Velocity, energy, etc. (I hate math)

[Robo_Railer]

I just acquired a "new" S&W 3913, and was looking around for info on carry ammo. Based on discussions about the "short barrel" Gold Dot JHPs in revolvers, I was thinking about the Speer 124-grain 9mm.
Technical data on one vendor's site showed the same muzzle velocity for "plain" and +P, with the +P having more muzzle energy. (No +P+ for me, thanks.) I thought velocity and/or bullet weight would have to increase for energy to increase. :confused: Can anyone enlighten me without too much algebra? (;) )

BTW, the price from the vendor mentioned above is about 48¢ per round (50-round box) vs. 80¢ for another company (with usually great prices) that only carries 20-round boxes. Now, if the one with the cheaper ammo also carried spare mags and stuff . . . :scrutiny:

[LHB1]

Quote: "Technical data on one vendor's site showed the same muzzle velocity for "plain" and +P, with the +P having more muzzle energy. (No +P+ for me, thanks.) I thought velocity and/or bullet weight would have to increase for energy to increase. Can anyone enlighten me without too much algebra? "

RR,
+1!!! Back when I studied physics, an increase in velocity and/or bullet weight was also necessary for energy to increase. I don't think rotation speed adds enough energy differential to warrant significant differences in energy so rule out different rifling twists. Could it have just been a misprint? Check data for other bullets of similar weight and velocity to see how they compare.

Good shooting and be safe.
LB

[logical]

Who is the vendor...so we can try to make sense of it?

[hksw]

WHich product numbers are you looking at? I can't find the numbers you are describing on Speer's website and didn't see anything unusal concerning the different grades of 124 gr 9mm loads.

[Robo_Railer]

Back when I studied physics, an increase in velocity and/or bullet weight was also necessary for energy to increase.Thanks, LB. It's nice to know that even though I'm math-impaired, the laws of physics haven't been amended or repealed. ;)

Yeah, it dawns on me now that I should check Speer's site or other sources to see if maybe some number got transposed somewhere. Either way, the Gold Dots seem like a good choice. I want to get a "goodly quantity" of 'em, for familiarization and to make sure they work with the 3913 and any spare mags I get for it.

Okay, just saw the two new replies. It was Streichers; I'll be back shortly with links to their pages, so we can sort out whether they've got all the right numbers in all the right places. I think there are three different bullet weights listed there, as well as "standard" (just called "hollow point" there), +P, and +P+, so it could be a typo.

[logical]

I looked at the Speer site. there are 3 different 124 grain 9mm rounds:
1) Regular 9mm @ 1150, 364 (energy, velocity)
2) + P 9mm @ 1220, 410
3) + P short bbl 9mm @ 1150, 364

The reason the + P short barrel numbers and the regular non + P are the same is due to test barrel length. 1) and 2) are tested in 4 inch barrels, 3) in a 3.5 incher.

So basically the +P short barrel load in a 3.5 inch gun gets the energy up to the level of standard (non +P) 9mm out of a 4 inch gun.
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this doesn't really directly adress your question, but as others have confirmed...if the weights and velocities are the same then the energiy numbers would have to be the same. I suspect the vendor is just a little mixed up with all the products out there. I have to wonder really if the short barrel loads are anything more than the +p relabled in a brilliant marketing move.

[Robo_Railer]

Ah ha! (And now we know why they call you Logical. ;) )
I wondered if it might've had something to do with barrel length. I prob'ly could've researched that myself, but I do enjoy getting answers from the membership here. It's kinda like going to a gun club meeting without having to leave the house. :cool:
Nice to know, too, that they're not just firing the stuff through some 7" test barrel and claiming big numbers for it.
Thanks, guys.
Now if I can figure out which of Streichers' stock numbers is for the "short barrel" stuff . . .

[Robo_Railer]

I emailed Customer Service at Streichers Police Equipment to see if they could tell me which of their stock numbers would be the 9mm GDHP-SB. I got this reply:
The ammo is $20.00 per box and they are only sold in boxes of 20 not the typical 50.

:(

[logical]

A buck per round is way high. The 50 round boxes are less common but are out there, I found some a sprtsmansguide.com a while back and it was under $20/box of 50.

[Robo_Railer]

Yeah, I think it was here that I first heard about Streichers. I did get a 20-round box of .38 (snubby stuff) from another vendor a few weeks ago, but was really hoping to find a better buy with the bigger boxes. Dang.

Sportsman's Guide only has 20-rounders right now, $12.17 and up, depending on caliber.
Thanks for the suggestion, anyway.

EDIT: Just checked Speer's site, and found their Law Enforcement page. That shows 50-round boxes only for #53921, the .38 Special, 135 gr. snubbie load. Looks like the stock numbers for 20's begin with '2' and the 50's with a '5'. Still Googling for "53611." No joy yet. :banghead:

[ball3006]

is much more important than energy/velocity.........practice, practice, practice.......chris3

[Robo_Railer]

Yeah, I seem to recall something about "A BB in the boiler room is better than a [some huge caliber] in [someplace else]. So when I "place" everything effectively, I want the fight to stop. Every little advantage I can get, I'll take.

"They don't pay me to fight fair; they pay me to win."