This is my very first post on this forum. I have been an AR owner since June '08. I bought a 16" LMT Defender and have been quite pleased with it. I plan to build the next couple and am starting them as pistols before I SBR them. Anyway, I am trying to drop a RRA 2-stage trigger LPK into a MEGA stripped lower. Everything went fine until I started to drop the trigger group in.
I had problems cocking the hammer back after the install and thought that I was doing something wrong with the hammer and trigger install. I couldn’t, for the life of me, figure out what I was doing wrong. This was my first lower build but I’m a fairly intelligent guy and this just wasn’t making sense. I decided to remove the safety to see what would happen and I was able to cock the hammer back and safely drop it (slowly, holding onto it with my other hand) by pulling the trigger.
I looked through the safety hole while doing this and saw how the back part of the trigger component would rise when I would pull the trigger to release the hammer. The height that the trigger has to rise to release the hammer is greater than what the notch cut into the safety will allow. Tell me what else I’m doing wrong. Does anyone have any experience with this?
The following pics show the trigger installed. All looks good.
In the following pic, I’m trying to cock the hammer back but it won’t go any further.
You can see the top of the safety selector installed. That is what is blocking the trigger component from traveling upwards far enough for the hammer to catch. When I remove the safety selector, the rear of the trigger component is able to travel upwards far enough for the hammer to catch. I don’t understand why this is happening.
Below are pics of the view through the space for the selector with the hammer cocked and with the hammer dropped.
Below is a pic of me engaging the trigger to drop the hammer. Look at how high the trigger component travels. There is no way that this is going to happen with the selector installed!
Below are some pics of the selector. It looks as though it could stand to have some metal shaved off to make room for the trigger movement. Of course, this begs the question: why would RRA sell a LPK w/ 2-stage trigger that is out of spec? Someone pointed out that my hammer is shaped differently than their RRA 2-stage kit hammer. Have I got a goose egg on my hands?
FP, do not alter the selector!!!
I have the same trigger assembly in 3 carbines and they all look like the one in your pictures. Did you follow the install instructions in order: trigger than selector than hammer. The selector will not move to the safe position when the hammer is in the forward position (fired position). When the selector is out of the lower the trigger will move more than it normally would, that is why you are seeing it through the selector hole. Remove the hammer and re-install the selector, when the selector is in place install the detent, spring and grip. Then re-install the hammer and see if that makes a difference.
I just completed an armorers course and this came up in discussion, following the correct install order. If this does not work you may want to find a AR15 armorer in your area who can look at it for you.
Good Luck.
I would disassemble the LPK, and reinstall in the proper order and then see what happens. I would absolutely not alter the selector lever in any way. Also, you may want to stake your end plate and castle nut.
Just installed a RRA 2 stage in a Larue lower and had the same issues; atleast I couldn’t get the hammer to drop. Simple fix. Took the dremel out and, litttle by little, ground a bit off the safety selector where you see that small circle. Did it til I could get it to drop. Works great. Don’t mees with the trigger itself.
If the correct assy order doesn’t work you’ll have to fit it to the safety.
I’ve installed well over 100 RRA triggers and about 15% need fitting of the safety to the trigger the other 85% drop in.
I guess I’ve got to go buy me a dremel. Next thing you know, I’ll be polishing magwells. Guess this is the beginning of the end… I appreciate the help, fellas.
I just installed the RRA two stage in my M&P15 and it was so tight with the safety i was worried. I just used a dremel cuttoff wheel to lower the shelf in the safety a few thousandths. Do not alter the trigger or the rounded part of the safety as this could result in an unsafe condition. Work a bit at a time until the hammer drops. Also do not drop the hammer without the upper installed or catching the hammer with your finger as you will damage your lower.
Should I buy a file instead and do it by hand? What kind of file is best for this? I know some files are wider at the base and then taper toward the end; is this the style/design of file I would buy or is there one with uniform width throughout? I would think that a file with uniform width from end to end would facilitate the process the best.
In my experience those parts are metal injection moulded or cast and are very hard. Filing by hand would be dificult. Gotm4 is right a miling machine would be ideal. that way you could keep it square. Have you tried to contact RRA? You may just want to try another selector to see if that helps. Sometimes you get stacking tolerances where in this case the hole is slightly off and the selector is slightly off together making the system unworkable.
