Hey .45 Colt/Red Dot shooters!

[96wa6]

Gang:

I just tried Red Dot in the .45 Colt for the first time and I need to know if you guys actually chrono-ed your loads. 6.0-gr. gave me 707 fps avg., and 6.5 gave me 756 fps avg., each of 12 shots. What could cause such a shortfall in velocity from the oft-quoted 850-ish fps?

Boolits were RCBS 255 LSWCs sized .452" out of a S&W 625 Mountain Gun (4" bbl, yeah a tiny bit short). The boolits would push through the cylinder throats with a tiny bit of effort, so they might be a TINY bit undersized. Apache Blue lube.

WW cases, WLP primers, built on Redding dies, Redding expander, and the boolits are tight in the cases (can't get 'em in by hand), and they've got a nice, heavy roll crimp on 'em.

I even weighed every charge (I do that sometimes when developing a load).

I've been reloading for over 30 years (and started on pistol loads way back), so I think I covered the bases.

What gives?

Marcus

[fredj338]

All guns a re diff. I have one 4" 357mag that runs 125fps slower than the other 4 w/ all loads. FWIW, I shoot a lot of 200grLRNFP o/ 5.2gr of RD. Makes about 750fps in a 5 1/2" Ruger.

[35remington]

This question's actually pretty easy.

The quoted velocity of around 850 fps was for a traditional conical bullet (454190) that seats deeper in the case. Reducing case space and combining with a very fast powder increases pressures and velocities.

Your lesser velocity is as expected.

[Trey45]

This question's actually pretty easy.

The quoted velocity of around 850 fps was for a traditional conical bullet (454190) that seats deeper in the case. Reducing case space and combining with a very fast powder increases pressures and velocities.

Your lesser velocity is as expected.

+1.
Succinct.

[TX Jack]

To name a few variables that cause velocities to change. Rifling as in the style and even the smoothness or lack thereof of the metal in the bore. The actual bore diameter, primer type, powder lot, brass thickness and basic volume, bullet style and hardness, seating depth, temerature, cylinder gap, barrel length, and several others that I am forgetting can all cause velocities to change and the smaller the case the more drastic the change can be. Pistol cases especially.

[Hardcast416taylor]

So far nobody has asked what was the alloy used? I load 6.5 gr. of RD in my 5.5" Blackhawk and cast the same RCBS bullet out of ww for my general purpose carry load. Haven`t had a critter complain yet about being shot with a low velocity load.Robert

[redbeard55]

For almost 20 years my standard 45 Colt load for my Ruger Blackhawks has been 7.0 grains of Red Dot. Typically gives 900 fps over my chronograph. Very consistent. The Blackhawks have 5.5 inch barrels

[Hondo 60]

Fps can vary greatly from one gun to another.
I have a S&W 10-5 4" that runs almost 100 fps faster than my 66-2
Same barrel length. In fact my 2''10-5 & the 4" 66 tend to shoot about the same speed.

I haven't slugged the barrels yet, but I'm guessing the 66 is quite a bit bigger than my 10s.