.

If anyone has a 1969 era load data book I’d appreciate knowing if these loads were within manufacturer’s limits back then. Sorry I can’t be more specific regarding the bullet type. That was a detail dad didn’t find important.

I checked on Hodgdon load site and both loads exceed the maximum recommended charge. Now Dad was a brilliant self- made man with possibly the worst penmanship I’ve ever seen. I never used his rifle reloads but know for a fact his shot shell loads were often brutal. I will always honor his memory but prefer to do so with all my body parts intact.
I have a few alternatives.
I can pull them down and salvage components or
Clean them up and use them, providing the charges don’t exceed the published load data for that time period.
Thanks

[Winger Ed.]

I'd pull 'em down, lighten the load a bit, and put 'em back together.
Something that might tell you a little more about them is if you can find a fired case or two.

Besides the other considerations--- max. or over loads usually aren't very accurate anyway.

[Bmi48219]

Thank Ed. You’re of course correct about max load accuracy. Just wondered since others have frequently commented that manufacturers are more conservative with load data these days. Pulling them down does seem to be the smarter option.

[txbirdman]

Been shooting a 7 Mag since ‘73 using H4831 and the 154 gr Hornady SP. I never loaded that hot. So I’d pull them, especially given the age of the ammo

[Winger Ed.]

I'm big on accuracy, and don't ever seem to shoot out past about 200 yards.
Of the 7mm and .300 belted Mags I've had in the past, I never really had the need for their full potential.

Even with the new generation books, I find myself loading at around 80-90% of their max. listings.
It works for me and I think it saves a little wear and tear on barrel throats and locking lugs.

[Paper Puncher]

Lyman 45th edition
154gr jacketed 4831 66gr max
175gr jacketed 4831 65gr max

[Bmi48219]

Thanks for the input guys!

[IridiumRed]

If in doubt, pour it out.

Life is too short to take a risk on getting hurt by something for no good reason

[dale2242]

From my older manuals. Max loads of H4831

Hornady 1973
Rem 700 rifle
154 gr 69.1 gr. 175 gr 64.9

Speer 1967
Rem 700 rifle
160gr 67gr. 175gr 64gr

Speer 1974
savage 110 rifle
160 gr 60gr. 175 gr. 58 gr

Speer dropped their max loads dramatically from 1967 to 1974.
Is it the difference in the rifles?

I`m not sure this is much help to you but this is what I found.

[dale2242]

From my older manuals. Max loads of H4831

Hornady 1973
Rem 700 rifle
154 gr 69.1 gr. 175 gr 64.9

Speer 1967
Rem 700 rifle
160gr 67gr. 175gr 64gr

Speer 1974
savage 110 rifle
160 gr 60gr. 175 gr. 58 gr

Speer dropped their max loads dramatically from 1967 to 1974.
Is it the difference in the rifles?

I`m not sure this is much help to you but this is what I found.

[Larry Gibson]

From my older manuals. Max loads of H4831

Hornady 1973
Rem 700 rifle
154 gr 69.1 gr. 175 gr 64.9

Found the same plus from Hodgdon's Data manual #22 (1974)

Max load with 154 gr bullet using 4831 is 68 gr at 55,100 CUP.

Max load of 4831 with 175 gr bullet is 63 gr at 53,800 CUP.

[Bmi48219]

Found the same plus from Hodgdon's Data manual #22 (1974)Max load with 154 gr bullet using 4831 is 68 gr at 55,100 CUP.
Max load of 4831 with 175 gr bullet is 63 gr at 53,800 CUP.

I’m going to pull them down. Not worth the risk. Thanks to all.

[MarkP]

From my older manuals. Max loads of H4831

Hornady 1973
Rem 700 rifle
154 gr 69.1 gr. 175 gr 64.9

Speer 1967
Rem 700 rifle
160gr 67gr. 175gr 64gr

Speer 1974
savage 110 rifle
160 gr 60gr. 175 gr. 58 gr

Speer dropped their max loads dramatically from 1967 to 1974.
Is it the difference in the rifles?

I`m not sure this is much help to you but this is what I found.

Testing methods;

Pressure barrels changed from copper crusher (CUP) to Piezo (psi) with Piezo you would see peak pressure, CUP is a small copper cylinder that sits on top of a piston and between an anvil, when the cartridge is fired the case vents gas thru the hole in the chamber and pushes the piston upwards thus crushing the copper cylinder.
Each lot of copper cylinders will have calibration chart in the box. The final height of the crusher corresponds to a CUP value. So a shorter crusher = higher pressure or higher CUP value. This system would not see a tall narrow spike in pressure, 7 mm Rem Mag is one cartridge that was reduced somewhat.

[shootinfox2]

From the 1979 Speer manual.

[shootinfox2]