E C TUNER/BRAKE TEST ON MY REM 40X 260AI

[piie]

Did not chrono my test.

I went and did a test string today - just to remember that the Labradar's mount is still on my tripod - which of course did not go with this time...

Anyway, I found something weird...

I loaded 30 rounds for testing, and 2x5 rounds to re-zero my scope after fitting new rings (so I did that before I started the EC Tuner test) - I also did 3 shot groups in increments of "2" on the tuner.

"0" started out OK, "2" was a bit loose, "4" was 3 through the same hole, "6" opened up again, "8" was a bit tighter, and "10" was good, but not as good as "4"... I continued until "14", and then decided to re-verify "4"

The second time around on "4" was the worst group so far...

I then tried "10" again, and it grouped the same as the first time.

I didn't hammer the rounds through the barrel, tried to pace it and keep the barrel fairly "cool", but not like in cold bore cold.

Have anyone else noticed that the tuner setting is perhaps temperature sensitive? I cannot think what else could cause this - obviously, I started at about 09:00 and last shots fell at about 11:30 - so the ambient temp and sun on barrel was much hotter than in the morning, but I had a good 10 rounds through the barrel by the time I got the first good group at the "4" setting...

 

[Bill Norris]

I havn't seen that yet but I'm still testing. Looks like you may need to work in the 10 area 9 10 11 and see how those groups look.

 

[Bill Norris]

Erik states that we should not settle for the first "lone group" and continue until we see two or more groups shoot tight. Below is a test with my 260AI that I started at zero and went thru eight. Later, at a setting of eight, ten and twelve the groups did begin to open up with the higher settings. I will do more testing later when the temps change considerably to see how that setting holds.