Nice, Pete. My PSA M16A2 lower is in the 816xxx serial range, so about 1000 before yours. So far, it has been great. Very accurate, though that is more a function of a quality barrel and BCG. I have been very pleased with the PSA lowers for two builds, and I have a PSA M16A4 lower waiting to be completed. I look forward to your video series for this rifle. And yes, ever since you showed me the set screw trick for the take down pin, I have done that for all my rifles. Great tip! The great thing about building your own rifle (one of the great things) is you can take your time and attend to little details like breaking the edge on the butt, shimming the buffer tube, etc. Very little cost and just a little time makes all the difference.
Thanks Gary! I have never had an issue on any build where there wasn't enough clearance on the gas key to receiver but I have seen where others did have that issue. This is the 6th A2 butt stock I have installed but only the 2nd one where I felt a shim was required. Got lucky on the other ones I guess. I can almost guarantee a manufacturer would just slam it all together with no concern about over torquing the plastic butt plate from excessive clearance. Thanks again for watching and commenting!
I believe that you are correct on the trapdoor being an A1 version. The A2 door follows the contours of the opening a little bit closer, but probably 99% of folks would never notice, & I'm not telling anyone!
Ha! Ha! Thanks! It starts out flush with the butt plate at the hinge but then goes a little below flush at the release pin. It's very tight and does not rattle at all. This is my third metal door A2 from Fulton Armory and they all fit the same. Thanks for watching and commenting!
I used to see folks bringing back Craftsman screwdrivers to Sears for"warranty" replacement when I would be shopping the tool section. The blades were usually driven at least half way back through the handles, and/or bent over at a nice angle.
From a budget brand standpoint, I bought first A2 buttstock kit from UTG. First A1 from Luth AR, definitely got what I paid for quality. Not making them like Bushmaster quality from the 90's and early 2000's.
I did take a look at UTG. I noticed the plastic door release latch pin and just couldn't. The rest of the UTG butt stock wasn't too bad. The Fulton Armory A2 is decent and you can still get the metal door although I believe the door it's actually for an A1. Not the best fitment but all metal.The Fulton Armory A2 hand guards are junk! Very little in the Retro world is the same quality as it once was and especially true for the furniture. The H&R A2 hand guard is good! The original Bushmaster was very good back in the day! In some regards better than Colt was! Bushmaster went to crap when the Freedom Arms Group (Remington) purchased the company from the original owner Richard Dyke! Interesting story how Remington destroyed Bushmaster and then not to much later themselves!
@@peteregger7928.. Freedom Group ruined a lot of companies. I just saw a video where S&W had purchased some years back all of the old Thompson Center brand with all the machinery and stock then just let it sit in a warehouse. Some guys bought it and are going it bring back to life. They're in the process of trucking it out of Springfield, Mass. Cool video on UA-cam about it. Your builds and content are the best to us that are into it. Thanks.
Good afternoon, Pete! Nice build you have started. Man, you have a full-time job building AR's. You're the busiest retiree I've ever seen! I love it! What brand lower parts kit did you use, if I may ask? I'd noticed on PSA's H & R parts section, there was an A2 retro selector switch for $16 and change. That seemed expensive, to me anyway. I looked at their 20" classic rifle, zoomed in on the selector switch and couldn't see a difference, although there probably was some. I watched your video of you shooting your Windham A2's this weekend. I really enjoyed that, and your "range" was a beautiful site. Nevada apparently has beautiful, secluded areas! I liked your shooting bench. I bet you made it. Were those "Ruddy Buddy" legs? I made myself a shooting bench from an old ironing board. I attached indoor-outdoor carpet to the top with double-sided Gorilla Tape. I had previously seen this on a U-Tube video, but, I left my carpet hanging over the sides and ends, folded it down, drilled 1/4" holes @ 6" o.c., installed #8 x 3/4" machined screws with washers on the outside to prevent the screws from pulling through the carpet. It works well for me. Thats the first A2 buttstock I've seen with a metal door. Fulton Armory, I think you said. Noce. I'll shut up, finally. Have a great day and keep up the great work, Pete! Oh yea, I know the video you related to about the man using Lok-Tite on a receiver extension! LOL! Good one, PETE!
