.450/.400 3" With 400grs Hydro - which COL?

[Bonde]

New to the forum, and hope some of you might have been down this track before.

Have aquired an old Jeffery .411" double which I intend to bring along hunting elephant next year.
After reading different reports on the Hydro, I finally got some og them in the mail.

IMR 4831 is the only powder I have thus far, if it works I dont want to go RL 15 and fillers...

My gun is a tropical 55grs powder 400grs bullet load.

What load would you suggest I start with..?

What is reccomended COL with this bullet? (Your COL if you have loaded this combo?)

 

[Pheroze]

Hi and congratulations

I have the following information from the Woodleigh Manual:

Hydro is actually 0.410". I have no idea how important the 0.001" is but hopefully someone one here does. Otherwise, Woodleigh does make a 0.411 RN. The Woodleigh manual claims the 0.410 FMJ is suitable for 0.411 groove diameter.

Woodleigh manual does have a single load for H4831:

H4831sc 80gr Fed 215 primer 1965fps

The Hornady manual shows maximum COL 3.735". It is a 0.410 groove diameter. Case trim 2.980" with a max case length of 2.990

The Hornady load for H4831 is:

Start 69.3gr @ 1800 fps
Max 82.3gr @ 2050 fps

 

[Pheroze]

I have been trying to find bullets for a 400 H&H (.411 groove diameter). I have found NorthFork and Cutting Edge Bullets to have the best selection of 0.411 diameter bullets. Everyone else has the .410 diameter standardized by Ruger. ugh

 

[Ridgewalker]

I have no clue, but I am jealous! It sounds like a fun project!
You said “old”. Just how old is it? You need to start with light loads and work up. H4831 is quite a bit slower burning than RL-15 according to the comparison charts I have read.
Find several reloading manuals, Hodgdons website, Alliant website, Ramshot, etc. do a comparison of as many as you can find, then start with the smallest amount and work your way up until the barrels are regulated as much as possible and probably around 2,150 FPS. You shouldn’t need more.
Good luck and please keep us informed!

 

[Bonde]

Thanks! It is a 1906 hammergun, finished 27th february, made by Leonard in Birmingham. Unfortunately no info of initial byer, but apparently taken in for some work in 1935. Probably has seen plenty of use, but barrels are good. The strikerholes has been reinforced by milling a flat area through the area of the striking holes from one sidenthrough to the other, and sliding in a bar. The work is very nicely done, and probably from 1935.
They should have used bushed strikers from the start, but apparently didn't.
I have only changed the broken recoilpad, and the rest of the gun is left unaltered.

26"bbl 10 1/4lb makes it s breeze to shoot!

 

[fourfive8]

I would certainly try to find some pressure data on whatever load and keep the load conservative for that older firearm. Remember that most all mono metal (copper/brass) bullets have the potential for causing higher pressures than conventional lead core- cup and core bullets even though the drive band design tends to mitigate the pressure spike problem with mono metals. Also be a good idea to use a powder that is not temperature sensitive- many such powders have become available recently. IIRC 4831SC is one of those. FYI, I believe Rel 15 is temperature sensitive. And, there are enough suitable powder options that you shouldn't need to try to use a filler- I would opt for a slower powder that maybe is less efficient but provides greater load density.... IMO

As to the OAL question... that all depends on the chamber and throat of the rifle. They all will vary some. I imagine that older chamber and throat will be somewhat liberal so shouldn't be an issue. What you don't want is an OAL where the front drive band of the bullet is into the lands of the bore when chambered. Just check and make sure there is some "jump" between chambered bullet and lands. I would think .050" jump would be a good place to start for minimum.

Also, you should put a good crimp on the bullet. Since it is a double, you want to crimp to prevent "bullet pull" of second bullet after first barrel fires. Soooo crimp should either be in groove or in front of a drive band- depending on and related directly to final OAL.