How much can you size down a plated bullet?

Copper has a pretty low friction coefficient. Not sure if Andy used lube but I would expect plated to size much easier than lead.

I tried "Imperial Sizing Wax" and "Dura Lube" (a synthetic lubricant) and found the Dura Lube more effective for this copper-to-steel sizing. I recommend synthetic motor oil.

I tried sizing them directly to 0.323" from 0.358" and it was too much. 30 thou per pass seems to be the limit for these bullets (construction and diameter are factors), and 15-20 thou is better. A limitation is what sizing dies are available - it's nice not to need custom sizing dies.

Fortunately for 0.358" to 0.323", Lee sells 0.339", 0.329" and 0.323" push-through sizing dies. I think for this application, 0.339" and 0.323" would suffice.

Don't forget that you're not just stretching the bullet, you're squeezing and stretching (11% down in diameter and about 23% up in length for the portion affected), and that helps the jacket stay in place.
 
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My order of bullet sizers finally arrived today. I used Lee .339, .329, .323 to size down campro 124gr 9mm projectile. For lube I initially used 5w30 motor oil, but quickly found out that hornady case sizing lube works much much better.

The hardest step was from .339 to .329 for some reason. Bullet just doesn't want to go through. The other 2 steps are very easy. My bullets came out the final die with .324 diameter.

With the same order I also picked up the .311 and .309 sizer, along with some campro 115gr 32acp bullets (at .313). I think I should've go with .308 instead of .309. It seems every die produces bullet 1 thou larger than marked on the die, so I get .310 instead of .309 I was hoping for. Only exception was the .311 die sized .313 bullet correctly to .311. Is this due to I'm sizing the bullet too much and it sprung back? I tried running the bullet through the die again but they still come out the same diameter.
 
My order of bullet sizers finally arrived today. I used Lee .339, .329, .323 to size down campro 124gr 9mm projectile. For lube I initially used 5w30 motor oil, but quickly found out that hornady case sizing lube works much much better.

The hardest step was from .339 to .329 for some reason. Bullet just doesn't want to go through. The other 2 steps are very easy. My bullets came out the final die with .324 diameter.

With the same order I also picked up the .311 and .309 sizer, along with some campro 115gr 32acp bullets (at .313). I think I should've go with .308 instead of .309. It seems every die produces bullet 1 thou larger than marked on the die, so I get .310 instead of .309 I was hoping for. Only exception was the .311 die sized .313 bullet correctly to .311. Is this due to I'm sizing the bullet too much and it sprung back? I tried running the bullet through the die again but they still come out the same diameter.

My theory on this would be that the integrity of the lead inside the jacket is upset & starts to separate apart in the first stage. the stages after that are easier because the cracking is already started.
 
I've used lead cast for 308 before and couldn't quite get it tune in. There always seems to be lead coming out wih the cleaning patch even if I dial down the velocity (9.5gr-10gr trail boss for 170gr non gas checked). That's why I try to stay away from it.

Sorry, a bit off the size down to 8mm topic, but I'm assuming that 308 is 308 Winchester. My experience has been the same with 308 Winchester, it seems to be an anomaly, as I've shot the same bullets in the 30-06 and 30-30 with excellent results. I'm at a loss as to try and explain it, as I was getting lead smeared on the outside of the neck of the case.

IMHO Trail Boss is not the solution for every situation, it has some weird characteristics that make it very good sometimes and not good in others. When compared to other powders it yields low velocities with higher pressures normally associated with those velocities. I've used it where I need a good whack to bump up the bullet, but want low(ish) velocity.

Shooting cast is not for those that give up easily.

Back to topic, for cast and not plated bullets, minimal sizing is best, somewhere around 0.003" things start to go aria. I'm assuming that a plated bullet has some limitation on sizing down. My brother has sized plated bullets a few 0.001", just to uniform them with decent success. I suspect that after about 0.005" you may see some compromise of the plating, just my WAG. I've used some coated bullets, Hi-Tek, and that coating can take a beating.

