300 Win Mag Load with PP Lee 90307

I am new to paper patching, but learning lots thanks to this forum. I have been reloading for around seven years, and want to try to push some PP cast boolits to around 2,600 FPS in 300WM with a 24 inch barrel. 1:10 rifling. This could become a longer range "friendly" competition load.

Here is my plan:
Cast some Lee 90307, should drop around 224 grain. See design here: https://leeprecision.com/cgi-data/instruct/90307.pdf
Size down to .301 with no lube
Paper Patch and size to .310, lightly lubed with 50/50 beeswax and vasoline before sizing.
Final load will be working up to no more than 77 gr of H1000 with Federal Mag Primers. Seat to .002 below the rifling, not sure on OAL.

Here are my concerns:
This boolit is a bevel base. I have not found a lot of information on PPing bevel based boolits, but I have found a couple articles where people have done this. I suppose this is conceptually possible, but any additional information on this would be good.
Is this going to be sufficient for 1:10 rifling?
Where can I get a .301 (ish) sizing die? I do not see that Lyman has them. Do you think .301 is too small to size it to?
Can I size down this much? I think the tumble lube design will help, but might need to size down twice in progressions.

Any thoughts, advice, etc. appreciated.

I have a couple of those molds and they cast .310-.311 for me. I use them unsized and Tl in my 7.62 X 39 Encore. Sizing them down to .301 is a stretch.

I bought this one from Accurate:

http://www.accuratemolds.com/bullet_...=30-190P-D.png

It casts at .303 +/- depending on my alloy. I do size it to .301 with a sizer that I bought from Buckshot. Unfortunately, he is no longer making sizers. I have never tried it in the 300 Win Mag, but I might some day. It works great in the 30-06.

I guess if you don't find someplace to buy a sizer you could buy a .285 lee push through and lap it with sandpaper around a rod in a drill til its 16 thou larger. might need two for steps. think I heard lee will make custom sizes also but it cost more. have you just tried wrapping them as is then doing your final sizing? bevel base should be ok, people paper patch ones with gas check shanks. I haven't managed to get accurate loads in a 10 twist over 2k fps PP or otherwise, still working on it.

When you get things just right with PP, you can get some pretty decent velocities (2500fps+) with good accuracy. The OP is on the right track with his sizing (.301>.310), but the boolit mold choice will provide a challenge for sure.

NOE makes very good body inserts for their size die. Got .301 and .302 for the core and .310 and .309 for patched round. I use Lee lube on the core and Johnson paste wax on the patched bullet. I turned down the size die so only about 1/4" sits below the press for max leverage. And no I do NOT have an accurate paper patch load yet.

if I just wrap one of my bullets as cast with 2 wraps tracing paper then push it through my .3097 sizer then unwrap it my diameter is .306, what makes it better if its .302 ? I never see an explanation just people saying to size the core first and some saying they let the paper size the core down how ever much it wants.

Thanks all for the posts. I think this seems viable at least, so I will continue searching for a .301 sizing die or have my brother mill me one. Since it does not need lube holes, this should be a pretty easy die for him to make. Now to get the wife to okay the funds...

I took a Lee .285 push thru die and lapped up to .303; not hard to do but took a while. While the "correct way" is to size to land diameter plus .001 or so; several posting here have had success with unsized boolits being wrapped and then sized, as you described. Might work great and I've not seen a post on using that design paper patched. Let us know how it works out for you.

I think you will have to lube your castings. That is way too much sizing to do it dry. Since you want the lube to come off afterward, something that can wash off is best. Lee case lube is washable or dish soap. In the old NRA book on cast bullets they had to use dry teflon spray on the paper and size with the NRA bullet lube to work with a 300 W. mag.
n.h.schmidt

Going from .285/.286 to .301 is going to be lot of sanding and polishing. Your going to remove roughly .015-.016 to get where you need to be. A small carbide boring bar and t could be bored out much quicker and easier. Your going to loose the lead in and the clearance out. The sizing band in a lee sizer die is sort of narrow band. But the lee sizer would save a lot of work in threading and drilling. Several hints 1) star with the Lee sizer die. this gives you the body and a pusher that can be modified.

2) make note of the band width in the die and rough location of it.

3) once indicated in bore out to size thru the die leaving a few ( .005) to polish when done.

4 cut leade in place at same angle or slightly shallower. again cut slightly under size for polish

5) cut relief in place and leave a nice angle on back side. .few thou over size dia is fine here

6) once set up and indicated in do all the boring in one set up, a small lathe would be easier but a mill will do. The angled leade and relief thru will be harder to do in the mill. Polish in to size with a smooth finish


Another consideration would be to convert a mould to smooth sided and a cup base. This will help ensure the paper releases at the muzzle and dosnt hang up in the grooves and be carried along. A nose pour cup based bullet gives a place for the fold under / tail to set making for a flatter base when done.

A pp bullet will shoot very good at close to full velocities when every thing is right, but on game I suspect at modern velocities penetration of the lead slug may be wanting. I have recovered 45-50 slugs 540 grns fired at 1200 fps from a sand backstop. They expanded from .443 dia to .980 with only about 1/8" of the base still showing, add another 1500 fps give or take and the bullet may be to explosive for game.