POI shift with/without moderator.
I have a .25 cricket, and have a POI shift 2″ to right at 50 yds when I take moderator off barrel. I don’t have any other guns with moderators on them, so is this normal or do you think I may be getting slight baffle strike? I would think it would change a little vertical, but not right 2″.
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You don’t have to strike/hit a baffle to shift POI, when a pellet gets to close to a baffles it will cause an air turbulences that will affect you POI. 1: Look like you have an alignment issues with the center bushing when the barrel threads are tighten. 2: one of the baffles you haven’t enlarge has a smaller hole that is causing the POI shift–cricket CNC are not perfect, when I make a single shot magazine that is perfectly fitted and work great, now I used the same mag on another cricket with the same caliber—be hold it wont fit or to loose because the breech opening isn’t consistent—the fix I put an o-ring on the front of the mag to make up the difference.
I’m here to help a fellow AG, email me and give me your address will ship you a 1/2″ 20 adapter that screw on your barrel then use your 1 1/4″ OD LDC, mean while send me your shroud I’ll test it for POI shifting if I have he same problem I’ll slightly enlarge all the baffles till no POI shifting at 30Y with and without the shroud on, I’ll even polish & crown the exist hole of shroud, and drill vent hole for you!!!
Ernest
You are looking for a solution in search of a problem.
Of course changing the tightness or removing the moderator will shift the point of impact in unforeseeable ways due to many variables. Tension,weight,harmonics, etc.
Can someone else try to loosen their moderator 1 turn and see if it changes point of impact any. I don’t see how it could change not striking any baffles. Could it be sealing the air off at muzzle and forcing it out with pellet? I have seen where some have vented their moderators toward back, did this change POI any?
No difference in air gap. I don’t believe it’s a baffle strike either. I can plainly see the crown and face of the barrel looking down the moderator. The moderator is flushing up good with barrel too. I have no idea now. The moderator is measuring .3450″ now.
When you are screwing your moderator on does the air gap between the moderator and the air tube change at all especially during the last three quarters of a turn before it tightens up?
Yes, it groups 1 hole groups at 50 yds. With moderator off or screwed all the way on except 3/4 turn it hits good groups. If I tighten moderator the last 3/4 turn tight on barrel it groups decent, just high and left 2″. It seems like the “body internal baffle alignment” the part the barrel screws into is not seating right against the end of barrel.
I would not drill anymore. Does it group well when the moderator is on?
Well, I have drilled and filed the baffles out 1/32″ bigger with no improvement. It started out at 19/64″. I am bigger than 21/64″ now. Should I keep drilling and filing or is there other issues here?
like I and Mark said bore it out to the next size, I had a members .25 for accuracy issue, what I found was the pellet was clipping the exist hole so I bored it out and the last baffle that’s the furthest I can drill with standard length drill bit. I was even going to use a long round file to enlarge the baffles holes , if the shroud is misaligned it will clip the furthest hole on the shroud first. corrected the accuracy issue. try it and may work for you. its the cheapest fix,
Ernest
When I tighten the moderator, it shoots 2.5″ high and left. When I loosen it about 3/4 turn or take it off, it has correct impact. It only shifts impact when I tighten it up the last 3/4 turn. I’m just hand tightening it, so it’s not overly tight.
Try looking at the bore in the endcap. You may be able to see where the pellet is rubbing it as it exits(if it is). Normally if the pellets are grazing anything it’s nearest the endcap, if the parts are not machined concentric things tend to get worse with pellet clearance the farther the moderator is from the end of the barrel. You may be able to drill from the endcap end as deep as you can and take care of the problem. The end caps are glued in and supposedly near impossible to get out without damaging them. I would suggest finding a local machine shop to drill or ream out the assembled moderator.
Ok, I guess the next question, is the moderator end caps threaded or pressed in? I don’t think I have a long enough drill bit to reach all the baffles from the muzzle end. Does it just unscrew or is there thread sealant on it?
bore out the baffles and through hole to the next MM size.
Ernest
hi blitzkreig
you shouldnt get no side ways shift,,vertcal yes ,i have silencers on all my rimfire and centre fire rifles, 2x 300 win mag ,204 ruger and a couple 22s,,i get NO sideways deviation at all,only vertical,can you check your baffles n your silencer for possible clipping?
rgds steve
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I sent you a PM Ernest.