Suspect Shooting Chrony readings

[Arktikos]

Hi all, I am relatively new at handloading and for the last few years I have just been loading mildish loads for my 45 Colts (Ruger BH and 1894) and 1895 45/70 using Unique, TiteGroup and Trail Boss in the 45 Colt and some 5744 in the 45-70 using commercial cast bullets from Lasercast and Dardas. I was given a new Shooting Chrony when I started reloading and have tried to make use of it right from day one without what I consider good results. Lately I have wanted to step it up a notch with both my 45 Colts and 1895 for use as bear defense rounds. I have gas checked 325 gr Beartooth for the 45 Colt and 525 piledrivers for the 1895. Beartooth bullets gave specific load data for the 525 gr Piledrivers and RL 7 listing a max load of 44.3gr which they listed at 1648fps and safe for Marlin leverguns. For the 525gr PD's I was just looking for something in the range of 1400 to 1500fps so I started out with 38gr, same brass, CCI 200's (they used Winchester) and the first reading of 1729fps made me a wee bit nervous! The case extracted normally, and the primer wasn't flattened like the pictures I have seen of overloaded hand loaded cases. The recoil wasn't that bad either nor did the lever pop open so I decided to fire another, 1792! That was enough for me, as I figure either I am well over max pressure or the Chrony is way off. The rest of the first 20 rounds are now tucked away in a drawer. Since that time I have loaded some of the 325gr in my 45 Colt, following a load I went with from Hodgdon site. They listed using Lil'Gun a starting load of 17gr and a max of 20.5 at 29,700 CUP, Win brass and non-magnum primers and a 325gr GC RNFP. I used new Starline brass and CCI 300's and chose a start load of 17gr and out of my 5.5" Blackhawk the readings were pretty consistent between 1133 to 1141 fps, a little faster than I was expecting but not out of the ballpark.. Then I loaded up more of the same exact rounds in my 20" barrel Marlin 1894 and the readings shot way up past what I ever expected a 325 gr cast out of a 20" barreled 45 Colt would safely be capable of achieving. I only fired 2, but the reads were 1906 and 1949 fps. This just seems way too hot considering the same rounds in the BH were 700 fps slower. When I got the hot readings with the 45/70 I shot some 22LR over the chrony with my Henry rifle as a test, using Federal Bulk and the readings were consistent at 1200 and change, just what the box said it should be .

I ran a similar thread about this over on Marlin Owners and the general consensus was the chronograph was not suspect, so in other words my hand loads must be. I even ran my old standby load of 27gr of 5744 with lasercast 405's and got 1868fps, what I consider way too warm of a reading for that charge and powder. According to Accurate's web site data which shows a start load for these Lasercast 405's of 30.6gr at 1468fps! How could my loads 3gr less than their start load be getting me 400 fps more?? And to think I have shot hundreds of this load through my Marlin without any apparent problems!
Any thoughts?

[Ranch Dog]

Honestly is sounds to me like the Shooting Chrony might be suspect with the rifle loads. Which model do you have specifically and what distance is the muzzle from the screens.

[Arktikos]

It is the Alpha model. I have been setting it up at 20 ft from the bench so as to try to rule out muzzle blast .. There have been other strange reads that go the other way. I was chronographing some Trail Boss loads, 14gr was around 1050 fps and 13.5gr was way slower, something like 750fps, all on the same day with the same 350gr cast. This unit has been my sole chronograph experience and part of me wonders if lighting here with the usual cloud cover, or maybe even the steep mts blocking some of the light could effecting it, but when I shoot something like the 22lr with a known velocity on the same day it came out correct.
I think that I am going to buy a different one and hope it wasn't the lighting after all..

Sent from my Milestone X2 using Tapatalk 2

[Ranch Dog]

I'm sure you have googled "shooting chrony problems", I just did, and see hundreds of listings on various forums that mirror your experience. I have a F1 that I bought as a inexpensive secondary unit for actual BC testing. I use this unit to establish the actual BC of the bullet against the calculated BC by sitting this unit in front of the target at 200 yards. I have yet to hit it but I wanted a cheap unit in case I did. For actual BC, a calculation is made between the chronograph at the "muzzle and the unit downrange.

I started by shooting it in line with my CED and immediate experienced the very same problems you and others have reported. I found the unit extremely sensitive to light and position. The position problems seem to be related to the screens being at anything less than a right angle to each other or the bullets path being anything other than a right angle to each screen. I have found it very, very sensitive to the angle issue over the light issue. I does fine once it is truly squared up.

I have used the CED Chronograph since it was available and think it is a premium unit at a reasonable price. I started with the M1 many moons ago and used it till I wore it out and CED ran out of parts and then upgraded to the M2.

