Tuning Crosman 1377 and red dot help...

This is my second try at putting a red dot on my 1377. I have the steel breach installed. First I tried two different cheap reflex sights that were defective. Ordered a Bushnell TRS-25 and mounted it on a dovetail to picatinny adapter. Tried to sight it in today. It’s shooting 4” low. Good groups at 10 yrds but can’t get it to elevate aim point. Maxed out elevation with no change... Is shimming my only option?
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HAWKE or Sun Optics 11mm to Picatinny adjustable mount or UTG with the built in droop buy Sun Optics us the surefire way you can adjust for any elevation correction. They were formerly B Square.

http://sunopticsusa.com/11mm-to-picatinny-weaver-11mm-to-picatinny-sm7021/

https://www-bhphotovideo-com.cdn.ampproject.org/v/s/www.bhphotovideo.com/c/product/1491827-REG/sun_optics_sm7021_11mm_to_picatinny_weaver_adapter_elevation.html/amp?amp_js_v=a6&amp_gsa=1&usqp=mq331AQHKAFQArABIA%3D%3D#aoh=16122725537649&referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fwww.bhphotovideo.com%2Fc%2Fproduct%2F1491827-REG%2Fsun_optics_sm7021_11mm_to_picatinny_weaver_adapter_elevation.html

https://www.adorama.com/susm7021.html

https://www.pyramydair.com/s/a/1_Piece_Adapter_Base_9_11mm_Dovetail_to_Weaver_Extension/8496#Reviews

NEVERMIND I JUST FOUND THIS YOU SHOULD AT LEAST BUY 10 SINCE THESE ARE DIRT CHEAP COMPARED TO HAWKE AND SUN OPTICS!!! DANG SHOOT YOUR AIRGUNS EASY PAST 300+ YARDS WITH THIS!!! FULLY ADJUSTABLE LIKE THE HAWKE AND SUN OPTICS!!!

https://www.amazon.com/MEOPTEX-Riflescope-Release-Adapter-Standard/dp/B07DKZYGT2/ref=mp_s_a_1_20_sspa?adgrpid=58911034274&dchild=1&gclid=CjwKCAiAjeSABhAPEiwAqfxURXz2A0qUdYd0GIYcZTUBc1QCb88VepymZYbXtCvRxSvrPNUwKfS7FRoCw6YQAvD_BwE&hvadid=410002666069&hvdev=m&hvlocphy=9032751&hvnetw=g&hvqmt=b&hvrand=11294803628115526180&hvtargid=kwd-300543549058&hydadcr=9820_11540322&keywords=11mm+to+picatinny+rail+adapter&qid=1612273475&sr=8-20-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzNDU1NzRJQ1lHMVhaJmVuY3J5cHRlZElkPUEwMjM0MjUxUDdUWTBRVkM3TlBIJmVuY3J5cHRlZEFkSWQ9QTEwMDA5NDQxUEoyOTRXSzc5VFdYJndpZGdldE5hbWU9c3BfcGhvbmVfc2VhcmNoX210ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=#