Procedure for accurate 8mm cast bullet loads
Alloy: Linotype has worked best for me and been the most accurate. Some considerate a bit on the hard side. To each his own. I have had good success with 18-22bhn but the Linotype is my favorite.
Design: Lee mold C324-175-R. This is a roundnose gas checked bullet.
Casting size: .324
Lube: Liquid Alox
Sizing: .323 Lee die
Weight: Mine throws 170 grains with the linotype
Brass: Remington Brass is my favorite for reduced loads. It is soft, easy to size and crimp. Cleans up well and is easily processed
Powder: 16 grains of Alliant 2400
Primer: CCI Large Rifle
The above is what I use for my 8mm bullets. The process is really what makes for accurate 8mm Mauser loads. The Old carpenters adage is “measure twice – cut once”. For someone wanting accurate 8mm Mauser loads its “weigh twice, measure twice and weigh again”. So here is my process for .75″ 5 shot groups at a hundred yards from a standard Yugoslavian M-48 with military trigger and barrel.
Install your 8mm gas checks after checking the bases to ensure that they have been properly cut and are square to the length of the bullet. To check this, stand a series of bullets up with bases touching and remove the “Leaners” then install gas checks and weigh your 8mm bullets. I suggest using a digital scale or it will take a lot longer. My mold can throw from 166-176 grain bullets. I segregate all my rounds on a piece of paper to within two grains: 168, 170, 172, 174, 176 and so on. Anything above or below my desired grain weight is re-melted.
Next, I tumble lube my 8mm bullets with Lee liquid alox. Run them through my Lee .323 bullet sizing die and tumble lube again. Let dry overnight.
While my bullets are drying I prep my Remington cases. I use a Lee Pacesetter 3 die set. The process is as follows:
Inspect and clean your dies.
Inspect and clean each case
Lube your cases. I make a case lube from 1lb. paraffin and two parts Bore Butter. This is a good cleaner and it is safe to handle with bare hands as it is natural lube. I run the cases and check their length with a Lee case length gauge. I have shot some of my bullets 15 times and have yet to have to trim them – but I check anyway. The reason they do not need full length re-sizing is the lower pressures produced by the 16 grains of Alliant 2400 do not cause the brass to run. (I have also used 15 grains of Red-Dot, but its not as accurate for me).
After sizing I clean primer pockets and chamfer the mouths.
Then it is on to the powder. I measure ALL my target loads with a Lyman powder scale, and yes, I get them to the grain, or at least as close to the grain as I can. I check the digital scale weight against the Lyman powder scale until the scale is set. My initial charge is from a Lyman Powder measure and I can get charges so consistent I rarely need to adjust the powder on the scale. I never charge from the powder measure unless I am making “plinking” rounds.
Next I seat my bullets to an OAL of 2.86 for my Yugo M48. (This is the best depth for the greatest accuracy in my rifle and I will cover how to find the OAL in another post)
So now, you may think “That’s it” but truth is – it’s not.
Re-check your OAL lengths and segregate in groups of five or ten depending on the strings you shoot. These are your rounds for a Match.
Now here is a video of “Bullet casting” from “Ammosmith” on “You Tube”. This guy is great. Although he is not casting for the 8mm Mauser – the procedures are the same.