Relative Power Factor For Revolver Vs. 1911

[MichiganShootist]

I have a pet load that I use in my .45 1911s.... and I plan on shooting a lot of revolver this year in IDPA and USPSA.

A friend and I were discussing if my load (which reliably makes a PF of 172 in all my 5 inch 1911s)... will also make the same PF out of a 625 with a 4" barrel.

Obviously a chrono session is in order...to REALLY know....but at 5 below zero.... that activity will have to be delayed. I was just curious if direct comparisons had been made by one of you shooters.

My friend's theory was that the pressure lost through the gap between the cylinder and the forcing cone would be much more than is lost in the autos operation and hence the 625 would need a hotter load to make PF.... especially with a 4" barrel.

What do you think???

BTW-- The load is 230 Grain Zero FMJ over 4.5-6 grains of TiteGroup with a 1.24" OAL... and all Federal primers

Edited February 7, 2007 by MichiganShootist

[Keith]

I run the same load in my 1911 that I run in my 625's, including a 4" 625.

I use clays now but I don't remember the exact load and I'm at work right now. There is velocity to spare in the 4" gun, though. It doesn't seem like a hot load to me.

[Carmoney]

There probably won't be as much difference in velocity as you might think. Around 4.1 (give or take a tenth or two) of Clays should be about right for both 1911 and 625.

[pskys2]

If you're using a Match Grade 1911 Barrel you'll probably have higher velocity than with a 5" 625.

I've been running 4.2 clays with 230 Bullets (Plated or Jacketed) and I get a 172 with the Revolver and 177 with an "Old" Clark MG Barrel 1911.

Different powders can narrow or widen that gap.

Rifling, Condition, Chamber Dimensions, etc... can all affect the velocity of you're 1911 and change everything I've written. The same can be said of the 625, adding Cylinder/Barrel Gap, etc...

Only a chrono will tell for sure.

[Bones]

MIchiganShootist,

Yes - but the load will be heavy out of a 5" 1911. You're friend is correct.

I use 4.7 gr TiteGroup and Berrys 230 gr RN bulllets. The load consistently makes 170 PF out of my 4" 625 MG and ~ 173 out of my Glock 21 and ~ 175 out of my 1911s. As you indicated, 4.5 will make it out of the 1911 but did not out of my 4" 625.

Good Luck in ESR,

Craig

PS - I confirm/chrono all my loads in the winter - you avoid negative surprises in the warmer months.

[Lee Bell]

I have a pet load that I use in my .45 1911s.... and I plan on shooting a lot of revolver this year in IDPA and USPSA. A friend and I were discussing if my load (which reliably makes a PF of 172 in all my 5 inch 1911s)... will also make the same PF out of a 625 with a 4" barrel. Obviously a chrono session is in order...to REALLY know....but at 5 below zero.... that activity will have to be delayed. I was just curious if direct comparisons had been made by one of you shooters. My friend's theory was that the pressure lost through the gap between the cylinder and the forcing cone would be much more than is lost in the autos operation and hence the 625 would need a hotter load to make PF.... especially with a 4" barrel. What do you think??? BTW-- The load is 230 Grain Zero FMJ over 4.5-6 grains of TiteGroup with a 1.24" OAL... and all Federal primers

I don't have anything that will shoot out of my autoloaders and revolvers, but I have some information that may form part of the answer.

Regarding the gap between the chamber and the barrel, your friend is right about there being some bas and pressure lost as the bullet crosses that gap. Acceleration through the barrel is affected. How much it is affected depends on the extent of the gap and other variables. In my opinion, there are too many variables to say how sugnificant the difference is, but not so many to be unable to say that there is some difference.

I have better information on the effects of barrel length. I built USPSA major loads for my H&K USP Compact, which had a barrel just a fraction under 4 inches. I fired the same load out of the Gold Cup that replaced it. The Gold Cup has a 5 inch barrel. Everything except the gun was the same. I got about 50 fps more out of the 5 inch barrel as I got out of the 4 inch one.

Adding effects of the gap between the cylinder and the barrel and the shorter barrel should make a noticable difference in muzzle velocity. How much difference, and whether your preferred load still shoots major, is something you're going to have to use a chronograph to be sure about.

Lee

[MichiganShootist]

Thanks for the feedback. All your information was helpful-- especially you Bones ... because you use TiteGroup.

I realize the only positive way to know the answer is with a chrono... and like I said with a -25 degress wind chill..... that will have to be put off for a while.

I just didn't want to spend my Winter months cranking out ammo that won't make major in the wheel gun.

[LPatterson]

Thanks for the feedback. All your information was helpful-- especially you Bones ... because you use TiteGroup.

I realize the only positive way to know the answer is with a chrono... and like I said with a -25 degress wind chill..... that will have to be put off for a while.

I just didn't want to spend my Winter months cranking out ammo that won't make major in the wheel gun.

I'm like you except I have a 5" 625 & discovered the 625 did not like my 1911 loads but it was more the barrel did not like the MasterBlaster moly. So when it gets above freezing & the wind drops to 15MPH or less I will run some loads thru the chrono. I have some Berry, Precision & Precision Delta 230's that I will be trying with American Select & WST. I threw together some 185gr Berry's & Clays but I don't think they make major & that 1000 is just to get some time behind the gun. The brass was loaded with CCI primers and I want to switch over to Federal primers after I lighten the action. The 1911 will have to be satisfied with WLP's as I have 2000 cases primed & 15,000 primers in reserve.

Monday it was 60 degrees with 40MPH winds & today it is in the teens with 2" of snow on the ground & more predicted over the next 5 days.

[hopalong]

Michiganshootist,

I think this will boil down to an idividual basis due to many differing things as mentioned before.........wear on the 1911, cylinder gap, and so on, and so forth.

But!

I can tell you this for sure.

MY match ammo that makes 170 PF in my 625s makes 200 PF in my KIMBER Eclipse.

I am loading Clays and am using Precision Delta 230s (Fed Primers) and mixed brass.

NOT what you wanted to hear, but what my Chrono told me about my loads this past fall.

Hopalong

[imashooter2]

Auto loaders measure barrel length to the breech face. Revolvers measure barrel length to the front of the cylinder. There is actually a half inch or so more tube to accelerate the bullet in on a 4 inch 625 than a 5 inch 1911. Will that make up for the pressure lost through the cylinder gap? Only the chrono can tell you...