Gas check bullet without gas check

[abunaitoo]

I tried shooting some Lyman 430di 300gr gas check bullets without the gas checks out of my 78 Vetterli and had slight leading.
With the gas check I get no leading.
I'm assuming the space left by missing gas check is causing this.
Could it be something in the lube or lead????
Shoots the same with or without.

[lead slead]

Sounds like the powder is melting the boolit causing some leading you could try lower velosity and it may help I can shoot non gs boolits out of my 30-06 with no leading using reduced loads around 1000 fps. Anything faster than that and I use the GS because I hate scrubbing the bore lol.

[windrider919]

I am told that leading is not from friction between the bullet and barrel but is caused by gas blow-by arond the bullet that removes some of the bullet and the lead deposits IN FRONT of the bullet on the barrel surface. The gas check is supposed to seal the gas behind the bullet. I shoot a 45 cal rifle and I have moulds for GC that shoot quite well without the check. But the bullet must fit the bore!! In 45 cal that means the bullet should be oversize by .001 or .002 of the groove diameter of the barrel. Ex; .458 barrel requires .459 cast bullet.

Have you slugged your bore to see what it truely mics? A lot of foreign cartridges have bores different than they are marked.

Also, if you are locked into a cast bullet that is slightly undersize and have no gas check to use you can replace the GC with a card wad and or lube wad. either or both work to seal the gas from getting around the bullet. If done correctly it will not affect accuracy. You can buy wads for most calibers or make your own. I leave the wax in the gas check shank area and use a .463 PE .045 wad under the bullet. I cut mine from cheap dough rolling mats from the dollar store. One mat makes thousnds of wads. Another wad material I have used is from the styrofoam meat trays from the butcher department at the grocery store. They work in some rifles and not in others, you just have to try to see.

[Bret4207]

It could be the boolit is leading regardless of the check, but the check is scraping it out each shot with the check on. Do a search on "w/o a GC" and you'll find scads of info.

[abunaitoo]

Bore slogged at 427.
Load is 9.0 of 700x.
don't know how fast the bullet is going, don't have a corni.
I'm thinking either the check is scraping the lead out or gas is blowing around the bullet.
I do leave the lube in the gas check area.
Maybe a harder lube?????
It's not really much lead, just a sliver or two after 20 rounds.

[Slow Elk 45/70]

When you use the check , it should be stopping the Gas Cutting , with out , you may have some depending on hardness of boolit , the small amount you describe after 20 rds is not that bad.

You don't say what alloy you are using , but you might try water dropping for a harder boolit if you are using WW or similar alloy , or you could go to 50/50-- WW/ Linotype for harder boolit.

[ronterry]

Your right Bret!!!