Swaging Blackmon round nose .308 bullets

[just bill]

Can Blackmon round nose .308 bullets be Swaged with a boat tail?

[rolltide999]

It requires a BT die set, but it certainly can be done.

[Ajax111]

Help me understand. How a boat tail, would help a round nose bullet?

[Ajax111]

I was not being a wise ass. Is there is a benefit from doing this?
I was led to believe the Boattail doesn't provide any advantage at say 300yard and under.

[rolltide999]

I am no expert, but I would say what you have been told is true, and an understatement of the facts if anything. The main reason for the boattail in aerodynamics to retain velocity and, to a lesser degree, minimize wind drift. First of all, from the OP's original question, with all due respect, if you are concerned about velocity retention, you are not going to be using a round nose bullet. Putting a boattail on a round nose is like putting a rear spoiler off a Porsche 911 on a VW Beetle, just of little or no practical value. Where BT are ultra important is on very long range hypersonic bullets. 50bmg bullets in "King of 2 Mile" competitions are likely to pass from ultrasonic to subsonic somewhere along the course. When that happens, the bullet becomes somewhat gyroscopically less stable, and this can effect accuracy, even on a good bullet and a good shot. So boattails, as I understand it, will increase distance to subsonic transition, and increase stability when it happens, and decrease wind drift. I put rebated boattails on a lot of my VLD long range rifle bullets for reasons stated above. I also put boattails on the front of big 458 Win Mag bullets so they act like SWC's on impact, and increase terminal ballistic effect. Interestingly enough, I was just reading in one of their Techinical Bulletins where Dave and Richard Corbin did testing on 25acp bullets, and found the SWC nose shape dramatically increased terminal ballistics on the nominal little self-defense round. Now we know that those broad meplat nose shapes penetrate deeper and straighter than round nose bullets on thick skinned dangerous game.

Now you know everything I think I know on the topic. That didn't take long.

[DsGrouse]

Dave and Richard Corbin did testing on 25acp bullets, and found the SWC nose shape dramatically increased terminal ballistics.

This is true across the spectrum of bullets. There are many hunters, myself included, who like shooting larger meplat bullets. This comes into play quite a bit with older cartridges like 38-55, and pistol cartridges adapted for rifle use such as 357, 45 Colt, 44 mag. Having that large sharp corner on a flat-faced bullet does a LOT of cutting and trauma. It's not the best for long-range accuracy, i.e., past 250 yds, but for many, being able to punch clean holes through animals is helpful. In the case of boar, or tougher game, terminal travel distance is another consideration. A 250grain 45colt hard cast Kieth style bullet that can do 30" in a deer or a boar is nothing to sneeze at. IIRC, somewhere around here I picked up a 30 or 32 cal SWC point form die. I'll put it on the list for swaging this fall and see how it fares for 170grn 30-30 bullets.

So, to add to the post. Why might one want a round-nose boat-tailed bullet? I can't really see a reason, but....

I've shot plenty of poly-coated 230-grain 308 bullets through my 300 Blackout. The issue? With a long barrel, the poly coat has enough time to be stripped away and thus gummed up the can. I tried gas-checked poly-coated bullets. No, not quite a rebated rim, but similar shapes. Once the gas check came off, which they did, I didn't shoot many, as I saw the first gas check blow out of the suppressor; the second was stuck inside the can and took quite a while to get out. That being said. I pulled what I loaded and popped the gas check off the remaining 25 or so that I had. I shot the rest of them without the gas check. I didn't expect to see any difference at 100yds, and there wasn't a noticeable difference and the can was still dirty.

If I wanted to shoot a long-range 30-30, I think I'd be better off single-loading a nice flat base spitzer. If I wanted a round nose 308 for 300blk and subsonic 308 Winchester hunting. I'd go with a flat-based exposed lead round nose. I'd not bother with a rebated rim. (I have the die kit, but man, what a lot of work for sub-200-yd bullets.

One of the first guys I spoke with on the phone about swaging cautioned me to think in terms of repeated actions/actuations. So you have your action steps,
(this assumes jackets are: clean, dry, and cut to length)
1 core cutter
2 core swage
3 clean cores
4 dry cores
5 core seat
6 point form

That's at least six stages. If you have only one press, that is 4 separate setups, assuming you have a station for a core cutter. If you do 100 bullets, that's 600 actuations.

IIRC Rebated boat tail adds two or three more steps to this process.

I dunno, for a sub-200 yd bullet, I'll see no discernible accuracy increase or terminal ballistics increase. I can't see it.

[Reload3006]

Talking to Richard Corbin and other balisticians I have been assured that a boat-tail boolit does nothing for you balistically until the projectile transitions from supersonic to subsonic velocities the boat-tail helps the bullet buck the shock waves. This is what I have read and have been told is it true ��*♂️. So why have it on a round nose boolit? Good question I personally would not go to the expense of the add on boat-tail dies if round nose was all I was making. That said a boat tail boolit is easier to seat in a case so there’s that is it worth the money? And effort? Only you can answer that.
Can you do it Yes