View Full Version : Safety selector tension.
Sorry to sound like an idiot, but I am having trouble with my safety selector/spring/detent/pistol grip (dont know which). I assembled a stripped lower from a reputable manufacturer using a good LPK (LMT selector). It seemed fine, there was not excess tension in the selector and when turned much further past 45 degrees from vertical or horizontal it would snap right into safe or fire with a nice audible click. It was very crisp, just like a factory gun should feel. I ended up having some trouble with my lower and had to send it back to the factory in exchange for a replacement lower, which I went ahead and rattle can painted while it was still stripped. I went to put the same parts in my new lower (same spring, detent, selector and pistol grip) and now my selector feels like s**t. It is very stiff and now lacks the crisp "snapping action" it had before. To get this out of the way, no the paint is not interfering with the rotation of the selector. Without the detent and spring the selector turns 360 smooth as butter. I have tried taking the screw out of the pistol grip and moving the grip down to reduce spring tension, just to see what it would feel like if I cut a couple coils off the spring, and I can reach an acceptable amount of tension (about 1/16" down) but it still lacks the crisp snap into position I had with the other lower. Also, to be honest, this makes it feel like it could easily be switched from safe to fire unintentionally. I just cannot figure out why the exact same parts that functioned flawlessly in one lower feel like crap in another. Thoughts on this before I start copping the spring?
Suwannee Tim
03-31-11, 21:58
This detent mechanism is very simple, just a plunger, a spring and the safety selector drum. The only thing that has changed is the lower, the safety, plunger and spring are known good, right? First, examine both holes with a strong light for a burr. You should examine to determine how the recesses on the safety selector align with the hole the spring and plunger reside in. Maybe a machining issue, one hole failing to align properly in one or the other dimension. My guess is there lies your problem. I might make a probe from a piece of wire the diameter of the plunger or a little smaller with an end similar in shape to the plunger. Insert the probe, put a little force on it as the spring would and rotate the safety. You might get a clue from this.
False alarm. I took it apart to inspect as you suggested and while I was at it I put a drop of Mobil 1 in the detent cutout on the selector and holy cow, what a difference. It is super nice now. I apologize for the unnecessary thread and thank you for your suggestion.
Suwannee Tim
04-03-11, 08:15
'Mazin what a little bit of lube will do!
I hope this isn't a hijack, but it seems the perfect place to ask: what to do if the switch moves too freely? I am looking at a complete LMT lower and the selector isn't stiff/firm enough. All of the LMT lowers at the shop are the same way. These have no "snap" when moving from safe to semi.
B.A.D. Ambidextrous Safety Selector. It will provide durably consistent function of that rather important component.
Suwannee Tim
04-05-11, 20:34
Agreed. You might want to experiment by carefully deepening the hole in the safety on a drill press holding the safety in a machine vise.
Thank you Hmac! The selector is one of the parts that gets a lot of human interaction time, and really is one of the most crucial parts, and certainly a very important part in safe weapons handling.
There are a few parts at play in this dynamics: selector, detent, detent spring, pistol grip, and the receiver.
If the selector moves too freely or the rotation is very light, most likely there isn't enough tension on the detent spring pushing the detent against the selector's detent groove. The pistol grip can affect this as well. Compared to an A2 grip, the Magpul and TD grips seat the spring slightly shallower (spring sits higher), couple of coils taller is enough to make a difference. You can swap out the spring for a new one, or add some spacer in the pistol grip's detent spring housing hole.
The selector itself is usually not the source of the ills whose cause is spring tension related, though the selector can make a difference in other areas such as rotation smoothness, detent engagement when it's on Fire or Safe.
As far as modifying the selector goes, for liability reasons, you should be very careful. If it's involved in a shooting, the opposing attorney (or prosecutor) can look into every detail, you don't want them to find out you modified your selector outside of factory specs. Liability issues notwithstanding, these parts are heat treated (hardened), if you drill into it, you now unmasked the material that's not been hardened. It will still hold up pretty well, but it may rust, I wouldn't want that.
;)
I have four of them. They all work identically - crisp and solid, no wiggling.
Frankly, I can't see taking tools to my safety selector in lieu of just buying one that's well-designed and well-machined in the first place.
tfltackdriver
04-07-11, 20:43
The cheapest thing to do would be to take it back apart and try a different detent. Call me crazy, but when I've rebuilt lowers, I've found those detents wear in. Or you could flip over the one you've got in there.
Try it. I'm curious now.
You can't flip over the detent, the cone shaped end goes up and against the detent groove and detent holes on the selector, the other end is flat for the detent spring.
If you put the flat side up, there will be no detent hole engagement, and the selector will not stay in either Safe or Fire.
Left is the stainless steel detent we include with our selector, right is a detent that came from an unfired rifle (already chewed up)
http://i75.photobucket.com/albums/i314/Duffypoo/SSSafetyDetent-1.jpg
Left is our selector, right is a cast/MIM selector, to show the orientation of the detent, also the way the detent's contact area on the detent groove.
http://i75.photobucket.com/albums/i314/Duffypoo/detentgroovecomps.jpg
I hope this isn't a hijack, but it seems the perfect place to ask: what to do if the switch moves too freely? I am looking at a complete LMT lower and the selector isn't stiff/firm enough. All of the LMT lowers at the shop are the same way. These have no "snap" when moving from safe to semi.
I've seen that before with out of spec pistol grips (the hole was too deep). It wouldn't surprise me if I learned that Ergo put out a batch like that (though I suppose LMT would probably catch it during inspection).
I had a problem with a POF lower, where there was very little tension on the selector and the selector had more play than usual.
I thought it was the LPK so I experimented with all known good parts, one at a time to isolate the problem but it never went away. I finally figured out the lower was machined incorrectly. It wouldn't let the safety detent move into the selector as much as it needed to.
That is my sample of one, cheers.
I had a problem with a POF lower, where there was very little tension on the selector and the selector had more play than usual.
I thought it was the LPK so I experimented with all known good parts, one at a time to isolate the problem but it never went away. I finally figured out the lower was machined incorrectly. It wouldn't let the safety detent move into the selector as much as it needed to.
That is my sample of one, cheers.
The POF billet lower?
The POF billet lower?
Roger, P415 Gen III
http://www.rainierarms.com/?page=shop/detail&product_id=834
tfltackdriver
04-08-11, 07:07
You can't flip over the detent, the cone shaped end goes up and against the detent groove and detent holes on the selector, the other end is flat for the detent spring.
D'oh! Only done this with takedown pin detents anyhow.
A reversible detent may not be a bad idea :D
Roger, P415 Gen III
http://www.rainierarms.com/?page=shop/detail&product_id=834
One of my friends had a POF billet lower (I think a Gen II) and the lower hole of the bolt release was too shallow. So, like, breath on it when the bolt was locked back and it released.
After he tried a couple different bolt releases (because he figured it was the Bolt release that was out of spec) he determined it was the lower. He sent it back to POF. When he got it back, sure enough, the lower hole of the bolt release was drilled deeper. The thing is will billet lowers, generally when one is out of spec likely hundreds of them are (since we're talking CNC).
vBulletin® v3.7.2, Copyright ©2000-2013, Jelsoft Enterprises Ltd.