Looking for a 357 magnum load. 300MP 140 Grain Hornady bullet
- Thread starter Deja vu
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Shoot an email to "Ask the Experts". They are always happy to answer these type of questions.
http://www.alliantpowder.com/questions/default.aspx
http://www.alliantpowder.com/questions/default.aspx
Top end 158 Gr GD is 18.6 gr. Top end 125 Gr GD is 22.3
You weight is in the middle.
You start with 158 gr. data and work up. @ 20 gr. of powder work up slowly as in .1 gr at a time because the difference in the spread between the two known values is 3.7. Me myself I would expect 20.4 to be max but your bullet is a cup and core and not plated like the Gold Dot. Without test equipment we are just guessing.
You weight is in the middle.
You start with 158 gr. data and work up. @ 20 gr. of powder work up slowly as in .1 gr at a time because the difference in the spread between the two known values is 3.7. Me myself I would expect 20.4 to be max but your bullet is a cup and core and not plated like the Gold Dot. Without test equipment we are just guessing.
With 158 grsin XTP's I went as high as 17.5 grains in my 2.25" SP101. I didn't want to go any higher with the little gun. The recoil was starting to get excessive. Average velocity was 1072 fps. 18.2 grains averaged 1362 fps from a 6" GP100. That's as high as I went. That's a lot of powder in a 357 case. This powder really shines in the 44 Magnum. 22 grains under the 310 grain trushot lbt style lead bullet averged 1360 fps out of a 3.75" barrel super blackhawk.
The key word is "published". As I recall, trying to use 300-MP, only Hornady has taken any interest in this powder, so you have to use the same bullets they did. I don't recall any load data anywhere for 300-MP with lead bullets. That is a complete swag. I got too low in my numbers and stuck a 240 gr bullet in my 629, 44 Mag.
Brian peirce wrote an article about pp300mp in Handloader magazine. and yes it has load data for lead bullets . It's easy enough to find this article. If I recall correctly these loads were sent to a reputable lab for pressure testing. It's not swag. My own testing over a chronigraph produced slightly less velocity, but not by much.
I asked because 300-MP is a really big powder. Without a doubt, it'll work quite well for the bolt action. Ideal, actually.
Might be a bit much for the Coonan (matter of opinion, I suppose). I'm just glad you didn't say a M60 snubby or something
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We all have our own load style and purpose goals for our ammunition. It's a beautiful thing. If it was me, I'd use the 300-MP only for the rifle, and probably only for bullets of 158gn or 180gn. Might be superfluous for 140's. And I wouldn't use it for a pistol at all. It's just too much (read: "slow"). Guaranteed to deliver tons of flash and recoil in a pistol in all but the longest barrel lengths. I'm just not into that sort of thing.
Anyway, the good news is that 300-MP is so slow that it'd be difficult to get into pressure trouble with it. Someone recommended starting with 158 grain data and work up from there. Sounds like good advice to me. But then, there's a reason why there's no 140 grain data for it - it's an "out of balance" combination.
Might be a bit much for the Coonan (matter of opinion, I suppose). I'm just glad you didn't say a M60 snubby or something
. We all have our own load style and purpose goals for our ammunition. It's a beautiful thing. If it was me, I'd use the 300-MP only for the rifle, and probably only for bullets of 158gn or 180gn. Might be superfluous for 140's. And I wouldn't use it for a pistol at all. It's just too much (read: "slow"). Guaranteed to deliver tons of flash and recoil in a pistol in all but the longest barrel lengths. I'm just not into that sort of thing.
Anyway, the good news is that 300-MP is so slow that it'd be difficult to get into pressure trouble with it. Someone recommended starting with 158 grain data and work up from there. Sounds like good advice to me. But then, there's a reason why there's no 140 grain data for it - it's an "out of balance" combination.
buck460XVR
New member
Over the years this is the conclusion I have come to when I cannot find recipes for certain bullet/powder combos. I figure after both have been out for a while, if there is not a legitimate source publishing a recipe for it, it's not because it hasn't been tried, but because it's does not result in decent performance. While most any powder/bullet combo will work in some fashion or another, they all don't work well.
Well stated buck460XVR.
However, I'm not saying that one should not load the 300-MP/140gn combo. That is a decision left to our OP. But whenever a load work up is approached, knowing that ". . . they all don't work well" is good to keep in the back of one's mind.
I used to load 110 JHP's with gobbs of W296 under them. Now days, I have that loading filed under "what the heck was I thinking!?." Ridiculous. Just ridiculous.
Doesn't appear to be much 140 grain or 300MP data at all on any of the assorted reloading sites. Never mind the manufacturers. There's exactly one 158 grain load on Reloader's Nest Handgun page.
Best you contact Hornady. http://www.hornady.com/contact_us?g=1
$5.99 for a magazine must be ancient. snicker. Kind of wonder where the data came from. Alliant shows 18.6 of 300MP as max for a jacketed 158.
Best you contact Hornady. http://www.hornady.com/contact_us?g=1
$5.99 for a magazine must be ancient. snicker. Kind of wonder where the data came from. Alliant shows 18.6 of 300MP as max for a jacketed 158.
Pearce used an odd bullet weight, and Lane Simpson incorrectly identified 300-MP as identical to H110/W296. I think extrapolating data to available bullets is risky with this powder.
Pearce's main article re magnums, showing loads for various magnum cartridges, has a single lead bullet load for 357 Magnum in the 1400-1500 fps range (again with his customary odd bullet casting weight and shape), which is certainly fast enough to lead badly. The other calibers/cartridges are more like 1200.
Sometimes extrapolation from articles like this is more like a SWAG.
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buck460XVR
New member
Nick_C_S, more or less what I was trying to say. Few years back when many powders were hard to find, folks were grasping at straws sometimes to find replacement powders. Even then, very few times did I see an Ahh-Haa! moment when a new combination was found from components that had been around for a while, that were any way vastly superior to those already known. Back when Alliant came out about it's concern about 125 grainers in .357 with it's Bluedot, many claimed it was the best load they had found in outta their .357 revolvers and were not going to quit using it despite the concerns. Who am I to tell them any different?
Bullet/powder manufacturers are in the business to sell bullets/powder. They are going to give recipes that give the best performance with either/both and hesitate to give recipes that give poor performance with either/both. They don't just give us the recipes they have tried. I surprised someone with the Quickloads program has not come along with a post about running this combo and coming up with this recipe. Again, while it is probably doable, will it perform well enough to make it worth the while?