Air-brakes on PBR 10mm for the moment

Started by Intercooler, May 08 2013 06:22:27 PM MDT

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Intercooler

It's listed on the stickied sheet. Roughly 679.

DocGlock

Quote from: Panzer on May 12 2013 04:32:54 PM MDT
So how do we convert the power factot to foot lbs? I guess I could look it up somewhere on the net.

Here's a very small excel spreadsheet to calculate it for you.  Just input weight and velocity.

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Panzer

Quote from: Intercooler on May 12 2013 05:00:27 PM MDT
It's listed on the stickied sheet. Roughly 679.

I thought of that this morning and was thinking to myself, "what an idiot"

Thanks for the reminder though. :'(
Blitzkrieg is the way of war.

sqlbullet

Quote from: Panzer on May 12 2013 04:32:54 PM MDT
So how do we convert the power factot to foot lbs? I guess I could look it up somewhere on the net.

Actually you can't.

Case in point.

A 200 grain bullet at 1000 fps will have the same power factor as a 100 grain bullet at 2000 fps.  That power factor is 200 (mass X velocity/1000)

However, the energy of the two will be very different.  In fact, the lighter bullet will have twice the energy of the heavier one (444 ft-lbs vs 888 ft lbs.

With ONLY power factor as an input you have no idea the energy of the round.

However, if you know the power factor and the bullet weight, or the power factor and the velocity, then you can derive the source variables of energy (mass and velocity) and calculate energy (mass X Velocity /450437).

--Mass is always in grains and velocity in fps for the above formulas.