The 8 x 57 has a unknown history, Danzig I think. The bore diameter is definitely .328. Keeping Flat bass bullets around 2000 ft./s I can keep the group under 2 inches. Anything faster and I end up with 12 to 16 inch groups. I’m almost tempted to try at 338 bullet. Tie a string to the trigger for the first couple shots at this point I’ve got nothing to lose unless there’s any suggestions .
8x57 with .328 bore?
- Thread starter MRP
- Start date
If you can find some 8mm bullets designed for the 8x50F French Lebel or some bullets designed for the 8x56R, they are .329 diameter.
Hornady did a run of them a few years back and you may be able to find a store with some in stock.
IMHO paper patching jacketed bullets is just an effort in futility.
Accurate Molds: Custom Bullet Molds
Go to the AM site and you can design your own mold with I would suggest a .330 diameter at least.
I would also suggest having a heel in the design for copper gas checks to be fitted. An ordinary and readily available .323 diameter gas check should do the job well.
I had a couple of Yugo M48s with oversize bores. One was .328 and the other was .330.
I used the Hornady .329 offerings in both of them.
Hornady did a run of them a few years back and you may be able to find a store with some in stock.
IMHO paper patching jacketed bullets is just an effort in futility.
Accurate Molds: Custom Bullet Molds
Go to the AM site and you can design your own mold with I would suggest a .330 diameter at least.
I would also suggest having a heel in the design for copper gas checks to be fitted. An ordinary and readily available .323 diameter gas check should do the job well.
I had a couple of Yugo M48s with oversize bores. One was .328 and the other was .330.
I used the Hornady .329 offerings in both of them.
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i acquired some swaged down 323 and shot them in the ruger #1 303... can you swage down the 338s?
i think these ended up .3145 but was told .315-316 from memory.... i checked them all prior ,as i did not size them there was some risk involved.
try swaging Speers? from memory they will work reasonably well when swagind down
i think these ended up .3145 but was told .315-316 from memory.... i checked them all prior ,as i did not size them there was some risk involved.
try swaging Speers? from memory they will work reasonably well when swagind down
woodleigh make a 318WR projectile too!
- Location
- Western Manitoba
Maybe try to contact Larch Valley Enterprise - Rick Lepp - he has had pretty odd ball sizings from Woodleigh in stock - about month ago I was able to get some .318" 200 gr RNSN from him - were actually made and are labelled for the 8x57I (or "J") bore. If Woodleigh makes it, chances are good that he might have it on hand?
From my own past fussing with similar - besides bore size, sometimes have to deal with the size of the neck portion of the chamber / thickness of case walls, and the diameter of the "free bore" or "ball seat", if your rifle has one. Almost always, the ball seat is slightly larger than the bore, but will always be a "first time"... My impression is that so long as cast or jacketed bullet fits the ball seat and can be chambered, then good to fire - all about pressure at that point - case in point - see SAAMI limits for "8mm Mauser" to allow .323" bullets to "accidentally" be fired in .318" "J" bore rifles.
From my own past fussing with similar - besides bore size, sometimes have to deal with the size of the neck portion of the chamber / thickness of case walls, and the diameter of the "free bore" or "ball seat", if your rifle has one. Almost always, the ball seat is slightly larger than the bore, but will always be a "first time"... My impression is that so long as cast or jacketed bullet fits the ball seat and can be chambered, then good to fire - all about pressure at that point - case in point - see SAAMI limits for "8mm Mauser" to allow .323" bullets to "accidentally" be fired in .318" "J" bore rifles.
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- Location
- Western Manitoba
Good point, tiriaq - I, for one, getting sloppy with terms - "bore" diameter usually means top of rifling to top of rifling - sometime called "caliber" - the diameter of the hole that was drilled or "bored" through the barrel, when it was being made. Groove diameter is bottom of groove to bottom of groove - what is left after riflings were cut or swaged - bullets almost always fully groove sized, sometime even a smidgeon larger.
If Wikipedia is correct the original M/88 Patrone cartridge - the "I" or "J" bore - had 7.9 mm (.311") land diameter, and .318" groove diameter. The change to the "IS" or "JS" size kept the same lands diameter of .311", but groove diameter went to .323". Hence the two bullet sizes - early ones at 318" and "modern" ones at .323". But "bore size" - top of lands to top of lands - stayed the same.
If Wikipedia is correct the original M/88 Patrone cartridge - the "I" or "J" bore - had 7.9 mm (.311") land diameter, and .318" groove diameter. The change to the "IS" or "JS" size kept the same lands diameter of .311", but groove diameter went to .323". Hence the two bullet sizes - early ones at 318" and "modern" ones at .323". But "bore size" - top of lands to top of lands - stayed the same.
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Potty, the OP was looking for larger than .323 bullets, not smaller.
Good info on Larch Valley, I had forgotten about him
If it's a Yugo M48, likely it will be the groove diameter.
Not many people have the proper anvil faces on their micrometers to measure bore diameters.
My question is will a loaded round with 0.330 bullet chamber. Case neck thickness and bullet diameter my be oversize. Neck of chamber my need to be reamed out.
Another bullet option is lead bullets. I have a 0.330 mould I use for 8x56R.
How are you measuring bore diameter?
Another bullet option is lead bullets. I have a 0.330 mould I use for 8x56R.
How are you measuring bore diameter?
Not enough to worry about, unless you're loading at over maximum pressures.
It's not unusual for these rifles to have bores on the minimum spec size and shoot bullets a couple of thou oversize.
Most North American made commercial 8x57JS ammunition is built to lower pressures because of litigation fears, when being shot through questionable condition rifles with .318 bores.
I've seen several older purpose built sporters, chambered for the 8x57J bore cartridge hand loaded by their owners that were completely oblivious to the difference between the two cartridges. They usually loaded them to manual maximum pressures, using .323 diameter bullets. None of them kaboomed or bulged the barrels.
This isn't rocket science. .005 in is not much to swage a bullet down, if you're loading to manual pressures.
Do a Google or whatever browser you use check on PO Ackley's experiments with oversize bullets in undersize bores.
Especially his experiments with the Arisaka action/barrel rechambered to 30-06 with an intact 6.5mm bore. The action and barrel survived a full case of 2400 powder under a 165 grain bullet jammed into the leade.
If the rifle is in decent shootable condition, a few thou, one way or the other, isn't going to make much difference.
Cast bullets are regularly over bore diameter in size as well, as that's when they shoot best.
Another example for you, some folks with 30 cal rifles that have oversized bores, like the old P17s or Springfields and even 30-40 Krags, etc, will shoot .310 bullets intended for Mosins chambered in 7.62x54R or the .312 bullets intended for the 303 Brit.
