Subsonic 243 ammo

**Vaal** · 01-04-2024, 12:46

Originally Posted by swakop_toe

How much Dacron do you use Vaal?
This oke use 1gr in his 308 loads and observes lots of fouling.
But 1gr Dacron seems quite a lot?
https://www.snipershide.com/shooting...7/post-8826384

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I use about 3.5 gn (grain) that about 50mm L ×12 × 20 loosely fluffed. Nearly the size of my pinky. Btw we cal it Dacron but it is actually polyester hollowfibre fill which is used in duvets and jackets.

The way I hear it is that flashover with a kaboom could never be duplicated in a lab or controlled environment yet.
But the theory is that too much powder gets ignited, in a too short time like in: a horisontal rifle case, the primer flame lighting the powder from the top down instead of from the primer hole to the bullet.

I once saw somebody shoot a shot with a whole wad of toilet paper and look like confetti.

**oafpatroll** · 01-04-2024, 16:47

Originally Posted by janfred

Flashover is 2-dimensional, from the top down. Flash through is 3-dimensional, from the inside out. Ignition squared as opposed to cubed.

One of the conditions for OBT reloading is to ignite as much of the powder as quick as possible.

And people have found out that powder burning in a column is not the most efficient way of propelling a bullet hence all the short, fat cases these days. A flash in the centre of the powder burning outwards. I.e. flash through.

The only thing people know about small charge kabooms is that it is due to small charges of SLOW powder. That is why subsonic loads use fast pistol powder. The mechanism is still unproven and unduplicated. The flashover theory is just that, an unproven theory.

There is enough that's unknown about the phenomenon that it's a thing I'm personally not interested in pursuing without someone funding the exercise for me as my supply of rifles, fingers and eyes is constrained. The kabooms that I came across references to were not restricted to small charges of slow propellant. Not suggesting that anyone else avoid it but it's worth bearing in mind that that there are precious few if any published major manufacturer recipes for things like subsonic .243. There is bound to be a reason for that.

**Heath Robinson** · 02-04-2024, 07:22

Originally Posted by oafpatroll

it's worth bearing in mind that that there are precious few if any published major manufacturer recipes for things like subsonic .243. There is bound to be a reason for that.

True, but quite possibly the reason is as simple as the fact that there are either dedicated calibers designed to shoot just about any bullet you could wish for at subsonic velocities, or ones that are very much better suited to it.

No matter what filler you use, a non-filler solution will be technically better.