A year ago I, for my 50th, I bought a beautiful Ed Brown 5" Special Forces 1911 in 45 ACP. Ran about 500 rounds of hardball, factory and reloads, thorugh it without a hitch and figured with the difficulty of obtaining either in quanity it was time to cast my own. So, I had Veral Smith send me one of his beautiful 2-cavity 230 gr LBT LFN molds. Bullets, made of WW, turn out at 231 gr and are really a nifty bullet. I'm in the midst of load development with 12+ powders I have on hand. The other day I got started and tested W231, Clays, Titegroup and just got into HP-38 when I had to pack up and head home. Within a day or two I was able to measure the groups and study all my chronograph readings. The accuracy was very pleasing for a few loads. It's the velocity readings which have me concerned. I am using the Hodgdon's 2008 Annual Manual as my reference guide. The actual velocity readings are quite low compared to the manual's starting and max loads.

I'll give some parameters to start. All loads were assembled on my 1984 vintage Dillon RL550 press in Dillon dies, using mixed brass, WLP primers, White Label BAC lube, with WW (13-14 BHN) bullets sized to .453" on an RCBS LAM sizer in a RCBS .452" sizer die. Powder is measured through the Dillon powder measure. I load up 10 of each powder charge and increase by .2 grains for each next step. Taper crimp is used. OAL is 1.200". Bore slugged out at .452"

Manual vs Actual velocity.

W231 starting load
4.3 gr should be 699 fps
4.3 gr actual is 608 fps
91 fps less

W231 max load
5.3 gr should be 834 fps
5.3 gr actual is 761 fps
73 fps less

Clays starting load
3.5 gr should be 716 fps
3.5 gr actual is 617 fps
99 fps less

Clays max load
4.0 gr should be 793 fps
4.0 gr acutal is 742 fps
51 fps less

Titegroup starting load
4.0 gr should be 751 fps
4.0 gr actual is 699 fps
52 fps less

Titegroup max load
4.8 gr should be 855 fps
4.8 gr actual is 795 fps
60 fps less

HP-38 starting load
4.3 gr should be 699 fps
4.3 gr actual is 604 fps
95 fps less

After some thought I think it might be

1) lube difference
2) primer difference (Hodgdon's uses F150)
3) Bullet design leading to different case capacity even same 1.200" OAL

Any ideas?

Thanks,

Alan

1. Did you slug your barrel to determine the correct diameter bullet?
Or did you just take it for granted that .453" would be the right size?
2. Notice the similarity of the HP-38 and W231 data? That's because they're the same powder, just different labels. You're duplicating your efforts working up loads with these powders.

I did slug the barrel and now have it in the original post. I see your point with the W231 and HP-38.

I'm thinking I could keep working upward with .1 powder charge increases until I hit book max.

Thoughts?

Thanks,

Alan

if they used a test bbl and you are using a real gun you are gonna have diffeences.
they are looking at pressure you are looking at velocities.
pressure is needed to create velocity.
but if your chamber/bbl is bigger then theirs you could have the same pressure and lower velocities.
for instance in my wifes 7x57 versus my 7x57 ackley.
her bbl is slightly smaller then mine less then 001.
when i use the same load in both of them her gun will have higher velocities than mine will
same everything except for chamber.
the difference is usually small 10-25 fps but there still.
on the other end though where her rifle will max out pressure wise i can keep going because of the increase in chamber volumn and the barely measureable bbl difference.

Lamar,

I understand what you are talking about. I believe nominal bore dimensions for a 45 ACP is .451. Mine being .452" means I start with a bigger pressure cooker before the trigger is even pulled.

Alan