Home Forums Hunting & Shooting Ask The Gunwriters MID-MAY column: Velocity of Factory Ammo

It was cheap, seemed to work OK for several years. Even when I doubted it, it was consistent at least the whole string was close to the same readings. The 7X64 low readings made me wonder, then some really high readings with a Sako 270. Expected 3000fps got almost 3400.. I like the Labradar idea as it is easy to setup on a public range, others not so much. They are expensive however.

I had the same experience with more than one Chrony--worked all right at first, then got weird as time went by.

Have also run into more than one shooter at the local range who set theirs up, took a couple shots, then said, "WTH?"

After first getting my LabRadar I set it up along with my old Shooting Chrony Beta Master. Using a semi-auto .22 I clocked the velocity from both at the same time. I was quite surprised that they agreed incredibly closely. The readings were withing 3 fps consistently for nearly every shot. In some cases the Shooting Chrony picked up a shot or two the the LR missed (I was just figuring out how to set the LR up). It gave me more confidence in the numbers I'd attained over the years with the Shooting Chrony, although I do know that changing light conditions affected the old SC in many cases. You could plainly see it on a day going from bright to overcast or vice-versa in a single shooting session.

However, I've found the LR to be sensitive to cold weather (at least low 20's F and below). Whether this is due to the unit itself not working well in the cold or due to the external USB battery pack being affected I'm not sure. I have a pic of my LR from late last December showing a velocity reading of 5,575 fps...and I was shooting a 7mm Remington Magnum with a 154g Hornady SP. So it was reading about 2,500 fps high. And that wasn't the first time it had given me a spuriously high reading in cold weather (but the first time I thought to snap a pic of it) although it didn't give a false reading on every shot and only did it during two shooting sessions that I recall. Next winter I'll have to remember to bring a hand warmer to lay over the battery pack to see if that alleviates the issue.

Azar,

Thanks for the info. I would suspect the Labradar might be sensitive to cold, given how much energy it requires. Which is why I have five chronographs!

But it also looks to be handy for certain purposes. And as somebody who writes about this stuff, I had to find out!

Well, the boss got me a Father's day present.. Will see how the new Labradar works out. Thinking it will be much better than the old Master Chrony, set up no doubt. Not going to sell it either, not something to pass on LOL.

Excellent write up.

I though that Brian used equipment that he made himself tp record over a 600 yard spacing. At least that is what he said years ago.

I recently shot some old W-W 243 ammo in my Tikka 243. The listed velocity is 3,070 fps with a 100 grain Power Point bullet. In my 22.4" barrel the velocity was 2,677 fps. Nearly 400 fps off listed velocity is pathetic. Accuracy was pathetic, too.

The old Lyman reloading manuals had factory ammo velocities listed, along with factory duplication loads and accuracy loads.

jwp,

Bryan has used various chronographs. In one of his books from a few years ago, he was using an Oehler 35P with (if I recall correctly) as 12-foot screen spacing.

One of the reasons many professionals (including me) used Oehler 35's over the years was the double-check of the velocity: You get two readings for every shot, which provides a better idea of the validity of the reading. But Bryan has a youtube video out now, showing how he uses two Labradars, for similar confirmation.

Jerseyboy,

Dunno how old your .243 ammo is, but if its listed at 3070 fps its REALLY old, since that was the original factory standard WAY back when--and was chronographed in a 26-inch test barrel. The present-day industry standard for 100-grain bullets in the .243 is (if I recall correctly) 2960 fps from a 24-inch barrel.

Plus, quite a few of the powders used back then deteriorated relatively quickly when stored in uncontrolled conditions. Which is why I wouldn't judge ammo made 40-50 years ago when fired today.

The 6th Speer manual was published in 1964, and included the chronograph results of a bunch of factory loads fired in more typical barrel lengths than the industry-standard 26-inch of those days. The Winchester 100-grain factory load got 2893 fps from the 22-inch barrel of a Winchester 88 lever-action, which is right in the range I'd expect from a 4-inch shorter barrel.

Factory Ammo???

Never heard of it...Lol

Trystan