is it normal to have a point of impact shift of 1 1/2 inches when i put my moderator on...with the adaptor only it shoots 1 1/2 inch higher,and 1/2 inch left,at 50 yards...is this normal?...i also see small streaks of leading on the inside of my sumo muzzle...all shots are consistant tho...if pellets were clipping wouldnt the poi be irratic?
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poi shift
- Thread starter wendellv
- Start date
I have had only one experience with pellets clipping the moderator. And yes, flyers were extreme, sometimes 6" off at 25 yards. Hard to say what is "normal", but POI will change with almost any type of muzzle attachment. If the groups remain good, then you just have to accept the change in barrel harmonics. I have to remove the silencer on my Steyr rifle to get it in the case. POI remains the same with its removal and re-attachment, so at least it is consistent.
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Streaks on endcap usually come from the hangers used when anodizing. He even says that on his website. POI shift with a moderator is pretty normal though.
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thanks hammer....i was wondering ,how the hell those pellets could be clipping,,,good to know they arent
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knowing what i know now,i will start playing with the little o-rings around the barrel liner,to see what i can do with harmonics
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I have the DonnyFL moderator atachement on my 350mm Leshiy barrel and the tatsu moderator. I take the mod off putting it in and out of the case and the other day took a few shots with the mod off and was shooting consistently 6” to the left at 50 yards. Put the mod back on and back to shooting dead on. I thought this was so odd but everything is consistent each time I had tested since.
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I think this is common as well as a velocity reduction. Air gun barrels are not solid like powdered weapons are. They are not as stiff and when adding weight to the barrel the barrel will droop and the harmonics will also shift. None of this is a problem, if the changes are consistent. My moderator is 8" long and weighs 354 grams. It is very effective. It changes the POI by 3.5 cm down and left at 20 meters, but the accuracy and grouping is exactly the same with and without the moderator mounted. Further this POI change is consistent and repeatable. My moderator also changes the muzzle velocity from 940 to 900 fps. I believe the amount of speed loss is a direct function of the effectiveness of the moderator
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