Why own a chronograph?

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • No preaching
  • Evaluate an old airgun
  • Test pellets
  • Evaluate a tuneup
  • For detailed tuning and product development
  • What it isn’t

Today is my cataract surgery. I don’t know how well I will be able to function online for the next several days, so will you veteran readers please help the new guys? I know you always do, but I’m just telling you what’s happening.

If you have read this blog for very long you can answer the title question for yourself, because I write about chronographs all the time. I use them for big things like testing the health of a new acquisition (the Sharp Ace Target and the Sheridan Supergrade), and things more subtle (testing the Air Arms Galahad).

No preaching

I used to preach about when to use a chrono and when not to, but I’m not going to do that today. Use it whenever you like and for whatever reason suits you.

I was disturbed by the airgunners who buy an airgun and then chrono it to find out whether it is a “good” gun or not. Yes, that does happen, and a lot more frequently than you might imagine. So what? If that pleases them it certainly doesn’t hurt me. No preaching today!

But that’s just one reason to own a chronograph. What are the others?

Evaluate an old airgun

When you acquire an old airgun, you can tell the state of its health with a chronograph. You have read where I did this with several old airguns, but how about one as an example? Do you remember back in 2016 I tested my Sheridan Blue Streak for you? I started the test as a memorial to my late wife, Edith, but when I got to test the velocity I saw how tired that old rifle was. With Crosman .20 caliber Premier pellets the best I could get was 486 f.p.s. from 7 pumps. The gun was 38 years old at the time and it was clear the seals had hardened with age. If anyone asks you how long a multi-pump pneumatic will last between rebuilds, the answer is 38 years.

I had the rifle rebuilt by Jeff Cloud, who I work with for the Texas Airgun Show. Jeff and I were talking as the 2016 show was getting close and I learned that he had taken up rebuilding older Blue Streaks, so I gave him my rifle to overhaul. When I got it back it would shoot the same Premier pellets at 582 f.p.s. on 8 pumps and 609 f.p.s. on 9 pumps. That’s a gain of more than 100 f.p.s. from the overhaul. And it took a chronograph to show it. I certainly would never have known all of that without one.

Test pellets

I would not rely on just a chronograph to test pellets, but chrono results can be useful. Think back to the tests you’re read where I got a 300 f.p.s. velocity spread with a particular pellet. That would be a pretty good indicator of a pellet that isn’t going to do well.

Evaluate a tuneup

You want to know what a tuneup has done for your airgun. I do this a lot. Sometimes it is an entire tuneup, but other times it is something small, like the replacement of a breech seal in a breakbarrel. I have probably done over a hundred such reports for this blog over the past 12 years, but the one I liked best was the 10-parter I did for the RWS 45, whose piston I buttoned. If you recall, that rifle was tuned for Johnny Hill, the owner of Tin Starr Bullets. He liked the rifle a lot, but I told him I thought I could make it shoot a lot quieter, and that entire series documented me doing that.

The part I liked best about that series was the fact that I wasn’t satisfied with the results of the tune and I disassembled the rifle to lube it one more time afterward. It was still more powerful than it had been when I got it, plus it shot as smooth as any air rifle I’ve tested. I was proud of my work, which is a job well done. And a chronograph told me what my work had accomplished.

A second favorite of mine was that tired old BSA Super Meteor Mark IV  I had to completely rebuild. That rifle put me through the wringer, but my chronograph kept track of where things were at all times.

The point is, without a chronograph I would never have known where I was starting from or where I arrived when it was over. But there is one more thing to say about this. A chronograph is just one tool you use to evaluate an airgun. If the gun isn’t shooting smooth or accurately when you are finished I don’t care what the numbers say; you are not finished!

For detailed tuning and product development

This one is for tinkerers and for the airgun companies. A chronograph can tell you when things work and, more importantly, when they don’t. I have a couple stories here. The first comes from a conversation I had with Ben Taylor — the Ben in Theoben — at the SHOT Show many years ago. We were discussing his Theoben Eliminator/Beeman Crow Magnum. He told me one of the worst decisions he ever made was to put a valve on his guns so users could adjust the air pressure in the gas spring. He said so many guys just pumped it up until they could barely cock the rifle, which is somewhere around 75-100 lbs. of effort. They thought they were getting maximum power then, but Taylor told me what they were doing was playing with a slide hammer and beating their airgun apart. After that Davis Schwesinger of Air Rifle Specialists sent me a piston seal that he removed from an Eliminator someone had destroyed that way.

Burned piston seal
This piston seal was vaporized by over-pressurizing the gas spring of a Theoben rifle. There is a deep hole in the seal where it was vaporized over time.

