.454 shotshell loads

[Shoot!]

I'm looking for ideas on shot loads for my Casull (Puma carbine). I was hoping for a little more capacity than the CCI capsules offer. So I'm considering trimming plastic .410 hulls down to around 1.6" and roll crimping over an overshot card. Another option I've considered is trimming down .444 Marlin brass. They have a base diameter about 0.01" less than the 454 (same as .410, I believe), but I believe this and the body taper could be eliminated with fireforming (a few grains of shotgun powder under a case full of cormeal). The rim diameter should work fine. I'm not sure about the rim thickness. I'm thinking that a felt overpowder wad and a glued-in overshot card or a crimped-in upside-down gascheck over around 1/2 oz of small shot would suffice without giving up the capacity that a plastic wad cup would take up. Anybody got any experience with anything like this? Any chance I could get a cut-down .410 hull to feed from the mag? Is the .444 brass casing a better idea? I'm thinking so, since the lack of a base wad would offer more capacity. Any input appreciated.
Thanks!

[John Traveler]

I've played with many combinations of .45 shotshells over the years, and have come full circle to using the Speer .45 plastic shot containers in .45 Colt cases.

The biggest problem in getting good shot performance from your carbine (or revolver) is that the barrel rifling spins the shot charge, ruining the pattern.  Hotter loads, or higher velocities  make it worse.  The Thompson-Center shot combo barrels in .45 Colt/.410 shotshell work by deep chambering, shallow rifling, and most importantly, the muzzle attachment that shreds the shot container and stops most of the spin.  .45 Colt accuracy is only "fair".

Cut-down .410 cases can be used in the .45 Colt/.454 Casul chamber, but powder and shot capacity are severely reduced from using the same size brass case because of the base thickness.

Try using fire-formed .303 British or .30-40 cases as the starting point instead of .444 Marlin.  These combined with cut-down .410 polyethene shot cups work okay, but still don't approach true .410 shotgun performance.  I found they make super snake killers, and deadly for potshooting rabbits and squirrels out to about 15 feet.

HTH
John

[Shoot!]

Try using fire-formed .303 British or .30-40 cases as the starting point instead of .444 Marlin.

John,
What don't you like about the .444 brass? It seems like it'd be a better fir in the 454 chamber.

[John Traveler]

Neither .444 or .30-40/.303 cases are a perfect fit in the .454/.45 Colt chamber because the base diameter is smaller.  But the larger rims are an advantage.  I guess I was thinking more about the double-action revolvers I've made shot loads for.

[dakotashooter2]

I think only your gun will tell you what will work. I have had good results in my 41 mag using cut off shotshell wads though I wish it had a little more capacity. Note: the wads are TIGHT in this case. Patterns seem to be pretty good with one exception. I use a 38 cal gas check over the shot and usually get a hole in the middle of the pattern from it. A card wad may perform better. I often question if the rifling in a short handgun barrel really has as much influence as most people seem to think. A longer barrel is likely to make more of a difference. It seems the 303 brass seems to be a more popular choice with those who have tried it.