Opinions Needed

[Pirate69]

I have purchased a Savage No, 4 Mark I with a two-groove barrel. Barrel slug mics 0.315". I have a Lee 7.62 X 39mm mold that is dropping a 0.3135" boolit. Inside diameter of fired cases measure 0.318"

Attempts at shooting the 0.3135 boolits with a GC and 7.0 grains of Bullseye gives a fairly tight group for the first 5-8 rounds. Then it starts to open up some; then there is a key hole, and then there is the "Where did that one go, it is not on the paper". We are talking 50 yards here.

It is obviously an undersized boolit problem. I got some aluminum tape and beagled the mold. With one layer on each side, the mold is dropping a 0.319-0.320 by 0.314-0.315 inch bullet. Have I over-Beagled the mold? If I load the boolits to the point they are just kissing the lands, does anyone see this as a problem. When the boolit starts to swage itself going down the barrel, the average diameter should be right at or slightly less than the measure ID of a fired round. Am I out in left field??

[montana_charlie]

I don't beagle, but...
Have you tried with tape on just one side of the cavity...the side away from the handle hinge?
CM

[Mk42gunner]

Pirate,

I haven't had to beagle a mold yet, but I'm sure I will in the future. With a .315" bore and a throat that sounds like it will accept a boolit of .317 or .318", you might be better off getting a mold for an 8mm and sizing it down.

I'm sure others with more experience will chime in shortly.

Just my opinion...


Robert

Robert

[Bret4207]

With dimensions like that you have a prime candidate for a custom mould or paper patching. The latter is less expensive. The alternative is to get in on a group buy for a "Fat" 30 mould.

Beagling may help. Try it and see. You sound like you're on the right track.

[StarMetal]

RCBS's 170 gr flatnose for the 32 Special will dang near fit that, especially with a little sizing. The mold I have barely makes .321.

[Larry Gibson]

The Lyman 325470 Lovern cast bullet sized, GC'd and lubed in a .323-.325 H-die and then pushed through a Lee .314 die honed out to .316-.318 should hoot extremely well in that rifle. Or even at .321, as starmetal mentions, if a fired neck case will take it.

Larry Gibson

[Pirate69]

Thanks everyone for the advice. I now have a number of options to try as I work through this problem. I tried the easiest one this afternoon. I removed the aluminum tape from one side of the mold. It is now dropping a 0.3160-0.3165" by 0.314" boolit. This has possibilities. The bullet will just slide into the neck of a fired case. After installing a GC, I believe there is enough tension to seat the boolit without neck sizing.

If I have to neck size, I only have the standard Lee dies for the caliber. I am concerned that I will reduce the neck size to the point that I swage the bullet during seating and erase all the good I have done with the one-sided Beagling. Any suggestions or tricks of the trade??

[Maven]

Pirate69, You may also want to send a PM to Jeff in N[ew] Z[ealand] about cast bullet options for the .303.