H4831SC needs magnum primers?

[Ganderite]

I have run trials using different powder coatings, including graphite, moly powder, and a list of retardents that might be propriartary info. Part of the 'black magic' of making powder is trying to change the burning characteristcs.

DNT is a significant modification to the powder surface. It runs 6 to 12% of the weight of the power. It is a major difference between, say, 4064 and 4831. Graphite, on the other hand, is a mere dusting. about 1/10 of 1% by weight.

Some stick power has a hole through the length of the stick. This means that as the interior chanel burns, the burning surface area get bigger as the exterior area gets smaller. The burning speed is uniform.

One variable is flame temperature. 3031 is one of the coolest - 4064 one of the hottest (of the single base powers). Double base powders are hotter. DNT also moderates the flame temperature, although MC is a better temperature moderator.

Powder has a moisture content (typically around 1%). It is one of the variables that determines the speed of powder and an important variable in the hands of the consumer. As powder sits in your power thrower, it dries out and speeds up. This is why a new can of power can seem slower.

 

[mike shickele]

I have run trials using different powder coatings, including graphite, moly powder, and a list of retardents that might be propriartary info. Part of the 'black magic' of making powder is trying to change the burning characteristcs.

DNT is a significant modification to the powder surface. It runs 6 to 12% of the weight of the power. It is a major difference between, say, 4064 and 4831. Graphite, on the other hand, is a mere dusting. about 1/10 of 1% by weight.

Some stick power has a hole through the length of the stick. This means that as the interior chanel burns, the burning surface area get bigger as the exterior area gets smaller. The burning speed is uniform.

One variable is flame temperature. 3031 is one of the coolest - 4064 one of the hottest (of the single base powers). Double base powders are hotter. DNT also moderates the flame temperature, although MC is a better temperature moderator.

Powder has a moisture content (typically around 1%). It is one of the variables that determines the speed of powder and an important variable in the hands of the consumer. As powder sits in your power thrower, it dries out and speeds up. This is why a new can of power can seem slower.

Sounds like you understand what your talking about..........I would have thought that graphite would have had a significant effect on the burn rate though.
Mike

 

[Bassmaster]

Sounds like you understand what your talking about..........I would have thought that graphite would have had a significant effect on the burn rate though.
Mike

not trying to ruffle feathers, but I work in an 'environment' where graphite is the material of choice for putting out uranium fires....

 

[Mystic Precision]

You were right, Mike. I went with a frozen bolt and ammo to the range and got the same issue again... in two different rifles! Aha! It's the combination of the cci200 primers and a slightly lighter load of powder that caused it. What I did notice was that when I tipped my barrel up before shooting I didn't have a problem in either rifle.

I switched to Winchester LR's and Winchester LRM's and had excellent success. Note to self... use magnum primers with H4831SC and don't look back.

Thanks for all the help guys.

BINGO - low charge density allowing the primer flash to go over the powder. Flash them alright but not enough zip to get the boom we want.,

A primer with more flash/brissance will solve your issues as you have found.

Also, a change in powder to increase load density will prove very beneficial your accuracy.

Jerry