Determining Muzzle Velocity without a Chronograph

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centralpadoug

New member
How can I determine the muzzle velocity of of a given hand load when the parameters of the load fall outside the range given by the powder manufacturer? I load 4.2grains of Titegroup into a .45ACP with a 185 lead SWC bullet. This is well below the 5.0 mimimum given by the manufacuturer, but functions just fine in my H&K USP45...in fact I find it to be an extremely accurate combination as well.

I want to ensure that I am staying above the min. power floor for IDPA competition.

Any ideas are appreciated.

Doug
 
M

Mike Irwin

Staff
Sorry, don't think there's a way to do it without a chronograph, unless you want to build your own ballistic pendelum (sp?), and that was just an early form of chronograph.
 
R

riddleofsteel

New member
it can be roughly done with a rifle by figureing the bullet drop at various yardages. this is provided you have the correct ballistic coefficent for the bullet i have done it with a rifle but never a handgun. HUMMM

before i had a chrono i had roughly figured the muzzle velocities of my hunting rifles and pet loads by calculating bullet drop at 100, 200, 300 yards ect. and comparing the figures to the drop tables in the Nosler reloading manual for those projectiles. when checked against the figures from my first chrono they were fairly accurate.
 
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WESHOOT2

New member
You will know after your wimpy load is chrono'ed at a big IDPA match and you find you're shooting for fun, not score LOL.

Only way to KNOW is chrono....in your specific individual firearm.
 
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Mal H

Staff
Doug - you don't have to own a chronograph to determine your bullet's velocity. You just have to know someone who does. :)

If there is one truism about the shooting sports, almost all shooters are willing to help out other shooters (within reason, of course) even if they will be competing against them in the next match. See if you can find someone in a local club with a chrono. 10 to 1 he/she will be more than happy to let you fling a few across the screens.
 
9

9x45

New member
borrow or buy a chrono, or build a crude ballistic pendulum, which is problamatic at best, especially for such low energy. I doubt 4.2grs of TiteGroup is pushing a 185 bullet even 800fps, because I have measured 230 RNlead .45acps at 4.2grs, and they were only going about 760fps. Just use the published load of 5.5 grs for 955fps.

For IDPA, at the club level, it doesn't matter, but at at state or national match, yes, be safe, use factory ammo
 
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WalterGAII

Moderator
Crapperdapper, you guys. Can't believe you never learned to measure m.v. without a chronograph. For the uninitiated, it's really simple, but it takes a shooting buddy to help you out. All you need to do is mark a line parallel to the bore axis of your firearm. Measure exactly one foot and mark same with visable marks perpendicular to the bore axis. (I'd suggest that this 1' marked line be three or four feet in front of the muzzle.)

Have a buddy with a stopwatch stand approximately three feet on whichever side of your firearm that he feels comfortable. When the gun is fired, the buddy just records the time that the shadow of the bullet takes to transnavigate the 1' marked line. Computation using that data is rudimentary.
 
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Mal H

Staff
True, Walter. I didn't know anyone else knew that method. I have found that as I get older I need to use a 2' distance. It is getting harder to start and stop the watch in only a 1' distance.
 
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WalterGAII

Moderator
I dont deserve credit for the information that I provided. I must give credit where credit's due. I was edified by a certain former SEEL who probably was posting from Levelingworth.
 
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