In What Order Do You Install The LPK

[prepare]

Out of curiosity, in what order do you install the lower parts kit (including the buffer tube) when building out a stripped lower?

Also what is the methodology behind the sequence?

[SteveL]

1. Trigger guard first because if I'm going to break an ear I want to get it over with.
2. Mag catch so it will catch on a vice block.
3. Bolt catch.
4. Pivot pin.
5. RE and takedown pin.
6. Trigger & hammer.
7. Safety.
8. Grip.
9. Buffer & spring.
10. Function check and stake castle nut.
11. Stock.

No particular reason for this sequence after 1 & 2.

[prepare]

1. Trigger guard first because if I'm going to break an ear I want to get it over with.
2. Mag catch so it will catch on a vice block.
3. Bolt catch.
4. Pivot pin.
5. RE and takedown pin.
6. Trigger & hammer.
7. Safety.
8. Grip.
9. Buffer & spring.
10. Function check and stake castle nut.
11. Stock.

No particular reason for this sequence after 1 & 2.

That seem like a logical sequence.

[556Cliff]

Order for assembling a lower with a carbine receiver extension.

1: Trigger guard.

2: Bolt catch.

3: Buffer retainer.

4: Takedown pin.

5: Receiver extension.

6: Mag catch.

7: Pivot pin.

8: Trigger & hammer.

9: Safety selector.

10: Pistol grip.

11: Stock.

12: Buffer spring and buffer.


Order for assembling a lower with a rifle receiver extension.

1: Trigger guard.

2: Bolt catch.

3: Buffer retainer.

4: Receiver extension.

5: Mag catch.

6: Pivot pin.

7: Trigger & hammer.

8: Safety selector.

9: Pistol grip.

10: Takedown pin.

11: Stock.

12: Buffer spring and buffer.


I used to install the safety selector and pistol grip before the trigger and hammer, but I occasionally run into lowers where you can't install the trigger if the safety selector is installed first, so I changed the order because that was annoying.

[SteveL]

Order for assembling a lower with a carbine receiver extension.

1: Trigger guard.

2: Bolt catch.

3: Buffer retainer.

4: Takedown pin.

5: Receiver extension.

6: Mag catch.

7: Pivot pin.

8: Trigger & hammer.

9: Safety selector.

10: Pistol grip.

11: Stock.

12: Buffer spring and buffer.


Order for assembling a lower with a rifle receiver extension.

1: Trigger guard.

2: Bolt catch.

3: Buffer retainer.

4: Receiver extension.

5: Mag catch.

6: Pivot pin.

7: Trigger & hammer.

8: Safety selector.

9: Pistol grip.

10: Takedown pin.

11: Stock.

12: Buffer spring and buffer.


I used to install the safety selector and pistol grip before the trigger and hammer, but I occasionally run into lowers where you can't install the trigger if the safety selector is installed first, so I changed the order because that was annoying.

I've always thought it was a pain to install the mag catch after the bolt catch is installed, especially if it's not a standard mil-spec bolt catch.

[556Cliff]

I've always thought it was a pain to install the mag catch after the bolt catch is installed, especially if it's not a standard mil-spec bolt catch.

I just use the standard bolt catch on most builds and I've never had an issue with the standard bolt catch getting in the way while installing the mag catch. Though I can definitely see having to reverse the order of installation if going with a non standard bolt catch as you mention.

[SteveL]

I just use the standard bolt catch on most builds and I've never had an issue with the standard bolt catch getting in the way while installing the mag catch. Though I can definitely see having to reverse the order of installation if going with a non standard bolt catch as you mention.

It was something I learned the hard way for sure. When installing something like FCD or Seekins Precision, etc. I've had to take them right back out to install the mag catch on a couple of occasions.

[prepare]

If/when you're building out a lot of lowers it's a good idea to have a system and a methodology. For consistency, efficiency, and quality work.

[556Cliff]

It was something I learned the hard way for sure. When installing something like FCD or Seekins Precision, etc. I've had to take them right back out to install the mag catch on a couple of occasions.

I'm glad you brought it up here, it might save me a bit of hassle (and a bolt catch roll pin) in the future.

[556Cliff]

If/when you're building out a lot of lowers it's a good idea to have a system and a methodology. For consistency, efficiency, and quality work.

Agree 100%. The most lowers I've ever assembled at one time was only two, but I had to put together many one offs to come up with my evolved routine. I'm always interested in picking up tips and tricks to make things go smoother. Having said that, I don't run into many issues anymore and at least 87% of that comes down to using quality tools.