Chad, Thanks for taking the time to do this! I want to note, I did not stake or torque the castle nut in fear the lower ended up being total trash.....LOL. I didnt want to put the sauce to the end plate until we confirmed the lower to be usuable after encountering the blatant issues. This seemingly was the correct choice haha! Again, thank you! Always enjoy a solid learning experience! J

Selling blems is one thing, selling a mostly out of spec lower as a "blem" is entirely another.

I really feel bad for the owner. This lower should not have been sold.

This guy is the AR Doctor!!! I’ve learned so much about what makes a good AR build watching this channel!!!!

The fact KAC charges people $300+ on a stripped lower while having stuff like this pass QC is inexcusable, guess this one just got tossed into the "blem" pile instead of the "trash" pile 🤷.

Built on a Friday at 4:57 pm.

This channel is criminally underrated! I have enjoyed these videos tremendously! School of the American 🇺🇸 Rifle should be a mandatory class for high school students. Thank you for sharing your thoughts and knowledge in such a fantastic way. The camera angles are very good to show the viewer exactly what they need to see.

I recently found this channel and all I have to say is this is this guy is the Yoda of the modern rifle. As a former machinist turned USAF jet engine mechanic I can greatly appreciate every aspect of these videos. Insightful, articulate, educational.... keep it up! In fact, I think you should write a book! You could call it "The mechanics of the American rifle....learn it you must"

Blems are still supposed to be fully functional.. I'd totally ask for a replacement.

This is my continued experience with KAC. I have had multiple sr15s and sr16 components that have been all over the map with tolerances and finishing details. Definitely paying for the roll mark.

In all the years watching gun channels and guys that claim to know their way around ARs this is the ONLY channel that actually shows his knowledge and process. It’s obvious that others are at best unknowingly shills and at worst complete shills. There are great brands but when guys act like good brands don’t fail it’s a lie. Thank you for what you do.

Really enjoyed the detail of this whole receiver. KAC fanbois gonna come out violent on this one 🤣

Be careful about buying during a panic buying period. QC gets rushed, machinery isn't shutdown for proper maintenance, and tooling gets run longer than recommended life cycles. Also increase in staff to fill orders means less experienced labor.

Really appreciate these videos. I don't think I've ever watched one and not learnt something new. You are doing your fellow Patriots a great service. I have an upper I'd love for you to go over. How would I do something like that?

As a DIY type, I have watched a lot of gun build videos and I gotta say, THIS one is the Apex of armor instructive videos. Thank you for making it.

I know this is an old video but just wanted to say I learned a lot from this video about the tolerance values for a lower receiver thanks to you! Thank you for showing all this valuable information!

Having worked at an aluminum extruder for several years, and aerospace machine shop for several more, i can tell you with relieve certainty that the reason for the holes all being oversize is with the anodizer. First step in anodizing is a caustic stripping which removes about .001 per surface which makes holes get bigger, but the anodizing makes the surface 'grow' which puts everything close back to where it started, in a perfect scenario. If the caustic solution is brand new or if someone didn't follow the 'recipe' right, or if there was a problem with some parts that need to be striped and re anodized your hole sizes can get blown wide open in a hurry. The mag well being undersized is a completely different issue.

Blems should be cosmetic not functional. Companies shouldn't sell lowers like this.

I like the fact you have inspection tools over and above the normal go/no go gauges, it shows the professionalism of your work.

Holy cow, you got some skills. Slapping that FCG in without a slave pin was impressive.

You are very thorough, you are the kind of gunsmith I want working on my gun. Thanks for the lessons.

Side note for people who run into this issue is ELF has a drop in trigger that uses screw instead of pins to keep it in place. Great video.

Wow! I understand this is a sample size of one but a “blem” is a blemished item, a scratch or wrong color, poor anodizing and other cosmetic issues, not every single hole being oversized. KAC should be ashamed. This lower should’ve been melted and made into one of proper dimensions.

Waiting for a physical on KE arms polymer lower 🙂

I love this channel. It just makes me more aware and cognizant of the details when building. thank you for your effort in putting out quality presentations.

I always thought the term "blem" meant a cosmetic imperfection,which is what l have read on web pages.An out of spec hole shouldnt be considered a blem.That would be a deal breaker for me.Kinda misleading.

I stumbled app on your channel while studying for a gun smithing cert have to say your videos are a great help and supplement to my classes

Your channel is a gem! A treasure trove of information! Thank you for the outstanding content! Also special thanks to you assistant!

I came across this channel a few weeks back. After watching the video suggested by youtube then, I subscribed without hesitation. This video is just as awesome as the past one. I love how in depth the explanations go. Keep up the good work.

Awesome channel. Thank you for your expertise and willingness to teach people. The fact that you teach us "trade secrets" is patriotic as hell 👍🇺🇸

What an incredibly educational video sheesh. I've just completed acquiring parts for a complete home build and I swear I learned more from watching this than everything I've read leading up to this lol. Great content and great camera work by the Mrs!

I want to thank you for putting out these videos... they are a wealth of knowledge that no one else is producing at even close to the same level.. I have a knights ambi lower with a tight mag well, love the gun but the mag well not dropping most mags freely is aggravating to say the least

I learn so much from these videos. And this goes to show even the best which is kac, hodge, lmt, bcm etc... can be out of spec. Although rare, it happens. But learning the signs and symptoms helps the average owner a ton. Thanks sir

These videos are fascinating. You present the information very well.

You’re so thorough, and do amazing work! Love the videos they’re awesome. Keep it up man!

