Tuner setting?

[TrxR]

I've got a 1959 40x with a factory barrel that has been recrowned and have a Harrells tuner I want to use on it. I also have one of the longer weights for it .

What's a good way of finding the right setting?

It was suggested to try Purdy Prescription as a starting point. So I read up a bit on it, to get my barrel length I'm thinking put a piece of used brass in then carefully insert a cleaning rod and mark with piece of tape or marker where it exits the barrel?

Now I'm a little confused about the EC number. Is it just the inner diameter of the inner tube multiplied by .3?

Also what harmonic figure should I try first?

Will this work on a longer barrel like the factory 40x barrel? I think it's somewhere between 27 and 28 inches , will have to measure to get exact.

Does this system work?

Thanks

 

[Dennis D.]

Tuning method

Like most folks who have been at this for awhile I've tried every method that has come along. So far the only two methods that have come close to agreeing with each other to final tune are the Hopewell method and the one outlined by I THINK by Mike Ezell, (getting old and can't remember s&%t anymore) wherein you shoot groups across a flat line drawn on a target and look for the groups that shoot at the peak of the wave. Someone here with a better memory will remember what post and which site the discussion it was on. Now this was a small sample of only two rifles so take it for what it's worth but it's the first time I've ever had two methods agree.

Dennis

 

[Fred J]

Set it on 186 and that should be a good starting point. Only you will have to be satisfied with the results.

 

[penn63]

Contact Tony Purdy, Packrat on this forum. He is very helpful and will walk you through the process. I used the Prx on one of my rifles and got within 8 clicks of the final setting. This method saves a lot of ammo.