I also have a happy story for this one. In 2005 I had approached the Crosman Corporation about building a unique new PCP that only had to be filled to 2000 psi. When I met with them in early 2006 their head engineer, Ed Schultz, told me he had initially thought I was crazy when I made my proposal. So he prototyped a Crosman 2260 CO2 rifle  (they are called Sheridans now) to see what would happen. To his surprise the rifle was shooting nearly 900 f.p.s, without any modifications to the CO2 valve. When he adjusted the valve he got it up to 1,000 f.p.s. with Crosman Premier lite pellets. He did this in three days, once my airplane reservations were made for the meeting.

If you have ever watched an infant soil his diapers to his great relief you have an image of the faces I confronted in East Bloomfield on that historic day when the Benjamin Discovery was born! They were beside themselves with joy and forced themselves not to smile too much. Ed (I know he reads this blog every day), I will never forget your expression! Obviously a chronograph was involved.

What it isn’t

A chronograph isn’t a substitute for joy. Joy comes from shooting an airgun that’s right in all ways. What the chronograph tells you is where that is, in terms of velocity. If you are hitting the target every time, stop worrying about the numbers. Annie Oakley never knew how fast her bullets were going, but that didn’t seem to matter.

55 thoughts on “Why own a chronograph?

  1. B.B.,

    I pray that your recuperation from the cataract surgery goes well and uneventful.

    I will always remember that you also call the chronograph as deliar. It puts paid to claims of high velocity especially if you tuning was only done by ear. The proliferation of cheap yet accurate chronographs have also opened the doors for backyard experimenters in the world of airguns to record and present their findings in a reliable manner.

    Siraniko



  2. B.B
    Wish you a very successful surgery and fast recovery Sir. My prayers are for you. I recently bought a Prochrono Pal & now know exactly how my springers(125 & Striker) are doing. Also got the power curve of my friends BT 65 SB Elite. This is an indispensable tool I would say! God bless.
    Errol


  3. BB,

    I pray that all goes well with you today.

    After all these years I have finally purchased a chronograph and I have not had the time or the weather to use it. Wouldn’t ya know it.


  4. A good reminder. After the TX200, a chronograph was the second thing I bought. I did Vortek tunes (2) and even spring chops and adding washers here and there. The chrony told me where I was at. They are almost a must to find the power curve on a PCP.

    But, as GF1 said,….. just shoot it. While a larger fps spread may not look good on paper,… the group may be no bigger over quite a range. I like to quantify tunes, adjustments, etc. and a chrony will give you that. Plus,… it is a good “health check” if you have new and down the road numbers to compare.

    A trigger gauge is nice too. I got a nice Lyman digital. While not a must,… it allows you to adjust triggers into a common range over several airguns. You will find that “I am a 1# to a 1 1/2# guy” for example. You know what direction to go because you can quantify adjustments. The Maximus would be an example. Stock 6#. Adjusted with added screws and lubed 3#. With the safety removed (less spring tension) less than 1#. The plan is to bend the spring lightly to mimic the no safety and see if I can get it down to 1-1 1/2#. The trigger gauge will leave no doubt as to where I stand.

    Good Day all,……. Chris



    • Chris U
      A chrony is a very valuable tool. I definitely use mine to check my guns health and performance with.

      But like you mentioned. I don’t get hung up on my chrony readings with spreads and all. I note what my gun does with the chrony. But also I note what my gun does on paper. If the gun is a good shooter and is grouping good then I’m happy. But if performance changes I sure use my chrony.


  5. B.B.

    Wishing you nothing but the best. I will keep my fingers crossed for you today!

    Yes I bought an Alpha Crony. First time I set it up, it worked fine. Now when I set it up it just blinks [ ] at me……
    Has anybody tried the Combro CB-625? This is the one that you attach to the end of your barrel. I understand that they may work better with PCP’s than break barrels?

    Keeping my fingers crossed,

    -Y



    • Yogi,

      No error messages? A 500W Halogen shined at a white ceiling above the chrony with no sun screens on it is a near no mistake set up. Indoors to eliminate the outdoor variables.


      • Thanks Chris,

        500W Halogen, YIKES! I think the strong bulbs I have are a 35 W GU2 and a 17.5 watt outdoor LED.
        Would one of those 500 Lumen + survival flash lights work? Not on strobe of course, LOL….

        -Yogi


        • Yogi,

          It works. If you search some of B.B.’s article on chronys, that is what he uses. Fluorescent lights in the area are bad news too. Turn them off. They “flash” super fast. You can’t see, but the chrony can pick that up.

          The 500W was 13$ at a big box home improvement store. They get hot! Keep us posted if you try it. When I first got mine,…. I was ready to shoot,.. IT!