Unfortunately because of the economy I will be slowing down on the builds but not stopping! Lol! I've had good luck with CMMG and sometimes Aero Precision for the LPK pins, mag release. bolt catch and selector but I don't use their triggers. I've been using AERO lately on the Retro builds because they don't dimple the take down and pivot pins. My Windham's have been solid rifles although I have been critical of them for not sticking with MilSpec dimensions on buffer tubes and not using the correct "F" marked sight bases and carry handles on their flat tops. Otherwise they are solid well finished rifles. Not sure what's going on with Windham right now but it doesn't look good to me? I did make the shooting bench using Rugged Buddy folding legs which last time I checked are no longer made. I know he was selling a boat load of them because they were always in and out of stock on Amazon. I'm going to have to see that ironing board bench you're talking about! The Fulton Armory A2 butt stocks are decent. You can get them with the plastic door metal latch release pin or the all metal door version. I believe the metal doors are actually the A1 design using the A1 release pin. They're not the best fit as far as being flush with the butt plate but they are tight and don't rattle. The FA A2 hand guards are junk! Lok-Tite on a buffer tube... nope! Have a good one John!
Thanks Malcolm! Usually no more than two coils or just a little less than the length of the set screw. The set screw usually has a little taper at the end that will just start to enter the first coil that it comes into contact with.
Thanks Chris! I haven't fired the H&R M16A2 medium contour yet either! Lol! Temps here in Vegas are starting to cool down a little so I should be getting out soon! It's like that planet in Chronicles of Riddick called Crematoria around here! Lol!
One more question, Pete, if I may ask. When installing the A2 buffer tube, do you just use your mag-well lower receiver block? Just wondering if that will hold it securely enough to prevent clocking. Would something like the NC Star Vism lower receiver block be the better choice? It's made for castle nut installation but would probably work in the A2 situation also. The A2 stock assembly kit from KAK looks good to me, but it's the first one I've ever seen in the flesh, er, in the polymer! The trap door is plastic as is the latch, but it's a nice-looking piece, black, not gray. The door doesn't open to 90 degrees, like your Colt, it opens about like your Windham A2, or perhaps even a little less. Thanks again, Pete!
I've found the vise block to work just fine for the castle nut torque. I usually stay just under or the very low end of spec for that one and use some lube. I recommend staking but I never do! Lol! Glad the KAK A2 worked out! Have a good one John!
I recently bought an LEO trade-in AR-15A2 carbine that has a Magpul MOE hand guard, a RRA flat top upper, & a modern P&S Colt pattern waffle stock. I'm wanting to replace those parts with something more akin to the original Colt parts. Pencil barrel & FSB are Colt oem. I would be interested in hearing your recommendations for more appropriate parts. I haven't yet researched the year of manufacture, but the lower is marked with the restricted nomenclature of the Biden ass ualt weapons ban era. You do quality work, which I can appreciate. TY.
Thanks Urbicide! For furniture I believe P&S was purchased by Prudent American Technologies (P.A.T.) cage code 8FW25. I'm not sure but I believe P.A.T. is presently only producing RAS rail covers and waffle stocks and they are usually listed as just MilSpec. Arms Unlimited sells the P.A.T. waffle stocks as Colt because Colt is using them as a supplier. I found trying to find NOS (new old stock) Colt, Knights Armament, P&S now P.A.T. has become increasingly difficult. If you can find anything used in excellent condition the price is usually way more than I'm willing to pay. I've had good luck with H&R branded uppers/lowers and the H&R branded A2 and Carbine hand guards recently from Palmetto State Armory. They do not have separate A2 rear sights if building from a stripped upper. If you can even find a new flat top Colt upper right now it's probably going to have the cage code on it and the same for the carry handle. I mentioned some of the flat top stuff in case your LEO didn't start out as an A2 but it sounds like it did. Finding a new Colt chalky deep charcoal grip has also become mission impossible and they may be gone for good? Finding affordable correct parts for your LEO can still be done but I think it won't be easy! I don't know what part of the country you're in but here in Vegas you can sometimes get lucky at pawn shops. Another possible source may be estate sales or firearms auctions.
@@peteregger7928 Thanks for responding. I'm in east-central GA. The waffle stock is the only part that has a cage code, 4U486, & looks relatively new. I was thinking about the retro B-5 carbine stock, if that type was correct. I've read about retro hand guards having either 6 or 7 holes, so that is another question of which number is correct. The rifle came from AIM Surplus, & all of these AR-15A2's were fitted with Rock River flat tops. Apparently they were all converted for some police department so that they could more easily run an optic. The MOE hand guard has a small section of pic rail for a light. I wonder if they pitched all of the fixed carry handles in the trash, or if they are sitting in some forgotten parts box underneath a work bench? It's ironic how yesterdays trash is today's treasure.
