sighting in with an arms 40

[contact148]

mounted my arms 40 BUIS on my 16" ar15 tried sighting it in and was NOT happy with the results

I started at 25M with the small apature up and got it sighted

moved to 50M tried the large apature and it was all over the place took a TON of adjustment on the front sight to get elevation right but it shoots way left so i adjusted that it still will only produce about a 4" pattern and when i flip between the large and small apature they are WAY WAY off each other

I turned on my eotech and the rifle shoots 1.5' groups at 50 no problems so its not the rifle or ammo

so ho do i properly sight in the arms 40 I have a 25 50 75 and 100 meter range to use

 

[G37]

One other suggestion (I myself encountered last weekend) make sure the BUIS is on nice and snug, I'd also recommend using blue loctite on the threads.

My BUIS was coming loose after every couple magazines. That will affect accuracy