Originally Posted by
ssc
The not cycling thread got me thinking. Before I begin a build, I spend at least an hour inspecting, measuring, test fitting and cleaning. Let’s keep this thread for lowers only. I am curious as what everyone does before building a stripped lower. I will outline my procedures.
I am no expert, but have built, repaired, stripped, rebuilt and replaced many parts. My guess is that I have been involved in over 50 builds from a stripped lower and many more from rebuilding etc.
The first thing I do is a visual inspection. I have seen grip screw recesses that wasn’t threaded. Had one that had plugs in the threads. Seen lowers that we’re not drilled for the bolt catch roll pin. Had four lowers from the same manufacture that were all out of spec regarding the distance between the front lugs. Etc.
If all looks good, I start test fitting. I have a set of all generation pmags and D&H and okay mags. They all need to fit and fall out. If so I install the mag catch and adjust and recheck. I test fit at least 3 uppers and check for fit and test fit both the pivot and take down pins. Then I test fit the bolt catch. Had a few that were out of spec and wouldn’t fit in the frame.
I always inspect the bolt catch plunger recess by installing two different plungers backwards. This is very important. If short drilled, I can remove the plunger via the nipple with needle nose pliers. Having had a short tapered recess that the plunger got wedged in and was a real bitch to extract, I consider this essential. Then I test fit the trigger pins and safety as well as the grip. Usually I have to work the grip off and on and remove some material while verifying the depth of the safety spring. Then check fit the remaining springs and detents.
Next comes the receiver etc. check fit the stock, spring, detent, castle nut and QD plate. Had a few plates and extensions that were defective. Then test install the receiver to the frame and check interface with the buffer detent. If all checks OK, I start my build.
That’s my preparation before I start to build a lower. What preparations does everyone else utilize?
Cheers, Steve
Bookmarks