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How does a red dot sight affect extraction and ejection?

3K views 16 replies 11 participants last post by  Szumi 
#1 ·
My 22/45 runs an RDS on a Pic rail. With most ammo types it works fine. With one type--Winchester (an ammo that often gives many rimfire and MK-series shooters fits with lack of consistency)--I get stovepipes, and failures to extract or eject. But here's the interesting thing: this happens ONLY when the RDS is mounted on the pistol. If I remove the RDS, the Win ammo immediately resumes working fine. Put the RDS back on, right back to multiple failures. Also tried positioning the RDS at different points on the rail, didn't matter.

So there's the mystery: Why would putting an RDS on a pistol that does not have a reciprocating slide, have any impact whatsoever on the cycling and feeding/extraction reliability?

You have to assume the Win bulk ammo itself is marginal in the sense of barely adequate to cycle the bolt at the right velocity. That's why it works in some rimfires not in others--it's right on the margins. The weird thing in this case is, what is it about mounting a RDS on top of the pistol that somehow affects the ammo/bolt interaction just enough to cause failures.
 
#2 ·
I'd like to see a picture of your gun and where the RDS is located. If it's just above the ejection port that could be the problem. If there is a large screw holding it to the rail the brass could be hitting it and causing the failures to eject. I had this happen on my 22/45 Lite when I had a Vortex Venom on it.

I replaced the mount with an EGW Dovetail Mount and I had no more problems.

 
#5 ·
Max I believe it is the WW ammo and your gun . RDS probably has no effect on the function and you would get the same failures with out the RDS on the gun.
However the RDS on the gun could have some effect on the dynamics of the gun based on small amount of extra weight. Try a more firm grip on the gun and see if that effects the guns function. All of this is physics and action reaction of force when the gun fires.
 
#7 ·
maximus83 said:
You have to assume the Win bulk ammo itself is marginal in the sense of barely adequate to cycle the bolt at the right velocity.
Winchester bulk ammo is my gold standard when testing a new gun or mod. If it runs Winchester well - it'll run any ammo well (stronger than CCI Quiet that is).

.. what is it about mounting a RDS on top of the pistol that somehow affects the ammo/bolt interaction just enough to cause failures.
Short answer is: It doesn't.

I think what the RDS does affect is how you're gripping the pistol. With iron sights, you hold firmly to keep the front sight aligned with the rear sight and the target. With the RDS, your hold is more relaxed because it's simple to just wait for the dot to be on the target before squeezing the trigger.

Like Jim suggested - "Try a more firm grip on the gun".
 
#8 · (Edited)
The limp-writing idea (Jstacy and T.E.) is plausible, and something easy to test. I'll check that next range trip and update here.

ETA: Although I just remembered to add something I didn't report above. On the day I was having issues, I also had one of the range trainers lay a 2nd set of eyes on the pistol, and check my form while shooting. He didn't anything obvious, but I still could've had too loose a grip.
 
#10 ·
Well I thought of that too except--the issue isn't happening when the RDS isn't mounted. The RDS does not have screws going into the receiver, it just attaches to the Pic rail that came mounted on the receiver. So if the screws from the rail were an issue, I'd expect them to cause an issue at all times, with or without RDS mounted.
 
#12 ·
Yes, tried three positions on the rail: over the ejection port, forward of that, and as far forward as possible.

I'm hoping to get to the range again next few days, I'll try the 'firm grip' theory. That one would at least make sense, although I have to believe that the ammo itself is ALSO partly at fault in that it must be marginal to begin with. Since the other ammo types are unaffected by my current grip when I run the RDS.

Ultimately this isn't a make-or-break, it's one cheap ammo type, I can avoid it in this pistol if needed. Just curious as I couldn't identify what the CAUSE of these failures was, in this case.
 
#14 ·
The only difference adding the red dot sight should make is the addition of a little weight which in theory should be a benefit in making the action cycle better. My guess is still with subconsciously using a more relaxed grip when using the red dot sight.
 
#17 ·
Wondering if your ammo is overly waxed. Periodically I discover partial boxes of Winchester T-22 in various range bags and containers. I bought a brick of it 20+ years ago and it quickly causes failures to extract in anything I try it in.
 
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