nody
Member
I did a search on 300-MP, and no thread came up on this relatively new powder, so I'll start a new one…
300-MP is a great powder, and at $3+ less per pound than H110/WW296, a bargain. It is as clean or cleaner than 296, and far cleaner than my old favorite, 2400. I could not get 2400 levels of accuracy with 296, but 300-MP is even more accurate than 2400, in my testing.
Here's what they both look like up close:
296 up close:
300-MP up close:
Some background on 300-MP from an expert of Handloader Magazine:
Using Hodgdon and Alliant data for jacketed 158 gr bullets, because published data for lead bullets always assumes swaged and hence low velocity loads, I worked up ladders on 296 and 300-MP. Common to all loads:
S&W 586-0, 6" bbl, factory Partridge iron sights, range 50 feet
Missouri Bullet Co 158 cast SWC, BHN 18
http://www.missouribullet.com/details.php?prodId=41&category=5&secondary=10&keywords=
Starline once fired .357 Magnum brass.
Winchester Small Pistol Magnum Primer, though Alliant says a mag primer is unnecessary, the Handloader article says he had better consistency and velocity with mag primers.
There was NO lead accumulation in barrel, other than the smear of lube that was the same after one or 100 rounds, and came right out with a WD-40 wet brass brush and one pass.
All case diameters were mic'd before and after firing. Conventional wisdom is that 5 thousandths of an inch (.005) is a "poor man's" sign of a reasonable upper pressure limit, and more accurate than flattened primers. Winchester primers (brass) flatten while CCIs (nickel) don't with the same load, for example.
The upper 296 loads ran to 6 thousandths (.006), but all 300-MP loads stayed at or below .0045.
This was the most accurate 296 load:
All the 300-MP loads were on average more accurate than their 296 counterparts, and this was my best 300-MP load:
My favorite 2400 load:
Disclaimer: These loads were carefully researched, measured, and worked up. I do not endorse them for your use, as I have no control over your actions.
300-MP is a great powder, and at $3+ less per pound than H110/WW296, a bargain. It is as clean or cleaner than 296, and far cleaner than my old favorite, 2400. I could not get 2400 levels of accuracy with 296, but 300-MP is even more accurate than 2400, in my testing.
Here's what they both look like up close:
296 up close:
300-MP up close:
Some background on 300-MP from an expert of Handloader Magazine:
Using Hodgdon and Alliant data for jacketed 158 gr bullets, because published data for lead bullets always assumes swaged and hence low velocity loads, I worked up ladders on 296 and 300-MP. Common to all loads:
S&W 586-0, 6" bbl, factory Partridge iron sights, range 50 feet
Missouri Bullet Co 158 cast SWC, BHN 18
http://www.missouribullet.com/details.php?prodId=41&category=5&secondary=10&keywords=
Starline once fired .357 Magnum brass.
Winchester Small Pistol Magnum Primer, though Alliant says a mag primer is unnecessary, the Handloader article says he had better consistency and velocity with mag primers.
There was NO lead accumulation in barrel, other than the smear of lube that was the same after one or 100 rounds, and came right out with a WD-40 wet brass brush and one pass.
All case diameters were mic'd before and after firing. Conventional wisdom is that 5 thousandths of an inch (.005) is a "poor man's" sign of a reasonable upper pressure limit, and more accurate than flattened primers. Winchester primers (brass) flatten while CCIs (nickel) don't with the same load, for example.
The upper 296 loads ran to 6 thousandths (.006), but all 300-MP loads stayed at or below .0045.
This was the most accurate 296 load:
All the 300-MP loads were on average more accurate than their 296 counterparts, and this was my best 300-MP load:
My favorite 2400 load:
Disclaimer: These loads were carefully researched, measured, and worked up. I do not endorse them for your use, as I have no control over your actions.