@@Urbicide Colt has a serial number look-up at their web site if your lower is Colt. they only list a fraction of what they built but for a small fee they will go into their archives and look it up and then also give you a letter of authenticity. It sounds like your's started out as a CAR15 pre-M4 so the waffle stock may not be correct. My old Colt CAR15 has an aluminum butt stock that most people refer to as two position but the way I look at it 3 position. Fully closed, midway and fully open. Mine has the 6 hole hand guard with the 1:9 twist 16" HBAR. Mine also uses the old style spanner locking ring instead of the newer castle nut for the buffer tube and was configured with the flat top receiver. Purchased in the mid 90's.
The replacement had both seals intact. The first one missing the hammer did not have a seal installed at the bottom of the box. There were no signs that one had been there to begin with.
Hello, Pete. I've got about all my parts gathered up for the A1 build. I'm waiting on the A1 upper receivers to be back in stock at PSA. (H & R). I probably should have followed your advice on using black instead of gray because I could have got an upper from AR15 Discounts and PSA has black A1 lowers in stock again, but, no, I wouldn't listen! LOL! Dang it! I've been known for that a few times. It's like my mom used to tell me, "Son, you'll never amount to anything, because you procrastinate". I replied, "You just wait"! No, I had a question, please. Do you torque your A2 buffer tube to the recommended 35-39 ft. lbs.? I've looked on the internet and have written all the recommended torque specs down. I remember you saying it's not a good idea to torque the muzzle device to the recommended 15-20 ft. lbs., you recommended 12-15 ft. lbs., if I'm not mistaken. I've found the USMC 1984 manual you use on the AR15 Repository site. Is that where you get the TDP you use from? Like the spring length and number of coils recently when solving, I think, the Wilson Combat BCG issue? Thanks, Pete and stay warm, its 36 here and hasn't warmed any today.
We got down to 29F last night! A little chilly for us desert rats! Yes, I just tighten the castle nut while in the vise block and stay under 40 ftlbs using some lube. If you're staking the castle nut you shouldn't have any issues being under the torque spec. The muzzle device is one of the areas I deviate from the TDP torque spec and try to land around 15 ftlbs. You can always use shims for timing. Got the TDP drawings from Gatalog.com.
@@peteregger7928 Great! I'll check Gatalog out. Thanks, Pete. Yes sir, chilly in the desert! I've always heard it feels colder in the desert. I'm using an A1 birdcage muzzle device so I won't have to worry about timing. I have a split washer, I think that's o.k. for the A1 compensator. So, you torque your A2 buffer tube to just below the 35 ft. lbs. recommended spec? Thank you, my friend and have a safe and great holiday season!
@@John-zf5wc I try although it's not always possibly to stay at the lowest torque specification. Just my personal beliefs but a lot of the TDP specifications are for "go to war". The one place I try really hard to stay in the middle is barrel nut torque. If I'm a little under on the buffer tube for me it's not an issue especially on an A2. If the buffer tube, spacer, butt plate, and butt plate screw and butt stock are all properly snug and in contact with the receiver and with each other it would be difficult for all of it to come unglued to the point of failure without the operator noticing. My old Marine Corp manual says 15-20 ft lbs for the compensator but if I got it timed at 12 that would be good enough for me. As you were saying timing an A1 won't be an issue. Barrel nut is listed as 31 but not to exceed 80 ft lbs. I shoot for anywhere between 40 and 60 but try very hard not to get past 70 ft lbs which is just my preference. Buffer tube is 35-39 ft lbs so I would just go 35 and a few pounds under wouldn't bother me. Most torque wrenches are +/- 4% of indicated value. Example would be a torque wrench that reads/clicks to a range of 100 ft lbs. In spec accuracy would be +/- 2 ft lbs at 50 or +/- 4 ft lbs at 100.
Nice, Pete. My PSA M16A2 lower is in the 816xxx serial range, so about 1000 before yours.
So far, it has been great. Very accurate, though that is more a function of a quality barrel and BCG. I have been very pleased with the PSA lowers for two builds, and I have a PSA M16A4 lower waiting to be completed.
I look forward to your video series for this rifle.
And yes, ever since you showed me the set screw trick for the take down pin, I have done that for all my rifles. Great tip!
The great thing about building your own rifle (one of the great things) is you can take your time and attend to little details like breaking the edge on the butt, shimming the buffer tube, etc. Very little cost and just a little time makes all the difference.
