Brake/choke fix?

[Don]

Brake/choke fix still-pictures and video.

"A" boss that appears to be off boreline.

"E" new sleeve that did not fix problem.

#56 picture bore offset visually.

#58 and #60 pictures measured bore offset of about .012".

#62 targets "F" and "G" no choke aimpoint and impact point is same, "H" and "I" impact point left and high of aimpoint.

Video showing live fire testing of barrel without brake/choke.

Now I have to figure out how to move the offset "A" boss part back onto center, do I unsolder and reposition if it can be unsoldered, or do I machine off the existing boss and add a new one?

Wonder how these were supposed to be installed originally?...................Don

#56

#58

#60

View My Video

 

[lefty o]

before the advent of screw in chokes, most poly chokes were soldered on.

 

[Don]

.

before the advent of screw in chokes, most poly chokes were soldered on.

It appears that this one was also soldered but with a large space between the boss i.d. and barrel o.d., in order to allow a gap for the solder to fill, unfortunately this large gap prevented a tight fit centering of the boss to the bore centerline, and subsequent part fits are also off center causing large impact to aimpoint differences.

Easiest fix seems to be to turn down the boss o.d. thread area, with barrel installed between centers, fabricate and solder a sleeve build up to this newly turned area, then re-thread new boss material while between centers, re-install brake/choke and test for aim/impact, unless someone has an easier or better suggestion/idea..........Don