Tag: Guns and such

My RFI is for someone in the north Texas / southern Oklahoma area who can weld heavy steel.  Anyone out there interested in doing a long-term project with me?

Here’s my line of thinking.  When a bullet strikes a soft target, you’ll get penetration to varying degrees (as we’ve been seeing here, for example).  That kind of measurement and analysis is made  possible with the use of ballistic gel.

I want to measure something a little different:  kinetic energy.  I know that ammo manufacturers usually supply this information in ft/lbs for their products (at least, most of the centerfire rifle stuff does);  but I want to try it for myself.

Here’s what I want to do.  We’re all familiar with the tractor-pull thing, where trucks compete to see who can shift a specific weight the furthest (with a shifting weight which increases drag over distance).  I want to apply that same principle, only using a weighted sled running on rails.

The methodology would be to have a stout piece of steel, e.g. a 1-ft x 1-ft x 2″ thick steel square — the target (solid, to avoid any thought of penetration) — welded to a  weight with four wheels (like below) attached.

Ideally, the whole weighted/wheeled target would weigh about 100lbs.

Then I’d want to get two lengths of steel I-beam laid on their side, upon which the wheels would run, set on level ground.  (I don’t know how long the beams would have to be;  10′? 15′?  We’d have to see.  Or if we needed shorter channels for ease of use, remove the wheels and replace with skids instead.)

  

The we could shoot the 1′-square steel target, and see how far the bullet(s) pushed the sled along the rails.

This all came about when I was talking to someone about the wisdom / folly of hunting a Cape buffalo with a .45-70 Govt vs. the Usual Suspects (.375 H&H, .458 Win Mag etc), and the guy (a seasoned hunter) said that it was all very well to use a round which penetrates a buffalo, but if it went all the way through, it was wasted energy;  he’d prefer to dump all the energy into the animal, to “knock it on its ass”, as it were.  A buffalo’s hide / body is tough, all right:  but the old “needle vs. bowling ball” argument always rears its head.

My goal in this is not to test rifle ammo, but to test self-defense pistol  cartridges.  I believe that if you were to combine ballistic gel-penetration numbers with the sled’s momentum / ft.lbs data, you’d be able to add yet another dimension, and judge a cartridge better than simply relying on the Lucky Gunner formula of muzzle velocity / bullet expansion / gel penetration.

If someone (e.g an engineer) has experience doing this kind of thing and wants to scope / design the project, please let me know.  Right now, I’m just blue-skying the thing out of ignorance.

Or has this, or something similar, been done elsewhere and I just missed the party?

Your thoughts in Comments.

Following on from my last post on the topic, let me turn to 9mm ammo, because I have little or no experience with the Europellet to speak of.

If I’m going to use lesser (than .45 ACP) ammo in my primary carry piece, I’m going to ask quite a lot of the ammo.  Specifically, I want substantial bullet expansion (to bring it up to .45 dimensions), and added velocity to punch the bullet home — therefore, using Lucky Gunner’s metrics, I want penetration greater than 16″, expansion greater than .5″, and velocity higher than 1,100 fps.

Casting my eye at LG’s 9x19mm test results, then, I see that two cartridges seem to be able to deliver said criteria:

1)

Man, this Federal stuff looks like just what I’m looking for:  deep penetration,  consistent expansion, and excellent velocity.

2)

The XTP lags just behind the Federal HST in terms of velocity, but it’s not bad at all, and almost as consistent in terms of expansion (albeit less than .5″).

For the record, here are the results for the load I’m currently carrying in the Browning High Power:

Not bad at all, although the greater expansion of the bullet on the extreme right is the one which dragged the penetration average down.  I like the ammo, though:  it’s wonderfully accurate in my elderly hands and still-more elderly gun.

However, there does seem to be a ringer in the 9mm ammo tested, and it’s this one:

Okay, the Speer looks outstanding — I’ve always been a fan of the Gold Dot, in other calibers — and the lighter boolet (115gr vs the others’  124gr) likely means less recoil.  The only negative to the lighter bullet weight is the penetration — barely breaking the 16″ criterion — but I’m adding it to the list nevertheless because as with the SIG load, one bullet over-expanded to bring the average penetration down.

Feel free to peruse the test results for your own conclusions.  Note, by the way, that several loads achieve much higher penetration than any of the above, but I think one can have too much  of that — think “innocent bystanders” and you’ll get my drift.

Have at it.  Are we having fun yet?

The guys at Lucky Gunner don’t just sell ammo at decent prices;  their ammo tests are superb.  Here’s the .38 Spec / .357 Mag test, using both 2″ and 4″ barrels(!), and the ability to rank by various factors such as speed and penetration makes the test just gold for guys like me, who want the very best combination of effectiveness, but lack the space or facilities to do the testing for ourselves.

Just looking at this chart for my 2″-barreled S&W 637, and given that I’d like penetration greater than 14″, expansion greater than .38″ and velocity higher than 800 fps, it would appear that these two loads would be my best choices for .38 Spec ammo:

Incidentally, my current carry load is the Hornady FTX, which seems to have better expansion and speed than the Federal.  But the Federal ammo seems to have the more consistent penetration (note the tight grouping) — and as a former statistician, I prefer results that are consistent with not too many “fliers”, such as Federal’s heavier load, which is all over the place:

 

Now, when I finally (eventually?) get my hands on a 4″-barreled S&W Model 65 in .357 Mag, I’ll be looking for penetration > 16″, expansion > .50″ and velocity > 1,300 fps — which means that these two cartridges will be getting my attention, you betcha:

There’s just this caveat, however.  As LG themselves note:

“Keep in mind that the loads with the best numbers might not necessarily be the best choice for your defensive revolver once the effects of recoil are taken into account.”

…so any of those options might not be my final decision, of course.  That would require… field testing!

I love this stuff.  And well done, Lucky Gunner.  When I test the ammo, I’ll be getting it from you guys:  it seems the right thing to do.