If I had known the sight blocks would evolve and start walking, I would have taken care of this earlier.
On my two .22 rifles (Marlin 795 and Marlin 989 M2) I have Tech Sights. Unfortunately, on both, the damn rear sight block does not stay in place. I cranked down the attaching screws as tight as can be, and even used loctite on one rail to see if that helps. While the loctite did help, even then, 100 rounds or so made the sight move slightly backwards. And I don't like the idea of using an adhesive to make sure my sights stay in place.
I've done some looking around, and this seems to be an issue with Tech Sights on Marlin semi-auto rimfires in general. The consensus is that the dovetails are not manufactured to tight enough tolerances. So the dovetail may have ever so slight dimension variations, that make it hard to really lock the sight down to it.
People mounting scopes often recommend using a one piece scope mount with rings that covers most or all of the dovetail. Folks using that setup report that the one piece mount does not walk back because it attaches so securely to the dovetail with three screws.
Oddly though, POI is not changing for me as the rear sight walks backwards.
So I figured I'd better get professional help. The rifles are at Gunco right now, to have a set screw installed which will lock the sight block to the rail. The gunsmith came up with a clever idea so that the work will not be visible. I'm looking forward to it being done and getting onto the range to see how well it works. I'm expecting the damn thing to stay put, no matter how many rounds I put through the rifle.
By the way, I don't think this has anything to do with the Tech Sights per se. The problem seems to be with the rifles' dovetail rails. It's almost enough to make me cry
as I have some weird attachment to Marlin .22 semi-autos. Yeah, I know, they're inexpensive mass market rifles... so you can't expect very high quality on every aspect. That said, both Marlins shoot very well and I'd buy another 989 M2 in a heartbeat. I like the 795 a lot, but I absolutely love the 989, even though the bolt does not lock back after your last round.
Cheers,
Neil
On my two .22 rifles (Marlin 795 and Marlin 989 M2) I have Tech Sights. Unfortunately, on both, the damn rear sight block does not stay in place. I cranked down the attaching screws as tight as can be, and even used loctite on one rail to see if that helps. While the loctite did help, even then, 100 rounds or so made the sight move slightly backwards. And I don't like the idea of using an adhesive to make sure my sights stay in place.
I've done some looking around, and this seems to be an issue with Tech Sights on Marlin semi-auto rimfires in general. The consensus is that the dovetails are not manufactured to tight enough tolerances. So the dovetail may have ever so slight dimension variations, that make it hard to really lock the sight down to it.
People mounting scopes often recommend using a one piece scope mount with rings that covers most or all of the dovetail. Folks using that setup report that the one piece mount does not walk back because it attaches so securely to the dovetail with three screws.
Oddly though, POI is not changing for me as the rear sight walks backwards.
So I figured I'd better get professional help. The rifles are at Gunco right now, to have a set screw installed which will lock the sight block to the rail. The gunsmith came up with a clever idea so that the work will not be visible. I'm looking forward to it being done and getting onto the range to see how well it works. I'm expecting the damn thing to stay put, no matter how many rounds I put through the rifle.
By the way, I don't think this has anything to do with the Tech Sights per se. The problem seems to be with the rifles' dovetail rails. It's almost enough to make me cry
Cheers,
Neil
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