  6. Cataract surgery works wonders for your sight. Couldn’t believe the difference in seeing after mine was done. In a day or two, you’ll wonder why you waited so long to get it done. I waited quite a while doing the first eye. Did so well, I told my doctor I wanted to do the other eye. He said as soon as you tell me you are ready, we’ll do it. Its a great operation and really does help your eye sight. Gook Luck.


    • Jonah,

      I didn’t wait. Ever since my right retina detached last April my eye has been getting steadily worse. I was hoping for this operation! I now cannot see very well at all, and I’m hoping to go back to where I used to be, which was 20/20.

      I understand I will have to wear reading glasses from now on, but I have been wearing bifocals for 25 years, so that doesn’t bother me. The left eye also needs to have a cataract removed, so after this one heals maybe I can get that one corrected, too.

      The surgery is completely covered, but the eye drops cost me $210 out of pocket. That was a shock!

      B.B.


      • They really rip you off for anything that is Medical. If you are in the hospital, even a box of tissues can be $30.00 or more. They get away with it because of insurance.

        Mike



  7. I have hope that all goes well with your surgery.

    Thank you for writing this blog… it’s the first thing I check in the morning! Your writing has the marks of someone who writes with care every day and has done so for a long time. The content is pretty awesome too!

    I love my chronograph!


  8. BB,

    Wishing the best for you with your surgery . . . .

    I would like to add another great reason to own a chronograph: to determine the BC of the pellets you shoot out of your own gun, at the speed you shoot them.

    While this clearly works best with two chronographs – having one at the muzzle and one down range lets us measure the speeds and thus calculate the BC of each individual pellet – we can do the same thing using one chronograph and the average velocity over a string of shots at two distances.

    The other great benefit from this is that we see how the variation in speed at a given distance is always far higher than the variation at the muzzle, leading to the inescapable conclusion that we have variation in BC – which I believe to be one of the greatest impacts on accuracy. I have found that sorting pellets does lead to a reduction in the variation of BC in pellets as shot.

    Anyways, I hope it all goes well, and thought I would add that one item to your list.


  9. B.B.,
    Praying for your quick recovery. Bought my Alpha Crony ,3 yrs ago and never regretted it. I am more interested in what is happening at the point of impact @ 20-40 yds . Built my own protector to prevent damage from those errant shots on windy days.

    Pete




  10. Hope all goes well for you BB!!

    As kids, we used to test the power of our pellet guns by timing how long the pellet was in the air.

    We would stand on the lake shore and fire with the rifle pointed just off vertical and use a stop watch to time from the shot to when the pellet hit the water.

    Crude, but it did give us an idea as to who had the most powerful rifle – and back then, bragging-rights were important 🙂

    Hank


  11. I have one of the first PACT precision cronos from the olden days that I basically quit using because the lighting outside had to be just right and indoors I had to set up lamps that gave unreliable results. Total pain in the butt. Then I shot a hole in one of the screens lately when I got my first PCP . Really wanted to find the magic “spot” in the power curve that everyone was talkin’ about, so I had to get a new screen. Ended up buying the ones with built in infrared light source and haven’t looked back. If you can afford IR screens and they are available for your cronograph, get them. I can’t remember having an error or missing a shot indoors since I bought them. They simply work, effortlessly. I use mine for a reason outside B.B.’s list; I just want to satisfy my curiosity. I just like seeing the data in case it reveals something to me. Weird,huh?


  12. BB,

    I hope your surgery goes well and you recover quickly. My mother had the same procedure several years ago and is very happy with the results.

    A chronograph is an essential tool for any serious airgunner. I have used mine to diagnose several problems over the years – like my R1 only producing 10 ft lbs due to a worn out mainspring.

    One thing does bother me, though: I have a Shooting Chrony that displays a tenth of FPS for values under 1000 FPS (760.5, for example). Since the manual states the device is accurate to within 1%, that digit past the decimal is essentially a random number and should be ignored (even better: don’t display it!) And yet some people dutifully copy the extra number and post it online. Just a waste of time.

    Paul in Liberty County


  13. Its a vital tool in the UK where there are muzzle energy limits (I must add I have never seen or even heard of the laws being actually enforced without some sort of prior misdeed being involved)
    In conjunction with a quick Google to find other owners typical muzzle energies it can be a good “quick and dirty” method to find if your new rifle (or more typically new to you) has any mechanical problems.
    In conjunction with a weigh scale you can see if you have consistency issues through over lubrication


  14. Everypne,

    I’m back home. The operation was a success. I was awake during the entire operation and saw the new lens when it went in. After that I could see again, normally. I haven’t had good binocular vision since last April

    Gonna take it easy the rest of today.

    B.B.


