I've seen generally positive things, both online and from talking to folks that were using them at a site I attended between lockdowns they fit and feed as their genuine counterparts (though if memory serves they do have a different follower). They didn't feel quite as nice, but it's a rigid enough design for it not really matter. I'm always wary of clear plastic because I just assume its cheap and flimsy but have yet to see anything to demonstrate it's a weak point. The risk with the repro things generally being QC/production processes may not be as consistent across batches as they are with the genuine article. Ultimately comes down to the price difference where you are I guess ?
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i used a jewelers half round file to do it so it gave the retainer a slight concave profile instead of straight across . And a little squirt of silicone every now and again . ?