10-21-2019, 01:14 PM
(This post was last modified: 10-21-2019, 10:00 PM by Flight Medic.)
The Lancer LCR5 Handguard installation instructions called for their "Receiver Extension Nut" to be installed with Red-Loctite BEFORE installation of the barrel (the barrel nut essentially becomes a jam nut).
![[Image: Rgs09B.jpg]](https://imagizer.imageshack.com/img922/2781/Rgs09B.jpg)
I completed this step and, while I was wondering if I could still heat the receiver with the red Loctite on the threads, a panic fell over me because I realized that, with the Lancer Receiver Extension Nut in place, I will NOT be able to visualize the index pin going into the recess in the upper receiver.
![[Image: 8k4rvD.jpg]](https://imagizer.imageshack.com/img924/3756/8k4rvD.jpg)
I figured this is not a issue for most people that have a barrel that slides right in at room temperature, but without being able to view the pin's orientation to the recess I would have ZERO confidence tapping/pressing the barrel into position. I thought about marking the barrel somehow with a line or dot that coincides with the pin location to make sure the barrel doesn't rotate. However, Sharpie ink is going to adhere to a frozen barrel, nor will masking tape. And while I'm pondering how exactly I'm going to accomplish this the red Loctite is drying. So, in full desperation, I decide to remove the nut. I tried by hand to remove, but it wouldn't budge. I had to use a large screwdriver, inserting it transversely through the slots, and use both hands to twist like a die handle wrench to force it off. It took some muscle, but once I got it spun one complete revolution it came off with nary a whimper
I cleaned out all the dry (and still wet) Loctite, heated the receiver threads with my heat gun and used some Rem Oil to lube the inside of the receiver collar. I grabbed the barrel out of the freezer and began to insert. It went in farther this time (about half way), but as soon as I heard the "hiss" from the cold barrel extension meeting the hot receiver the barrel just froze in place. My heart sank when I noticed the pin was slightly off center from the recess slot and the barrel wouldn't turn at all. I attempted to use my Knipex pliers, but the rubber jaws simply spun on the frozen barrel. I immediately grabbed my bench mat and, with the rubber-side to the barrel, began attempting to pull and twist the barrel out. I was seeing slight movement outward, so I persisted until the barrel was completely removed.
Making sure the pin was lined up this time, I reinserted the barrel as far as it would go by hand. Then I removed the semi-mated pair from the vise,
![[Image: k5eePU.jpg]](https://imagizer.imageshack.com/img923/1277/k5eePU.jpg)
placed the barrel vertically (thread-side down) on my wooden bench with the factory rubber cap over the barrel threads and began to firmly tap the back of the receiver with short strokes. The receiver slowly slid down the barrel extension and mated flush with the receiver flange. I did NOT have to strike nearly as hard as I feared. I then reapplied red Loctite to the Lancer Receiver Extension Nut threads (rather than the receiver threads), re-mounted the Receiver Extension Nut and let it sit for the recommended 24 hours.
![[Image: 68Ttf2.jpg]](https://imagizer.imageshack.com/img922/7902/68Ttf2.jpg)
(you can clearly see on the right side of the U-shaped cutout where the screwdriver dinged-up the aluminum from the force needed to break the half-dried Loctite. This needed shaving later on in order to slide the carbon fiber tube in place.)
`
I completed this step and, while I was wondering if I could still heat the receiver with the red Loctite on the threads, a panic fell over me because I realized that, with the Lancer Receiver Extension Nut in place, I will NOT be able to visualize the index pin going into the recess in the upper receiver.
I figured this is not a issue for most people that have a barrel that slides right in at room temperature, but without being able to view the pin's orientation to the recess I would have ZERO confidence tapping/pressing the barrel into position. I thought about marking the barrel somehow with a line or dot that coincides with the pin location to make sure the barrel doesn't rotate. However, Sharpie ink is going to adhere to a frozen barrel, nor will masking tape. And while I'm pondering how exactly I'm going to accomplish this the red Loctite is drying. So, in full desperation, I decide to remove the nut. I tried by hand to remove, but it wouldn't budge. I had to use a large screwdriver, inserting it transversely through the slots, and use both hands to twist like a die handle wrench to force it off. It took some muscle, but once I got it spun one complete revolution it came off with nary a whimper
I cleaned out all the dry (and still wet) Loctite, heated the receiver threads with my heat gun and used some Rem Oil to lube the inside of the receiver collar. I grabbed the barrel out of the freezer and began to insert. It went in farther this time (about half way), but as soon as I heard the "hiss" from the cold barrel extension meeting the hot receiver the barrel just froze in place. My heart sank when I noticed the pin was slightly off center from the recess slot and the barrel wouldn't turn at all. I attempted to use my Knipex pliers, but the rubber jaws simply spun on the frozen barrel. I immediately grabbed my bench mat and, with the rubber-side to the barrel, began attempting to pull and twist the barrel out. I was seeing slight movement outward, so I persisted until the barrel was completely removed.
Making sure the pin was lined up this time, I reinserted the barrel as far as it would go by hand. Then I removed the semi-mated pair from the vise,
placed the barrel vertically (thread-side down) on my wooden bench with the factory rubber cap over the barrel threads and began to firmly tap the back of the receiver with short strokes. The receiver slowly slid down the barrel extension and mated flush with the receiver flange. I did NOT have to strike nearly as hard as I feared. I then reapplied red Loctite to the Lancer Receiver Extension Nut threads (rather than the receiver threads), re-mounted the Receiver Extension Nut and let it sit for the recommended 24 hours.
(you can clearly see on the right side of the U-shaped cutout where the screwdriver dinged-up the aluminum from the force needed to break the half-dried Loctite. This needed shaving later on in order to slide the carbon fiber tube in place.)
`