358/375 RUM (Texan)

J E Custom

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Having a love affair with the RUM cases and having built three wildcats on these cases that exceeded all expectations I am going to start another to add to my list of Texans. 30 Texan, 338 Texan, 416 Buff and now a 358 Texan to fill the gap. all of these cartridges are based on the 375 RUM case with a case capacity ranging from 95 grains to 119 grains powder capacity depending on the cartridge design.

With the changes to the cartridge for the 358 Texan powder capacity should be in the neighborhood of 112 to 114
grains of powder and make use of some of the newer powders. Bullets will range from 250 to 350 grain depending on performance and availability. It will have 20 to 30 grains of capacity over the existing 358's.

J E CUSTOM
 
Long ago I necked the 378 to 35. With 7828 and a 250 I was getting 3410. lol, A giant varmint rifle. With a 250 speer it was shooting poorly. The 100 yd target looked like a frag round hit close by. A big hole surrounded by holes about like 7 1/2 shot. Bullet was debriding just flying. Enough for that experiment. That was in the early 90,s and no hammers or triple shocks then.
 
Long ago I necked the 378 to 35. With 7828 and a 250 I was getting 3410. lol, A giant varmint rifle. With a 250 speer it was shooting poorly. The 100 yd target looked like a frag round hit close by. A big hole surrounded by holes about like 7 1/2 shot. Bullet was debriding just flying. Enough for that experiment. That was in the early 90,s and no hammers or triple shocks then.

In my experience the big bores do well if you plan the rifle around the cartridge and bullet. Most want to use traditional thinking and go with a fast twist, but this can cause problems. If spun to fast they can shed the jacket because centrifugal force due to the large diameter. I have found great accuracy If the rifle, cartridge, powder and bullet are all part of a package that work together.

The rifle will be used for Elk, Bear and moose using 250 to 300 grain bullets. Range limits are only limited by the bullets and the shooter. (Mainly for 1,000 yards and in)

Big bores can be extremely accuracy If set up correctly, and Very powerful. The 416 buff Exceeds 7,000 ft/lbs of energy with a 400 grain bullet and has shot my best group to date. (0. 034 thousandths. (1/ 29th MOA).

It will be an interesting project and I should/could learn something in the process. With the newer powders and a better bullet selection, I an expecting better performance of the big 358 than in the past. 👍

J E CUSTOM
 
In my experience the big bores do well if you plan the rifle around the cartridge and bullet. Most want to use traditional thinking and go with a fast twist, but this can cause problems. If spun to fast they can shed the jacket because centrifugal force due to the large diameter. I have found great accuracy If the rifle, cartridge, powder and bullet are all part of a package that work together.

The rifle will be used for Elk, Bear and moose using 250 to 300 grain bullets. Range limits are only limited by the bullets and the shooter. (Mainly for 1,000 yards and in)

Big bores can be extremely accuracy If set up correctly, and Very powerful. The 416 buff Exceeds 7,000 ft/lbs of energy with a 400 grain bullet and has shot my best group to date. (0. 034 thousandths. (1/ 29th MOA).

It will be an interesting project and I should/could learn something in the process. With the newer powders and a better bullet selection, I an expecting better performance of the big 358 than in the past. 👍

J E CUSTOM
I agree with what you say. That was a 12 twist but even if the twist was slowed down a cup and core would be too soft except maybe a 275 woodleigh. Hammer will make you whatever you want. A 280 or 300 with that 12 twist would be a monster killer. Even a nosler partition or swift a frame would be under great stress. In my experience a nosler partition behaves best if they are not going over 2800 at impact.
 
In my experience the big bores do well if you plan the rifle around the cartridge and bullet. Most want to use traditional thinking and go with a fast twist, but this can cause problems. If spun to fast they can shed the jacket because centrifugal force due to the large diameter. I have found great accuracy If the rifle, cartridge, powder and bullet are all part of a package that work together.

The rifle will be used for Elk, Bear and moose using 250 to 300 grain bullets. Range limits are only limited by the bullets and the shooter. (Mainly for 1,000 yards and in)

Big bores can be extremely accuracy If set up correctly, and Very powerful. The 416 buff Exceeds 7,000 ft/lbs of energy with a 400 grain bullet and has shot my best group to date. (0. 034 thousandths. (1/ 29th MOA).

It will be an interesting project and I should/could learn something in the process. With the newer powders and a better bullet selection, I an expecting better performance of the big 358 than in the past. 👍

J E CUSTOM
The 416,s. I built a 416 weatherby in 1989 on a P14 with a lilja 6 weight. 25 inches and no brake. It would get your attention but when used in anger you never felt it. With Jack Carters trophy bonded and imr4350 I was getting 2785. With a factory CZ 416 rigby I am getting 2700 and no fuss no muss. And proper headstamps. I have built many wildcats also but now I do not so much unless a factory round won,t do it. But there always seems to be a better way. I designed a 6.5 on the 300 win mag case. Faster than the nosler and as fast as the weatherby but burns 10 grains less powder. Tipping point. You can only use so much powder in a certain size hole. Many know that.
 
.............I agree with what you say. That was a 12 twist but even if the twist was slowed down a cup and core would be too soft except maybe a 275 woodleigh. Hammer will make you whatever you want. A 280 or 300 with that 12 twist would be a monster killer. Even a nosler partition or swift a frame would be under great stress. In my experience a nosler partition behaves best if they are not going over 2800 at impact........

We ran the .358 long magnum Ackley version same 12 twist. Barnes quit making their 275 Original about that time. The 250 Hornady would shoot great fire forming, but the wheels would come off when pushed hard. The 250 Nosler was devastating on game, but never lived up to the cartridges potential of 3000 fps.

Too old to require that kind of firepower anymore, but I too am tempted to have Hammer turn up a good 275 grain bullet just to say it works
 
Having a love affair with the RUM cases and having built three wildcats on these cases that exceeded all expectations I am going to start another to add to my list of Texans. 30 Texan, 338 Texan, 416 Buff and now a 358 Texan to fill the gap. all of these cartridges are based on the 375 RUM case with a case capacity ranging from 95 grains to 119 grains powder capacity depending on the cartridge design.

With the changes to the cartridge for the 358 Texan powder capacity should be in the neighborhood of 112 to 114
grains of powder and make use of some of the newer powders. Bullets will range from 250 to 350 grain depending on performance and availability. It will have 20 to 30 grains of capacity over the existing 358's.

J E CUSTOM
I have 4 boxes of northfork 270,s if you are interested
 
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