Short version:

I am looking for some assistance on modifying a 505 Gibbs load. Published load data is scarce and powder availability limited.

Current Load
525 gr Woodleigh
143 gr IMR 4831
Fed 215 primer

Desired Load
600 gr Woodleigh
1?? gr IMR 4831
Fed 215 primer

I can get my hands on IMR 4350 and H4831sc easily and possibly others if that helps.

Long Version:

My father in law passed away suddenly a few months ago. I know he enjoyed this forum and the wealth of knowledge among its members. He was not that active recently but his handle was Blake7062. He loved his big bore rifles. 450 Dakota, 375 Black Mesa Express, and 505 Gibbs. I am care taker of his collection for a little while and trying to make sense of his load data, make up loads to use up his stock of bullets, and take his daughters to the range to shoot them. Blake taught his daughters to shoot and it is a lot of fun to watch them pull the trigger on big bores. There is nothing quite like watching 4 young women center punch targets with a 450 Dakota and take the recoil like a pro. This also allows us to remember and morn the loss.

Good on you for getting away from the 525gr shirt button bullet, stupid idea to build in the first place.

140 grains of Retumbo fills the Jamison cases nicely in my 505 Gibbs under either 600gr Woodleigh soft or solid, velocity is a very shootable and accurate 2150 fps, I use FED-215 primers.

I have, and you can if you wish continue to add Retumbo for 2450 fps with either bullet, however, recoil is horrendous.

BTW, you can start at 135 grains of H-4831 and workup accordingly, it will safely go to 2450 fps with 600gr Woodleighs as well.

2,450 with a 600gr bullet? That's a squib load for you, Jerry :-)

quote:

Originally posted by Biebs:
2,450 with a 600gr bullet? That's a squib load for you, Jerry :-)

LOL, not anymore Big B, I'm looking hard at six 0 in the windshield ; ]

I used 148gr of RETUMBO under the 600gr Woodleigh in mine with Norma brass and Fed215 primers. Way over 2300fps with that load, so I dropped it down to 145gr. Recoil was stiff, but my CZ550 Safari Custom weighed only 9lbs, even with the 1lb mercury recoil reducer.
Have fun with the 505, those 600gr bullets pack some punch at both ends.

Cheers.

Good Man, carrying on the family tradition.

I found H4831 "long cut" most accurate with a 558-grain S&H brass FN at 137.5 grains with F215 primer in Jamison brass >>> 2238 fps 5-yard velocity,
from a 24" barrel.

Ah, well, you wanted a 600-gr Woodleigh, so I look to the Woodleigh manual:
.505 Gibbs 24" barrel, F-215 primer, Bertram brass, 3.85" COL
Filler used: 6 to 7 grains of Dacron, or 2.5 grains of foam wad
H4350 109 grains >>> 2100 fps (the velocity advertised for Norma PH ammo)
H4831sc 121 grains >>> 2125 fps

quote:

Originally posted by tsibindi:

quote:

Originally posted by tsibindi:
The following is a load I used to kill four elephant.

Jamison brass
Fed 215 primers
108grs R-15
600gr Woodleigh FMJ bullets
Small foam filler
Rifle; Granite Mt Arms 23.5" barrel
Average across the screens @ 15' corrected to the muzzle: 2153fps Five shot average.

Real world good stuff tsibindi, Thank You, I've read about 55 to 60+ inches of penetration through Ele head on back into the body, and always wondered how mine may do with the 600gr Woodleigh solids on fleeing Buffalo should I ever bring it to Africa, was hoping both 600gr Woodleigh soft and solids would behave better at 2150 fps as opposed to running them at 2450.

Thank you all for the info and kind replies. Thank you for helping to fill the knowledge void left by my father in-law.

I found the following other load info.

The smith who made the rifle uses 140 gr IMR 4350 for 525 gr Woodleigh To get 2450 FPS, but never shot 600 gr. My rifle is one of four he made. Jim Wisner of Waisner’s Inc.

Loads from other forums for 600gr
IMR 4350 136 gr 2250 FPS
IMR 4350 140 gr 2500 FPS

I am starting with 130gr IMR4350. This results in 90% case fill. I have never used case fillers And not too keen on trying them. I think I am safe at this fill level. Saturday is the trip to the range to see what happens.

This is my farthest foray from published load data.

I opted for RL-15 and IMR-4350 but even then I was in my late 60s or early 70s..I loved the gun, but it was definatly too light and wasn't fun to shot, and off the bench it cut my glasses in half and gave me a loopy slice!! I just waited too long to give it a try, and it was more gun than I could or wanted to handle, I shot a buffalo or two with it and sold it in the old Gun List paper..BTW it weighed 7-3/4 lbs. naked and the scope came out off the bases when it got me between the eyes, so got a peep sight. Went to the 458 Lott, loaded it down to 2200 fps with a 500 gr. bullet and liked that real well,but in the end I returned to my beloved 404 Jeffery, 416 REm, and 450-400s..Today at 85 I like my 375 Ruger and 9.3x62, 338..its the natural process I suspect. And live with the bursitis that goes with the lifestyle of big bores. I hunt elk, mule deer behind my house, and whitetail in Texas, The big bores are a thing of the past..