View Full Version : Sizing Bullets

July 2, 2009, 10:39 PM
I have a 1912 vintage Mauser sporter bored for the 8X57 I bore (.318) bullet. The only factory .318 bullets I have found are 200 grain - much heavier than I need - and are not cheap. I have been looking at the bullet sizing dies offered by Lee. I can order one to size bullets to .318, but I assume they are intended for sizing cast bullets. Does anyone know if it is possible to push a regular .323 8MM jacketed bullet through a sizing die & resize it to .318? If so, would one first use say a .320 die and then push them through the .318 die, or is it possible to swage them from .323 to .318 in one step? (This is assuming, of course, that it is possible to re-size a jacketed bullet in the first place.) Any opinion on whether or not it would be possible to re-size a .323 colid copper bullet to .318 with one of the Lee dies? If anyone has done this or anything like it I would be grateful to hear how it came out.

July 3, 2009, 04:54 AM
0.005" is a lot to size/swage down a jacketed bullet. There's a good chance that concentricity will be ruined. There's also a chance that the bond between the jacket and the core will be disturbed (not an issue with the solids.).
Then, again, it might work.

July 3, 2009, 11:05 AM
I would say NO! The pressure required would need a very heavy duty press, and a lot of force on the handle. Also, doing it dry, without lube would be impossible.

As darkgael said, the core of the bullet would then be loose inside the jacket. And the concentricity would also be suspect, um I mean I suspect it would NOT be concentric.

July 3, 2009, 12:56 PM
I agree that it either won't work, or it won't work well. But a lot of boolit casters have have great luck with gas-checked cast lead rifle boolits in this caliber. I suggest you head over to http://castboolits.gunloads.com/ for info and try to find a source for GC cast lead .318 boolits.

Definitely have to be careful with the .318 bore 8mm's. In fact, these older and smaller bores are the reason that much of the 8x57 commercial ammo is so light and handloads bring out the best in the more modern 8mm Mauser rounds.

July 4, 2009, 06:40 PM
The dies made for sizing cast bullets will not - in my considered and humble opinion - survive re-swedging jacketed bullets.

There are several companies who make swedging dies and presses, Corbin in Oregon for one. The dies and presses are somewhat dear in price.

The practical problem is guilding metal has more spring than lead. So, in altering the shape and size of the bullet, the jacket has a tendency to 'pop out' away from the lead core that does not 'pop back'. Changing bullet sizes of jacketed bullets works best when 'bumping' a smaller diameter bullet to a larger diameter. Again, that takes specially made dies and presses.

I'd go for cast bullets. Hard cast bullets are available and useful. With proper lube, one can shoot them at respectable velocities.

I'm sure there are jacketed bullets in lesser weights available somewhere. I would google search for .312" bullets. The Olde Western Scrounger, now back east somewhere and Huntington something or other deal in odd calibers. Finding this sort of stuff is part of the fun.

July 4, 2009, 06:49 PM
Thanks to all for taking the time to offer your insights. It is a problem that will take some looking and experimenting, but, as Archie said, that's what makes it fun.

July 5, 2009, 10:40 PM
The Winchester .32 Special and .32 Remington rifles use a bullet that's .321" in diameter, vs. the usual .323" of the 8x57JS round.

I've had good luck with a custom-ordered Lee bullet sizing die, swaging .323" 8mm Mauser bullets down to .321" for my Remington Model 8 in .32 Remington. (There was a dry spell on factory .321" bullets for the .32 Special at the time, and I wanted spitzers vs. flat-nosed, regardless) Granted, it was designed for cast lead bullets, and I'm only resizing the bullet .002", but that's enough for my rifle.

Something tells me that if you get factory .321" jacketed bullets intended for the .32 Special, they'll swage down to .318" quite easily with the beefy Corbin swage die.

July 6, 2009, 10:54 PM
Thanks for the suggestion - I think I'll try it. I measured the slug I drove through the bore with 4 different micrometers and got .318, .319, .320 and
.320 so if I can push a .321 jacketed bullet through a .318 die without having it "bounce" back too much, it seems like it ought to work. I will take careful measurements of the results and see what I come up with. If I learn anything of value during the process I will be happy to post it here for the benefit of anyone who may be interested. In the meantime I will be making a chamber cast to make sure that it is an 8X57 chamber rather than 8X60 or something even more exotic, and looking for a set of claw-type scope rings.

