300 BO surplus powder question

[milsurpcollector1970]

I recently started loading for 300 Black with surplus wc820

Im using H110 data with Lee 180 and Lee 160 gr

I am using 18 grains with the Lee 160 gr and 15 gr with Lee 180

I am getting blown primers with these charges even though they below maximum.

Is there something wrong with the powder? Am I doing something wrong?

[bosterr]

I've loaded WC820 in .357, .41 and .44 since the 80's and have found the different burning rates for the different lots are all over the place. Some lots you can use data for H110 but I have about 5 pounds in a jug that seems more like Unique and I don't know what caliber to use it in. It's possible you may have a fast lot so back off a ways and start working up.

[Ford SD]

I recently started loading for 300 Black with surplus wc820

Im using H110 data with Lee 180 and Lee 160 gr

I am using 18 grains with the Lee 160 gr and 15 gr with Lee 180

I am getting blown primers with these charges even though they below maximum.

Is there something wrong with the powder? Am I doing something wrong?

Having loaded the 300 BO I would reduce your charge by 1-1/2 to 2 g and work up by .2 g at a time using small batches

the 300 is very dependent of Case volume / seating depth

Heavy cases = less volume and higher pressures

Are you using a mag primer or a reg SRP primer ?

[MT Gianni]

The WC 820 I have shot 10 lbs of uses AA9 data, not H110.

[ARKANSAS PACKRAT]

I have loaded 14.5 of WC820 behind 169gr. jacketed and 174gr cast with no pressure signs or function problems.

[dale2242]

Like MT Gianni, my lot of WC820 says to use AA9 data.

[mdi]

I still have the jug my WC820N came in. Bartlettes info states use H110 data minus 10%. I have worked up loads for 44 Magnum that were about .3 grain below the max -10% formula, many times. Easy extraction good accuracy and no leading with my 12 BHN alloy...

[Green Frog]

Never used WC829, (CORRECTION:820) but shot beside Dale53 when he did and I shot what was said to be the same surplus powder as sold by Hodgdon as H108. They seemed to behave identically to each other and were said to behave grain for grain like the early lots of AA#9. We were shooting it in custom chambered single shot rifles that used a 357 Mag case straight tapered to a true 32 caliber (Charlie Dell’s 32/357). It also behaved equivalent to #9 in my 32-40.

If I ever decide to load for my 300 BO, I’ll likely start with AA#9 data.

Froggie

[mdi]

Never used WC829, but shot beside Dale53 when he did and I shot what was said to be the same surplus powder as sold by Hodgdon as H108. They seemed to behave identically to each other and were said to behave grain for grain like the early lots of AA#9. We were shooting it in custom chambered single shot rifles that used a 357 Mag case straight tapered to a true 32 caliber (Charlie Dell’s 32/357). It also behaved equivalent to #9 in my 32-40.

If I ever decide to load for my 300 BO, I’ll likely start with AA#9 data.

Froggie

OOPS! Yep, typo. Fat fingers and 9 is too close to 0. Should read WC820N

[milsurpcollector1970]

Thanks everyone

I am pulling all my 300 Black loads and starting over with AA#9 data, whats interesting is I have used it in other catridges with H110 data with no issues. 44 mag, 38-55

The load data for AA#9 on quickload is much less than H110 which would explain my overpressure signs Max load with Lee 180 is 12.8 gr AA#9

I am using standard small rifle primers, mostly CCI

My jug of WCC820 is about 15 years old, it is stored in a climate controlled basement