[Diamondback]

I have been looking over the ballistic data table for .38spl. loads fired out of a 2" S&W model 60 in "HANDSGUNS MAGAZINE" and I noticed that the data listed for the 10 fatory loads that were tested raised some questions for me. In most cases there was not much of a drop off in velocity when the load was fired into bare ballistic medium and then clothed medium. Wouldn't an added layer of clothing significantly slow the velocity of a bullet and show a measurable decrease in speed? And why in some cases was the penetration into the clothed medium greater than the penetration into bare ballistic medium? Again I would assume that clothing would decrese penetration. I am sure that I need a short lesson in physics here. Anyone care to enlighten me ?

see: http//www.handgunsmag.com/ammunition/pocket dynomite

Thanks,
Chris

[fourdeuce82d]

"In most cases there was not much of a drop off in velocity when the load was fired into bare ballistic medium and then clothed medium. Wouldn't an added layer of clothing significantly slow the velocity of a bullet and show a measurable decrease in speed?"

The velocity is measured prior to impact with the target.

" And why in some cases was the penetration into the clothed medium greater than the penetration into bare ballistic medium? Again I would assume that clothing would decrese penetration."

Most handgun rounds that are intended to expand rely upon a hollow cavity at the front of the bullet- the pressure of flesh/blood/odd bits of person on the inside of the cavity forces the cavity to open up. If the round is plugged up w/clothing, the pressure may not be transmitted as efficiently to the sides of the cavity- the round is less likely to exapand, and thus retains a narrower profile, allowing it to penetrate more deeply.

[Diamondback]

Thank you ! This make perfect sense ! Is there anything in this particular test that sparks your interest ? For me I was stuck (no pun ) by the data on the 125g Hornady XTB round. Although the bullet does not significantly "open up"....the velocity for a standard .38 load seems impressive........and penetrates deep......thanks to you, now I know why !

Chris

[Jim March]

In that data, the Speer Gold Dot 125+P and the Winchester 130 Supreme did the best.

The XTP basically has an extra-thick jacket that doesn't open very far, but it's very tough and resists "overspeed problems" where the nose opens up but then shreds apart. Load these rounds in an 18" barrel carbine and of them all, the XTP is probably going to be the best round.

But in these snubbies, it's not the round I'd pick. It's really a hunting load and good for 357s.

[Diamondback]

Jim, I get confused when I look at the data in the aformentioned "Handguns Magazine" article that shows the Gold Dot 125g+p and the Winchester Supreme 130g+p opening impressively with good penetration in a 3 layer cloth ballistic medium and then see that in the Ammo Lab tests these same loads did not open much in a 4 layer denim covered ballistic gel. Pehaps this seeingly conflicting data is a good reminder for me to concentrate on bullet placement rather than raw data...... still one likes to try to make sense of things and optimize their load choice when using a J frame .38spl.
Thoughts.....?

[Jim March]

Ya, first thought is that four layers of denim is just crazy, at least for somebody like me in CALIFORNIA :D.

Even by moderate winter standards, 4 layers of denim is crazy. That's more "materials density" than most people wear in the rain.

The Handgunner Mag test with "three layers of cloth" (unspecified thickness, but I assume less dense than denim) is in MY opinion a more real-world test for any situation this side of a snowstorm.

[Old Fuff]

The basic problem is that expansion probabilities of a hollow-point bullet is dependent on many factors, most of which can’t be predicted in advance. One can run all kinds of tests on various mediums, but as has been noted a particular bullet/cartridge combination may perform differently in approximately similar tests.

This would suggest, yet again, that there is no such thing as a “magic bullet,” that placement is the main determiner of success, and the surest thing in an expanded bullet is one that is big in the first place.