Reduces load in .45 ACP with TightGroup

[Kiwi cop]

I shoot two events (Cowboy Wild Bunch and an Australasian Service Match) using a .45 ACP 1911. Wild Bunch mandates lead projectiles with minimum n 150 PF, the Service Match has a PF floor of 120.

l have been shooting 230 gn LRN bullets at a 155-160 PF and they have worked well, but the 230 gn lead bullets are getting hard to source Down Under.

I have a large supply on hand of 200 gn Cowboy LRNFP projectiles. To use these I would be looking for 750-800 fps.

Hodgden lists a minimum charge weight of 4.8 gn TightGroup for 887 fps. How much below this is a safe way to go? Is 4.2 gn going too far?

 

[rockquarry]

You're estimates are probably about right. In a 1911, I've chronographed the H&G-style 200 gr. cast SWC at 890 fps with 5 grs. of Titegroup. I wouldn't be at all hesitant to go down to 4.2 grs. as long as it was accurate. That should be pretty close to the velocity you want.

My target load with Bullseye is only 3.5 grs. with the above-listed bullet. Bullseye's burn rate is similar to Titegroup. MV of my load is 675 and I wouldn't want to go slower.

 

[Forrest r]

Bullseye shooter have been known to use 185gr cast bullets and as low as 3.8gr loads of titegroup.

Don't know what spring you're using but that's something to keep in mind when using reduced loads.

Myself, I keep the variable power springs in my 1911/45acp anymore. I can easily run anything from the 3.8gr bullseye/2.5gr clays 155gr hb swc loads up to the 220gr/1000fps p+ loads using the sme spring.

 

[gwpercle]

My notes & Lyman CB #4 Edition show ...
and depending on your guns recoil springs for functioning ...
Lyman 452460 - cast 200 gr. SWC

Try Starting Load 4.0 grs Titegroup (which may not cycle standard weight springs)

My AMT Hardballer functions 100% @ 4.5 grs. Titegroup (my pet load)

To max target load of - 4.8 grs Titegroup (801 fpsapprox. velocity)

I have settled on 4.5 grs Titegroup the velocity is about 765 fps with the 200 gr. cast lead SWC . Accuracy is very good with this powder .

Gary