350 Mashburn Short Magnum - seeking dies!

[MGMLVKS]

Recently acquired a quite nice example of Mashburn 350 short Magnum in what I believe to be a custom Mashburn Stock. Pic below - and the other link takes you to Flickr with several additional pics. Receiver is M1903A3. Barrel is marked "Mashburn Arms Co, .350 Short Magnum".

Problem is - this is the least common of the Mashburn Magnums and I have no dies and no cartridges. It seems pretty easy to make the cartridges from 300 H&H, but still need to run them through the die at least once to get the shoulder set. I do not plan on shooting this a lot - so only need to make a few of them!

I would gladly beg/borrow/rent/buy/trade for a set of dies if you have one! In-person meeting in Greater KC Area (or further) preferred - or if one can trust attorneys - we can use mine as a go between to ensure everyone is happy with the exchange of hostages!

Mike
Leavenworth, KS




More pics - https://flic.kr/s/aHBqjCuUA3

 

[Sniperhandle]

Be patient and save a search on Feebay, I have gotten lots of hard to find die sets on Ebay that way, Also check Gunjoker, Sometimes a good deal on something like that pops up.

And lastly, CH-4D has an unbelievable list of caliber they can make dies from. Go to their website and peruse the the pages, Your dies may be on there and all things considered, Their prices for custom dies are fair.

 

[MGMLVKS]

"Be patient and save a search on Feebay, . . . . CH-4D has an unbelievable list of caliber they can make dies from . . . "

Thanks - I have done most of those things! Most interesting is that after contacting many of the die makers (including CH4D) nobody seems to have specs from a prior life, requiring two or more fired cases (or reamer details - haha!), a few hundred buckazoids and up to 24 months turnaround. Some are now out of the custom die manufacturing as well.

While I will keep looking - am pretty sure there will be a way to use dies for similar case/calibers and some creativity to solve the problem. Also re-reading (from decades ago) the whole "fireforming without projectile" process. Guess that is why I bought 50x .300 H&H brass!

 

[Sniperhandle]

Thanks - I have done most of those things! Most interesting is that after contacting many of the die makers (including CH4D) nobody seems to have specs from a prior life, requiring two or more fired cases (or reamer details - haha!), a few hundred buckazoids and up to 24 months turnaround. Some are now out of the custom die manufacturing as well.

While I will keep looking - am pretty sure there will be a way to use dies for similar case/calibers and some creativity to solve the problem. Also re-reading (from decades ago) the whole "fireforming without projectile" process. Guess that is why I bought 50x .300 H&H brass!

Yeah I have been able to load a lot of calibers that I don't have dies for by using tools such as Hornady's universal neck sizers and Frankford arsenal's universal bullet seaters, And by chopping dies down, Using other dies that are close etc.

Unfortunately Hornady doesn't make those neck dies anymore but I have been able to find all of them on Feebay.

 

[MGMLVKS]

Great progress today - I've said before - getting to the final product will "cost somewhere between irrational and idiotic". Came right up to staring at "idiotic" today and decided to calm down and take stock of where I think I am going! Helps that both 308 and 358 Norma Magnums are close to the Mashburn 350 SM in many aspects all being based on 300 H&H Magnum!

• Found a 308 Norma Trim Die on EekPay. Will use it to cut the 300 H&H cartridge from 2.85" to 2.56" of the 308 Norma Magnum
• Bought 308 Norma Case length Gauge (Lee). Will remove about 0.06" from the pin and use the cutter to get the case down to the recommended 2.5" length before FL Sizing
• Bought the Hornady 358 Diameter neck Sizing Die and some 250gr bullets from Midway to use on the 2.5" modified 300 H&H brass.
• Studied the distance from base to shoulder in the 358 Norma Magum (2.085) and the Mashburn 350 SM (2.05). See pic. Figured I (or hopefully a more skilled person) can cut 0.03 or 0.04 off the bottom of a 358 Norma Mag die. Even found a set of dies that were priced in my range noted above, just not sure how close to the 'Idiotic" side of they scale they are!
• Read up on my just arrived 2011 Copy of "Handloaders Manual of Cartridge Conversions" about using about 10-15gr Bullseye and the rest packed with cornmeal for fire-forming! They suggest using the trim die, but I would have to use the rifle unless I come upon a Mashburn trim die!
• Will probably need another Lee Case length Gauge in .358 to modify to meet the Mashburn Cartridge Length of 2.475

Anyway - an interesting and productive day. I welcome any observations and comments on my approach.

** UPDATE ** Just realized I would need to move the spot where the belt headspaces in the die up .03" or so INSIDE the die - not in my skill set!

Mike

 

[Sniperhandle]

Great progress today - I've said before - getting to the final product will "cost somewhere between irrational and idiotic". Came right up to staring at "idiotic" today and decided to calm down and take stock of where I think I am going! Helps that both 308 and 358 Norma Magnums are close to the Mashburn 350 SM in many aspects all being based on 300 H&H Magnum!

• Found a 308 Norma Trim Die on EekPay. Will use it to cut the 300 H&H cartridge from 2.85" to 2.56" of the 308 Norma Magnum
• Bought 308 Norma Case length Gauge (Lee). Will remove about 0.06" from the pin and use the cutter to get the case down to the recommended 2.5" length before FL Sizing
• Bought the Hornady 358 Diameter neck Sizing Die and some 250gr bullets from Midway to use on the 2.5" modified 300 H&H brass.
• Studied the distance from base to shoulder in the 358 Norma Magum (2.085) and the Mashburn 350 SM (2.05). See pic. Figured I (or hopefully a more skilled person) can cut 0.03 or 0.04 off the bottom of a 358 Norma Mag die. Even found a set of dies that were priced in my range noted above, just not sure how close to the 'Idiotic" side of they scale they are!
• Read up on my just arrived 2011 Copy of "Handloaders Manual of Cartridge Conversions" about using about 10-15gr Bullseye and the rest packed with cornmeal for fire-forming! They suggest using the trim die, but I would have to use the rifle unless I come upon a Mashburn trim die!
• Will probably need another Lee Case length Gauge in .358 to modify to meet the Mashburn Cartridge Length of 2.475

Anyway - an interesting and productive day. I welcome any observations and comments on my approach.

** UPDATE ** Just realized I would need to move the spot where the belt headspaces in the die up .03" or so INSIDE the die - not in my skill set!

Mike
View attachment 1699242

Good job.

You cant cut 30 or 40 thou off the bottom of the 358 Norma die because that's where the belt will be, You could do that and use it as a neck sizer, But you can cut the top section off of any Belted magnum die and use it to size the case body and the belt.

There are a number of ways you can do it and it sounds like you are on your way.

 

[Sniperhandle]

Also, I would not cut up 300 H&H brass as it is getting hard to find and expensive. 300 Win mag would be cheaper and a lot easier to find.