Home Forums Hunting & Shooting Ask The Gunwriters Bullet Swagging Jacketed rounds for the 9x57 Mauser

Swaging jacketed bullets down can be a problem as the jacket springs back slightly and the core does not. I don't know whether such a slight down-swaging as you suggest would encounter this problem.

With careful attention to your loads and how they perform, you may be able to safely use 0.358-inch bullets in a 0.356-inch bore. I've read, somewhere or other, that you can, but I'm not sure enough of such a practice to advise it. I'd try it, myself, but awfully carefully. At the very least, I'd expect chamber pressures to be higher, of course, and safe maximum loads to be lighter.

To make things easy, I had my custom 9x57mm built with a 0.358-inch barrel. (Yeah, I know � yours is a European rifle, already is whatever it is. You ought to slug the bore to make absolutely sure what the groove diameter really is. It might even be as much as 0.359 inch.)

I'd check with Corbin. Back in the 80's, when I got my pre-war 8x57JR drilling, that's where I got the die to swage standard 8mm S bore .323" bullets down to .318" for my J bore. J bore bullets were not available in the US back then. I only did this with cup and core jacketed bullets - no premiums. I got sub MOA when I waited at least 90 seconds between shots - drillings don't do rapid fire well. Killed a little 6 point in Oklahoma with these bullets. I think I was using Speer bullets.

http://www.corbins.com/

I was swaging them .005" so I wouldn't worry about .002".

I've heard of some 9.3 shooters swaging down .375 bullets, though I can't imagine an excuse for that myself.

Slug your bore first. I have one that I contemplated doing just what you mention until I found out that it measures .358". You could get lucky like I did.

I make my own bullets and swage. The accepted maximum that you can swage down without causing a loose core is 0.006 inches. Your intention is a 0.002 inch reduction and will be no problem.

Save yourself some money and check out www.CH4D.com. They offer ring dies and are more affordable than Corbin. When the page opens, you will see a menu on the left. Click on Bullets and look for Bullet Sizing Dies.

Initially I had some .35 caliber Hornady SP bullets in my inventory (even bought a .358 expander die from RCBS in hopes of making this work). On my test round with a spent primer with just a .35 Cal 250-grn bullet over an empty case i could barely get the bolt handle to close. (it had to be forced) I tried various seating depths and even a fire-formed and sized case; both with the same result. Which i assume meant the tolerances are to tight for the .358" is that correct?

I have looked up slugging a bore on youtube and seen how the process works. One question i have is, where do i get a hunk of appropriate sized lead (approx .35 caliber) to initially try this with? I don't have any casting materials around. Are there any other clever or common substitutes i could use for this?

I found a beautiful Mauser and bougtht it right because nobody knew the caliber. I discoverd it was 9x57 and the Riflesmith who was cleaning it up offered to rebore it to 9.3x62. It shoots .5MOA now. Probably made before WWI.
Think about getrting it rebored.

The bore diameter is more or less irrelevant. What does matter is the neck and throat diameter.

First, take a cartridge or preferably several, loaded with your brass of choice and bullets of the proper .356" diameter. Fire them. Then take a .358" and see if it will slide easily into the necks of the fired cases. If that doesn't happen, you'll have to either turn the case necks until you get proper clearance or you'll have to run a larger reamer into the chamber.

If it passed that first test, the next thing to try is to seat a bullet in one of the cases and try chambering it. If it won't chamber, make sure you aren't jamming it into the lands. If it isn't jammed, and it still won't chamber, then you have no choice but to use proper size bullets or run a throating reamer into the chamber.

If it passes BOTH these tests, you are golden. I'd just shoot the .358"s. In the grand scheme of things, .002" is almost nothing.

Note that if it fails test 1 and passes test 2 and you go ahead and load it w/.358"s anyway, you are asking for real trouble. The case must be able to release the bullet unimpeded.

Grissins,

I encountered much the same problem as you a few years ago. What I did, was get a Lee push-thru type die in .355". I did discover that the bullet after being pushed thru the die, did indeed, spring back to about .356", I tried using liquid Alox for lube, but in the end, I found that Imperial Sizing Die Wax worked about the best with the least fuss, bother, and mess...

I shot about 50 bullets sized like that. Then I tried unsized bullets and couldn't really tell the difference. Use a good, accurate micrometer. (Not a dial Caliper!) and measure various bullets. I think you'll find that few of them actually measure .358" More likely you'll find them to be .357"-.3575", irregardless of what is printed on the box.

BTW, the rifle I owned then, slugged .355". The one I own now slugs .357" and the one I have in the works slugs .358"...

GH

P.S: PM incoming...

Grasshopper nailed it.

Ask Lee to make you a 0.355" push through bullet sizing die ... their cast bullet sizing dies work great on jacketed. Spring back is about 0.001". A reduction of about 0.004" per go is maximum, although you can go further in steps. Lee makes a 0.357" die which you can try first, then through a 0.355".

For slugging a barrel, use a bean sinker that's larger than the barrel diameter. Pre-condition the bore with WD40, then place the bean sinker on the muzzle so the hole in the sinker runs in the same direction as the bore, place a block of wood over it and hit it with a mallet. The crown will cut the lead so it fits and the excess gets cut off as a donut. Neither lead nor the wood will damage the muzzle. Then push the slug back out with a cleaning rod, drive it out with a mallet rather than tapping it lightly. Bean sinkers should be pure lead which prevents them springing up in size when driven out.
Cheers...
Con

Grasshopper, did you use this type of lee push-thru die? As it mentions specifically not effective on 9mm (though they are implying 9mm pistol not rifle) Lee Bulge Buster Kit

In the Custom services ... you want to order at 0.355". You need a good press, I use a Lee Classic Cast as its strong enough for the drawing down stresses.
Cheers...
Con

Lube and Size Kits

Maximum bullet diameter is .575.

We need:

1. Payment of $35.00 ($30.00 + $5.00 processing fee)
2. Desired diameter to the factory

Grasshopper did you have to special order your lee bulge buster push-thru die in .355"?

sorry, Con missed your last comment that answered my last post. Thank you both!

Not GH, but I think he means this:

http://leeprecision.com/xcart/Lube-and-Sizing-Kit/

Custom order the size you need.

The Bulge Buster is for pistol cases.

A friend of mine has a nice commercial Mauser chambered for the 9x57 cartridge. He has successfully used .358" bullets (the Hornady 250 grain RN) for many years without any issues. YMMV

No, not the brass sizing die, but a Cast bullet sizing die. I just looked and it is .356 dia. I believe that is the smallest that they make. But as has been suggested, they will likely make you a .355. I would slug the rifle first and get a die -.001 to whatever it slugs, because as CON pointed out, they will spring back about .001". Hope this helps...

GH

Yup! That's the one...

I always thought that I wanted a 9x57mm but have never
taken the plunge, from the sounds of it might be easier/
cheaper to buy a 358 win

You might try these guys. Look under the pull down for bullets and you should find bullet sizing dies. They recommend not sizing more than .004 in one step, easily accomplished in this case. Good luck.

bullet sizing dies

Mart

Oops, I missed Steve's post where he already recommended them. I guess I should read all the posts before I jump in.