Chrony distance from muzzle

General Firearms Reloading & Ammunition
1

I’m loading up some M193 and M885 for SHTF and was wondering about something. As far as the development of the load goes (powder type, charge, cas, primer etc…) I’m good as gold, but I am wondering how far from the muzzle I should set up my chrony. I plan on setting up a target at 100 yards and load several batches of 5 with varying powder charges (i.e I will have 5 at 24.3 gr of H-335, 24.9 gr H-335, 25.4 gr H-335 etc… until I reach the max load listed in my data for a 55gr FMJBT) as for the M885, I have found data from many sources that give me some reliable charge weights using BAL-C-(2)

I have a manual with specifications for each of these loads, it is a military publication with specs for almost all military ammo but would like to know how far I set my chrony up from the muzzle to get an accurate velocity measurement for these loads intended purposes based on how far the military sets up a chrony for testing.

Same question goes for developing V-Max loads for Varmint evaporation using Varget

Barnes Tac-X L/E, MPG and Varmint Grenades.

These are pretty much all of the projectiles I am reloading. Would like some good chrony advice for these type of loads. Especially the M193 and M885.

Additionally, I am duplicating the military’s 9mm M882 using WCC cases (NATO spec cases), 124gr FMJ sierra special jackets, 8gr blue dot. What about the chrony distance for pistol velocities?

2

Most chronographs state 12-15’, I set mine at 15’ rifle and pistol.

3

That seems like a good, safe distance to me, the miltary manual I was talking about says to set up chrony at 25 yards!!:confused: I am AFRAID of shooting my chrony. I was thing 15 to 25 feet, I just want an accurate measurement for the particular load of the M193 and M885.

4

10-15" will work. Just remember about sight offset. Aim high up on the rods because the bullet will be about 2.5" below your line of sight at that short distance. Aim too low through the rods and you just performed a terminal performance test on sheet metal and electronics!

5

Thanks for the advice…shooting chrony at the range = humiliated :stop:

6

I do 6 - 7’ from the muzzle to the front skyscreen. This allows me to set the PACT chronograph on an adjacent table - out of the way and easy to see.

7

You want it far enough away that the muzzle blast does not affect or blow over your screens.

Pistol distance will be different than rifle distance.

By a Chronograph that is a separate box of electronics from the screens. It is easier to have the chrony next to you and the screens only out front and if you shoot the screens by accident usually a lot cheaper :slight_smile:

I have an old Alpha Chrony or whatever it is called (fold in half tyupe for storage) that I shot. It actually still works except that the sensor is loose in the box. The bullet thankfully only hit the very top of the box and broke the mount for the sensor but did not hit anything vital.

I have since upgraded to a CED M2

8

I always set it up at 15’ for rifle and pistol