Pact 1 Chronograph accuracy

[ptf18]

Purchased a Pact 1 Chronograph maybe 30 years ago. Rarely use it and had to send it back for "accuracy issues" 20 years ago. The few times I have used it over the years it has "worked" if you have it set up correctly, ie lighting, position, weather, etc.

Had it out a few times recently to check some .223 loads out of an AR. For the most part I got readings that "made sense". Yet, while shooting the same load ( shot a variety of different charge weights) on occasion I would get some reports of "odd" velocities with a fired shot. Sometimes the 1st few shots would be "odd" then the remainder of the string would report what I "thought" they should be. The POI of the "odd" shots are in the same "area' as the non-odd shots.

I'm beginning to feel that this Chronograph may have "issues" and I'm wondering if others here have one and what their experiences have been with it. I don't think Pact even services it anymore and parts (sensors) are not available.

Perhaps an "early" X-mas gift is in order.

Thoughts?

 

[jepp2]

Thoughts?

I thought I was the only one shooting over an older chrono. I have a Chrony Gamma Master that has served me well, and I haven't shot it YET.

I have no accuracy issues with mine, but I concur that some shopping is in order for you. So many choices these days.

 

[JimSC]

I have a Pro Chrono which works great but may get myself a Magnetospeed sporter down the road just for the ease of setup. I had a Labradar for about a month but sent it back to Brownells because of various technical problems it developed. Faulty USB socket and bluetooth connection problems to be specific

However here is a confession from a recovering chrono addict who chronoed and kept every test shot fired in a Excell file.

One day I realized that the best groups on paper seemed to directly correlate with the best numbers on the chrono so why bother with the hassle of setting up the chrono. When load developing why not not just go with what the target tells me. I kicked the chrono habit and now just look for the results on paper and chrono five or ten of the best group after I decide on the load so I can get my come ups.

Seriously which would you choose ? A great grouping load on the target but has crappy velocity numbers or a load that has looks like it was fired from a shotgun but had great chrono numbers. Think about it

 

[jr600yd]

I have a Pac chrono....I think......in the garage? Yeah I’ve got one haven’t shot over it in ???? 20 years?

 

[powderbrake]

I use a Labradar, and chrono all my shots. Yes I occasionally get a wierd reading, but don't worry about it. I seldom strive for more velocity once I have found an accurate load

I agree with JimSC, the target tells you the best load.

My use of the chrono is for the average velocity, which I use in my ballistics program for making my sight adjustments for range and windage.

There is no way the average person can certify or calibrate a chronograph, so you live with the results. Comparing one chronograph's results to another chronograph's results is like laying two rulers next to one another, and trying to decide which is more correct. We tend to believe the more expensive one is more correct.

 

[INTJ]

The best use of a chronograph is to know actual velocities and evaluate your loading technique.

If you have a bad group with a tight velocity spread, then most likely that load isn't good in that barrel. If you have a bad group with a bad velocity spread, then you don't know if it's out of tune or sloppy loading.

Also, a chrono allows you to find good long range loads at short range. A great group at 200 yds with a velocity spread of 30 fps will likely not be a great load at long range. A great group at 200 yds with velocity spreads in the teens or single digits probably will be a good long range load.

The the original question, I don't think chronographs give bad readings very much. The issue is usually getting one to read at all. If the timers trigger then the velocity is likely correct. When you think of how a chronograph usually works, this make sense.

As far as I know, there are only two chronographs that give you backup readings, and that is the Oehler 35 and the Lab Radar.

As to accuracy, I once put a Pro-Chrono immediately behind a Oehler 35. While individual shots varied by as much as 20 fps--when corrected for distance, the average of five shots was only 4 fps different between the two chronographs. So if you just need average velocities than any chronograph will work. If you need to be as accurate as possible to evaluate velocity spreads, the get on Oehler 35 or a Lab Radar.