FF3 removing and putting it back on

[2eagles]

I want to use my SX4 as a duel purpose gun, turkey and waterfowl. I had it drilled & tapped for a Sumtoy base. Great mount for sure! Added the FF3 and it is a turkey killer. Because the SX4 has an aluminum receiver, it was recommended not to take the base off and on to prevent wear on the screw holes.The Sumtoy is no higher than the vent rib, so leaving it on shouldn't be a problem. Go kill ducks and geese.
QUESTION IS. When I put the FF3 back on, should I expect to be pretty much sighted in or will I have to start all over? I'm very short on my Hevi13 shells and don't want to waste them, but don't want to mess up a shot either. Looks like Iowa will allow #9's next spring so maybe I'll switch to tss, then I will be starting over with stupid expensive shells.

[lunghit]

You'll probably be real close but there is only one way to find out and personally I wouldn't feel confident hunting if I didn't take a shot to confirm. This is the exact reason I got rid of my Trijicon RMR and went to a FF3. I like to remove batteries in my electronics after the season and with the RMR you have to remove the sight.
What you can do is see if your expensive turkey rounds hit with cheap skeet rounds. If they hit the same you can take a shot or two with the cheap stuff every spring and now know that your turkey loads will be same POI.

[Tail Feathers]

You could use some heavy 6's in lead shells and get a 20 yard pattern with them.   Take care to note exact POI.  When you put the sight back on after duck season, sight in with the same heavy 6 load at the same distance and you should be good to go.

Me?  I'd have to shoot a hunting load at 40 to verify, but probably it would only take one.  This is pretty muc what I do each spring even tho I leave my red dot on year round.

[BBR12]

Definitely need to shoot it.  I had to loosen the barrel nut on my 870 this year and put a plug in it for a state that requires it. The company that coated my gun didn't put the plug back in it and I didn't realize it till I was on the road. I tried my best to not let the barrel move any but it obviously did.
Anyhow it cost me a Turkey about 1000 miles from home. My gun was off by about and 1"-1.5 high and left at 15 yds. Which was enough to miss one and it hurt bad. 

[King Cobra]

Like a few others have already mentioned, use field loads at a shorter distance. Then hopefully one shot at 40 yards with a premium shell, that should get you close enough to dial it in.

[guesswho]

You could use a bore sighter before removal.   Then when you put it back on use the bore sighter again.  I take a piece of cardboard and mark my POA and where the red dot from the laser hits the target and write the yardage on it.   If you put the sight back on then line the two marks on your paper back up at the same distance you should be good to go.   Be sure and keep the same distance, and I noticed you need to mark your bore sighter so it's in the barrel the same way.   I put a mark on mine at the 12 o'clock position.   But even after doing this I always shoot once to make sure it's ok.  So far so good.  I've even replaced a Venom with a Holosun using this same method and it was dead on when I shot with the new sight.  Beats running $10 down your barrel multiple times. 

[Tom007]

You could use a bore sighter before removal.   Then when you put it back on use the bore sighter again.  I take a piece of cardboard and mark my POA and where the red dot from the laser hits the target and write the yardage on it.   If you put the sight back on then line the two marks on your paper back up at the same distance you should be good to go.   Be sure and keep the same distance, and I noticed you need to mark your bore sighter so it's in the barrel the same way.   I put a mark on mine at the 12 o'clock position.   But even after doing this I always shoot once to make sure it's ok.  So far so good.  I've even replaced a Venom with a Holosun using this same method and it was dead on when I shot with the new sight.  Beats running $10 down your barrel multiple times.

X2 here. I record all my guns optics with the Laser Bore Sight chart paper. It is dead-on if I remove a scope or red dot and re-sight it with the laser again. Never had to adjust any of them again. Works good if you bump an optic while hunting....

[RND1983]

I have never had an issue removing it and putting it back on. When I travel, I always remove the FF3 from my Sumtoy base and put it in the original box it came in for more protection in the air. I put it on when I reach my final destination and have had zero issues. You are putting it on the Sumtoy base which there is only one way it can go on there. I've also deep cleaned my gun mid season and removed everything, put it back together with zero issue. There's only one way everything can go back together. I always make sure to tighten the barrel nut to the original location from when the gun was patterned.