Free float that barrelMay 6 2013 at 2:35 PM
|Mach-1 (Login Mach-1)|
Response to Benji Discovery/Katana POI shifts.. still not there..now what?
Remove the barrel bands. Test it. If that solves the problem then you just need to keep if free floating. Try it.
My hunting 22 cal Discovery is free floating. Only use one barrel band at the end. But the band has been drilled out to 1/2". So it is just there to keep the barrel from getting bent. The barrel does not actually touch the band at all.
If free floating doesn't fix it you could have a barrel issue - small imperfections inside the barrel or on the crown.
My 22 cal did that POI shift thing too. But the shifts were only very small amounts in my case. Like you though the shifts were sudden and not predictable or explainable. It would drive tacks for 50 shots and then suddenly open up and then settle down to driving tacks again but in a different spot.
Then finally the barrel must have broken in and that POI has not moved at all since then. As a major bonus it stopped being pressure picky. Went from 1750 - 1500 psi sweet spot to 2,100 - 1,100 psi sweet spot. I did polish the snot out of the barrel with bore paste... just maybe not enough.
My second Discovery is 177. I polished the snot out of it and then polished it again... and then again before shooting it. It is a tack driver and has not shifted POI one time in the thousands of shots it has seen.
So if you're having this problem consider going back to the bore paste and polishing it again. Test and repeat as needed until you fix it. It is a bit of work... but you'll pull out less hair.