Thanks Gary! I have never had an issue on any build where there wasn't enough clearance on the gas key to receiver but I have seen where others did have that issue. This is the 6th A2 butt stock I have installed but only the 2nd one where I felt a shim was required. Got lucky on the other ones I guess. I can almost guarantee a manufacturer would just slam it all together with no concern about over torquing the plastic butt plate from excessive clearance. Thanks again for watching and commenting!
I believe that you are correct on the trapdoor being an A1 version. The A2 door follows the contours of the opening a little bit closer, but probably 99% of folks would never notice, & I'm not telling anyone!
Ha! Ha! Thanks! It starts out flush with the butt plate at the hinge but then goes a little below flush at the release pin. It's very tight and does not rattle at all. This is my third metal door A2 from Fulton Armory and they all fit the same. Thanks for watching and commenting!
16:25 I always wondered why flat head screwdrivers were wedge shaped and not parallel.
Almost like they were actually meant to be chisels.
Ha! Ha! I use some of mine to dig holes! So many rocks here in Vegas it's impossible to use a shovel or even a pick!
I used to see folks bringing back Craftsman screwdrivers to Sears for"warranty" replacement when I would be shopping the tool section. The blades were usually driven at least half way back through the handles, and/or bent over at a nice angle.
@@Urbicide Ha! Ha! Yep! Back then no questions asked!
From a budget brand standpoint, I bought first A2 buttstock kit from UTG. First A1 from Luth AR, definitely got what I paid for quality. Not making them like Bushmaster quality from the 90's and early 2000's.
I did take a look at UTG. I noticed the plastic door release latch pin and just couldn't. The rest of the UTG butt stock wasn't too bad. The Fulton Armory A2 is decent and you can still get the metal door although I believe the door it's actually for an A1. Not the best fitment but all metal.The Fulton Armory A2 hand guards are junk! Very little in the Retro world is the same quality as it once was and especially true for the furniture. The H&R A2 hand guard is good! The original Bushmaster was very good back in the day! In some regards better than Colt was! Bushmaster went to crap when the Freedom Arms Group (Remington) purchased the company from the original owner Richard Dyke! Interesting story how Remington destroyed Bushmaster and then not to much later themselves!
@@peteregger7928.. Freedom Group ruined a lot of companies. I just saw a video where S&W had purchased some years back all of the old Thompson Center brand with all the machinery and stock then just let it sit in a warehouse. Some guys bought it and are going it bring back to life. They're in the process of trucking it out of Springfield, Mass. Cool video on UA-cam about it. Your builds and content are the best to us that are into it. Thanks.
Good afternoon, Pete! Nice build you have started. Man, you have a full-time job building AR's. You're the busiest retiree I've ever seen! I love it! What brand lower parts kit did you use, if I may ask? I'd noticed on PSA's H & R parts section, there was an A2 retro selector switch for $16 and change. That seemed expensive, to me anyway. I looked at their 20" classic rifle, zoomed in on the selector switch and couldn't see a difference, although there probably was some. I watched your video of you shooting your Windham A2's this weekend. I really enjoyed that, and your "range" was a beautiful site. Nevada apparently has beautiful, secluded areas! I liked your shooting bench. I bet you made it. Were those "Ruddy Buddy" legs? I made myself a shooting bench from an old ironing board. I attached indoor-outdoor carpet to the top with double-sided Gorilla Tape. I had previously seen this on a U-Tube video, but, I left my carpet hanging over the sides and ends, folded it down, drilled 1/4" holes @ 6" o.c., installed #8 x 3/4" machined screws with washers on the outside to prevent the screws from pulling through the carpet. It works well for me. Thats the first A2 buttstock I've seen with a metal door. Fulton Armory, I think you said. Noce. I'll shut up, finally. Have a great day and keep up the great work, Pete! Oh yea, I know the video you related to about the man using Lok-Tite on a receiver extension! LOL! Good one, PETE!
