pressure or velocity for reliable cycling Glock 21 or 1911?

[cpileri]

I am seeking advice on the best path to pursue for loading for a 45ACP glock 21 and secondarily 1911 style pistols.

The bullet I want to use is Rim Rock bullet's .451 250 gr. RNFP BHN 15, which as loaded by Buffalo bore is by far the most accurate bullet I have fired in a Glock 21.

Buffalo bore loads "+P" ammo, and I am not necessarily looking for a +P load; just one that will cycle reliably.

Load data for the 250gr lead bullets is scant, at least pressure-tested loads are, so I am extrapolating from published loads by Alliant for their 260gr jacketed bullet.

these loads are:
45 ACP, 260 gr JHP
Bullet Powder Weight Powder Velocity OAL Primer Source
JHP 8.3 gr Blue Dot 780 fps 1.21" Fed 150 Alliant
Pressure: 19,000 Suggested starting load: 7.5 gr

JHP 4.5 gr Bullseye 725 fps 1.21" Fed 150 Alliant
Pressure: 19,400 Suggested starting load: 4.1 gr

JHP 5.9 gr Herco 750 fps 1.21" Fed 150 Alliant
Pressure: 18,600 Suggested starting load: 5.3 gr

JHP 5.4 gr Unique 760 fps 1.21" Fed 150 Alliant
Pressure: 19,400 Suggested starting load: 4.9 gr

(hope those pasted in understandable format)

Anyway, should I be looking for velocity or pressure (all are 18-19K, but still) to reliably cycle the autoloaders?

Alternately, does anyone have any experience w a load, preferably pressure-tested, using the 250gr cast bullets; that worked well w the Glock 21 or 1911 platforms?

many thanks,
C-

 

[Dudedog]

I don't mean to sound "preachy" but start at the reccommend starting load. I would think you would ok using the 260 data with the lighter bullet. I would only load about 10 rounds there and check for function.
If they cycle your guns (all of them are different!) then you have the answer.
If you don't get proper functioning increase the charge. (slowly, carefully)
If like a lot of us you have to drive someplace to shoot then I would also load 10 rnds at .2 gr steps in case the first ones are to light. Always approach the MAX with caution as the listed MAX might be more than the MAX for your firearm.

I have not loaded 250s but I am sure others here have.
It would probably enable them to help you out better if you let everybody know what powders you have available.

 

[GLOOB]

Anyway, should I be looking for velocity or pressure (all are 18-19K, but still) to reliably cycle the autoloaders?

In a Glock, slide velocity is largely a function of bullet momentum.* I would use the rule of thumb of starting jacketed load less 10% for cast. Maybe less 5%, since you're using a lighter bullet, and you're shooting a Glock 21.

I've got plenty of really accurate loads for my G21, but none using 250 gr bullets. In fact, almost all of my G21 loads have been accurate. If you like 200 gr cast, try MBC IDP#4. Seat and crimp in one step with no shaving, because the bullet has a crimp groove!

*However, you might get more interesting answers on a gun forum.