45 Colt issues

Not my cast boolit, but Berry's plated .452 230 grain flat point over 6.5 gr of HP-38 and a cci large pistol primer. Most I shot seemed fine, but a bit light. But, I stopped after my second squib that puked unburnt powder down my barrel and cylinder of my Virginian Dragoon. The ones that blew powder seemed to show cratering of the primer more than the others, more soot, and harder to extract. All leading me to overpressure.... except the unburnt powder. Went back to 225 gr lead pills over 5.6 gr of 38 from the same can and all was good. What am I missing?
45 Colt mixed brass Interarms Virginian Dragoon

That light a charge of HP38 or 231 will not ignite uniformly in the .45 Colt with a bullet that light. The soot on the cases indicates that the pressure is too low to obturate and seal the cartridge case. The primers backing out or flattening are indicative of pressure being too low for the case walls to adhere to the chambers, so that the cases are "pistoning" back against the frame.

According to the Lyman Cast Bullet Handbook 4th Edition (2010) p. 285 the starting load with similar Winchester 231 powder with the RCBS 45-230CM bullet is 6.6 grains for 797 fps at only 9,300 psi. A charge of 7.8 grains approximates factory load pressure being 13,800 psi for 991 fps. The increased bore drag of the plated bullets will produce lower velocity than a lubricated lead cast bullet.

My hodgden book (granted older) showed 6.5 as mid-range load. For a cast bullet, of 230gr and Berry's says to load for cast, plated or jacket can be used.

Does hp tend to stack up pressure nearer the top end? Hodgden website shows 7.3 as max for a 230, and 5.8 as start. 6.5 should have been middle....guess I'm pulling and topping a bit higher... Or swap powder? Suggestions please

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Originally Posted by okietwolf

My hodgden book (granted older) showed 6.5 as mid-range load. For a cast bullet, of 230gr and Berry's says to load for cast, plated or jacket can be used.

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The older Hodgdon HP38 data was probably for military surplus WC230 which was faster than the current stuff, which are simply non-canister lots of 231, which may be subject to greater lot-to-lot variation than the canister Winchester powder.

I gave up on 231 also because every time I changed caddies of powder I had to re-establish charge weight to get the desired velocity. The stuff didn't repeat. Every lot was different. I never had that problem with Bullseye and I can use the same loads with current Alliant product that I did with older Hercules which I bought at Camp Perry in 1984.

Does the larger case volume have a tremendous difference on it's round to round variations? It seem to work great at mid/upper end of 38spl and 357 mag. Hell the 158gr Berry's hollows I loaded up near max for the 38 ran the cleanest I've ever gotten it to.

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Originally Posted by okietwolf

Does the larger case volume have a tremendous difference on it's round to round variations?

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Yes. Compare the percentage of free airspace remaining in the case with .45 Colt vs. .45 ACP, .38 Special or .357, the difference is readily apparent.

I've been reading it's also rather position sensitive also. Might have run better if I carried rounds nose up and/or held the muzzle high before shooting

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Originally Posted by okietwolf

I've been reading it's also rather position sensitive also. Might have run better if I carried rounds nose up and/or held the muzzle high before shooting

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Perhaps... A faster burning powder like Bullseye or TiteGroup is a better choice for standard-pressure loads in .45 Colt. Consider that next time you buy powder.

Main reason I got involved with the hp-38 was it supposed to have worked well across the board for what I load for. Guess I need to keep it out of the big cases and try summin else lol

Another contributing factor might be that you can get a better crimp on the cast than with the plated.

Good old Unique has been synonymous with the old Colt 45. Bullseye or tightgroup do well also but ... Unique does very well for me and has for a long time.

Another powder that I love in the old Colt round is Trail Boss.

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Originally Posted by bigted

Good old Unique has been synonymous with the old Colt 45. Bullseye or tightgroup do well also but ... Unique does very well for me and has for a long time.

Another powder that I love in the old Colt round is Trail Boss.

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Unique works very well in the .45 Colt for full charges of 7 grains or more with heavy bullets, of 250 grains or more, but it does NOT burn completely or ignite uniformly in reduced charges or with bullets lighter than about 230 grains.

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Originally Posted by Outpost75

Unique works very well in the .45 Colt for full charges of 7 grains or more with heavy bullets, of 250 grains or more, but it does NOT burn completely or ignite uniformly in reduced charges or with bullets lighter than about 230 grains.

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I totally agree. Unique is a great powder to replicate the old black powder loads ... WITH the 230+ grain boolits. 8 grains behind Lee's 255 grain or Lymans is the equivalent to the Black Powder loafs using 32 to 27 grains of 2 or 3 Fg powder.