Unfortunately because of the economy I will be slowing down on the builds but not stopping! Lol! I've had good luck with CMMG and sometimes Aero Precision for the LPK pins, mag release. bolt catch and selector but I don't use their triggers. I've been using AERO lately on the Retro builds because they don't dimple the take down and pivot pins. My Windham's have been solid rifles although I have been critical of them for not sticking with MilSpec dimensions on buffer tubes and not using the correct "F" marked sight bases and carry handles on their flat tops. Otherwise they are solid well finished rifles. Not sure what's going on with Windham right now but it doesn't look good to me? I did make the shooting bench using Rugged Buddy folding legs which last time I checked are no longer made. I know he was selling a boat load of them because they were always in and out of stock on Amazon. I'm going to have to see that ironing board bench you're talking about! The Fulton Armory A2 butt stocks are decent. You can get them with the plastic door metal latch release pin or the all metal door version. I believe the metal doors are actually the A1 design using the A1 release pin. They're not the best fit as far as being flush with the butt plate but they are tight and don't rattle. The FA A2 hand guards are junk! Lok-Tite on a buffer tube... nope! Have a good one John!
@@peteregger7928 Thanks for all the great info! Have a great week!
Nice.
👍
I may have asked you this before; how many loops do you snip off the rear detent spring before you install the set screw? Nice work, btw
I could be wrong as I have never done it, but would seem to me to balance out you cut the spring the length of the set screw.
Thanks Malcolm! Usually no more than two coils or just a little less than the length of the set screw. The set screw usually has a little taper at the end that will just start to enter the first coil that it comes into contact with.
@@ar-15techtipsinunder5minut8 That's how I do it.
@@peteregger7928 makes sense, thanks.
Great Video Chief. Keep them coming.
Thanks Chief! More to come!
Really Nice 👍🏼 Build Pete Hope Too See Part 2 Of This Build Soon 😀 Very Good Tips Have You Fired The M4 Clone Yet 😊
Thanks Chris! I haven't fired the H&R M16A2 medium contour yet either! Lol! Temps here in Vegas are starting to cool down a little so I should be getting out soon! It's like that planet in Chronicles of Riddick called Crematoria around here! Lol!
@@peteregger7928 🥵😮💨🥵
One more question, Pete, if I may ask. When installing the A2 buffer tube, do you just use your mag-well lower receiver block? Just wondering if that will hold it securely enough to prevent clocking. Would something like the NC Star Vism lower receiver block be the better choice? It's made for castle nut installation but would probably work in the A2 situation also. The A2 stock assembly kit from KAK looks good to me, but it's the first one I've ever seen in the flesh, er, in the polymer! The trap door is plastic as is the latch, but it's a nice-looking piece, black, not gray. The door doesn't open to 90 degrees, like your Colt, it opens about like your Windham A2, or perhaps even a little less. Thanks again, Pete!
I've found the vise block to work just fine for the castle nut torque. I usually stay just under or the very low end of spec for that one and use some lube. I recommend staking but I never do! Lol! Glad the KAK A2 worked out! Have a good one John!
I recently bought an LEO trade-in AR-15A2 carbine that has a Magpul MOE hand guard, a RRA flat top upper, & a modern P&S Colt pattern waffle stock. I'm wanting to replace those parts with something more akin to the original Colt parts. Pencil barrel & FSB are Colt oem. I would be interested in hearing your recommendations for more appropriate parts. I haven't yet researched the year of manufacture, but the lower is marked with the restricted nomenclature of the Biden ass ualt weapons ban era. You do quality work, which I can appreciate. TY.
Thanks Urbicide! For furniture I believe P&S was purchased by Prudent American Technologies (P.A.T.) cage code 8FW25. I'm not sure but I believe P.A.T. is presently only producing RAS rail covers and waffle stocks and they are usually listed as just MilSpec. Arms Unlimited sells the P.A.T. waffle stocks as Colt because Colt is using them as a supplier. I found trying to find NOS (new old stock) Colt, Knights Armament, P&S now P.A.T. has become increasingly difficult. If you can find anything used in excellent condition the price is usually way more than I'm willing to pay. I've had good luck with H&R branded uppers/lowers and the H&R branded A2 and Carbine hand guards recently from Palmetto State Armory. They do not have separate A2 rear sights if building from a stripped upper. If you can even find a new flat top Colt upper right now it's probably going to have the cage code on it and the same for the carry handle. I mentioned some of the flat top stuff in case your LEO didn't start out as an A2 but it sounds like it did. Finding a new Colt chalky deep charcoal grip has also become mission impossible and they may be gone for good? Finding affordable correct parts for your LEO can still be done but I think it won't be easy! I don't know what part of the country you're in but here in Vegas you can sometimes get lucky at pawn shops. Another possible source may be estate sales or firearms auctions.
