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I just cast some non water dropped bullets that came out at BHN14 and are softer then the BHN22, I will give them a try. Because of the low velocity of cast bullets they do not bump up into the rifiling like the higher velocity jacket bullets do so they have to be cast to the bore/grove size or a bit larger. Jacketed bullets that are only .311 will bump up enough to work/seal in the rifle even with a .317 grove size enough to shoot within Mil spects. Ray
Ok, I just thought in that in addition to the softer bullets I made and loaded. I loaded a few paper patched bullets. For those that are unfamiliar with paper patching, it is sizing a bullet below the rifles bore and grove dia. and wrapping the bullet in paper to bring back to the proper size.
Paper patch bullets are fired without gas checks as the paper is designed to cover the bulet base also and the paper acts like a jacket on the bullet and they can be fired to the velocity of light jacketed bullet loads, much faster the plain lead bullets can be fired.
My thinking is that the paper may grip the rounded lands and grooves of the Metford rifling better.
I will be going to the range tomorrow to try these loads. As I only made a few of each, it won't give me a true measurement of accuracy but I think it might elimiate some right away that won't work. Ray
Well none worked well so back to the drawing board or just back to using jacketed bullets and forget trying cast bullets, Ray
You might make a chamber cast if your are trying to shoot a Type 38 or any other Japanese Metford type. My Type 38 and Type I rifles have 4 groove Metford type rifling.
I have not made a cast of my Type I but the Type 38 has no step at the end of the chamber. It just has a long taper from the case mouth to the land diameter. There is no parallel sided throat. This chamber leade to land diameter funnel might work better with oversize cast gas check bullets.
The bullet needs to be long and have a fat nose so the bore is sealed when the base pops out of the case neck.
Good info ireload2. I have even tried sizing down 8mm, (.323) cast bullets to .319 which is a good deal oversize the rifles grove dia's and that didn't work. I am just begining to maybe accept the fact that Metford rifling just does not work well with cast bullets and that rifling needs a harder jacketed bullet to fully grip that rifling. But I haven't given up yet. I will keep trying different cast bullet loads in both the 7.7 and 6.5 Japanese rifles for awhile. Who knows, I just might find the right loads. Ray
Ray,Quote:
Originally Posted by rayg
Try a harder alloy, linotype or beyond, to grip the rounded Metford style rifling. I'd suggest some Stonewall Babbitt, bhn23, responds to further heat treatment too. I've also had better luck making my own cases, either by swagging down 7.62 Nato, or using .303 Brit or 30/40 Krag. They're a lot better fit in the chamber than the old Norma. I wrote Norma about 6 or 7 years ago, and supposedly they changed the case dimensions, however I've heard from folks who say they can't get the new cases from Graf's or Midway, even though Norma says they have shipped the newer cases to them. I'm speaking of the 6.5 cases here, not the 7.7. Using US milsurp 7.62 allows you to custom turn the neck size too! Got the swagging dies from CH4D. You need a heavy press and really good lube.
I may have found the right combination using cast bullets and paper patching. I paper wrapped the bullet but this time I sized the wrapped bullet to .319 instead of .314.
I had loaded up only five rds and only fired four, one wouldn't chamber for some reason, and one I just fired without actually sighting just to see if it would hit the target. That left three and I fired them at only 25yrds and all three grouped under an inch.
Maybe this is the right combination so I'll be loading up a few more to try next week at a little further distance.
The advantage of using paper patch cast bullets is they cost nothing if you get the lead free or pennies if you need to buy some lead. Commerical jacketed bullets run on average about $25 per 100 and the paper patched bullets can be shot at the jacketed loads. They are even cheaper then regular cast bullets to shoot as you don't need the cost of a gas check either and some of the reports I've read is that they can be even more accurate then the jacketed bullets. Ray
Much as this galls me to say it, but there were a lot of dead chinese, British soldiers, American soldiers, and American Marines who could have told you the Arisaka was not that inaccurate, if they had survived.
Keep on in there rayg! You're getting somewhere at last! Metford rifling was an invention from the latter days of muzzle-loading percussion rifles, when paper-patched bullets were state-of-the-art, because they enable lead bullets to be driven much harder without stripping. Many modern competition muzzle-loader shooters use paper-patched bullets - and get superb results.
And there are modern Heckler & Koch military rifles (I forget which ones) that also use polygonal rifling. But as I pointed out in a previous and very long posting, as there is no cutting of the bullet, that kind of rifling is quite touchy about bullet size. What hardness are you using now for the paper-wrapped bullets?
Good luck with your further experiments!
Patrick
Well it's getting there. I now need to fine tune the loads to close up the group but at least there's no flyers and it's actually about the same as my jacketed reloads shot.
I fired 7 shots at the bottom target first and then took a little better time and aim on the top three.
Only 35 yrs but there is potential. Will try 50yds next and then 100yrs later after I feel I've gotten the right load.
This was a pretty substancial load of 38 grs of I-3031 powder which would have been way too much for a plain cast bullet. The paper patched bullet were sized at .319 and the grooves mike out to .317+ on the T-99 long I fired it in.
The best part is the lead was free and the computer paper was next to nothing. Beats paying for jacketed bullets. Ray