175gr SWC .45 load advice

[n0val]

Hello guys, I'm new to the forums and to reloading. I have looked around for a starting load for the .45 175gr SWC bullets and haven't had any luck. I did find some numbers for 185gr & 200gr using the same powders I have but not really sure if it'll work...safely. I have made 20 rounds with this combination, 4.4 of titegroup (auto disk #.37) 175gr SWC with OAL 1.25. I read titegroup was not a good combo with lead so I got some Bullseye and was going to do this, 4.0 (auto disk #.43) 175gr SWC with OAL 1.25.
Question for you guys is, are these numbers a safe start for the 175gr? Any advice you could give me would be greatly appreciated.

[stubbicatt]

You will likely find 185 grain SWC load data in your manual. I would start with that data. If you are loading for a semi auto pistol, arriving at a suitable OAL may take a little experimentation for consistent feeding. The general advice is to load the bullet in the case so that approximately a thumbnail's thickness of bore diameter slug is protruding outside the case mouth. Your load manual will give you good advice. A proper taper crimp, and you should be ok.

YMMV.

Regards,
Stubb

[g.willikers]

On the other hand, if you load these shorter 175 grain bullets the same recommended oal as the longer 185 or 200s, there should be a safe margin of error.
Staying within the powder manufacturers load data, of course.
Then see how they feed and what they do through a chronograph.

[T. O'Heir]

The 180 grain data on Hodgdon's site, et al, is close enough. Five grains won't make any difference. However, there is one cast 175 grain load using 5.0 of Win 231(start load for a cast 180 on Hodgdon's site) on Handloads.com.

[Unclenick]

Yes, and 5 grains of Bullseye is an old recipe for 230 grain ball. Way more than safe with something as light as a 175.

I was never able to get good accuracy out of 175's. They were developed to let people load up to major power factor for IPSC shooting without as much recoil as heavier bullets give at that level, but they don't need conventional pistol target accuracy on the IPSC targets, so giving up a little of that for more velocity was fine. The super light 155's weren't even around when I was competing, though.

IME, the 200 grain H&G 68 with flat base is still the most accurate cast bullet in .45 Auto. Even the 185's, though I shot them in gallery loads, would not drive tacks as consistently as the 200's did.

[9x45]

OP, you'll get much better accuracy with 200 gr, 220 gr and 230 gr and they will feed more reliably. Plus if you shoot competition, the felt recoil will be much softer with the heavier bullets to meet the major power floor of 165 for USPSA and 170 for IPSC.

[n0val]

Thanks for the advice guys. The only reason I bought the 175gr was the price (I got the press, dies, brass, etc. the same day) I will be getting some 200gr-230gr
next time. I checked the Hodgdon site for 180gr with Titegroup, since they say the starting load is 4.2 and the max load is 5.2 I should be fine with 4.4 right? Also, does the c.o.l. of 1.14 mean that's the shortest you can go safely, so again, I should be good at 1.25?

[Mike / Tx]

Also, does the c.o.l. of 1.14 mean that's the shortest you can go safely, so again, I should be good at 1.25?

You should be as long as they hold while cycling through the mag and into the action. I'm with the others having only shot as light as the 185'ish SWC's so I don't know how much shank is actually on those. As long as they stay put your fine you just don't want them to be driven back as they cycle.

Shouldn't be an issue but better to check an not have it than the other way around.

Like posted though for top end accuracy the #68 is HARD to beat. Loaded over 4gr of Bullseye I get groups like this pretty regularly,
http://thefiringline.com/forums/show...2&postcount=12

[Unclenick]

nOval,

The COL is bullet shape and weight dependent. A bullet with a blunt nose will be seated less deeply into the case than a longer pointier nose bullet will be when the COL's are the same. It is actually seating depth into the case that matters, as that affects the size of the space the powder has to burn in.

To find COL, you need to know bullet length. For case length, use the cartridge case maximum from the SAAMI drawing (0.898" for .45 Auto), and not your actual length, as it is the distance from the bullet base to the bottom of the case that actually matters in defining the powder space.

Seating Depth = Bullet Length + Case Length - COL (use 0.898" for 45 Auto case length).

Once you have that seating depth number for an existing recommended load, you can determine the new COL that gives that same seating depth with your different bullet shape by rearranging the above formula and using the seating depth you just found.

COL = Bullet Length + Case Length - Seating Depth

The two times this fails are: 1) When the bullet bearing surface (cylindrical full diameter portion) disappears below the case mouth. This means your bullet nose is too long to use for that COL, and you need it to be longer. And 2), when the bullet sticks out too far from the case and won't seat in the chamber because it's nose is too short for the calculated COL. It then has to be seated shorter. In that case you want to reduce powder charge to compensate for the tighter space until a load workup tests it to be safe at a higher level. For the 45 Auto, figure approximately 20% reduction of the charge for every tenth of an inch deeper seating, or 2% for every 0.010" inch deeper seating. This assumes same bullet weight and type (jacketed, cast, swaged).

That's ideal, though. In the real world I've seen pressures in short pistol cases fail to rise as much as seating depth would indicate because the primers seem to help unseat the bullet. So you need to reduce the charge, then test and work back up.