300 Blk Bullet for dummies (easy to cast, powder coat, and load bullet for subs)

I think Al doesn’t do partial RG molds.  He does RG 2’s or RG 4’s or regular.

how big of a hollow point?  The wider the hollow point, the more difficult it will be to feed in AR’s and such.

HP version

What about the nose?  Think the unsupported nose is too long for the base?

Thanks for the specific feedback.  One of the difficulties of drawing up an “easy to cast/pc/load bullet” for 300 blk is the differences in PC processes of the different users.  Some people use the HTC thin coats, some people use the shake n’ bake method, etc…  Some people’s PC coating is a lot thicker than others’ coatings.  The .310 diameter was originally proposed with a few things in mind, (1. some people might be coating with the hitek coating which doesn’t add much, 2. some people might be using a softer alloy for their subs which would drop the diameter a little, 3. the “band diameter” can always be sized).  Nose sizing is a tough cookie, however, and makes things a bit difficult if any portion of the nose is too thick (which requires seating the bullet deeper in the case in order to chamber) especially with some chambers which are tighter.

Another tricky part is that most users are going to be using the bullet in their AR15’s with slightly different chambers.  Bolt actions can be a little more forgiving on bullet to bullet differences (ie: coating thickness, coating imperfections, etc…) but semi-autos will just jam if the coated bullet is a tad too thick in one area–or if you have a little PC “booger.”  The idea with this bullet is to make a bullet that is very forgiving on coating thickness and alloy used.  Not having the perfect chamber fit will probably mean a sacrifice of accuracy, in trade for ease of coating/loading/chambering in a variety of guns, but primarily in the autos.  I guess more of a “easy plinker” type of bullet.  If we can make some of your changes mentioned while still maintaining the intention of the bullet, I’m all for it.  As mentioned above, I think we can offer the bullet with a gas check or plain base (with my coating process, I get better results with the squared plain base–I do not stand my bullets on end when baking).

Do you have a drawing where you can show me the changes you’ve mentioned?

I’m interested in this but have some questions regarding the proposed design.

The nose base is .298″, then an abrupt step to body diameter of .310″, neither of which make sense to me.  Most coatings add about .002″ to the diameter, so wouldn’t we want the body diameter to cast right at .308″?  Many 300 BLK chamber throats have a .3095-ish entrance and like a bullet no larger than that, so we could easily post size down some if necessary, or coat them to .310″+, or use a richer alloy and adjust mould and alloy temperature to make them even larger if necessary, but if specified at .310″ with WW metal, they will likely cast a thousandth larger if typical, then be coated, so we end up at .313″ and might need to size down to .3095″, and to exacerbate things further, the driving portion is solid and will be highly resistant to beong drawn down any significant amount.  Regarding the .298″ nose base and abrupt step, I don’t understand how that is supposed to fit the throat.  What’s needed is a secant ogive which blends into the body so it follows the ball seat better, and if it is the correct arc radius, can be seated to accommodate any throat entrance size or coating thickness per the principle concept of the design.

I would also like to see micro-grooves on the body portion, like a tumble-lube bullet. The reason is to ease engraving resistance, for if that resistance is too high, the base can begin to rivet inside the neck, or with faster powders like may be used in bolt rifles, perhaps rivet inside the case body.

A slight bevel base may be of some benefit both to facilitate seating and to improve accuracy for those who shaknbake powder coat and stand up to cure.  Plain, flat-base bullets tend to get flashing on them when cured on their bases and it’s made worse when push-through sized after coating, which can degrade accuracy.  Also, the traiing-edge tails from the rifling engraves are more likely to cause problems with sharp base edges than if there is some relief from a bevel.  Honestly, a gas check shank has been more accurare for me than a sharp, plain base when using polymer jackets.  A boat tail will make the bullet a lot less stable on flight at subsonic speeds and is of little benefit imo.  A GC option or bevel base would be my request.

As drawn, I am not concerned about th unsupported nose length.  I shoot several different bullets in my blackouts and .308s that have more unsupported nose than that and they do moa or better…..but they fit the throat closely and don’t have much unsupported area in the back.  What does concern me is having a very poor fit and alignment in the ball seat and throat entrance area, that part will make or break accuracy.