PC on the boreriding portion of the boolit

[Chamokaneman]

First time casting for rifle:

The boolit is a Lyman #308241 cast from half range scrap / half magnum shot and powder. They come out at .311 / 157 grains and I sized them with a .308 Lee sizer and powder coated / water dropped them after sizing. They're ending up at .3085-.309. I loaded them with 10 grains of Red Dot at a length of 2.510. I decided on this length based on an ancient Ideal manual I have that says what groove they are designed to be seated to. They are going to be shot in a Henry single shot rifle. The load is from the 1980 edition of the Lyman cast boolit manual.

Everything is fine except that I tried tweaking the extractor off the rim and "plunking" them in the chamber. Most of the need a gentle nudge to go the last couple thousands into the chamber. You can open and close the breech on all of them just fine. I ruled out several other things that could be happening, i.e. neck clearance, case length throat size, etc and finally came to the conclusion that the powder coat on the bore sized portion of the bullet is just barely touching the bore.

Question is: Are there negative implications to the bore riding portion of the bullet being a little oversized or is this good?

[Conditor22]

Is there a reason you don't just seat them a few thou deeper? Being snug to close now with a little variation in seating won't close at all. Many prefer seating .002 - .005 off the land.

Will there be negative implications? probably not. You need to see what your gun likes best and go with that. Our hobby involves a lot of experimentation with seating depth, alloy hardness, powder charge (within documented parameters from manufacturer or loading manuals), crimp, case neck pre-expansion before loading, what lube/coatings you like/works best for you/your gun, ......

[Chamokaneman]

Well, I could seat them deeper of course. The .308 sized portion of the bullet is way off the lands. It's the unsized nose part of the bullet that seems to be touching the bore due to the powder coated nose being a little oversized that I'm wondering about. Maybe a little bit of the nose touching the bore is good...or bad...I just haven't ran on to much about it.

[charlie b]

These look like a plain based bullet with not much nose beyond the last drive band. Correct? If so then I will assume that a lot of this bullet is well below the neck.

Yes, the nose is the issue. A bit extra size due to the PC means it touches the rifling before 'normal'. It means you have two choices. You can seat them a little deeper, or, you can size the nose to fit your bore, which allows you to seat them out a bit. All depends on which way is more accurate for you and if you want to mess with nose sizing.

I have two types of bullets I shoot in my .308. The 165gn XCB (NOE 310-165) and the 210gn Eagan (Acc 31-210E), both powder coated. The XCB is not a bore rider and is seated deep with the ogive set to be a jam fit in the throat. It gets body size at .310".

The 210gn is a long bore riding bullet. It is body sized at .310 and nose sized at .302 (after PC). The nose is an interference fit in the bore and the first driving band is a jam fit into the throat. Both are solid 1.5MOA bullets (at ~1800fps).

I do not hunt. Jam fit of bullets can be an issue. If for some reason I need to unload a cartridge that is chambered it usually means the bullet will be stuck in the bore and must be pushed out from the muzzle with a range rod. If you hunt I would not seat the bullets to jam into the rifling.

[Chamokaneman]

Yeah, it is plain based. From what I understand a very old and successful design. Definitely before powder coating was ever thought of https://uploads.tapatalk-cdn.com/20210630/d15980d042f3b8a79dd6e94cc9f0206b.jpg

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[Wayne Smith]

Shoot 'em! You have close to the perfect fit - you know your boolit is centered in the bore and that is the beginning of good things.

[popper]

bore riding portion the mould is either bore-riding or not. Either can cause a problem chambering. 38W has a ball seat chamber that doesn't much care if they are 'jammed' for accuracy. I don't use a crimp groove, just remove the flare from the case mouth. I don't like stuck bullets, powder gets into the action when pulling. Jamming on beak actions is hard on the pivot. I seat ten thous off and made a checker for fit so I don't have a problem. The CVA BO won't close on long seated.

[GregLaROCHE]

I had that problem with a 6.5 Swede using a RCBS mold. I simply seated the boolit deeper and everything worked out.

[oldblinddog]

I would just shoot those as is and see how they do. Vary the loaded length on the next batch if you don’t like the results you get.

[Win94ae]

First time casting for rifle:

The boolit is a Lyman #308241 cast from half range scrap / half magnum shot and powder. They come out at .311 / 157 grains and I sized them with a .308 Lee sizer and powder coated / water dropped them after sizing. They're ending up at .3085-.309. I loaded them with 10 grains of Red Dot at a length of 2.510. I decided on this length based on an ancient Ideal manual I have that says what groove they are designed to be seated to. They are going to be shot in a Henry single shot rifle. The load is from the 1980 edition of the Lyman cast boolit manual.

Everything is fine except that I tried tweaking the extractor off the rim and "plunking" them in the chamber. Most of the need a gentle nudge to go the last couple thousands into the chamber. You can open and close the breech on all of them just fine. I ruled out several other things that could be happening, i.e. neck clearance, case length throat size, etc and finally came to the conclusion that the powder coat on the bore sized portion of the bullet is just barely touching the bore.

Question is: Are there negative implications to the bore riding portion of the bullet being a little oversized or is this good?

Yes. You think your action is opening and closing well enough, but it might not be. I had that problem with mine, my POI had shifted on me with the powder coated bullets.


https://www.youtube.com/watch?v=k8LI38PU7LM

Then I seated the bullets deeper into the case and ended up with the proper POI.


https://www.youtube.com/watch?v=NqxMQ5b_Iig

I would make sure they don't engage the lands.

[Super Sneaky Steve]

I use an OAL gauge and a modified case when loading new boolits.
https://www.hornady.com/modified-cases#!/

PC does make a difference.

[Chamokaneman]

Thanks for all the help. I finally shot them and they grouped very poorly. I've decided I need to to size them bigger at the base and try sizing the noses down so I ordered the NOE kit to have the capability to nose size. I have another mold, a Lee 200 grain with a nose that is longer and fatter yet when powder coated. I haven't tried to load any of these up yet but I'm pretty sure the ability to nose size powder coated bullets is going to come up.

The tinkering is actually the fun part:-o

[405grain]

I was having problems with bore riding boolits too. after powder coating the nose was too fat. I machined up a nose sizing die that uses neck sizing bushings and screws into a single stage reloading press just like a reloading die. It didn't work. It would size the nose, but then the nose and the driving bands wouldn't be concentric. Then I decided to go in another direction and only powder coat the driving bands. So far this has worked great, but it's still a process under development. The first boolits that I made like this were swirl lubed in a very light amount of carnuba based liquid wax after the powder coating and sizing/gas check seating. Then I baked on the wax coating at around 250 degrees. This was a lot of work, so now I'm trying a slightly different way: powder coating just the driving bands and giving the nose a light coat of alox. The alox dries on and is a little stickier than the hard wax shell, but if it turns out to be more accurate I'll use it. There's still a lot of testing to do.