Chronograph

[Larry Gibson]

No, you don't need a chronograph to reload.  However, if you reload a lot and are concerned about accuracy then a chronograph is a very good tool.  It not only tells you that actual velocity of a load but also, and more importantly, the consistancy of the load.  The consistancy is measured via the extreme spread and the standard deviation.  Shooting for group at 100 yards can be very misleading as to accuracy if you shoot at farther ranges.  Without the chronograph the only way to tell if a load is accurate is to shoot it at the farthest range you will shoot it at.  With the actual velocity and a few other measurements of your rifle you can also make very accurate use of numerous ballistic computor programs.  Without a chronograph and knowing the actual velocity the use of those programs is just a guess. 

I own 3 chronographs (Oehlers including a M43) and do not consider any of them a pain to set up.  The really nice thing is that I not only shoot for groups like those without a chronograph but I get all the factual data on what the load is doing in my rifle.  The others who are just shooting for groups are just guessing at what theirs is doing.  Each of us must make a chioce on how much information we need with our shooting. 

Larry Gibson

[Autorim]

I appreciate having accurate info that the chrono gives me. I do not use the chrono when I am shooting groups. I test various loads for accuracy then chrono. When I use the chrono that's all I do that session. I set up and usually shoot 10 or 20 rounds of each load I am testing and I may test 10 or so loads at each chrono session. Usually I am testing both rifles and handguns. It's also useful for testing consistency of rimfire ammo.

[300HH]

When I first got my chronograph I thought now I'm really in business wrong!!!!!! yes it measured speed which help to sort of know where the bullet is going at distance but to my surprise my 7mag was really slow with said bullet and even bigger surprise my 300HH was way faster. But as it has been said before not one harvested animal complained about the speed. So yes useful but critical for me anyway.

[Dave in WV]

One thing a chrongraph is great for is to check your load's speed when you change to a different lot # of powder. My son bought some H4350 last year and loaded some ammo for hunting. His 30-06 ammo showed a sign of low pressure. When he got back to his home in NC he clocked them and had to load 1.5gr more powder to get the same speed. Once he did he got his accuracy back. BTW, his original load wasn't max nor is the current load.

[Oldshooter]

Wow! thats a big variance, Who da thunk there would be so much difference in lots of powder?

[Sweetwater]

Guess I've lived a sheltered life. Dad's loads were developed in the late 50's, without a thought of a chronograph, only that of tiny groups and devestating terminal ballistics. Many pounds of powder later, we are still using those same loads with the same tiny groups and devestating terminal ballistics. I've read a bunch about lot to lot variances in powder, we've just never seen it. Even my Alliant Blue Dot is as even as the day is long. My chronograph can't help, as we don't know what we started with, only what we have now, and what we have now is just fine.

Regards,
Sweetwater

[john keyes]

I just ordered the shooting chrony F1 for seventy bucks from Midway.

I have an identical load that shoots two different same weight bullets 5" difference at 100 yds.

Been scratching my head over that one for years....don't know if the one that is higher is slower and coming out of the barrel later (higher up) or if it is faster.

I personally have been reloading for about twenty years. 

should be interesting

[Sweetwater]

I just ordered the shooting chrony F1 for seventy bucks from Midway.

I have an identical load that shoots two different same weight bullets 5" difference at 100 yds.

Been scratching my head over that one for years....don't know if the one that is higher is slower and coming out of the barrel later (higher up) or if it is faster.

I personally have been reloading for about twenty years. 

should be interesting

For my buck, that F-1 is the best Chrony in the bunch, and we have 3 different ones.

The phenomena of same weight bullets hitting very different downrange with same powder charge has plagued us for years. My take on it is this: Though they are the same weight, they have a bit different profile yielding a bit different bearing surface, resulting in a slightly different "spin". Results downrange become slightly different, or not so slight, depending on the variance in the spin. Consequently, when we get different bullets hitting the target similarly, it is that they have the same spin. In my 8x57, 150gr and 175gr Sierras hit the same place and 200gr Noslers hit a bit over an inch low, all at 100 yards. Not exactly an earth shattering difference. 150gr Speers are several inches out and 150gr Hornadys are somewhere between. I can stand correction on this, but this is as how I understand it, though possibly misinformed.....

Regards,
Sweetwater

[roper]

I reloaded almost 20yrs without one and the only time I use one now is to check velocity on an accurate load I worked up. 
For me it's a distraction trying to work up loads and chrongraphing at the same time.  When I comment about the 5r barrels in the gunsmithing forum using a chronograph helps established one of the advantage to using that type barrel.

About the last 15/16yrs I chrongraph the same time I'll start a 8AM finish latest be 9:30AM if i need more time I'll come back the next day.  I may have 2/4 rifle to do and I like having a cold barrel to start with and since I load at the range I can fine tune something if needed.

Last year took me afew days but I ran a primer test tried 8 different ones with same load with 150gr bullets then switch bullets to 140gr for my 270WSM be surprised what you find out.

Chronograph is a tool and you can look at some of the drop table in back of the reloading manual compare that to your rifle and come up with a good idea on your velocity.

