Looking for data from MP300 in Maximum

[cwlongshot]

Hello guys. Does anyone know of sources for this powder in the smaller 35’s like Mag Max and 350Legend?

I like what i have found so far and would like some data sources beyond the minimal what I have found.

CW

[bluejay75]

I just emptied an 8 pound jug of 300MP. Not sure what your results will be burning such a long column of it...But it is a wonderful powder in 44 MAG and 357 MAG.

Seems like the lower pressure and slower burning qualities of this powder lends itself well to use with cast. Results were that I now have near MOA full Magnum rifle loads with Plain Base Boolits.

[cwlongshot]

Still looking...

[Silvercreek Farmer]

Have you contacted Alliant?

[cwlongshot]

Yup with no replies...

CW

[curioushooter]

Look longshot, you and every 357Max shooter probably wants this data. Nobody has tested it yet (that I am aware of), and it's not on Quickload, despite 300MP being a decade old. From my experimentation in 357 Mag I do think 300MP has more potential in the max than any other known powder, but unless you can convince someone with a ballistic lab to run some 300MP in 357 Max you are going to only get "well it seems to work fine and didn't blow up my gun." For now I use Lil'Gun, which performs very well and Hornady and others have performed pressure testing.

[megasupermagnum]

I never saw where 300mp was any different from H110 to make it worth buying. I'm far from an expert, but I was not all that impressed with H110 in the 357 maximum. IMR 4227 was easily the best I've tried. Even Reloader 7 was a very good performer.

Maybe 300mp behaves differently, but H110 is the perfect magnum handgun powder, and not much else. There is too much air space in 357 maximum.

[AlaskaMike]

Do any of the published manuals these days contain any data newer than 10 years old? When I looked at getting a couple new manuals at Cabela's a couple months ago, they all simply appeared to be reprints with the same data but with snazzy new covers. I'm specifically thinking of Lyman and Speer.

Alliant does have some basic data for 300mp out in their online reloading guide, but only for the more common calibers:

http://alliantpowder.com/reloaders/Powder.aspx?powderid=29

I'd say if you continue to not get any email replies, don't hesitate to call them. (866-286-7436)

[onelight]

Hornady 10th edition has some 300 mp loads but not for 357 max.

[Hamish]

(Obi Wan voice) "This IS the powder you were looking for."

http://castboolits.gunloads.com/showthread.php?223093-Heavy-357-Max-load-help-please!

[cwlongshot]

I just got the new NOSLER manual. I have to say I am impressed its very nice!

But not what I was hoping to find.

Gonna PM 357 Maximum. Hopefully he can shed some light here.

CW

[Hamish]

357 Max self banned. Use the search button for info.

[Hamish]

Look, Power Pro 300-MP is right at 110/296, 4759, N-120. It's just a tad faster than 4227.

Use start loads for any of those powders and work up.

I don't know about any of the other editions, but the '2000 edition has a lot of data, and is well worth having as it covers many cartridges.

253308

[cwlongshot]

253309


Thats a good reference book that I regularly use!!

I have most manuals but still buy these “load books” fro some calibers just to have data complied in one book.

I have done a bit of “extrapolations”. I understand principals for watching pressures knowing Primers are not in that equation. Id still like to have someone with real pressure equipment print data some day.

CW

[Hamish]

I'm not sure if Moleman ever did any pressure documentation, but his 357 AR threads/posts have a lot off useable info.

http://castboolits.gunloads.com/google.php?cx=partner-pub-6216953551359885%3A1942134700&cof=FORID%3A9&ie=ISO-8859-1&q=Moleman+357+max+rimless&sa.x=0&sa.y=0&siteurl=castboolits.gunloads.com%2Fshowthread.php% 3F387274-Looking-for-data-from-MP300-in-Maximum&ref=castboolits.gunloads.com%2Fsearch.php%3Fsearch id%3D5939910&ss=20223j47461205j25

[AlaskaMike]

Look, Power Pro 300-MP is right at 110/296, 4759, N-120. It's just a tad faster than 4227.

Use start loads for any of those powders and work up.




I'm not sure I'd go with the first statement. The second statement for using start loads, sure, no problem. The problem I have with the first statement where 300MP is "right at 110/296" is just not accurate. Book loads for H110/296 with .357 Mag are about 16.5 - 17.0 grains with a 158 grain bullet. Alliant's 300MP load data is 18.6 grains max for the same weight bullet. That's a great deal different. We're not talking a couple tenths of a grain here. Unfortunately they don't show starting loads, so we can't examine the range that Alliant thinks is safe.

I do not believe using H110/W296 load data with 300MP would be at all dangerous, but it's clear that 300MP is significantly slower from the other powders that you just can't use the H110/W296 data interchangeably.

Just my $0.02. Merry Christmas all.