Swage a 358 JACKETED rifle bullet down for 357 mag use

You might not need to swage it down at all. Speer used to have load data for their .358" 180 grain rifle bullets in their 357 Magnum data.

Some jacketed 38/357 bullets measure .358". I have some Zero 38/357 110 grain jacketed bullets that measure .358".

Hornady uses .358 rifle bullets in their 357 Maximum Contender load data.

A good closed arch reloading press (don't use an open press) and a lee sizing die of the correct size works just fine. Be sure to get sizing lubricant. A .001 inch change should be fairly easy, you might need to use a .356 die instead of a .367 die as you can get some spring back with jacketed bullets.

I have resized .458 diameter jacketed bullets down to .452. I did that in two steps going .458 to .454 then .454 to .451 and the finshed bullet measure .4515-.4522. You can get just a little spring back. The dies a pretty cheap.

If it's and actual .358" diameter cast bullet, no need to swage at all. The bigger issue is that most commercial rifle bullets may be too hard. If 357 Max, maybe velocities will be enough, but a 22 BHN bullet is generally speaking, too hard and could cause leading. If it will chamber, it will shoot, just make sure that your 358 rifle bullet is actually .358" and not .360"....

I loaded .452 jacketed bullets in 45 auto (intended for 460 mag) during one particular shortage. I want to say I reduced the charge for a given weight by 10% but its been a few years. You may want to just load a few with reduced loads and check for pressure signs.

There isn't an issue with shooting a .358 jacketed bullet through a handgun. It won't create any noticeable pressure difference. A friend of mine that has pressure testing equipment tested some .357 9mm bullets out of a 9mm barrel and could not get pressures to show any difference in 9mm between the .357 and the .355 bullets.

longdayjake said:

There isn't an issue with shooting a .358 jacketed bullet through a handgun. It won't create any noticeable pressure difference. A friend of mine that has pressure testing equipment tested some .357 9mm bullets out of a 9mm barrel and could not get pressures to show any difference in 9mm between the .357 and the .355 bullets.

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Good information. Did he slug the barrel to confirm the groove diameter?

fxvr5 said:

Good information. Did he slug the barrel to confirm the groove diameter?

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^^This^^
A 9 mm Luger barrel can be .355"-.359" and be within SAAMI specs.

98s1lightning said:

What kind of equipment cost is involved in swaging down a 358 bullet to 357???

Bullet being too tough is OK. To keep discussion on topics let just say this is for 357 maximum and heavy bullet choices are low.

Is it an "easy" operation with a large arbor press or?

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I could send you a handful of 180 gr Hotcore or 200 RN bullets if you want to try before buying a bunch.

kcofohio said:

^^This^^
A 9 mm Luger barrel can be .355"-.359" and be within SAAMI specs.

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Yes. It was a test barrel and it measured .355"

longdayjake said:

Yes. It was a test barrel and it measured .355"

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That is good to know.

longdayjake said:

There isn't an issue with shooting a .358 jacketed bullet through a handgun. It won't create any noticeable pressure difference. A friend of mine that has pressure testing equipment tested some .357 9mm bullets out of a 9mm barrel and could not get pressures to show any difference in 9mm between the .357 and the .355 bullets.

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longdayjake said:

Yes. It was a test barrel and it measured .355"

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Don't let LiveLife see this. He'll have a cow.

fxvr5 said:

Don't let LiveLife see this. He'll have a cow.

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I'll take the cow off his hands. I've run .358 jacketed bullets in 357 mag without issues. The accuracy was impressive.
I recommend people do the things that I have. I had a mullet at one point in my life. And I definitely don't recommend that.

I used the Speer 180 grain flat point (.358) in a 357 max TC 14 inch with no problems

Back to the original question, swaging a .358" jacketed bullet to .357"; yes, sizing down a jacketed bullet just .001" is fairly easy. I'd pick up a Lee push through sizing die in .357" and use a decent press, no need for an arbor press. Use a case lube and try a few. I once needed some .318" bullets for an Enfield with a groove diameter of .318". Used a Lee .314" die honed to .318" to size some jacketed 32 cal bullets (,323"). It worked and they seemed to shoot OK, but .005" was hard to swage and may have been too much for one pass...

The equipment would be nothing, because you shouldn't need to resize the bullet. The diameters should be the same between pistol and rifle.

.358 is ok, just drop your load down a little and work back up. years ago i shot a boat load in a 357 super mag.