[john keyes]

I just got mine last week or so, too busy hunting to get to the range (which I can't wait to do).  I finally set it up and tried it with my 22 benjamin pump

3 pumps

5 pumps


from what I understand if it is sunny and no clouds, use the shades.  A buddy of mine who is a hoarder later dropped off a killer tripod for me. As suggested I am going to replace the metal skyscreen rods with wood so if they get shot they will break and not mess up the whole chrono.  Also I am going to put tape across the three piece skyscreens to make them one piece. 

[quickdtoo]

Be sure to use clear tape, or the chrony won't work I don't think, it won't be able "see" the bullet against the dark background, I used super glue to make the 3-pc screens one piece, they won't fit in the box, but I never put em in there anyway, it was too much hassle! 

Tim

[Sweetwater]

After hitting the screens the first time, we quit using skyscreens and put drinking straws over 4d finish nails. These act as guides to aid in aiming as "the book" says how high above the photocells the shot needs to be. We sometimes shoot in a light rain, and placed a beach umbrella over the Chrony. Makes a huge skyscreen!!
According to the book, the skyscreens create a "shadow" so the photocell picks up the bullet quicker, easier, so not sure that your tape idea needs to be clear tape. Just a thought...

That F-1 is a dandy!! It's the same unit I shot twice - on different days. The first time, it took out the skyscreens (see above). The second time, I was using my Marlin rifle 41Mag and it was all about the angle of the sights vs angle of barrel vs target vs skyscreens. The geometry got too tight and I was probably getting more tired than I thought. It was shot #49 of 50. Missed the front panel, severed the ribbon wire, and punched a hole in the back panel. Tapped the hole back together, soldered the ribbon wire, and the next shot didn't change the group average or extreme spread - so we guessed it to be ok for our purposes. One tough unit! After that episode, I read the paragraph in the book where it states, "do not shoot off-hand; use a bench with the Chrony!" To that I say, +1!

Regards,
Sweetwater

[quickdtoo]

According to the book, the skyscreens create a "shadow" so the photocell picks up the bullet quicker, easier, so not sure that your tape idea needs to be clear tape. Just a thought...

You can't see a shadow in the shade, that's why the diffusers (skyscreens) are translucent allowing light to pass thru to create a light background so the bullet can be seen against it, that's why the screens are required on a clear day and not on a cloudy day, but I usually use them all the time regardless since it gives a consistent light background and 100% detection on my F-1 Master. 

Tim

http://www.shootingchrony.com/manual_F1M1.htm#how%20it%20works
The Chrony has two eyes (or photo sensors) located in each of the black plastic housings at the front and back of the main unit. They are located under the Twin Lenses at the bottom of these housings and they detect the passage of a bullet over them by sensing the change in the amount of light. (They detect a momentary change in light intensity.)


http://www.shootingchrony.com/manual_F1M1.htm#sos
5. The Shooting Area. Every Shooting Chrony and Master Chrony comes equipped with an adjustable-size, triangular shooting area (actually an upside down trapezium) from 8"X8" to 14.5"X14.5" (Fig. 2). All Chronys come equipped with four 9.25" wire rods as well as four 6.5" wire rods with brass connectors attached. The 9.25" wire rods are to be inserted at an angle into the outer holes visible on the black plastic boxes of the unit. On bright, sunny (blue sky) days, install the white plastic diffusers on top of the wire rods (to simulate clouds). The photo-sensors are pointed at the diffusers, which create a white background (clouds or diffusers). On cloudy days, use wire rods for alignment, but without the diffusers.

[Sweetwater]

Thanks, Quick!

Regards,
Sweetwater

[drdougrx]

Yeah Sweet!!   My 223 has harvested a few screens on my Oehler once or twice.....

[wncchester]

"What is the purpose of a chronograph other than to know the speed ..."

That's it.  What you do with the data goes passed the intrument itself.

[Dand]

Good comment huntducks.  I have to agree but I still like having my old Ohler for checking loads now and then.  The most recent use was developing hunting loads in my 41 mag with 250-265 bullets where there is little loading and performance data. I've found it interesting to compare the same load in different guns with different barrel lengths too. Back when there were no kids and much more time I used mine quite a bit - I agree with a lot of what has been posted here.

[john keyes]

got my $5 tripod and hooked up my Chrony




I have to hand it to Chrony for putting a weld nut here, greatly simplifies attaching



the first bolt I got out of my used fastener bin fit, looks like a Ford oil pan bolt maybe



in addition to the adjustable legs, this tripod has a crank for up and down, nice feature





hunting season is OVER (well, at least deer anyway...kids are out of school for MLK but manana I'm hittin the range and can't wait

[Sweetwater]

Hey John Keyes- Nice Setup and pics!! Looks like mine, though the ribbon wire as it crosses over the "middle wall" was cut nicely by a 41Mag bullet from my Marlin. Same bullet put a 50caliber hole in the "back wall" of the Chrony, but missed the photocell. A touch of solder and some judicious hammering and we were back in business. You can bet I use a shooting bench - now. LOL

Regards,
Sweetwater