Blue Dot & 45 Colt

[Pipe]

New for t guy here looking at old threads. I have worked up a load of 12.5 Gr. Blue Dot with the Lyman 452424 that gives me about 990 fps in my Ruger BH 4 5/8" & about 1100 fps in my Colt 7 1/1" 3rd gen revolvers. I have aftermarket grips on the Ruger & it is very comfortable with this load. It is a little stiff in the Colt but shoots to point of aim @ 25 yards. I could up the load some in the Ruger but i don't see the need. I think this might be a little over the top for the colt. What do you guys think?

[charlie b]

I did load it up a bit in my old BH many years ago. But, it was also the first time I experienced and issue with a load being position sensitive.

If I raised the muzzle, lowered it to the target and fired I got reasonable velocity (IIRC ~1200fps). If I tipped it down and raised it up to fire I got an excursion. Much louder, heavy and sharp recoil, much higher vel (IIRC ~1500fps).

[Pipe]

Wow. I have never had that. Have you noticed that with other powders?

[Kosh75287]

This effect CAN be expected to happen when you have propellants that only partially fill the case volume, and there is enough room for the charge to "lay down" in the case with the firearm is horizontal to fire. MY experimentation in .45 Colt, using Red Dot, was quite similar to Charlie B's, when raising the revolver between shots and lowering to fire. I was getting a very consistent 840 f/s from this method. When I pointed the muzzle to the ground and raised to horizontal, velocities were as much as 150 f/s lower, and highest and lowest velocities were 100 f/s apart.
I switched to Unique for most of my "general use" .45 Colt rounds thereafter, and 2400 for hunting.

There is a website, Reloadammo.com, which (at one time) went somewhat into depth about the effect of powder position on velocities in various calibers. I would not be surprised if that info is still there, somewhere.

[Walks]

I discovered this phenomenon years back. Lower muzzle after each shot = bigger group. Raise muzzle after each shot = smaller groups.
I even tried this when TiteGroup came out. Same results as Bullseye, W231, Clay's, 700X, Unique and Green Dot.
All powder seems to perform better more accurately when back against the primer.

[charlie b]

I have not noticed it in other pistol powders simply because I have never loaded them below 60% density. The .45Colt case is oversize for regular loads. It really shines in a BH or similar strength pistol and heavy loads.

I have noticed it in rifle loads with lower densities, common with cast bullets.

There is a point with faster powders in larger cases and load densities much lower than 50% where you don't need to do much about it. The primer will basically ignite the whole charge at once no matter where it is in the case. 8gn of Blue Dot in my .308 is an example.

[Pipe]

Thank you guys for sharing valuable information. I have been aware of this in rifle cartridges but never given much thought to it in pistol cartridges. I believe i will not feed my Colt anymore of these. I have a good supply of Unique, so i will start using that in the 45 Colt.

[Wireman134]

I use BD in my NM Blackhawk. Speer #10 shows 260gr Speer JHP in Ruger only starting 13.8gr-14.8gr max. 14gr. under a 255 Lee SWC or RF burns good for the Rugers. BD needs higher pressures to burn consistent. 14gr is very accurate in my revolver.

[black mamba]

I also settled on 14 gr of Blue Dot under a 255 SWC in my NM Blackhawk. Great all-around load.