Working Up Magnum Loads

[gunboy]

very familiar with load work-up on rifles and watching for flattening primers, sticky bolts, shiny extractor marks etc etc.

Very little data available for my new gun a 445 Supermag....As I work up loads on a revolver what are some of their signs of reaching max?

How temperature stabile is H110?

My first loads will be with H110 and Cast Performance 300gr GC's. Any sharing of experiences from you revolver pro's is very appreciated.

[JD45]

For magnum revolvers, I stick with the loading manuals. Reading pressure signs in revolvers (and most handguns) is risky business. Those 5-shot custom .45 colt conversions by Linebaugh and Bowen have been loaded to around 62,000cup and cases would extract easily. That should be a warning to all of us with normal sixguns.

I have noticed a different sound and feel when I get near the book maximum with some calibers. Load a 125gr. 357mag to the max listed in some manuals and the blast is severe enough to kill small rodents.

There are so many variables. Like chamber and throat dimensions, BC gap, brass hardness, ect. . Unless you have access to pressure testing equipment or access to a guy like Linebaugh that does, I would stick to the manuals.

[sargenv]

I would stick to what most people say, sticky brass, flattened primers, etc. The first stuff I loaded for my GP100 way back when, was an extrapolated load (I know, not smart, but I still have all my fingers ). It was something like 19 grains of Blue Dot with a 88 gr .355 .380 bullet. Woo hoo talk about flattened primers.. At the time I was used to loading shotshells to "the data stated in the book" and didn't understand the whole "back off 5-10% then work up your loads". This was also before the big boom at Hercules (now Alliant) when you used a lot more Blue dot per given load. All I remember was that stuff was pretty warm, with the flat primers and such. They were however fun to shoot. I now wish I had a chrono. I figure since they were .355 and the bore was .358, the pressures were a tad lower due to not fitting correctly in the bore.

Can be filed under "Stupid thing I did when I was a newbie metallic reloader".

Vince

[gunboy]

Thank you for the replies. I'll have to rely on common sense signs and ones listed as there are no published loads for this cartridge (or none that I have been successful in finding so far). I have talked to Sierra and gotten some very basic load data using their 300gr Sportsman bullet which is what i will start with and H110 as a powder. Any other info or experiences appreciated.

[Les Snyder]

Gunboy....I don't do a lot of custom reloading any more, but found that the VihtaVuory (spelling) manuals were the closest published velocities to those chronographed.... I shot a lot of cast bullets in the 240 t0 250grain range with H110 in .44mag but think that I would look at the VV loads in the 3xx series pistol powders..... regards Les