Increasing just the nose diameter on a Lee 309-150-F

[Centaur 1]

I bought this mold to use as a plinking round in my Marlin 336SS 30-30. I removed the gas check step with a .311 reamer, but I left enough of the step to create a third lube groove. I've been playing around with Unique and Trail Boss at around 1200 fps. I've been doing a lot of reading and thinking about how to get more accuracy from this boolit, I can't seem to get any better than a 3" group at 50 yards. The nose diameter is .2995"-.300", which should be the proper size to ride the bore of a rifle with standard rifling. I'm thinking that since micro-groove rifling has a bore diameter of approximately .304", that it might help to increase the nose diameter to that size. Has anyone been able to leement just the nose, let alone open it up .004"? Any ideas or suggestions would be appreciated. Times like this that I wish that I had a lathe.

[geargnasher]

Centaur, you might be time and money ahead to get the Lee mould for the 303 British and flatten the noses a bit with a flat top punch in your sizer, or load them one at a time. The one I used to have cast about .3130" or so on the bands and .3035" on the bore riding portion when cast slightly frosty with ww metal and a 650 pot temp.

I've screwed up more moulds than I've fixed trying to enlarge them.

Gear

[Maven]

Centaur1, Geargnasher's suggestion is right on the money. Until you order that mold, however, try shooting those small nosed 150gr. CB's unsized and maybe with a smear of liquid alox on their noses as well. Btw, the microgroove rifling doesn't degrade accuracy at all, but an undersized CB, particularly a PB bore riding type, is quite likely to.

[swheeler]

Centaur1; sounds like you need to Beagle your mold to try a few, costs almost nothing and after a couple minutes work you can be casting bullets with larger noses. Do a search for Beagleing, John even included pictures IIRC

[Centaur 1]

Sounds like I should just save this mold for my 30-06. I'm hoping to get a mold from Ranch Dog soon, so I'll just try and use them unchecked for plinkers.

[geargnasher]

I'll give you a hint on how to get a plain-based boolit to shoot in that gun: Run it subsonic. I can get very nice groups at 50 yards with my 336 using 6.2 grains of Longshot running right at 1095 fps. The occasional flier almost always registers 1110+ on the chrono, makes me think it's going supersonic for a few feet and getting upset on the way to the target.

BTW, I just did some work over the weekend with paper gas checks and a Lee group buy 311041 that drops an honest .3115", sized in honed Lyman die to .3110 (.3105" wouldn't cut it), I got up to nearly 1500 fps with RX7 and no signs of leading whatsoever, also holding less than two inches at 50 for 10 shot groups, probably better but my eyes are giving me problems right now and that front bead is pretty big. If you're interested I explained a bit more about it over on the gas check forum, all you need is a manilla folder, a 7/16" hole punch, and a Lyman/rcbs/Saeco style lube/sizer.

Gear

[Centaur 1]

Thanks Gear, I'll try backing the charge down a little. I could care less if it's going 1200 fps or 900 fps, I'm just getting cheap range time with my favorite rifle. Once I order that RD mold I'm sure that it'll work without a check at slow speeds. I don't have a lube/sizer, I've been using the Lee sizing dies for a couple of other calibers, but that Lee .309 mold dropped boolits at .311 so I never bothered buying one and just shot them as cast.

[excess650]

You could order that Ranch Dog cut plainbase, or order one of the plainbase from BRP (BaBore). He only lists the conventional type groove design on his site, but does have a TL groove type.

[peerlesscowboy]

...... I don't have a lube/sizer, I've been using the Lee sizing dies for a couple of other calibers, but that Lee .309 mold dropped boolits at .311 so I never bothered buying one and just shot them as cast.
If you were using a lube/sizer that sized the bullets nose-up I think you could with a little practice "bump" the noses up .004" at the bottom of the stroke? You wouldn't have to worry about bumping the shanks 'cause they'd be down in the sizing die when the extra "omph" was applied.

John C. Saubak

[Centaur 1]

You could order that Ranch Dog cut plainbase, or order one of the plainbase from BRP (BaBore). He only lists the conventional type groove design on his site, but does have a TL groove type.

I was actually thinking about opening up one of the six cavities like I did with the Lee mold.