[Arktikos]

Well about the alignment issue, that really makes sense to me, and so far I probably haven't paid that close enough attention. Maybe it is the old broken watch being right twice in a day thing but it does seem to produce believable, maybe even accurate reads at 1050 through 1250 fps and anything above or below that speed range really gets skewed too fast or too slow. I have nothing to confirm this with since I have nothing but what my expectations for the particular load are.
This has given me an idea for setup to really get it aligned true without having to eyeball it so much. My thought is to bring out my torpedo level that has a laser built in and set it up on the bench rest and point it at the target. Then set up the chrony on the tripod and align it to the beam.

That CED looks like a quality product and for a pretty reasonable price. While it should be easy to set up my Shooting Chrony to be aligned using the laser beam, the weather here in Juneau is out of my hands. Some days the overcast is so thick we almost need headlights on at noon. Other times, especially in the winter if it is clear the sun will be low enough in the sky to give problems. If I can't get this sorted out I think I will start saving for the CED. Your ideas are much appreciated!

[Quinc]

I have the chrony master and it is extremly sensitive to light. You might try during different times of the day and use the difusers. Might even try painting the bullets black with a sharpie.

[Arktikos]

I have the chrony master and it is extremly sensitive to light. You might try during different times of the day and use the difusers. Might even try painting the bullets black with a sharpie.

I have had this chronograph for a few years but haven't been using it much due to the inconsistencies in the reads. For the past year I have just been loading plinker loads and trying for accuracy and haven't really needed to see my velocity. Now with these big bear stopper 525 piledrivers I am wanting to step it up a little without going over pressure and so am interested in the chrony once again. I guess I would rather be working up loads than troubleshooting the chronograph, but will give it a few more tries before giving up on it. It sure sounds like it is the sensitivity to light and alignment that is causing my troubles rather than the chrony itself..

[Quinc]

I use my chrony for my .223 loads and would say its accurate. Velocities are in the 2500-3000 range depending on bullet weight. 55gr -80gr.

[deaddoc4444]

Been shooting over a Chrony for years with GOOD results.
NOW , the results are good, ONLY when I do my part also . EVERY TIME I set up the Chrony I test it with KNOWN factory loads . Usually 30 WCF ammo.
I have found that the Chrony's are EXTREMELY sensitive to light and position . IF I get an "off the wall reading " after initial set up with the 30/30 ammo I adjust the Chrony in position and toward the light source or screen set up, till it appears its reading correctly , OR I don't use it . USUALLY over the years it has been extremely accurate IF SET UP RIGHT >
I have a new one I just bought so MAYBE the newer models are far less sensitive than the old, I will know soon enough . The old one worked fine for years but now the hole that measures .458 through it , renders it obsolete OOPS

[Arktikos]

Been shooting over a Chrony for years with GOOD results.
NOW , the results are good, ONLY when I do my part also . EVERY TIME I set up the Chrony I test it with KNOWN factory loads . Usually 30 WCF ammo.
I have found that the Chrony's are EXTREMELY sensitive to light and position . IF I get an "off the wall reading " after initial set up with the 30/30 ammo I adjust the Chrony in position and toward the light source or screen set up, till it appears its reading correctly , OR I don't use it . USUALLY over the years it has been extremely accurate IF SET UP RIGHT >
I have a new one I just bought so MAYBE the newer models are far less sensitive than the old, I will know soon enough . The old one worked fine for years but now the hole that measures .458 through it , renders it obsolete OOPS

Mine remains a mystery. Each and every time I have shot my 22lr over it I get good consistent and accurate reads. Then I'll fire my 45-70 or 45 Colt over it and they read consistently off, usually too high, (but sometimes too low with Trail Boss) and I am not talking about the occasional odd read anomaly, but every load in the string with a fairly tight spread. My pet 405gr lasercast with 27gr of 5744 reads WAY scary too hot, something like 1850fps, which with this speed of powder being faster than what I would ever consider using for full tilt loads It probably should have done damage to my gun after just a few rounds (I have shot hundreds of these). I believe (I'm going by memory here) Accurate lists something like 34gr with the 405 Lasercast and 300 fps slower than what my 27gr loads read. The 525gr Beartooth, backed off something like 12% of BT's RL7 published max went 1750 fps! That is TOO fast for a 525gr pill out of an 1895 GG! Then right after that I shot the 22lr, and it read 1250fps, 15 rounds hardly any variation to speak of. The last time I tried the chronograph I remember I was getting 1900+ fps out my 45 Colt Marlin with 325gr Beartooth and 17gr of Lil'Gun. Then something new started happening, the reading would disappear after about 10 seconds and say "error" and would need to be shut down and restarted to clear it. I have used a laser beam for setting up to help make certain I was in perfect alignment, placed the chrony out to 25 feet to make certain muzzle blast wasn't affecting it. Had high overcast, and good light without shadow. And it isn't just my warmer rounds that read wrong. My trail boss loads will often times read consistently just 450 fps, which I know for certain is just way too slow. For now I have suspended any load development and just loading target loads with data I know to be well in the safe zone until I get a new chronograph. I have had some expenses incurred lately so my gun budget has taken a hit for the rest of the year so this will have to resolve itself at a future date. Thanks for your suggestions!