    • B.B.
      Great news Sir. I thank the Good Lord for giving you back your vision. Was a bit worried for you cos of the retina issue or else it’s a simple operation. I too got a cataract removed from my right eye in April last year which was trauma related & had the same experience. I suffered an injury as a result of playing with homemade guns when I was very young. I neglected it for a long time not knowing it was a cataract & terrified of all surgery. But when it got real bad I was forced to see a surgeon who did a good job & the eye is just slightly below 20/20 so I have to wear glasses for perfect vision. I was a right hand shooter but had to shoot left handed when my right eye got bad. The left eye is 20/20 & now I’ve adapted to left handed shooting. Please use the eye drops exactly as prescribed & don’t strain your eye for a couple weeks and you will be fine. The price of the meds are shocking! I too used US made drops which was much cheaper. Take care.
      Errol






    • BB
      Im glad it all turned out ok. With everyone that prayed for you (including me), how could it not go well? My eye doctor says Ive got the beginnings of cataracts so Im not far behind. Godspeed.


  15. BB
    Great to hear you’re home already. Take good care of that eye now while it heals!!
    I have an old Chrony from the early 90’s. I’ve had to replace the 9 volt battery connector twice and the cardboard shades are just disintegrated and useless but the Chrony still works well without the shade’s. The only thing it doesn’t like is bright sun so it has to be used in the shade. As long as it can see a bright clear or cloudy sky it works well. It does have a few problems with shiny steel BB’s though as about 25% don’t get recorded.
    I don’t use it for much other than to get muzzle velocities to plug into Chairgun so I can get pellet drop tables as most of my shooting is at variable ranges.
    I don’t really care about the MV of any of my BB Action Pistols so never chrony them. All I care about is their accuracy at 10 to 15 yards.
    Once I get a springer broken in I also like to have the MV just to see how it compares to the manufacturers specs. Surprisingly, most of my rifles were still in the same ball park as the specs. The yellow guns as well!!
    As well BB, if the gun seems to be acting up, the chrony is a great diagnostic tool. I used to chrony my guns every few hundred shots or so but have since found that after a pellet count of about 250 a light oil lube is all that’s required to maintain most of my guns up to thousands of shots. I have an AK style B3 side lever maintained that way that I put over 10,000 shots through one summer and which chronys now the same as the day it was born 15 years ago. It has a leather piston seal and every 250 shots got a small drop of oil down the transfer port as well as a drop on the spring. The chrony tells me that I have a great gun there.
    Chronys are definitely usefull but I would rather be shooting than chronying.
    Cheers BB and take care.
    Dave


  16. So glad to hear the operation was successful and you are home again.Will you will be able to shoot irons again when you become completely fit ?
    I just used a chrony this Sunday, and found my gun producing low power, and disassembly showed I had fried out the piston seal. The chrony takes a lot of guesswork out of the equation, and there is no arguing with numbers.
    BB, did you design the discovery?


    • Riki,

      I believe I will be able to shoot with iron sights again.

      I did design the idea for the Discovery. I took the idea to Crosman in a proposal and they contracted with me to help develop the rifle and the sales and support literature.

      I didn’t design the hardware. That was Ed Schultz. I just gave him the performance parameters, like the fill pressure.

      B.B.


  17. I use my Chronograph in my basement. Had much difficulty with it until I found out the sensors are most sensitive to infra red (IR) radiation. After installing IR light sources I have not had a bad reading in two years. After rebuilding a Schimel I use the chronograph data to help sell it.


  18. Hi every one. I am new to posting, but not to reading. A lot of good stuff in here.

    I do have another reason to use a chronograph.
    I recently purchased a Hatsan 125 in .22 cal.(knowing I would be tuning it up), and the first thing I did after cleaning it was to push a pellet through to check the bore. Not Good. The breech was so tight that without a pellet seater I could not get a pellet to clear the breech seal. Once in, it re-sized the pellet and pushed through the breech-block with relative ease. At about 5-1/2″ in, the pellet dropped through the rest of the way with no pressure. Running a pellet through from the muzzle to the breech, pellet goes in with very little force but does need to be pushed all the way through. When it reaches 5-1/2″ from the breech, it gets very tight.
    I tried some penetration tests comparing it to my Ruger AirHawk (5 years old,very accurate and hits hard). After about 20 rounds through each gun, the AirHawk was topping the Hatsan in every way. Even two different 9gr alloy pellets couldn’t break the sound barrier.

    To make a long story longer, Hatsan USA would not say whether or not it was covered under warranty until I could get them some chrony readings. So I bought a Pro Chrono Digital (been wanting one a long time).
    Tests showed about 200 fps lower on 4 different pellet weights than what it should be.
    No more communication from them except an RMA # and a shipping label.
    They should have received it by now, so I waiting to see what they are going to do.


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