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. 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 . . .

 

[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 It's nice to know that even though I'm math-impaired, the laws of physics haven't been amended or repealed.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.
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]

Bad news from Streichers

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]

Remember, bullet placement....

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."