Curious

[InfantryWeaponsOfficer]

I don’t cast rifle bullets but a friend asked me to cast some for 7.62 x 39mm. At first he wanted me to use an old Ideal 308329 he had, it casts a 185gr spitzer. I finally convinced him to cough up 20 bucks for a Lee mold specifically designed for 7.62 x 39mm. At any rate that matter is settled.

I’m curious about something. We loaded up a dummy to check something and discovered that in order to maintain maximum OAL, the bullet is seated so deep about 3/8” extends below the base of the neck. I don’t think it would cause any issues with capacity in this particular load, but what are the possible issues of that much cast bullet and gas check extending that far into the case- if any?

 

[358156hp]

Is it a bullet sizing issue? By that, I'm asking if the bullets diameter is too large for the rifles bore & throat, forcing you to seat the bullets deeper than normal. Seating the bullets base below the case neck could possibly (and possibly not) cause issues with powder contamination from bullet lube in hot weather, increased chamber pressures (depending on the chosen load), and most disturbing possibility involves the unsupported bullets base "riveting" to a larger diameter, also causing really high chamber pressures. Does LEE offer a recommended overall length for loaded cartridges with this bullet?

 

[InfantryWeaponsOfficer]

Is it a bullet sizing issue? By that, I'm asking if the bullets diameter is too large for the rifles bore & throat, forcing you to seat the bullets deeper than normal. Seating the bullets base below the case neck could possibly (and possibly not) cause issues with powder contamination from bullet lube in hot weather, increased chamber pressures (depending on the chosen load), and most disturbing possibility involves the unsupported bullets base "riveting" to a larger diameter, also causing really high chamber pressures. Does LEE offer a recommended overall length for loaded cartridges with this bullet?

It’s just a very long bullet, used primarily in long .30 cartridges. The Lee mold is specifically designed for the cartridge so were golden moving forward.

The powder contamination issue occurred to me. That’s why I recommended a new mold. What concerned me was the ‘riveting’ you mentioned but I have no experience with cast bullets in rifle cartridges. I was starting to wonder if I had been over-thinking it.

 

[Nevada Ed]

When the military switched from the 30-06 to the 308 with the shorter case, the same thing happened when the loaded 180 gr bullets in that case....................

For some reason it did not matter and went on to win many a
shooting contest over the old 30-06. It just limits the amount of powder in the case and can lead to lower velositys..........but this has been proven to not be a bad thing,in target use.

As long as you can get a correct OAL length, I would think that bullet should be ok, for medium velositys.

 

[Frank46]

Lee does sell two molds for the 7.62x39 and both are about 150 grains and gas checked. One is a tumble lube design with many lube grooves and the other is a lubed bullet set up for a lube sizer. think that both are Ed Harris designs. And I believe you can get them in two cavity and six cavity mold blocks. Frank