Developing unusual loads

[Pheroze]

I am building a 400H&H. There are only a few sources for load data, such as CEB and fellow travellers. A starting point can also be drawn from the 416 RM. But, there are .411 bullets available in 320 gr and 317 gr. Also, the literature claims .41 caliber pistol bullets make a good plinking load.

Can someone help me understand how to build loads for bullets and weights that have no precedent such as these? How do you know where to start? Also, is there a way to predetermine how fast they should go, or is it only by looking for pressure signs?

 

[Pheroze]

In trying to answer my own question, I came across the Powley Calculator

http://kwk.us/powley.html

It actually seems pretty cool.

 

[375 Ruger Fan]

This doesn't specifically answer your question, but it's still an interesting article on the 400 H&H, if you haven't already seen it.

https://www.americanrifleman.org/articles/2017/2/27/not-a-question-of-need-the-400-hh-magnum/

 

[Pheroze]

Thanks. I believe this article is one of the ones that says you can use 0.41 cal for plinking. But, I am not aware of anyone that actually does this.

 

[Ray B]

If you don't have access to a Powley Computer, actually it's a slide rule; I have one and if you give a couple measurements I can run a calculation for you. the results will involve IMR type powder and a load that runs around 45K psi. the numbers needed are case volume (to bullet base) in terms of water weight, bullet weight, bullet diameter and sectional density and the length of the bore, measured from the base of a loaded bullet to the muzzle. I think that's everything.

 

[Pheroze]

If you don't have access to a Powley Computer, actually it's a slide rule; I have one and if you give a couple measurements I can run a calculation for you. the results will involve IMR type powder and a load that runs around 45K psi. the numbers needed are case volume (to bullet base) in terms of water weight, bullet weight, bullet diameter and sectional density and the length of the bore, measured from the base of a loaded bullet to the muzzle. I think that's everything.

Thanks! I did find an online version. I was hoping to use one of my usual powders (Varget or h 4350), but if that's how it is done...when in Rome..... Those slide rulers are cool btw

 

[stug]

Quickload will give some pretty good places to start. You will either need to buy the program or some nice person could run the data for you.

 

[Hogpatrol]

What he said ^^^^^, Quickload. I use it for wildcat loads or bullets with no data in any manual.

 

[Bert the Turtle]

Thanks. I believe this article is one of the ones that says you can use 0.41 cal for plinking. But, I am not aware of anyone that actually does this.

I don't have a 400H&H, but I do have experience using pistol bullets in my 404. Accurate Powder was able to give me loads using 5744 and for even lower velocity, one can use Trail Boss with the usual technique (http://www.imrpowder.com/PDF/Trail-Boss-data.pdf)

 

[Pheroze]

I don't have a 400H&H, but I do have experience using pistol bullets in my 404. Accurate Powder was able to give me loads using 5744 and for even lower velocity, one can use Trail Boss with the usual technique (http://www.imrpowder.com/PDF/Trail-Boss-data.pdf)

I have no experience with Trail Boss, this looks like a ton of fun actually, that is.

 

[Ray B]

The Trail Boss powder differs from the other smokeless powders in that it is designed to be measured by volume. A case is filled to what would be the base of the bullet and that is the maximum load. The amount is weighed, reduced by .3 (multiply by .7) and that is the minimum load. According to the manufacturer the weight of the bullet (within reason)doesn't matter. I've loaded some .429' 230 grain bullets that I ran through a reducing die to get them to .424" and they seem to work well for the desired purpose through a 404 Jeffery. I won't be winning any matches with them, but they provide a lot of range time without the expense or recoil of regular loads.

the Powley computer was designed to show the appropriate load with IMR powders, but can be used as a starting point for Varget and H4350, using IMR 4064 and IMR 4350. Since the powders are not identical I'd reduce the loads by a couple grains as a starting point.

 

[Pheroze]

I think I am going to give the trail boss a whirl. Sounds like a very workable solution. Also, for my standard calibers to just get trigger time