So I broke out the chrono for the 1st time today...

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BsChoy

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Boy are my rounds slow!! My Garand shooting 150's over 47.0 of 4064 in HXP brass average 2550 fps....my 223 with 25.8 varget under a 60 grain vmax 2950!! And my swede M38 1941 Husky with 47.0 or Reloder 22 under a 140 hornady...2570 fps average (although with a great low SD). What an eye opener!
 
is it 30 below up there or something?

did you SBR that garand? :)
 
A chrono is a very interesting tool to verify just exactly where your reload velocities are. After going without one for many years, it's amazing how much of an eye opener my chrono has been for me. Just make sure you don't accidentally shoot it:eek:, I did this once. Not only is it good for rifles, but I use it for my bow also.

One thing my chrono has done is made me loose faith in Varget when I reload for my .30-06 and .223. I never could get the claimed velocities with Varget, so I switched to RL15 for both.
 
Its amazing how close some loads are to the book velocities, and how far off others are:D Yeah, don't kill the chrony!!:cuss:
 
In the 30-06 I use HXP greek brass....223 is new winny as is the 6.5x55 brass...wow low it was about 45 this morning in upstate ny
 
Do you guys use the wooden dowel trick?
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Whenever possible. I hardly ever use steel rods except on the brightest sunny and clear days.

Wax paper taped between diffusers for when bright sun is at a bad angle helps a lot, too.
 
Is there a simple explanation for how/what a wooden dowel helps? I borrowed a friend's chrono (he's never used it for anything except paintball and airsoft) and had a very tough time getting it to work the way the directions said it would. For me, the chrono worked fine with .22LR on a sunny day, but anything heavier like 38, 9mm and above caused it to return error upon error. I could tell the muzzle blast was affecting it b/c it would also error code when the guy in the next lane shot off his AR. I tried taping up some cardboard screens around it and got it to return a reading on some weak 9mm rounds, but still nothing but errors on my 45 and 357, never mind my rifle rounds.

What do I need to do with wooden dowels to make this thing work better? I was using the little metal rods to hold up the diffuser screens (I also tried it without these rods and screens in place but got the same lack of results).
 
Replace the steel rods with wooden dowels. I use bamboo skewers with a couple turns of tape to thicken the ends up. This way, if you nick one, it doesn't destroy the whole chrono, it just snaps the wooden rod.

The wooden rods won't help if you center punch the brains of it though.
 
XS,

When that happens, you may be too close. Give about 10'-12' between the muzzle and the chrono and see if you get valid readings.

Koski
 
More on the rods and diffusers.... since there was a question from the audience. :)

Really bright sun directed into the sensors can cause the bullet's shadow to be missed, resulting in errors. So you use the diffusers. When used corrrectly, the diffusers block the direct sunlight into the sensors. Using diffusers usually requires that the steel rods that came with the chrono be used for their strength and rigidity.

See in this pic why I had so much trouble the day I did a chrono tests? I had to tilt the whole unit over so far that it was difficult to shoot thru the rods without worrying that I'd hit something.

Chronograph-tests-in-the-pi.jpg

Cloudy/overcast days oftentimes don't require using the diffusers at all. That's when I use wooden dowels. The unit can remain perfectly upright and the dowels give you a nice "V" to sight and shoot thru. Like Koski said, if you hit a skewer the shock wave won't damage the sensor or brain.

Now, sometimes there are times that I chrono test when the sun is at a bad angle. Either it's too low (like in the picture), or the direction I have to shoot toward my backstop doesn't let the diffusers shade the sensors. That's when I sometimes tape wax paper to the wooden dowels to create shade as well as form a canopy so the bullets shadow will register without getting errors.

Be careful if it's windy!
 
Early morning right after sunrise for an hour or so and afternoons about an hour or so before the sun sets are the best times in my experience for using a chrony. Overcast days are great too anytime. During these times no diffuser is required.

The diffusers only get broke out if the chrony is being used in the times between those noted above and - well - maybe I've been lucky - but I've never really had a problem then either.

The only time I ever got errors with or without a diffuser is when I placed the chrony too close to the gun; you can only measure the velocity at 10' or more. 10' out is what the book says and that's where it goes. You can't measure actual velocity at the muzzle with a standard chrony because the smoke and the flash disturb the sensor's ability to start/stop based on the shadow created by the bullet passing over the sensors.

I've found over the years that regardless of what I think the manual is usually right and I'm not. :D

Soooo...
RTFM!
 
