Red dot troubles

[Warrior75]

I decided to jump into the open class in icore. Using my a S&W 627. I bought an Allchin brand mount for the rmr / holosun. Mounted a holosun 507c. I tried to sight it in today. At 15yds. The closest I could get to zeroed was 3 inches high. I ran out of adjustment with the dot. I tried it at 25 yds with the same result. At 7 yds was right on. First shots at 15 yds were 12 inches high. The sight has a 25 moa adjustment range. Shooting short colts at 125pf. Does anyone have any suggestions on what to do to correct this? Was shooting benched and off a sandbag at 15 and 25 yds. Thanks

[missed it by that much]

I'm far from an expert on this subject. But I have the same mount with a vortex red dot and didn't have this trouble. I know in general a slower bullet is. One with less velocity shoots higher. So you probably could go with a heavier bullet moving slower but not sure you'd get 3 inches. Something you'd have to play with. The other option would be to shim the red dot. I'm sure someone else will come along with a more definitive answer. Good luck. 

[AzShooter]

I have the same mount on my 9s9.  I have used it on my 627s as well.  The idea is to sight in about 1 inch low at 7 yards.  That will put you dead on at 15 and about an inch high at 25. 

 

First thing I would do is take the sight off and then re-mount it.  If that doesn't work call John Alllchin and tell him your problem.  I'm sure he will be very helpful.  

 

Shimming it works as well.  Get some small stirps of copper or aluminum from Ace.

[Tampa-XD45]

I use the Holosun 507c with a similar mount (Raptor) and have not run into the problems you're having.  Is it a new sight?  Do you have access to a laser bore sight?

 

[alecmc]

If you are truly out of adjustment, you'll need to shim the dot where needed so you can gain the needed space. Get some shim stock thats a few thou thick and go from there. 

[Warrior75]

5 hours ago, alecmc said:

If you are truly out of adjustment, you'll need to shim the dot where needed so you can gain the needed space. Get some shim stock thats a few thou thick and go from there. 

Where do you get it or what do you use for shim material in this situation? Thanks.

[AzShooter]

Ace Hardware has thin aluminum and brass shims you can use.

[alecmc]

51 minutes ago, Warrior75 said:

Where do you get it or what do you use for shim material in this situation? Thanks.

 

You can purchase an assortment of shim stock off amazon, or just use an old set of feeler gauges.  Cut them to size where needed with a pair of scissors. 

[Lesliet]

This may or may not be applicable to your situation, but I had an HE508 mess up such that even at the max adjustment, it was putting bullets in the dirt at 25 yards. It had previously been working quite well for the entire previous season, so it was a sudden change. Shipped it off October 9th, haven't heard a peep.  ( Your post reminded me to send them a follow up email.) 

    Have you used the sight on other guns?  Might be worth trying it on a different gun to see if it can be sighted in properly, and/or sight with a laser bore pointer, so you can see what it's doing.  Could be a problem with the sight, rather than the mount. 

   I've heard from others that Holosun is pretty good with customer service, not really sure what to think so far, myself.  Hope it didn't get lost in the mail. 

[MWP]

On 11/1/2020 at 9:59 PM, AzShooter said:

I have the same mount on my 9s9.  I have used it on my 627s as well.  The idea is to sight in about 1 inch low at 7 yards.  That will put you dead on at 15 and about an inch high at 25. 

Those numbers seem a bit off to me. Even with a bore to site distance of 1.5” (cmore standing up) and a 15yard zero, you aren’t 1” low until 4 yards. 
 

Fun fact: with that bore height and 15 yard zero, that’s also a 45.23yard zero, and the most the trajectory is ever off by is +.5” from 25 to 35 yards. This example will hold an X ring from 0-63 yards. 

[Warrior75]

I ended up shimming the front part of the mount up. I have an EGW mount on order, but it's apparently lost in the mail. Got it zeroed at 15 yards. This past weekend. I have a club match this week. I will see how it works and if I can get used to the optic. Thanks for the suggestions for helping to fix this issue.

 

[Lesliet]

Holosun got back to me, apparently I'm getting an upgrade, but they are waiting for stock with about a 6 week lead time.  *shrug*  understandable, given all that's going on. 

 

   Glad you got something sorted out on yours, @Warrior75, hopefully the EGW will be an improvement.

[Warrior75]

12 hours ago, Lesliet said:

Holosun got back to me, apparently I'm getting an upgrade, but they are waiting for stock with about a 6 week lead time.  *shrug*  understandable, given all that's going on. 

 

   Glad you got something sorted out on yours, @Warrior75, hopefully the EGW will be an improvement.

Hope you have better luck with the new optic.