Well that's interesting. Running out of lube?

[jonk]

1893 Turk mauser. Lee 175 gr group buy. Both grooves filled with lube. Regular 50/50. Nothing fancy.

Mild loads. Red dot, 4759. Bullet drops at .326, I'm sizing to .325 as the fired brass measures .326 across the inside of the neck. Bore is .325 as well. Not ideal but with a good hard cast bullet and nothing too heavy, should be ok. Bore is ever so slightly frosted, but strong and shiny overall.

So I fire 10 rounds. No lube star at the muzzle, and leading at the end of the bore. Not BAD leading, but leading just the same.

Ok....

I tumble lubed the bullets after lube sizing figuring the LLA would be fairly compatible with the 50/50 and it might offer enough to get the last bit of bore that wasn't being lubed. Same issue.

Ok.....

I switch to an 8mm mold that drops a bit under 250 gr, run by buckshot some years ago. Big thing, lots of lube grooves. Like, 5 of them. I go whole hog this time and lube them all.

Same result. Every indication of running out of lube.

Strange strange strange! I've shot long barrel mausers with just a tumble lube, or with 1 groove lubed, and it didn't run out. This thing, it seems it's like a sponge, it just sucks it up.

Any ideas?

[Dale53]

I suspect undersize bullets. It's certainly not a lack of lubricant (you proved that with lubing all of the lube grooves. Another thing "might" be is your alloy is too hard to allow obturation.

Try shooting the bullets "as cast".

Dale53

[sqlbullet]

I think Dale hit it. The lube is getting 'blown' out.

[runfiverun]

up the pressure.
change the lube, add some carnuba.
wet mop the bore before shooting. [ a bit of atf should do]

[jonk]

Re: Upping the pressure... I also tried 32.5 gr of 4064 with filler. I hadn't mentioned it as I got the same result there too, and figured that was too hot for the ACWW.
Re: fatter bullets- please note my dimensional measurements of the fired brass. I can't go much fatter, MAYBE 1/1000".
Re: wet mopping the bore- last time I fired a gun with an oiled bore I got a ring in the barrel about 5" from the muzzle. No way.

A different lube will be tried, though, at some point.

[dromia]

If your bore diameter is .325" what is your groove diameter?

[cbrick]

1893 Turk mauser. Lee 175 gr group buy. Both grooves filled with lube. Regular 50/50. Nothing fancy.

Bullet drops at .326, I'm sizing to .325. Bore is .325 as well.

Not ideal but with a good hard cast bullet

Same result. Every indication of running out of lube.

Any ideas?

Dale nailed it.

Yep, couple of ideas. First you said you were using WW alloy, WW will probably size UNDER marked die diameter. You said your bore slugs .325" and you are sizing .325" and your alloy will likely size to .3245". The first idea is that the high pressure gases are blowing past your boolit and blowing the lube right out of the grooves. I'd bet your right, your running out of lube.

Second idea, I cringe every time I hear the words "hard cast". Too hard of an alloy causes more leading, accuracy problems than anything except a poor fitting bullet and we have already pretty well determined that you have a poor fitting bullet.

So you have poor bullet fit and you have "hard cast" bullets and your bore is leading. Hhmmm.

Rick

[jonk]

Well......hard cast in that it isn't soft lead. Air cooled wheel weights. I admit I use the term a bit loosely.

cbrick, I like your suggestion (implied) of checking bullet diameter after sizing... or even after seating!

Dromia- .325 is the groove diameter. Again, I may get a bit loose with terminology and say 'the bore measures x' when I may mean the grooves, but I figured it was understood. But for inquiring minds- .325" groove, .316 (near as I can make out with the calipers and micrometer) on the lands.

[Calamity Jake]

Dale nailed it.

Yep, couple of ideas. First you said you were using WW alloy, WW will probably size UNDER marked die diameter. You said your bore slugs .325" and you are sizing .325" and your alloy will likely size to .3245". The first idea is that the high pressure gases are blowing past your boolit and blowing the lube right out of the grooves. I'd bet your right, your running out of lube.


Rick

If blowby were the case then there would be leading in the throat and lands, he doesn't have that.

What condition is the barrel in in the last few inches where the leading is?
Is the bore dia. bigger at the muzzle?

[sqlbullet]

Jake has articlulated what went through my mind yesterday as I was trying to reconcile the leading just at the end.

Perhaps the barrel is a little bigger at the end, or has a slight bulge near the end that allows blow-by? Not even sure how you would tell for sure. Empirically by how the slug feels as you drive it through doesn't seem really valid.

[Shiloh]

Beagle the mold or add some linotype for a larger boolit, What about sizing at .326?? You would be lubing and seating the gas check.

Shiloh