Ah, thanks for the info. I may be out of luck then with this chrono (Shooter's Master Gamma) - I had it somewhere like 10' out in front of me when I had these problems, at least, I had it stretched out as far in front of me as the phone cord thingy would allow. I guess perhaps I could set it up even further away but then the remote control would be in front of the firing line and we'd have to go cold for me to go out and use it :(

I like the idea (cheap!) of wax paper shade canopy. The only time I got any results at all even with 9mm was when I taped up some cardboard around it. Glad I wasn't the guy who shelled out $100 or $200 for this chrony! Now I'm afraid to buy any kind in case the same problems pop up.
 
BsChoy,

You need to add about another 1.5 - 2.0 grains of 4064 for your Garand load.

Guys,

Regarding the Chrony and sunlight:

The absolutely worst time to be using one is at about 11am on a sunny day. The diffusers do nothing, since they are directly overhead and the sunlight is not. You will get erroneous high readings. What I do is tape something, such as a large paper target, between the two diffusers so that it hangs over the sides and blocks the direct sunlight from shining on the sensors.

Don
 
USSR, I have tried up to 48.0 grains of 4064 but the groups opened up on me every time...do you think they will settle down if I go higher? Its been this way with varget too....
 
USSR, I have tried up to 48.0 grains of 4064 but the groups opened up on me every time...do you think they will settle down if I go higher? Its been this way with varget too....
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Don't know, but it won't hurt to try. I've used between 49.0 and 50.0gr of IMR4895 with 144gr FMJBT's in LC brass, and although your bullets are a few grains heavier, your powder is also a little slower. 2550fps is a bit slow for a 150gr bullet.

Don
 
Chronographs sure are eye openers. I have a Oehler 35P.

Lots of guys have asked me over the past 18 years or so if they can run their ammo thru it. I always say yes.

However, most of them went away very angry, sometimes even telling me my machine was screwed up. Nobody wants to believe that their pet rifle load, whether store bought or hand rolled, is 200-300 feet per second slower than they were led to believe.

In my experience, only my .300 Weatherby rifle makes "book" velocities routinely. In handguns, my Kimbers in .45 ACP come awfully close, usually +/- 25 fps. The four inch ProCarry is usually about 50 fps slower than the five inch Eclipse.

I have had two instances where I was way over book value. The first time was with .44 magnum. The book said that I should have gotten 1200 fps when, in fact, I got 1700. Scared me so bad I took the remaining loads apart and checked them all. I found nothing wrong, but I did not use that load again.

The second instance was with my Model 70 Featherweight in .280 Remington (7mm Express). With 160 grain Nosler Partitions I was getting 2880fps. The absolute best deer killing load that I have ever developed. I was afraid to duplicate it again, though.

Just last week I discovered something that I thought was a bit odd. I have always used 59 grains of IMR 4350 under a Sierra 150 grain bullet for my 30'06 deer hunting loads. They usually clocked at 2800+/- fps. The loads that I rolled last week clocked at 2950 fps. Did something change with IMR 4350?
 
.44 magnum. The book said that I should have gotten 1200 fps when, in fact, I got 1700
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Sheesh! Couldn't feel the difference in overall recoil when you fired them? No overpressure signs on the cases? What weight was the bullet? Since you were looking for 1200fps, I'm assuming it was fairly heavy...

Factory loaded Hornady 32g VMax's out of my .204 shoot fast, around 4150fps, but are badly inaccurate. A 39g Sierra over W748 loaded to about 3900fps is _way_ more accurate for me. Speed != Accuracy. Accuracy is the name of the game, for me. Delivering a few more foot-pounds of energy doesn't make near as much difference to me as putting the slug where I wanted it to go.
 
Chronographs sure are eye openers.
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That, they are. Varying chamber dimensions, varying barrel quality, to say nothing of the different reloading components and practices make for some eye-opening results. Just to give you an example: I have a Winchester Match Rifle with a 26" barrel in .30-06, and a custom built Winchester Tactical rifle in .30-06 with a 26" Krieger barrel. With the same exact load, one does 2875fps, while the other does 2950fps.

Don
 
So what are you guys getting for velocity for real out of a 22 inch barrel and 60 grain bullets?? Quickload was saying around 3100 fps with 60 vmax over 25.5 or so of RE15...about the same for a little less Varget...I ain't seeing it.
 
Chronograph is damaged

I was making speed loads for my T/C G2 14" barreled .357 Rem Max. 158gr copperplated cast bullets din´t like 2290 fps speed. They shall to braek down. Chips was hitting to the chonograph. :cuss:
 
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