Trail Boss - 458 WN, 470 NE (and math!)

First, I want to acknowledge DonnieWeps' posting "Shooting My Ruger No.1 in .458 Win Mag"
http://www.rugerforum.com/phpBB3/viewtopic.php?f=4&t=274497 , which prodded me to try reduce loads for my M77 Tropical


My take of the Hodgdon's Trail Boss recommendation is that Volume is the key factor, so I loaded just going on volume.

For 458 win mag, the published average case volume is 95 grains of water, which is ( 95 X 0.065 = ) 6.17 cc's

Loading Barry's plated 350 grain flat nose to the cannelure puts 0.46" into the case. The volume left available for powder would be
Case volume minus volume of bullet seating
6.17 - (0.458/2^2 X 3.141 X 0.460 X 16.387 = 4.93cc
4.93cc being the 100% loading with the starting load being 70% (3.45cc).

Being lazy I just used the 141 Lee dipper that came with the Classic Lee Loader, which throws (141 X 0.0164 =) 2.31cc two times for 4.62cc giving about 94% volume fill.

I was actually a little nervous as I hammered them out.


Here are the first two rounds I have reloaded in decades.


One of the many reasons for not shooting has been health, so I was a little worried about touching off a 458 in any loading again. SURPRISE, The recoil was less than a 410 dove load!

Velocity across the Oheler screens was 1280 fps, thus less than Barry's max velocity for this bullet of 1700fps

The expected ballistics shows about 13" drop at 100 yard so just short range PLINKING.


The other rounds I want to try with Trail Boss will be
44 Mag
30-06
416 Rgby
460 Wby
470 NE

Excellent, happy it worked out for you, thought it would. Merry Christmas. Don

JFB said:

First, I want to acknowledge DonnieWeps' posting "Shooting My Ruger No.1 in .458 Win Mag"
http://www.rugerforum.com/phpBB3/viewtopic.php?f=4&t=274497 , which prodded me to try reduce loads for my M77 Tropical

My take of the Hodgdon's Trail Boss recommendation is that Volume is the key factor, so I loaded just going on volume.

For 458 win mag, the published average case volume is 95 grains of water, which is ( 95 X 0.065 = ) 6.17 cc's

Loading Barry's plated 350 grain flat nose to the cannelure puts 0.46" into the case. The volume left available for powder would be
Case volume minus volume of bullet seating
6.17 - (0.458/2^2 X 3.141 X 0.460 X 16.387 = 4.93cc
4.93cc being the 100% loading with the starting load being 70% (3.45cc).

Being lazy I just used the 141 Lee dipper that came with the Classic Lee Loader, which throws (141 X 0.0164 =) 2.31cc two times for 4.62cc giving about 94% volume fill.

I was actually a little nervous as I hammered them out.

Here are the first two rounds I have reloaded in decades.

One of the many reasons for not shooting has been health, so I was a little worried about touching off a 458 in any loading again. SURPRISE, The recoil was less than a 410 dove load!

Velocity across the Oheler screens was 1280 fps, thus less than Barry's max velocity for this bullet of 1700fps

The expected ballistics shows about 13" drop at 100 yard so just short range PLINKING.


The other rounds I want to try with Trail Boss will be
44 Mag
30-06
416 Rgby
460 Wby
470 NE

Click to expand...

Shooting reduced rounds can be very fun. Most of my .44 Magnum rounds are less than full power and I've also shot some reduced .30-06 loads as well. I don't own an elephant gun so I can't speak to the other three on your list.

Trail Boss is a unique powder as its design obviates the need for published load data as a full case of it will not exceed black powder pressures (16,000 psi). You can achieve the same effect with using small loads of shotgun or fast-burning rifle powder as well, but these typically operate at higher pressures and you will need published load data to do these safely.

The .44 Magnum is an older, very popular revolver round and there are a bunch of published reduced loads, some of which will be real popgun loads, such as shooting a 180 grain LRN at 750 fps. They typically use a tiny amount of a very fast burning shotgun powder such as Clays or a fast pistol powder such as Bullseye. You can use Trail Boss in a .44 Magnum but with the vast amount of published data out there, you do not need to do so.

The .30-06 is old enough and popular enough that you can find published reduced load data using a number of powders. I've personally shot a number of 150 grain bullets in front of 28-29 grains of 2400 using Alliant's data from the early 2000s giving a max load of 29.2 grains in front of a 150 gr JSP for 2300 fps. That's a fun load and essentially like shooting a .30-30 out of a full-sized bolt gun. It's accurate as well but it just hits 10" low at 100 yards compared to that same 150 grain bullet with a MV of about 3000 fps. Do note that 29.2 grains of 2400 in an '06 is pressure limited and runs just below 60,000 psi. Lyman has some Unique loads in the '06 that push a 150 grainer at about 2000 fps and are also close to max pressure (50,000 CUP.)

Another good option for reduced loads is using H4985. Hodgdon states you can down-load H4895 to 60% of any published maximum load and still have a safe load. Hodgdon lists (full power) loads for the .458 Win Mag and .460 Wby Mag, so you can base a reduced load off of that, however, you will need to chronograph it yourself as their starting loads are about 95% of the maximum.

Getting over my fear of not being physically able to withstand recoil is serious for me.

My rememberance from 30 years ago, H4985 reduce loads still had a punch to them. I have just under a 100 what I "think" were 350 gr reduced BUT I can't find my log book from back then to confirm how much powder is in them. I keep thinking since the trail boss loads had virtually no pain, maybe I could withstand the ones loaded with H4985, but I can't afford a bruise/sore shoulder.

My current 10 minutes a day I have for myself have been getting the 470 NE brass ready. Today I deprimed the 16 Bell cases I found. For the 470, besides me, the rifle is old and I don't wont to push it even though it was reproofed when I had it restored

Next......470NE

My classic big bore is a 470NE hammer, double rifle sold by Lyon and Lyon



For 470 NE, the published average case volume is 146 grains of water, which is ( 146 X 0.065 = ) 9.49 cc's
Loading Barnes "475 Wildey" 250 grain flat nose 0.30" into the case. The volume left available for powder would be
Case volume minus volume of bullet seating
9.49 - (0.475/2^2 X 3.141 X 0.30 X 16.387 = 8.62cc
8.62cc being the 100% loading with the starting load being 70% (6.03cc).



I used a 3.1cc Lee dipper twice for 6.2cc.
The 470 case length makes it difficult to use the press.



Velocity across the Oheler screens was 1530 fps, thus the expected ballistics shows about 9" drop at 100 yard

While ballistics is one thing, for a side by side regulation is important. Going off hand, at 35 paces, using the low rear leave, the shots were on elevation, not crossing by 1 inch on either side of the mark.



It is hard to believe the lack of recoil and report!

Made 4 round boxes