Subsonic expandable bullet ideas

[Valornor]

Making a cost effective jacketed expanding subsonic bullet for 300BO is something of a holy grail for bullet manufacturers. All the designs I've see are expensive, and from some of the testing we did, not reliable. One brand, which offered a monolithic bullet, stuck bullets in the bore in when the ammo was chilled.

Half jackets are definitely one way to go, those look nice Brian . When we were playing around with the idea we made a skiving die. Once we staked the core in the jacket we ran the core and jacket about 50% of the way through the die which cut three grooves on the outside of the jacket about .015" deep. Then proceeded to form the ogive as normal, leaving the meplate about .080". They expanded beautifully. We never got past proof of concept as there were other priorities.

[Mauser 98K]

i know one thing, a thinner pure copper jacket and the softest lead core you can find works wonders for expansion/fragmentation of slower velocity bullets.. it has a jacket, it does not matter if the lead is soft as butter as the jacket separates it from the bore. the ones i make for my SKS will make almost flat buttons at speeds as low as 1,200fps. have not tried slower yet but will get around to it.

the biggest problem is the jacket material and the core wire as i said above. the standard alloy jacket has zinc in it. while this makes them less inclined to foul the bore it also makes the jacket tougher and less inclined to deform at the lower speeds. a thinner jacket of around 0.015-0.020 also helps a lot. im not even going to get into the brass jackets and the impossible feat of making them mushroom at subsonic velocities without putting slits in the jacket so it opens up like a flower.. as for the lead, as stated you want the softest you can find. you basically want a rifle version of a pistol bullet, the only difference would be the point shape. there are pistol bullets that will mushroom at lower velocities and all you need is to copy the material used..

another thing that is often overlooked is the point itself. a very sharp point is more inclined to penetrate and hold together than to deform and mushroom at the slower velocities.. you want a good ogive shape that is more blunt than the traditional ice pic shape and an open tip with about an 1/8in cavity in the nose so that a fluid medium can get inside and start peeling the jacket back. what works for super sonic bullets will not work when they drop to subsonic..