F. Guffey
July 7, 2009, 12:13 AM
BAW, I have some tough presses, then I have two arbor presses (rack and pinion).


F. Guffey

F. Guffey
July 7, 2009, 10:18 AM

Click on link, bullets, bullet sizing dies, they recommend sizing in steps of .004 thousands increments, bullet memory and recovery, a sudden stop will cause the bullet to recover diameter but at a cost, the bullet will shorten, the bullet is held by 'bullet hold' others call it neck tension, no matter what it is called, the bullet does not recover its shape after being being sent down the barrel or after sizing, it does not have a memory and does not recover.

And I use a sizer die to crimp some 45ACP cases, it is like crimping with case support, cases crimped in this manner do not look like they swallowed a bullet.

F. Guffey

July 7, 2009, 12:01 PM

Welcome to the forum.

Sounds like you have a micrometer problem or a slug problem. First, terminology: many folks say "micrometer" when the mean "caliper". See image below. IMHO, you NEED an OD thimble micrometer to get useful information from a slug. Calipers can be off by up to 0.002", depending on brand and your skill in using them without deflecting the beam, while the micrometers have ten times the resolution and accuracy of the calipers and are more difficult to err with, as long as you remember to wipe off the anvils and check the zero reading before making a measurement. The least expensive O.D. thimble micrometer with 0.0001" Vernier scale is adequate for bullet and slug measurements. They are less than $20 at Enco (http://www.use-enco.com/CGI/INSRIT?PMAKA=510-2202&PMPXNO=8915769&PARTPG=INLMK32).


Second, it is important that the slugs be nearly pure lead. Harder casting alloys spring back out when you measure them and can throw your measurements off by a thousandth pretty easily. Hornady swaged round balls for muzzle loading are pure lead and work. Bullets cast from stick-on wheel weights are also near enough to pure lead. Bullets cast from recovered standard velocity .22 rimfire ammunition are also close enough to pure lead.

One other thing a pure lead slug will do that a cast bullet alloy will not do is let you feel constrictions. The springy nature of the harder alloy makes a bore feel uniformly tight even when there are small diameter changes. A lead slug changes the feel of its resistance going in and out of constrictions if you push it slowly down the bore. Slug from both ends to get the full experience; it won't feel the same going the other way unless the bore is perfect. If you are going to shoot lead accurately, constrictions other than a taper to a tighter muzzle need to be lapped out.

Since getting the right size jacketed bullets is difficult, I would suggest you firelap (http://www.neconos.com/details2.htm) the barrel. This will do two things: One is that it will make the gun dramatically easier to clean (i.e., harder to foul with metal). That lets you fire cast bullets with gas checks into the 2200-2400 fps range without a lot of special fuss or effort or excess cleaning problems. Second, it will open the breech end up maybe half a thousandth, tapering down to the muzzle from that end. That, taken together with the friction-reduction from the smoothing will make it possible to fire slightly oversize jacketed bullets without as much pressure concern.

I know that last point sounds scary, but consider that U.S. military .30 caliber barrels have groove specs of 0.3065"-0.3095" and shoot jacketed bullets up to 0.309" OD. That means up to 0.0025" oversize bullets can find there way through these barrels OK. Is that best practice for accuracy? Probably not, but it doesn't cause catastrophic pressure problems, either. Moreover, what determines how much a bullet is squeezed is the cross-sectional area of the bore verses the cross-sectional area of the bullet, and different rifling arrangements change that even for correct size bullets.

If your bore is smoothed down by firelapping and the throat is widened to 0.3185", you will find you can work loads up with the 0.321" bullets without going through all the sizing effort and the potential problems it can cause. Let the barrel be your sizing die. Just start the loads an extra 5% below normal starting loads and work up carefully, watching for pressure signs. If you are still spooked by the idea, you can go to moly plated bullets or to giving the firelapped bore a lube treatment with Moly-Fusion or with Sprinco Plate+ and get the same effect as bullet coating, plus some added help keeping the fouling away. The friction reduction will make the swaging down of the jacketed bullet go even easier on the gun.

