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Old 02-06-2018, 12:25 PM
Test_Engineer

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Quote:
Originally Posted by moreguns View Post
It looks like I will have to have the pin that the bolt stop lever fits under, micro laser welded in. I am petty sure that I will have to cut higher that I originally thought, which will bring the cut into the hole that the pin is pressed and or peened into. Its not that big of a deal to me to have it welded because the potential reliability of the pistol will be better.
It appears that Ruger drills the hole and chamfers the backside to form a "holding pond" for the displaced pin metal. They then press the pin to fill the pond and grind the surface flush.

If your pin is tight (so you can't turn/rotate it), you should be okay without welding. The pin only receives any side force when you are manually activating/deactivating the lever on an empty mag, so a tight press job should stand up pretty well. I haven't had any issues without a weld.


Quote:
Originally Posted by hamden View Post
How about some pictures to help us understand these ideas..
Okay.

When a round is released from a loaded mag, the next round gets pushed all the way up against the bottom of the bolt like this:



The feeding round is then captured by 3 points on the bolt, which holds it secure until the front feed lips can push it up behind the extractor.



On MKII and later pistols, the bolt stop is activated when the last round is released. But the stop holds the follower about 1/8" too low to provide 3 points of contact between the bolt and the rim. Maybe 1 or 2, but never 3. So the last round is only lifted like this:



Weather the round remains low like the above picture, or if it bounces like this-



-the result is a very poor feed. The bullet often gets tweaked on it's way into the chamber. It may get shaved a bit, or it may get bent in the case neck. The result can be: Fliers, Light Strikes, OOBs, or FTFeeds.

Even if the problem result only occurs one time in ten, is a 1% failure rate (assuming you always load 10 rounds in a mag) acceptable? Not in my book!

So here's some pictures of the modified bolt stop. The cardboard shows the line the stop's lower edge followed before the mod.



Here's a back-side view that shows the pressed out back side of the pin. You can see the chamfered circle has been cut into. The modifying cut is curved instead of straight across in order to keep enough material to retain the pin reliably.



Here's a top view of the cut that shows how the pin is pressed into the chamfered hole. The chamfer isn't easy to see because the displaced metal from the pin is very tight in the "pond".



The next picture shows the stop installed, being lifted by an empty mag, and the bolt face at the front of the rear feed lips. The red lines show how much further the follower has been allowed to lift because of the mod.



One last picture. This is the same as above, except looking in through the ejection port. Compare the follower position to your own.



This restores the 3-point feed control of the last round. It's a shame that Ruger didn't see this issue when they designed the bolt stop. They could easily install the pin 1/8" higher and trim the bottom up without changing the functionality at all.

I don't really expect many people will modify their stops. That's perfectly okay. This mod is for people obsessed with reliability.
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