Wadcutter Hyper-Boat Tail 38s (Backwards 9mm)

[Fizz]

I had a lot of Berry's 147grn plated RN 9mm (.356) projectiles I didn't really have a use for since I stocked up on factory 9mm 147grn RNs stacking coupons/rebates to get OTD costs to $0.06/rn a while ago.

Had some fun making these into a .38 load. Don't get me wrong, these don't perform that well. Probably could tune it a bit (lot) more, but I loaded these just to shoot some components.

The lack of neck tension means some cases were just too loose (not an insignificant risk of projectiles falling out and binding the cylinder. Setback was also possible. However, if the projectile rested on the powder it would be near pressures of a 9mm load, which slightly compresses max loads of Unique about the same charge weight. They also required more crimp than I like to put on plated. That combined with the fact that these were loaded over 4-4.4 grains of Unique the cartridges didn't appear to get good into a good pressure range and I'm sure all the excess case volume didn't help. Smokey and dirty.

Though, no keyholing. Unsupported 10 yards and I'm not a good DA shot. Punched holes like a hole punch.

[KahrMan]

What were you trying to achieve? The times I have seen this done were with hbwc or full wadcutter 38 bullets.

[Fizz]

What were you trying to achieve? The times I have seen this done were with hbwc or full wadcutter 38 bullets.

Put holes in paper with backwards bullets to shoot excess components. Really, no goal other than to make ammo that went bang and the novelty of backwards 9mm RNs in a 38/357 revolver.

These do perforate targets like a hole punch (just like normal wadcutters). I guess a practical application would be to minimize components, you can make wadcutters by simply loading most anything in reverse.

[saki302]

Be warned- this does increase pressure, probably due to the curved base it's introducing.

I made a couple for fun in .45 auto rim, same light powder loading. MUCH more case deformation resulted, and I never did it again.

One of the gun magazines tried it with rifle bullets and also noticed a pressure increase.

-Dave

[Fizz]

Be warned- this does increase pressure, probably due to the curved base it's introducing.

I made a couple for fun in .45 auto rim, same light powder loading. MUCH more case deformation resulted, and I never did it again.

One of the gun magazines tried it with rifle bullets and also noticed a pressure increase.

-Dave

I would expect the only reason for a pressure increase doing this is the decrease in case volume vs a projectile pointed in the normal direction. Even such, 4 - 4.4 grains Unique in a 38 special case has more volume than 9mm with unique for the same projectile weight and 4.4 grains is about a max charge in 9mm for 147grn projectiles (which has 0 excess case volume at functional seating depths for all bullet profiles I've ever tried that will cycle semi-auto).

All the evidence in my testing showed that these were underpressure. Smokey, bunny fart recoil impulse, not enough case expansion under firing to seal the case to the chamber (gas blow by on the outside of the case mouth), a lot of unburned powder on the shooting bench. Definitely no primer flow etc.

These projectiles 1 thousandth under what they should be for a 38 special. You can drop the projectiles right through the cylinder. In this instance, factors that might increase pressures were dwarfed in comparison to those that would reduce it.

[saki302]

Here's the rifle results:

http://www.alloutdoor.com/2015/03/31/bullets-testing-upside-down-rifle-bullets/

On my .45AR, I was using reduced loads and SWC projectiles, so it should not have had much effect, if any, but it did. Plenty of case capacity and powder volume (Bullseye powder)
I suspect the angled surface does something odd to the pressure curve- I could be wrong but this is what I saw firsthand.

It was a shame too- they seemed relatively accurate and made nice big holes- would have been great for target shooting (they don't commonly make DEWC in .452 caliber- I just use DEWC in .38/357).

[Fizz]

Here's the rifle results:

http://www.alloutdoor.com/2015/03/31/bullets-testing-upside-down-rifle-bullets/

On my .45AR, I was using reduced loads and SWC projectiles, so it should not have had much effect, if any, but it did. Plenty of case capacity and powder volume (Bullseye powder)
I suspect the angled surface does something odd to the pressure curve- I could be wrong but this is what I saw firsthand.

It was a shame too- they seemed relatively accurate and made nice big holes- would have been great for target shooting (they don't commonly make DEWC in .452 caliber- I just use DEWC in .38/357).

Fun video. He made no mention of adjusting powder charges or seating depths; he appeared to merely reverse the projectiles and seat to an arbitrary depth and definitely didn't work up a load. My guess is the reduced case volume and depth caused his over pressure conditions.

I think we can conclude that reversing a projectile definitely increases pressure everything else the same. In my case, I didn't start with a 'normal' cartridge and reverse the projectile, I started with a minimal charge and reversed it, even with the work up from 4-4.4 grains, not even the top end of the spectrum showed pressure conditions and all of them showed underpressure conditions.

There may also be some differences between straight wall and necked cartridges. However, the pressures that pistols/rifles operate and that explosive pressure exerts force (mostly) all directions uniformly, I don't think the boat tail aspects do anything significant, the pressures are so high as I think any influence would be minute. Further, the slope of the boat tail wouldn't only channel gasses into a 'pocket' thereby exerting extra pressures around the neck, but the surface area to push the projectile forward is actually increased (this should cause it to move sooner in the pressure curve and be further out before the pressure peaks).

His conclusion was to never reverse a projectile, but IMO, it should have been don't reverse it without a work up.

It would be interesting to see the effect in velocity and pressure in a HBWC load in forward and reverse directions; this would allow you to see the difference in minute changes in effective case volume, while maintaining the same bullet/neck travel distance.

[NaClAddict]

I used to shoot a lot of miwall reloads. Occasionally some would have a backward projectile. I would trade them in for good rounds. A roommate asked if he could shoot them out of his gun one time. I warned him it could be catastrophic and dangerous. Bring the college punk he was he didn’t care. I never saw any signs of over pressure. I’m not a reloaded, but no obvious signs.

[JagerDog]

Fun video. He made no mention of adjusting powder charges or seating depths; he appeared to merely reverse the projectiles and seat to an arbitrary depth and definitely didn't work up a load. My guess is the reduced case volume and depth caused his over pressure conditions.

I think we can conclude that reversing a projectile definitely increases pressure everything else the same. In my case, I didn't start with a 'normal' cartridge and reverse the projectile, I started with a minimal charge and reversed it, even with the work up from 4-4.4 grains, not even the top end of the spectrum showed pressure conditions and all of them showed underpressure conditions.

There may also be some differences between straight wall and necked cartridges. However, the pressures that pistols/rifles operate and that explosive pressure exerts force (mostly) all directions uniformly, I don't think the boat tail aspects do anything significant, the pressures are so high as I think any influence would be minute. Further, the slope of the boat tail wouldn't only channel gasses into a 'pocket' thereby exerting extra pressures around the neck, but the surface area to push the projectile forward is actually increased (this should cause it to move sooner in the pressure curve and be further out before the pressure peaks).

His conclusion was to never reverse a projectile, but IMO, it should have been don't reverse it without a work up.

It would be interesting to see the effect in velocity and pressure in a HBWC load in forward and reverse directions; this would allow you to see the difference in minute changes in effective case volume, while maintaining the same bullet/neck travel distance.

Directing the pressure outward to the neck could cause deformation or splits. May not be pressure at all. And ya, reduced case volume would tend to ramp up pressure on an established load of say 60 kpsi. Different animal than what you were doing.

[hermosabeach]

Why not sell the 9mm and buy or make 147 lead wadcutters

Correct bullet
Correct diameter
Etc

[Fizz]

Why not sell the 9mm and buy or make 147 lead wadcutters

Correct bullet
Correct diameter
Etc

There's no novelty in that.