Sizing 8mmx57 boolits

[ilcop22]

Good evening,

I had a quick question for y'all and I hope you can help.

I decided my Kar98k was too good for J bullets and to switch to cast. I slugged the bore and came out with a .323" reading. I know the general rule of thumb is +1-2 thousands over with cast, but as it turns out, Lee doesn't make a .324 sizer. Will sizing to the .323 make a significant difference? I've only ever shot boolits sized +1k, so I have no experience here.

I appreciate any help you may provide.

[Bret4207]

Lee sizers can be opened easily with a simple steel rod and some abrasive paper. I took
.329 Lee die out to .332+ in exactly 400 rolls across my thigh using a cleaning rod and 320 paper. The actual sizing area is rather small. Should be no problem to open a .323 to .325. Or you can get Buckshot to ream one for you for $23.00. PM him if interested.

The answer to your question is a definite "maybe". Sometimes, in some guns with some loads .001 can be all the difference in the world. Others are more forgiving. In your case I'd open the die, but first I'd try some boolits "as cast", ie- unsized. Just tumble lube or hand lube a few, snap the GC on if you're using one and load them up. A GC will often seat enough on the GC shank to work and once it's in the neck (don't seat below the neck of course) the powder burn will keep it in contact with the base. I've done this a number of times and had no issues with checks falling off. Unsized boolits often shoot extremely well for me.

[AviatorTroy]

I have a Lee .324 sizer. But its probably 15 or 20 years old.

[dromia]

As Bret has alluded to, try them unsized first, unless you are using a boolit that is too big for the case/throat.

What diameter is your chosen boolit/alloy dropping from the mould?

If you have a Lyman lubesizer it comes with a gas check seater, it will fit the RCBS with the judicious use of a file.

NOE makes a press mounted gas check seater.