SR-7625 w/ Rainier 200gr 45 Plated

[SeabeeMan]

I have about 1400 Rainier 200gr RN plated bullets I'd like to load up for my 45ACP 1911, and a pound of SR-7625 I'd love to get used up. No point hoarding one pound if I'll never see any more. I know that you should use lead or mid-range jacketed data for these but the only one I can find is from Hodgdon's online source:

200gr Cast LWSC
IMR SR 7625 .451" 1.225" 6.2 836 13,000 CUP 6.9 952 17,200 CUP

200gr Speer JHP
IMR SR 7625 .451" 1.155" 6.0 861 13,600 CUP 6.6 941 17,100 CUP

With this I would think I would start at about 6.4 gr with no more than 6.6 or so. My Lyman Auto Pistol book also lists 5.4 to 6.7 gr of SR-7625 with a Lyman 452630 200gr. Does anybody else know of anything with this powder and a 200gr bullet in 45ACP?

Also, how do you go about figuring out C.O.A.L. with something like this? 230gr RN usually list an OAL at 1.275", and a 200gr Speer Gold Dot JHP is listed at 1.178". I see some other discussion in forums talking about setting them at 1.200", but can anybody confirm?

[50target]

I've not used the SR7625 in 45 acp but loaded some tonite in 32-20 for rifle. As to the coal and using it in a 1911 I think I would seat it until it just cleared the inside of the front of the magazine and check it to see what the coal length is. That may give you some idea of what the length is and what it takes to work. I would be more leery of seating too deep as opposed to too far out as too deep would likely raise pressures. Typically I load and check for mag function.
Bob

[SeabeeMan]

Thanks for the COAL advise. From everything I've been able to find, it sounds like 1.250 to 1.265 is a good COAL to shoot for, but that is a good starting place for future reference. Other than some 185gr XTP's here and there, this is one of my first shots at loading 45.

[Hammerhead]

I didn't have the best luck with 7625 in .45 with plated 200 grain SWCs. A lot of unburned powder and wide SD/ES numbers unless you push it. I always use jacketed data with plated, they always seem to agree with jacketed data and these tests seem to agree.
http://38super.net/Pages/How%20Fast.html

[Hammerhead]

Looking back on my notes I was using 5.8 grains 7625 with a Rainier 200 plated SWC @ 1.225" oal and got 760 fps with a 120 fps extreme spread, unburned powder and poor accuracy.
I would think 6.4 would do better in all categories.

Thanks to 3leggedturtle for the use of his Chrony.

[SeabeeMan]

6.4 is exactly what I was thinking of using for these. I have some OAL numbers at home that I figured would make a good starting point and I'll post my results.

[SeabeeMan]

I tried a magazine of 6.4gr seated at 1.257" in mixed brass. They chambered, cycled, and had fine accuracy based on my 10 yard test. I am noticing some unburned powder though. I've never had this before and felt a bit of debris hitting my forearms. It wasn't hot or anything like that, just felt like sand. I checked the gun and the magazine follower and chamber did indeed have 15-20 specks of unburnt SR-7625 in there.

I've done some reading and it sounds like my options are:

Switch loads (I'd rather get this 7625 used up with these Rainier's for plinking ammo)
Tighter crimp...I'm already at about 3/4" of a turn down on my Lee FCD
More powder
Less powder

Everything I've found puts this powder with a 200gr bullet/boolit between 6.0 and 6.9 grains. This certainly wouldn't put me in the excess powder range, and I wouldn't imagine this is so light that I'm not completely igniting everything. What would you all suggest for the next step?

[SeabeeMan]

6.6gr seemed to work well. Still light recoil but no issues with cycling. The gun was noticeably cleaner afterwards. Starting with a clean gun, the 6.4 grains left powder everywhere and the feed ramp was sooty, as well as the brass. The brass was still not shiny by any means, but 7 rounds of 6.6gr didn't have nearly the residue of the 7 rounds of 6.4. I'm going to call this a winner and finish off what's left of the pound of SR-7625.