Help with my M380 please. Long...sorry

[paulaboutform]

Just tightened up the tek screws on the scope and trigger assembly. Dialed in at 20yards, shooting the X out of a 5 spot blue and white face target. About dime size groups. Went to 30 yards and had tac zone dialed at 348 fps. Shooting 18" BEA with 2" blazers and brass inserts. Arrow weight is 398 gr.. Was shooting about 1" groups in the 10 ring and suddenly the arrows were about 4" LOW. All screws still tight, re-adjusted scope to 330 fps but it continued to go lower. Dialed it down to 300 fps and it hit the bullseye but then continued to drop so I packed up and thought I'd look for some help here. I determined my 30 yard mark by holding the tip of the 30 on the X and moving it to where the group was. (4"low and dropping)
I hope someone can tell me I've temporarily lost my marbles and there's an easy fix. Oh yeah, I'm shooting the matrix 380. Thanks for the feedback.

[Hunter from Hell]

I am not a expert but I have a 380 and with the stock equipment 18"
Diablo with 150g field tip I am 355 fps and zeroed at 20 hit the same at
50 yards I have the tac zone set at 355 and it is right on my yardage is with a range finder

[paulaboutform]

I am not a expert but I have a 380 and with the stock equipment 18"
Diablo with 150g field tip I am 355 fps and zeroed at 20 hit the same at
50 yards I have the tac zone set at 355 and it is right on my yardage is with a range finder

I'm suspecting that something else is going on. I just want to know why the dropping bolt?

[newbie]

did you recheck your 20? could be the scope not holding zero.

[Lake shooter]

Don't have any answers for you. All I know is that I'm shooting the stock Diablos with 125 gr BHS and my speed ring is set on 375 to be on at 20 and 40 yards.

[racking up points]

did you recheck your 20? could be the scope not holding zero.

I've had this happen with rifle scopes too.

[Mo wannabe]

Mine is set on 360 to be on at all yardages. I'd recheck ur 20

[Hunter from Hell]

Could your String be stretching???
Just throughing thoughts out

[Dash]

Doesn't sound good. If I understood your explanation correctly, your bow sounds like it shot stable for numerous shots, then it happened suddenly dropped 4"within a shot. And now continuing to drop. Sounds too erratic for string stretch.
Do you have another scope to swap out temporarily? that's what I'd try to cancel out first?

[vixenmaster]

CK scope, rings,mount, then ck if'en trigger is loose in rail n stock. Last would be limbs!

[shooter00]

My Tac Zone scope was total garbage.
Mine did the same thing.
Zero at 20 and five or six shots later it would be 2 or 3 inches off and kept drifting no matter how many times I zeroed it.
Sent it to Danny Miller and paid the $100 or so upgrade fee and got the Leupold 2x7x33 heavy duplex and have not looked back....

[paulaboutform]

UPDATE: I did check the 20 and it was also low. This is my second tact zone. The string didn't stretch and I was checking all the screws. ??? Another defective scope?

[newbie]

double check no scope movement ie scopemount and rings then reset your twenty and go from there. happens again yes another bad one.

[paulaboutform]

did you recheck your 20? could be the scope not holding zero.

What exactly do you do if the scope is not holding zero? How do you fix it?

[paulaboutform]

double check no scope movement ie scopemount and rings then reset your twenty and go from there. happens again yes another bad one.

Thanks newbie, appreciate it. That's what I was afraid of. I'm really losing faith in these scopes. I wonder if the one on the 405 will be better or should I upgrade to the leupold?