On a Quest with a Quest, part II

[70GTvert]

Now that I have the Quest firing with less than a 10FPS deviation from shot to shot, and it has about 1000 shots through her, I started playing around seriously with accuracy. I've heard a lot of bad news out there about not getting consistent groupings with almost all comments leading to the bushings at the barrel hinge as the culprit. However, those those few that posted after addressing this issue noted they were still getting inconsistent groupings.

My results started to show there was indeed a problem with the barrel lock up with this one too, but the data showed it was unlikely to be those plastic bushings as it was strictly and up and down POI issue, not a windage type issue. Looking over everything carefully, I found that the barrel side locking wedge had some up and down movement when pressing my fingers against it. That, and there was very little overlap of the wedge faces when the barrel was locked up to the breach.

I removed the barrel side wedge and made two modifications to it. #1 was to grind the opening that limits the back and forth movement of the wedge to allow another 2 mm of forward movement (removed material from the rear of the opening). This provided me more overlap of the two faces when locked together To limit the up and down movement of this wedge, I took some thin brass stock laying around from some of my HO railroad projects and used it to "shim" this part (any decent hobby shops have this in stock, but I do not have the thickness here, it is about as thick as that duct work aluminum tape from the hardware store). I soldered this to the wedge and filed it smooth, checking fit from time to time until it fit snugly but was able to move back and forth but NOT up and down. Then I reassembled Johnny 5.

Seems this has taken care of the up and down POI changes. Winds started gusting to about 20-30 mph while I was working on this project, so windage of course suffered on the follow up testing, but the drastic changes I was seeing earlier from time to time in the up and down impacts is now gone.

How long this will hold up is unknown at this time, brass is soft, solder softer. Best bet would be to machine a new one that fits snug from some hi-grade round stock and then heat treat it, but I don't have the facilities for this.

Hope I am not reinventing the wheel here and that this is actually helpful to other Quest owners.

[kiwi]

I just got a used Remington 3 weeks ago, It had probs with the barrel lock
Think its the same by a diffrent name.
what I noticed was that the cross pin was only just in contact with the wedge.
My fix ---  I put a bigger  pin in 7mm dia had to grind a flat on the top of it to
let the barrel step clear it. i used a 7mm drill then cut the top off the drill
to make the new cross pin.
there was not much spring pressure on the wedge pin so I removed it &  put
3  4mm flat washers in the bottom of the hole  & reinstaled the spring / pin.
Put yer finger over the join between the barrel & chamber shot it and see
 if yer can feel it move.
I picked up the prob with mine when I put it on the rest a bit hard and
 noticed the barrel flicked