@@peteregger7928 Thanks for responding. I'm in east-central GA. The waffle stock is the only part that has a cage code, 4U486, & looks relatively new. I was thinking about the retro B-5 carbine stock, if that type was correct. I've read about retro hand guards having either 6 or 7 holes, so that is another question of which number is correct. The rifle came from AIM Surplus, & all of these AR-15A2's were fitted with Rock River flat tops. Apparently they were all converted for some police department so that they could more easily run an optic. The MOE hand guard has a small section of pic rail for a light. I wonder if they pitched all of the fixed carry handles in the trash, or if they are sitting in some forgotten parts box underneath a work bench? It's ironic how yesterdays trash is today's treasure.
@@Urbicide Colt has a serial number look-up at their web site if your lower is Colt. they only list a fraction of what they built but for a small fee they will go into their archives and look it up and then also give you a letter of authenticity. It sounds like your's started out as a CAR15 pre-M4 so the waffle stock may not be correct. My old Colt CAR15 has an aluminum butt stock that most people refer to as two position but the way I look at it 3 position. Fully closed, midway and fully open. Mine has the 6 hole hand guard with the 1:9 twist 16" HBAR. Mine also uses the old style spanner locking ring instead of the newer castle nut for the buffer tube and was configured with the flat top receiver. Purchased in the mid 90's.
18:29 was the seal broken on the replacement box?
The replacement had both seals intact. The first one missing the hammer did not have a seal installed at the bottom of the box. There were no signs that one had been there to begin with.
Hello, Pete. I've got about all my parts gathered up for the A1 build. I'm waiting on the A1 upper receivers to be back in stock at PSA. (H & R). I probably should have followed your advice on using black instead of gray because I could have got an upper from AR15 Discounts and PSA has black A1 lowers in stock again, but, no, I wouldn't listen! LOL! Dang it! I've been known for that a few times. It's like my mom used to tell me, "Son, you'll never amount to anything, because you procrastinate". I replied, "You just wait"! No, I had a question, please. Do you torque your A2 buffer tube to the recommended 35-39 ft. lbs.? I've looked on the internet and have written all the recommended torque specs down. I remember you saying it's not a good idea to torque the muzzle device to the recommended 15-20 ft. lbs., you recommended 12-15 ft. lbs., if I'm not mistaken. I've found the USMC 1984 manual you use on the AR15 Repository site. Is that where you get the TDP you use from? Like the spring length and number of coils recently when solving, I think, the Wilson Combat BCG issue? Thanks, Pete and stay warm, its 36 here and hasn't warmed any today.
We got down to 29F last night! A little chilly for us desert rats! Yes, I just tighten the castle nut while in the vise block and stay under 40 ftlbs using some lube. If you're staking the castle nut you shouldn't have any issues being under the torque spec. The muzzle device is one of the areas I deviate from the TDP torque spec and try to land around 15 ftlbs. You can always use shims for timing. Got the TDP drawings from Gatalog.com.
@@peteregger7928 Great! I'll check Gatalog out. Thanks, Pete. Yes sir, chilly in the desert! I've always heard it feels colder in the desert. I'm using an A1 birdcage muzzle device so I won't have to worry about timing. I have a split washer, I think that's o.k. for the A1 compensator. So, you torque your A2 buffer tube to just below the 35 ft. lbs. recommended spec? Thank you, my friend and have a safe and great holiday season!
@@John-zf5wc I try although it's not always possibly to stay at the lowest torque specification. Just my personal beliefs but a lot of the TDP specifications are for "go to war". The one place I try really hard to stay in the middle is barrel nut torque. If I'm a little under on the buffer tube for me it's not an issue especially on an A2. If the buffer tube, spacer, butt plate, and butt plate screw and butt stock are all properly snug and in contact with the receiver and with each other it would be difficult for all of it to come unglued to the point of failure without the operator noticing. My old Marine Corp manual says 15-20 ft lbs for the compensator but if I got it timed at 12 that would be good enough for me. As you were saying timing an A1 won't be an issue. Barrel nut is listed as 31 but not to exceed 80 ft lbs. I shoot for anywhere between 40 and 60 but try very hard not to get past 70 ft lbs which is just my preference. Buffer tube is 35-39 ft lbs so I would just go 35 and a few pounds under wouldn't bother me. Most torque wrenches are +/- 4% of indicated value. Example would be a torque wrench that reads/clicks to a range of 100 ft lbs. In spec accuracy would be +/- 2 ft lbs at 50 or +/- 4 ft lbs at 100.