Pistol Powder In Fat 30's

[Hi-Standard]

I've just come upon a quanity of AA#2, AA#5, 700X, and 800X. I was wondering about your experiences with gas checked/non-gas checked cast bullet loads in fat 30 calibres such as 303 Brit, 7.65 Mauser, 7.62x54R Russian, etc, without the use of fillers. Have used Unique with great success without fillers from 10 to 14 grains. I suspect the 800X maybe a little too slow not to use a filler in. I'll be using a LEE 185gr. mold and a LEE 160gr and I really do not want to have to use fillers, but I also do not want to creat a high pressure detonation either, and Unique is the only powder that I am aware of that is not placement sensitive. Thanks.

[Larry Gibson]

Hi-Standard

The "high pressure detonation" of fast burning powders in cartridges theory (assuming you're meaning the powder detonates under high pressure) was disproven some time ago. However if you mean the rifle "detonationing" (exploding) from too much pressure then that possibility is always present with fast powders used in larger cases. The key there is to ensure there is no double or triple charge of powder in the case. Otherwise the use of such powders as you mention is entirely safe.

With such powders you can load to light and get poor accuracy because of inconsistant ignition. Or you can load to heavy and get poor accuracy because the pressure curve is to fast for the alloy. The key is to find a load that balances consistant ignition with accuracy. Some powders just won't work because that balance can not be achieved with the desired weight of bullet. However in your case you should achieve both with the bullets you are using.

With those bullets in those cartridges using those powders you should be looking at consistant ignition within a veloacity range of 1200-to 1600 fps. The faster powders will be at the lower velocity and the slower powders at the higher velocity end of that range. The easiest way is to work up loads using a chronograph and grouping at 100 yards. The chronograph will tell you when the loads are igniting efficiently when the ES of a 5 shot string is under 50 fps and the SD is 25-40% of the ES. Grouping at 100 yards will give a much better idea of the actual accuracy than at 50 yards. If the ES stays small and the groups begin to get bigger you have gone beyound the "balance" point. Waht you are looking for is that "balance point between consistant ignition and accuracy. When you have the smallest ES with the smallest group you have found the balance point and it is "the" load for that powder/rifle/bullet combination.

I would suggest well fire formed cases, neck sized with the flasholes drilled out with a 28 to 30 drill bit. This allows the primer flash to get into the case much quicker and leesons the "position sensitivity. In the case of rimless cases with light loads it also prevents the shoulder from setting back and headspace problems developing. Of course these then become dedicated cases for these light loads and mid range cast bullet loads. They should not be used for regular "service" loads.

Larry Gibson

[Hi-Standard]

Hi-Standard

The "high pressure detonation" of fast burning powders in cartridges theory (assuming you're meaning the powder detonates under high pressure) was disproven some time ago. However if you mean the rifle "detonationing" (exploding) from too much pressure then that possibility is always present with fast powders used in larger cases. The key there is to ensure there is no double or triple charge of powder in the case. Otherwise the use of such powders as you mention is entirely safe.

With such powders you can load to light and get poor accuracy because of inconsistant ignition. Or you can load to heavy and get poor accuracy because the pressure curve is to fast for the alloy. The key is to find a load that balances consistant ignition with accuracy. Some powders just won't work because that balance can not be achieved with the desired weight of bullet. However in your case you should achieve both with the bullets you are using.

With those bullets in those cartridges using those powders you should be looking at consistant ignition within a veloacity range of 1200-to 1600 fps. The faster powders will be at the lower velocity and the slower powders at the higher velocity end of that range. The easiest way is to work up loads using a chronograph and grouping at 100 yards. The chronograph will tell you when the loads are igniting efficiently when the ES of a 5 shot string is under 50 fps and the SD is 25-40% of the ES. Grouping at 100 yards will give a much better idea of the actual accuracy than at 50 yards. If the ES stays small and the groups begin to get bigger you have gone beyound the "balance" point. Waht you are looking for is that "balance point between consistant ignition and accuracy. When you have the smallest ES with the smallest group you have found the balance point and it is "the" load for that powder/rifle/bullet combination.

I would suggest well fire formed cases, neck sized with the flasholes drilled out with a 28 to 30 drill bit. This allows the primer flash to get into the case much quicker and leesons the "position sensitivity. In the case of rimless cases with light loads it also prevents the shoulder from setting back and headspace problems developing. Of course these then become dedicated cases for these light loads and mid range cast bullet loads. They should not be used for regular "service" loads.

Larry Gibson

Larry thank-you for that very informative read. I was unaware that low charge detonation, and that's what I was refering to, had been disproven. I am very interested this summer in shooting some cast loads, and was very impressed with the results I've had in the past with Unique. But fellow shooters had warned me about detonation, due to the small amount of powder in a large case burning all at once instead of a controlled type of burn. I had always believed that was the cause of detonation anyway. Anyhow, I only have 1 lb. of Unique left, but a much larger quantity of the powders mentioned in my first post, and I only shoot enough handgun in the run of a year to use up a pound of powder, if that even.

[3rptr]

Larry Gibson,
Have you gone in search of the Secondary Explosion Effect?

IE, dropping loads down excessively without case pressure problems..

I wouldn't doubt your word, you seem knowledgeable here, I'd just like to know where the research is.

All my rifles have shot better than my own capability.
Once the optimal load is found for the rifle, bullet, and powder, the remaining option is to look for efficient gallery loads, which I enjoyed quite a bit more than barn blasters that would penetrate a manhole cover nailed to a tree in the next county.

Thanks Larry, look forward to directions
3rptr