I got one of the new type which is held on to the end of the barrel with rubber bands. Tried it out and POI with it attached dropped by 11/2 inches at a range of 45yds shooting at 900 fps muzzle velocity. This on a FX Ipact. Seems rather a large discrepancy with such a light weight attached. Will have to use it without mounting it on the barrel. Anybody else have this problem?
FX Radar Chrono POI Shift
- Thread starter jonjo
- Start date
I've tried it on every gun that I own (over 10) and none of them have a POI shift from that very light weight. But I don't own an Impact or gun with STX barrel liner system...
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then I guess you either miss the accuracy or distance to notice it
I have a Magnetospeed, which is even a bit lighter, and I do notice it when it’s attached on my POI at 100 meters. Even on 50 meters I can clearly see it with alle my barrels, and that includes a 18mm thick stainless steel barrel. Even on thick powder burner barrels you can still see the difference with it attached.So yes, every weight you attach to the barrel will influence your POI. Also adding a silencer will cause a POI drop because it’s also a weight.
By the way, this is mostly only visible with free floating barrels, non free-floating barrels often don’t have this issue but they have lots of other issues
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I do find it ironic that the only gun I've owned that I can't hang the FX Chrony on is an FX Crown with a free floating barrel. The chrony works fine but causes pellet clipping.
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I use to having the same issue, until I installed bottle/barrel band on my Impact. No more POI change after installation. I also like to mount my Chrony on LCD and every time my POI changes. Now I use bigger and heavier silencer along with chrony and no POI change with same accuracy. 
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then I guess you either miss the accuracy or distance to notice it
Good one. Thanks for the laugh.
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I use to having the same issue, until I installed bottle/barrel band on my Impact. No more POI change after installation. I also like to mount my Chrony on LCD and every time my POI changes. Now I use bigger and heavier silencer along with chrony and no POI change with same accuracy.
Is the bottle barrel band 3d printed and is the file on thingyverse? If its not 3d printed do you mind sharing who made it?
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I'm not surprised, but why is it a problem? When I do a chrono run I don't really care about POI, and I would never shoot for score or group with it attached anyway. it's simply a tuning tool.
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It does drop my POI from when not using it, but I know what that value is, so I adjust for it in my scope when using it. Also, every moderator I’ve used has shifted the POI (consistently, just different). I don’t find it to be an issue with groupings and such. I just adjust my zero.
I also have an adapter than I can attach to the tank instead and hold it out under the front of the rifle to use it instead of rubber bands. I like the rubber bands better.
I also have an adapter than I can attach to the tank instead and hold it out under the front of the rifle to use it instead of rubber bands. I like the rubber bands better.
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then I guess you either miss the accuracy or distance to notice it
So yes, every weight you attach to the barrel will influence your POI. Also adding a silencer will cause a POI drop because it’s also a weight.
By the way, this is mostly only visible with free floating barrels, non free-floating barrels often don’t have this issue but they have lots of other issues
I find most of this post to be a lol. Have had many guns non floating and never had a single issue with them Like Taipan, Uragan, kricket, Edgun, daystate Regal and others with tensioned barrel designs that are IMO even better. I've had more issues with POI shifts with free floating barrels than non. Have also had guns that had no POI shift with a LDC. Do have guns that do shift but have had multiple with no shift.
Also Centercut won 2 competitions at EBR last year so funny how he lacks the accuracy.
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First time I’ve heard that suggestion. Is that a proven hack? If so is there a source for the o-rings?
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