Pistol Primers question: LP - LP Magnum adjusting powder charge

[RC46]

With primers and Gold being worth about the same, and not being able to find any LP primers, I find myself having to use LP Mag primers to reload 45 Long Colt ammo. I have always heard you need to drop the powder charge about 1gr when using mag primers. Any input on this? Necessary? I shoot a 94 Legacy & Ruger Vaquero if that matters.

[nhyrum]

Have to? Probably not. Are you willing to bet your hand and gun on it? I dunno. I personally would reduce a bit.

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[Outpost75]

In the .45 ACP and .38 Special comparing velocity data for standard target loads with the H&G#68 in the .45 and H&G#50 in the .38 Special, magnum primers required a 10% reduction in charge weight to produce the same velocity, which amounts to about 0.3 grain reduction in the .38 Special and 0.4 grain in .45 ACP, when loading the fast-burners similar to Bullseye, TiteGroup, 231, WST, 452AA. I did not test slower burning powders such as Unique, as it has been my experience that it doesn't burn completely in less than full-charge loads with a standard-weight bullet for the caliber.

Recently I've tested Cowboy loads in the .45 Colt and .44-40 for use in pre-1900 Colts and Winchester 1873s. I found that the 10% charge reduction rule for magnum pistol primers held true when using the common, fast-burning flake pistol and shotgun powders normally used for standard-pressure lead bullet and Cowboy loads not exceeding about 14,000 psi.

I have NOT used magnum primers with Trail Boss and I do not recommend doing so in the absence of credible pressure tested data.

But using magnum primers with black powder loads appears to do no harm, and in rifle cases larger than the .44-40 appears to produce a cleaner burn and more uniform velocity.

[downzero]

I would want to know what powder you're using. Also, there is no such thing as 45 "Long" Colt. The cartridge is called 45 Colt.

[Kevin Rohrer]

Also, there is no such thing as 45 "Long" Colt. The cartridge is called 45 Colt.

Officially, you are correct. Unofficially, many (including me) use the "Long Colt" designation to differentiate it from the .45ACP.

[RC46]

Outpost 75, your evaluation was most helpful. thx.
On the 45 "long" colt, without that the next question is do you mean ACP? Several ammo boxes I have are marked long, for same reason. In 1873 the US Army adopted the 45 Colt, a couple of years later the 45 Schofield - Schofield fits in Colt, Colt doesn't fit Schofield. Chaos, so the Army required to specify 45 Colt (long), therefore 45 long Colt. An interesting bit of history.
On the load I was thinking of: using Hornady 250 gr XP/XTP bullets (to start because I have a box) and (standard load) #1 - 23 gr WW296 and #2 - 18gr 2400, and then reducing load by 10% for LP Mag primer.

[Outpost75]

Same 10% reduction rule applies with any of the fast burning powders in pistol cases regardless of size.

Difference comes to about 0.2 grain in .32 ACP, 0.3 grain in .38 Special wadcutter, 0.4 grain in .45 ACP wadcutter, 0.5 grain for full-charge .45 ACP 230-grain, 0.7 grain in .45 Colt, .44-40 etc. with powders similar to Bullseye, TiteGroup, 231, WST.

Cannot speak to the slower burners like Alliant #2400, 296/H110 in magnum charges.

I would not substitute primers with those powders lacking credible pressure tested data.

[downzero]

Outpost 75, your evaluation was most helpful. thx.
On the 45 "long" colt, without that the next question is do you mean ACP? Several ammo boxes I have are marked long, for same reason. In 1873 the US Army adopted the 45 Colt, a couple of years later the 45 Schofield - Schofield fits in Colt, Colt doesn't fit Schofield. Chaos, so the Army required to specify 45 Colt (long), therefore 45 long Colt. An interesting bit of history.
On the load I was thinking of: using Hornady 250 gr XP/XTP bullets (to start because I have a box) and (standard load) #1 - 23 gr WW296 and #2 - 18gr 2400, and then reducing load by 10% for LP Mag primer.

296 requires magnum primers.

2400 does not and I have read accounts of pressure issues using magnum primers with 2400.

Your listed loads are definitely in the "Ruger Only" range. I would NOT be loading those in a small frame Vaquero. Hopefully you know this already? They'll be fine in your rifle.

45 Colt is fun to load for and hot rod for the right gun, but I would not recommend downloading W296 loads or substituting primers for this kind of loading. The loads you are talking about are clearly into the "magnum load" territory.

[mdi]

Basic Reloading Safety 101; whenever changing any component, drop powder charges and redo a load work up. Many say drop charge by 10%, but it depends where the load is between min.-max....

[RC46]

Thanks guys, good info and a place to start. I have grown very fond of the 45 Colt since playing with the Ruger & Win.. And the Vaquero is one of the early lg frame beasts - I don't understand why they changed it, guess for sass.