Home Forums Reloading Big Game Rifles ProChromo questions

I got a ProChrono and hope I bought the better one.

I have a question for those who have used this. First off do I find an accurate load that shoots good groups and at least close to book max first? I just loaded for the 6mm Sierra 70gr Match and using the One Book One Caliber it shows H380 power range from
39.6 to 42.0 and accuracy was fair. (probably better powders for this bullet like IMR6064). Do you all first find an accurate load, and perhaps adjust seating to get more accuracy and then shoot over chrono to see what speeds you are getting?
Or do you use the chrono while developing a load?

I shoot at a public range and even if I get there first in the morning it is not long before the crowds get in. Obviously the chrono needs to be level with the rifle (the front of our covered bench gradually slopes away) I think I read somewhere that we should not go past the book Vel for that load so I am guessing this is where we know to stop unless pressure indicators show up etc.

BTW the rifle in question is a eifle I got second hand and I pulled the barrel and see that someone tried to bed this action and definitely needs to be redone. However I got other rifles that are very accurate with a Douglas Premium so I will use those. And at the same time order Devcon and attempt to barrel this rifle with a poor bedding job.

I have a Pro chrono.I find it to be most accurate when shooting in the mornings if I'm shooting north or south.When I shoot to the east on a rising sun, my velocities change quite a bit as the sun rises.The Pro Chrono seems to be a very good chronograph and is a very good tool when working up your loads.

I also have a Pro chrono, I point mine northeast and found the best time to use it is in the morning between nine and eleven. Only issue that I have is that some times I get multiple readings, example, I will shoot five rounds and two of them read the same, I know I am not that lucky and my loads are not that perfect. I delete one of the multiple reading and keep shooting until I get five different readings.

Freddy,

You're wasting your time and ammo. The reason smaller chronographs often show more than one reading exactly the same is the distance between the light-screens is so short the readings will be in larger increments. It has nothing to with whether they're exactly the same or not, but how closely the instrument can measure.

In other words, if you get two or three readings at 2756 fps, that doesn't mean they were all exactly 2756. It means they were within a few fps of 2756. So deleting one one (or more) of the multiple readings is meaningless.

So then I should not delete those readings and accept them when i review the readings, they do make the standard deviation look good.

I bought a Magnetospeed a few years ago, and boy howdy I do not miss the Shooting Chrony in the least. What a hassle.