:)

Already tested them in my 457 Texan using Lee Precision R.E.A.L. molds two years ago.

Had to open up the base band (sent mold off to a professional moldmaker/ modifier) to get them to preform at a basic level...

but never got them to shoot as well as some other designs. Part of that is they are just too heavy for most .45 air rifles (a slug designed for a smaller calibur could be designed for a more appropriate weight of course). The other is that pellets do well as hollow base but slugs not so much.

Yes, they revolutionized warfare at the time but that time 'may' have passed. Note that in a black powder rifle the base obturates to fit the rifling BUT I found it did NOT in the air rifle.

You should buy a mold and try your luck and report.

I believe Accurate Molds could make one to your design for $90 or so if they do not already have one in their catalogue. Check.

Mountain Molds also makes custom molds for around $90 too.

My testing has proven to my satisfaction that reduced bore friction from wide spaced narrow bands easies rifling engagement / chambering and gives higher velocities. Used that in designing my .357 hunting bullet NOE is producing molds for http://noebulletmolds.com/NV/product_info.php?cPath=35_590&products_id=5620

Or another great bullet NOE is producing molds for in various caliburs from 22 to .35 which basically have two contact bands is http://noebulletmolds.com/NV/product_info.php?cPath=35_578&products_id=5489

If you look at pages 15, 16, 17, etc (and other pages for other caliburs) of the catalog you can see that many good designs exist and picking the right weight your rifle can handle and using the guidelines of 'most groove width and narrow bands = low bore friction' AND having the most length of contact (usually a bullet is guided better if it has at least as long as bore contact as it's calibur). I stay away from wide bands because they tend to foul / lead more, like smooth sided bullets have in my experience unless well lubricated... Which is a whole Pandora's box of debate right there, haha

http://www.accuratemolds.com/catalog.php?page=15

Note that it's a .300 diameter in that drawing so would be undersize for a .308 barrel.

The solution is to request a custom size in the Notes when you order, which Accurate can do. I usually slug a barrel to confirm it's bore size so I get something that can be sized down a bit (too much sizing hurts accuracy sometimes too). I have a .308 air rifle that actually slugs .3094 [and of course no pellets or any commercial bullets I bought shot well in it because the barrel is oversize from the manufacturer, it required a cast bullet to fix the rifle] so the first mold I had to get was a Lyman .311. Later I had Accurate make one that was 'just right', .001 over bore. I recommend the NOE sizing system as the sizing bushings come in many sizes and are cheap. I bought one in .309 and polished it open a bit and it fits and shoots great.

http://noebulletmolds.com/NV/index.php?cPath=104

I use a cheap Lee press MOUNTED UPSIDE DOWN which let's me drop slugs in easily and they drop into a cup I hang under it

https://leeprecision.com/reloader-press.html

Shop around, the sell for about $35 lots of places



All this turned an 6" grouping rifle at 50 yards into a one hole groups shooter ( a 1/2" ragged hole actually)

The one that has the oversize barrel is a Hatsan Carnivore.