I like my 8mm Mauser, a great caliber IMO, and have been thinking about buying a mold and casting up some bullets, but it's a bit of a commitment. Perhaps when I run out of loaded ammo. (I bought a 100 rounds from a shooting buddy, and I only shoot it occasionally, so I'm probably good for a while.

Nitro
 
My theory on this would be that the integrity of the lead inside the jacket is upset & starts to separate apart in the first stage. the stages after that are easier because the cracking is already started.

I've sectioned a bullet after doing this and the copper remained fully bonded to the lead. The lead didn't fall out of the copper like some think it would, neither could I separate it at all with a sharp knife.

When it's sized down, the copper and lead are both sized down in concert, both reducing in diameter and lengthening to the same degrees.

That said, I've discovered on Gun Forums that long-held beliefs are imperviable to testing that proves otherwise. When it comes to "safety", people are going to cling to the inside of the box.

As for me, I'll continue to do what I've been doing.
 
Now the (million $$$) question is how will they shoot?

Will squeezed down 124 grs bullets stabilize in a 8mm Mauser twist (1 turn in 9.45"),
or would it be better to start with 147 grs (9mm) bullets?

I did some test as of lately using Campro 115 grs .32 caliber bullets, they shoot very well in my Enfield N0 4s with 7grs of Bullseye.
The 124 grs Berry's bullets (.311) are not well liked by the Enfields, but my Argentine Mausers love them.

Just remember the COL should be as long as possible with these short bullets.
 
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Some updates to report back:

I made some load using trail boss going from 10-15 grains at 1 grain interval and tested them indoor at 20 yards. From 13 grain and up grouping were promising. I picked 15 grain so that the POI lines up with the sight's windage on my M48.

COAL was super short because my expander ball is setup slightly undersized for .323 bullet. These bullets comes out at .324~.3245 so it's hard to get them to sit straight unless I push them into the case more. The short COAL does affects feeding smoothness though. So here are some funny looking 8mm mauser rounds:
IeyoQ1J.jpg


Today I took it out to the outdoor range and shot at 50 yards. Zero was achieved by setting the rear sight to 500m mark on the yugo M48. No windage adjustment were required.
ZLm1P5T.jpg


The 10 shots group were pretty decent to my surprise. Toward the end my trigger finger is hurting from the heavy pull weight so I went sloppy on my shooting technique.
qINxDrv.jpg


I fired a couple at 100 yard gong, but nothing connects so I stopped. Probably need to dial in more elevation.

Overall I was pretty happy. This achieved exactly what I wanted, a cheap round for practicing shooting off hand at the gong with 8x57. It could probably be made more accurate but I was only concerned about hitting 6" gong at 50 yards.
 
This is why I love this forum. Thank you for trying it out for me. Time to order some lee sizing kit.

I'm pretty new to hullet sizing, what kind of lube should I be using? Since I'm sizing plated bullet, can I get away with case sizing lube (I'm using lee case sizing lube) or do I have to order some lee liquid alox?

Lube - in another application (sizing die), instructions called for Imperial Sizing wax - very good stuff, I am told, but not available around here. On Amazon was $40 or $50 for a two ounce or so tin of it. I bought a tube of EP (Extreme Pressure) grease at Napa store - 15 or 16 ounces for like $9 or $10. And a one liter jug of acetone for $12 or so to remove the grease afterwords. Sometimes "reloading stuff" is vastly expensive and over rated, the other things work just as well...
 
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Will squeezed down 124 grs bullets stabilize in a 8mm Mauser twist (1 turn in 9.45"),
or would it be better to start with 147 grs (9mm) bullets?


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Not sure why you were concerned about shorter than normal bullets stabilizing.......

What are the before sizing and after sizing lengths of these bullets?

Anyways, they seem to have shot well. The concern I always have with very short bullets is that they can be free of the neck before they engage the rifling and that can cause hangfires.

Sounds like you didn't have any hangfires, but do you know if they engage the rifling before they're free of the neck? One easy way to check that is to seat a bullet just barely in the neck and then chamber it. If it comes out seated deeper, or if it doesn't come out (gets pulled out), that means it engaged, if it comes out the same as it went in, it didn't.
 
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