Wimpy Fed 9mm EFMJ +P

B

BrokenArrow

New member
Stuff hasn't looked bad at all, but I just got around to chronographing it.

Avg 1105, ES 21, SD 8 336 ft lbs

From a BHP/Beretta 92, two different lots of ammo.

Not too zippy for a +P eh?

Bare jug: 4th/.55

clothed jug: 3rd/.53

All below clothed:

Fed 124 +P+ HS (1211 fps): 3rd/.62

Speer 124 +P GD (1266): 5th/.49

Rem 124 +P GS (1180): 4th/.65
 
I wonder if the nature of the bullet leads to higher chamber pressures, thus causing the +P rating. I agree, though, that it is not quite the speed I expect from a +P loading. Anybody out there got a strain gauge so we can verify chamber pressures on this stuff?
 
BrokenArrow,
Mind if I ask how you measured the ft/lbs rating? Did you just use the formula or is there some sort of scale that measures the "energy?"

Thanx,
Ben

------------------
Almost Online IM: BenK911
ICQ # 53788523
"Gun Control Is Being Able To Hit Your Target"
Different, just like everyone else. (Ben Original)

[This message has been edited by Ben (edited October 04, 2000).]
 
KISS: divide the bullet weight in grains by 100 (124=1.24), multiply that by the velocity in fps squared (1105x1105=1221025), divide that by 4500.

The .xx is the recovered diameter. The GD looks like the jacket petals folded back against the core; I suspect it was bigger before that happened?
 
Broken Arrow,

Tell me if I'm wrong, but part of the "energy" comes from the bullet coming to a halt. That formula doesn't seem to take into account wheather or not that round decelerates to zero-velocity in 12 inches or 40 inches. The rate of deceleration is depended on hollowpoint expansion. So with your formula, a 1200fps 124 grain hollowpoint would create the same "energy" as a 1200fps 124 grain roundnose.

It seems like that would be something to take into consideration.

Ben

------------------
Almost Online IM: BenK911
ICQ # 53788523
"Gun Control Is Being Able To Hit Your Target"
Different, just like everyone else. (Ben Original)

[This message has been edited by Ben (edited October 05, 2000).]
 
Ben, energy is energy. What you are asking for is a calculation as to the effect of the energy, which doesn't really exist. The Fuller Index is used to calculate energy dispersion patterns in gelatin and extrapolate that into the effect the energy would have on the target. But, it's highly contested in terms of validity and accuracy.
 
Just go this from Federal:

THE REASON FOR THE SLIGHTLY LOWER VELOCITY IS THE COMPOUND IN THE NOSE. THIS
MAKES IT A LONG BULLET AND YOU RUN OUT OF CASE CAPACITY.
 
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