I'm trying to find a mild 357 load using Berry's 158 gr plated flat point bullets. I use the same bullet in front of 6 gr of Power Pistol in the 38 spl and average about 950 fps. I'd like to push that to 1050 or 1100 in the 357. I have Power Pistol, Unique, 2400 and H110 on hand.

Unique or Power Pistol will get you there, look at load data in your manual for a cast 158 and jacketed 158, the charge for the plated will be somewhere between those. If you want to push them a little faster, those plated bullets should be fine up to 1200 fps with 2400.

For real mild loads try Trail Boss using the lead bullet data on the Hodgdon website.

Thank you for the replies. Look like 6 gr is good starting place for Unique. Might as well start PP at the same and work up. These will be used in a 3" bbl so I'm inclined to stick with the faster burning powders.

Faster burning powders are only more efficient in their burning in shorter barrels. That translates to flash. If you want velocity, always use slower powders. This has been proven over and over for more years than I have been reloading.

Efficient does not translate to velocity. Expanding gases for however long the barrel is seems to translate directly though!

FWIW

Do you think I would better served with something like 2400? I'm not looking for maximum velocity. Just a litte bit more than a typical 38 spl +P out of a 3" bbl. I'm aiming at pushing a 158 gr bullet to between 1050 to 1100 fps. Given multiple lods that can accomplish this, the powder can do at a lower pressure would preferred.

I have always stuck with using lead bullet loads for plated bullets. The plate is very thin and not a jacket. Some of them are making extra thick plated bullets for rifles and I wish they would offer this for pistol bullets as well. You are also supposed to be able to use jacketed bullet loads but back down ten percent.

I would use Unique for what you want.

I use that bullet in front of 2400 with awsome results, should be pushing 1100 fps. Berry says don't exceed 1200. Start with about 11 gr, up to about 14 if you can stand it

I think you're right, start with a charge of 6.0gr Unique and work your way up until you get to the velocity you're looking for. It shouldn't take much more than 6.0gr to get there either.

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You said you wanted lower pressure so the slower powders are the way to go for that. Only problem will be finding the one that doesn't mind being down loaded. Most Magnum friendly powders (slow burners) work best at the upper end of their load range.

Dave

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Sorry, must be getting old! Missed this question altogether!

If all you are trying to do is push a 158gr bullet out at that velocity, and you are using 357Mag brass, I would suggest Unique or something in that burn rate. Personally, I like SR4756 but you have to use unpublished data to get it to work right.

AA#5, would be a good choice too, as well as maybe W231/HP-38. They are all pretty close on the burn rate chart and should work for what you are trying to do.

Have fun, be safe!

Thank you all for further instruction. I feel better now

I just shot some with the plated 158 gr. and 6.5 gr of Unique
thru my 686 and they were very accurate at 30 yds.

I just got back from the range where I tested my latest reloads. I had 50 each of Berry's 158 gr FP over 6 gr of Unique and 6 gr of Power Pistol in Federal 357 cases. I couldn't set up a chronograph today but, judging from perceived recoil, both loads were performing about the same as commercial 38 +P ammo. Both provided excellent accuracy. Neither load showed any over-pressure indications and, in fact, the primers the commercial Speer Lawman ammo my wife was shooting showed more flattening than the Winchester primers in my handloads.

The Unique was a lot less dirty than I remember and had much less muzzle flash than the Power Pistol. If the chronograph confirms my perceptions, I will have to re-evaluate my opinion of Unique.

I also blew off a box of the American Eagle 357 magnum just because there is something special about seeing the targets on the adjacent lanes being moved by the muzzle blast from a full bore 357.