PP'ing a boat tail

[DeanWinchester]

Ya'll know Lee's new mold for .300 blackout that has a boat tail on it. Well, a friend ordered one and the stupid thing is dropping a .305-.307 boolit depending on the cavity. We discussed Lee-menting it, but he called Midway and they just gave him another one.

SO, I thought, why couldn't this be PP'ed up to .311 and used in another 30 cal rifle? What would you do different for the boat tail?

Thanks for any thoughts.

[303Guy]

Two things I might try, first would be a short skirt patch that just reaches and goes over the base edge and the other would be a patch that goes about half way down the boat tail.

[DeanWinchester]

I don't know if it'll work or not, but I have a single shot 30/30 I'd like to use them in.

[Nobade]

If it were mine I would run a .308 or whatever the body size is when cold chucking reamer into it and make a plain base.

[pdawg_shooter]

I have patch up .308 BTs to use in a .318 bore 8mm Mauser. Worked fine.

[CJR]

The only way to know for sure, is to shoot the bullet and see what you get.

For what I'm doing, i.e. shooting PPCB @ close to/greater than 3000 fps, @ close to 50,000 psi, I feel the BT would swage flat. If it swages slightly to one side, accuracy would suffer at 200,000 RPM on muzzle exit due to bullet imbalance. Recently, after many, many long discussions with LBT's Veral Smith, we agreed that for what I'm doing the BT would not work, accuracy-wise, and so Veral cut me a long range 150 gr. PPCB with a short GC shank and three (3) PP retaining grooves. This profile is slightly slimmer than the 160 gr. NRA PPCB and should drop less at long range. It drops from my four (4) cavity LBT mould at around 150 gr. and 0.301"D. Veral does not list this mould yet, so we shall see how it performs.

Preliminary results (1st shooting) are encouraging (approx 1" groups @ 100yds, 5 shot groups) with chrono'd average velocity of 2934 fps w/ WW748. Today, I'll be firing many different load combinations to "tweak" this beauty. Life is good!

Best regards,

CJR

[geargnasher]

Use a compacting filler like BPI Original shot buffer and a 100% density load of slow powder and filler. Understand and apply the usual cautions applying to compacting fillers in bottlenecked cartridges.

Gear

[Reverend Recoil]

I do not see this mold on Lee's online catalog. What is the part number for this new mold?

[DeanWinchester]

I do not see this mold on Lee's online catalog. What is the part number for this new mold?
http://www.midwayusa.com/product/938614/lee-2-cavity-bullet-mold-tl309-230-5r-30-caliber-309-diameter-230-grain-300-aac-blackout-tumble-lube-5-ogive-radius