There are several firelapping kits out there. Avoid the cheap Wheeler kit at Midway; its abrasives and its instructions are both not correct, IMHO. My preference, despite its cost, is the NECO kit (http://www.neconos.com/shop/?cart=232719&cat=20) for this kind of project. They make a "roll your own" kit for .321" bores that has 10 pure lead bullets included for slugging. They will work fine in a .318" bore. The instructions have a good level of detail, and the lab grade abrasives they supply cut faster and don't contain the wide range of over and undersize particles you find in standard grades that make rougher scratches and slow cutting. You will have to supply your own firelapping bullets. Bullets cast of wheel weights and sized 0.001"-0.002" over bore diameter and that are not quenched typically have the right hardness range. However, I have found embedding abrasive into gas checks on harder cast bullets will themselves work well at removing constrictions. One kit will roll enough gas checks to do dozens of rifles.

F. Guffey
July 9, 2009, 09:10 PM
Lurch, I do not hear of people doing that but I do read on forums someone repeating what they read on the Internet about making sizer dies, the first person got it correct, he said back in the old days when gunsmith made a rifle with an improved, modified or wildcat chamber, the gunsmith made the reamer, cut the chamber then re-cut the reamer and made the dies.

The sizer die reduces the case dimensions, neck, body and case length, cutting a die with a chamber reamer will make a chamber gage. The die blank cost $40.00, a set of used dies can be found for $25.00 or less, that is the box, sizer die and seater die, if the die blank requires heat treatment, carbonized etc., annealing a die for reaming is a similar required skill and worth consideration.

My favorite reamer is the 25/06 Ackley Improved, the neck and throating part of the reamer is small enough to ream other chambers when a bushing is used on the pilot for centering, meaning a 25/06 Ackley Improved reamer can cut a die with the 270 improved shoulder and body without changing the neck size or length? to remove all of the original chamber the die will need to be shortened, and may require the neck portion of the sizer die to be lengthened (with a neck reamer die).

Next most favorite reamer is the 280 Remington for 8MM, 338 and 35 Whelen, instead of 8MM06 I have 8MM/280 Remington, 338/06 to 338/280 and 35/280, sizer dies for each requires a 280 Remington sizer die and a neck sizer for each.

I have 62 chamber reamers, having one reamer with alignment bushing makes the money go further.


F. Guffey
July 9, 2009, 09:47 PM
BAW. sorry about that, I offer no excuse, sizing bullets? I took a picture of my gages without micrometers, the picture weighed 400lbs +, the same for reamers, the N size drill is .302, the O size drill is .316, the P size drill is .323. A drilled hole is not smooth enough for sizing but oversized drills and reamers are available, especially for 5/16 (.3125), if it was important to size the .323 down to .318 I would look for an O index drill and a reamer, then tapper the hole to allow the .323 bullet to feed, an arbor press would work, a heavy reloading press would work also, modify the ram to push and load the sizer from the bottom.

F. Guffey

July 10, 2009, 10:49 AM
as I under stand the 88 rifle bore is .321.the 88 rifle when modified for the 8 mm mauser spitzer was just reamed for the throat.and the spitzers only have a very small section that is .324.most reloaders use the 32 spec or 32/40 bullet at .321.actualy you can use .324 lead bullets.as they will size in the bore.that gun used a 88 sized bore.I will be shooting an 88 commision rifle with .324 lead bullets.dont try to swedge jacket bullets down,only bump up.
I know I have done it.trying to doen size 7.35 carcano to 6.5.broke the steel die.and I had along taper in it.:rolleyes: :D

F. Guffey
July 10, 2009, 11:13 AM
"I know I have done it.trying to doen size 7.35 carcano to 6.5.broke the steel die.and I had along taper in it".

http://www.ch4d.com/ call C&H 4D PLEASE!!!

.311 done (down) to .264 is .047, C&H 4D has recommentations for sizing bullets down and the amount of diameter to be reduced in stages, for them .004 is not a problem. The 88 barrel could be anything after 120 years, it started as .311/.318 and was throated later, the barrel may be able to handle 8/57 ammo, I would not trust the action.

The 8/57 in 1905 became .311/.323.

F. Guffey

F. Guffey
July 11, 2009, 08:21 AM
Teddy, forgive, something did not look correct, 7.35 = .297 thousands, still that is a .029 thousands difference, a .277 diameter bullet would have been a better choice but that would still be .013 thousands difference.

F. Guffey