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Took the new to me TRP-3 to an indoor 25 yd range today. It has a 36 Weaver and the Jard set at 2 oz. Pulled the tuner, had the table set up with quality front rest, windage top, rabbit ear rear bag and Master M, Eley EPS, Wolf MT, Aguila, PMC, Fed GMM, etc etc. With tuner off, wanted to verify there was enough wgt on it to start work. Shot 5 then reinstalled tuner.
Shot 5 more, same poi. Hmmmm, from what I've read I needed at least a half inch drop between the two configurations. Screwed on an additional 5 oz, same results, added yet 3 more oz and same/same. Whaaaaat is this I have going on here? I am a stone newbie at rf bench work, tuner set up and bench/bag tecnique but this has me stumped from what I've read.
I did shoot some sub .2's from time to time so wasn't tossing shots/groups hither and yon. I found out that the white fibreglass/plastic 42" table I picked up from WM is better than a card table but still not solid enough for anything resembling precision bench work. Was able to take the shop's reworked 10-22 with factory double digit trigger plus gravel slide and managed a couple of 5 shot groups at or under .250 but interestingly enough, the can acted as a tuner in that the shots went vertical w/o it. I'd like to try that one with a solid bench and 2 oz trigger.
Anyway solons of the rimfire tuning world, why didn't the poi change more than maybe .100" from tunerless to tuner with 8 more oz? Is there something I missed along the way of my reading?
PS Tried some Eley yellow rifle cheap stuff and the Aguila shot as well. Left the current mfr Dynapoints at home (grin).
Reply with quote #2
I have always got about 1/2 inch with both my bench guns, but at 50 yards. I don't know what to expect at 25 yards but would guess should be less than 1/2 inch. I am not familiar with your rifle, whether it has one or two action screws on if your bedded in bare wood or pillars.
Couple of things. I have found the tuner setting to always be the same going from one lot of say Master M to another. Or any Lapua with the same bullet and lube, (Master, Midas or Multimatch). I just tried some Lapua Center-X and initial testing it looked like the same tuner setting worked as with the Master M I was tuned for even though the bullet looks different.
But I have found the action screw torque sometimes changes. Sooo if you have two pillars I would recommend leaving the tuner off and testing the different ammo's. I use a Hoppe;s sighting in target with all those verticle and horizonal lines about every inch. I can do a lot of shooting on it without changing targets. Have a notepad as to which row is which ammo and when you clean. I would definitely clean when switching ammo's. Then shoot what ever fouling shots your rifle requires to settle in. Find the optimum action screw torque for each. With pillars you should be able to start around 30 inch pounds and go up to 50 and find an optimum setting. If no difference you might have better than average bedding. But most guns will show a preference. Once you find the setting for one ammo the others should be within 5 inch pounds of that.
After testing with no tuner you may find one ammo that shoots best. You may go through a couple of boxes each getting this far. Put your tuner on and then stick with that one ammo and lot.
Now you hear a lot about the Hopewell method. Stick with it and see what happens. A caveat. I know one great shooter who tunes at 25 yards. A number tune at 35 yards. Most feel tuning at the distance you will compete at is best. But you got to go with what you have to work with. I would be concerned that tuning at a close distance of 25 yards if you are competing at 50 yards it wouldn't show much difference for two settings at 25 yards but the greater distance of 50 yards would show one was definitely better that the other. Sometimes I find when tuning at 50 yards that if I am close to a great setting I will get 4 shots in a tiny hole and one out or 3 in one tiny hole and two in another. Sometimes one more click will do it. Good luck. By the way, I shoot 5 shot groups. But if the first two or three look terrible and I thought I did my part I go on. No sense wasting ammo on a poor setting wheather adjusting the action screws or tuner. Get a good inch pound torque wrench. 10 to 75 pounds would be ideal. Besides setting the action screw torque I use mine for scope and tuner mounting among many things. Rich