Love your videos Wish I could take your classes but for now your videos have helped me immensely.

I can't believe the amount of slop that was built into a top tier lower. It should be replaced with a new one. It's funny that a friend of mine brought me his friends AR from a home build with a loose castle nut and buffer tube not timed right. Had to replace the keeper and spring and then you put this video out. Keep up the good work learning more everyday.

Inspectors pencil whipping their first articles, and machinists not checking their parts. Gotta love it.

I love these videos. It goes to show that ALL manufacturers make mistakes, have various degrees of QC issues, and that we the end user are responsible for the purchases we make. What makes a company great isn't so much the mistakes or lack thereof, its how they remedy it and treat the customer.

well, after two videos on this channel, I realize I know little to nothing on the AR platform. Subscribed.

I have several of these KAC lowers, and honestly I have PSA lowers that are nicer. I sent one back and got a replacement from KAC because it would barely accept and drop a whole handful of mags. Super disappointing receiver given the manufacturer. Mine were also NOT marketed as blems.

Chad, thanks for putting me onto Vibratite VC-3, I use it on my red dots on my pistols, have had them mounted for about a year with no movement, previously I'd need to remount them every 6-9 months with locktite, VC-3 works fantastically!

I really can't understand why they would put these out on the market, "blem" or not.

Love your videos, knowledge and advice, this lower could be replaced for less money than your costs to repair. But, yes, there are many ways you show to fix problems for these issues. Great to see this for fixes for SHTF type scenarios, otherwise this lower just needs to be replaced for longevity and increased functionality.

You are a great gunsmith and teacher I use Anderson lowers and some PSA the Anderson usually has never give me much trouble and mostly everything fits pretty good you have taught me a lot these high-dollar companies nowadays seems like just markup the money for the name they're not putting time in building the rifles undoubtedly are they have unexperienced workers

Thank you for everyone of these videos I’ve learned so much from your content.

Ironically I just had a similar issue with a Griffin Armament blem lower I put together for my brother in law. The take-down pin detent spring hole wasn't drilled out. It was sold as a "cosmetic" blem, not a defective blem. I didn't realize it till I began assembling it and the spring wouldn't go beyond a quarter in the hole. Luckily it wasn't a big deal for me to bore it out with a simple hand drill; but most people who have no experience would have been screwed, or terrified to drill into the lower... It was a christmas gift for him, so there was no time to send it back to Griffin and frankly, the prospect of them doing anything was nill, since as Rainier told her, "you ordered a blem lower and they are sold as is"... which is true; but this wasn't a "cosmetic" blem; but rather an actual defect...

Removing the selector arm properly is a testament to your knowledge, experience, skill, and most important, patience. It's learned, not taught. Hat's off to you.

I had a buddy that bought one of these lowers, and he encountered the exact same issues with the roll pin and magazine well issues. The Pmags we had would drop free, but the USGI aluminum mags we had on hand wouldn't. It was such a weird issue. He contacted KAC about it. They did send him a new lower but it took about a month for them to respond.

I've learned so much from your videos! Thank you!!

very informative video for me I'm no gunsmith by any means I learn what to look for and have some insite on possible way to fix it or leave it or use a professional gunsmith ...I would not have thought about the safety not working properly and that's golden knowledge to have .

Excellent. Video. I really enjoy your lessons. I have learned so much. Thank you.

For all the 80% guy's out there , you opened my eyes with this video. Receiving inspection will be done before I make a gun that is maybe bad and I have to take a hammer too because it's a gun and can't be shipped back.

your thoroughness is amazing

Great vid. Wish there were more teachers like you. Very thorough. 5 star.

Could you do a lower forge plant tour? On how these are born at the forge birth place? Like their has to be good and bad places that make these. But thank you for putting this on yt and enjoy just listening to the knowledge y’all provide.!! Have a safe Christmas during this trying times.!

Always great videos. For a gunsmith to fix properly costly for the customer, as you stated the company can assist or reject 🤔. Customer has to think about what is the best course of action.

Fascinating video today. Learned a lot.

Interesting stuff. Learn something every time thanks for the lesson bro.

Awesome video! If I was the owner I would send it back with a copy of the video! KAC is not cheap, this is what you expect from Anderson !

I guess I should invest in a set of gauges if I’m going to be finishing 80% lowers. I’m going to reference this vid for years to come. Thank sit🙏🏽

Thank you! I always learn valuable information with each video.

I love my AERO M4e1 lowers. Those are the only ones I buy. The threaded bolt catch is best thing since sliced bread.

I love this channel! Thanks for the videos.

The Poor's are gonna love this!

Thank you I really enjoy your videos.

Always very interesting and informational! Great views of everything as well! Merry Christmas! And Happy New Year ! God Bless!

I bought a block and hold because you gave a discription of yours. Fantastic tool. Also JP has a really nice upper vice block - two piece. Check it out. I like mine way better than a reaction rod. Thank you for sharing your skills with us.

I'm sure KAC would make good on replacing this lower receiver. I would have at least contacted them, in a civil manner, to see what they had to say. Crap happens. I'd even settle for another "Blem", but with in spec safety switch holes this time, please. Love the videos. Doing great work here, SOTAR.

For a company that really doesn’t offer much commercial it seems the commercial stuff they do roll out gets a ton of complaints. Makes me feel like I won the lottery with the upper I received. Also for 200 plus dollars. What a freaking rip off

I appreciate the audio quality in your videos.

Class III technical difficulties. :) Thanks for the information. Peaning the holes may give the lower added life. Not a great solution, but better than oversized.

Id LOVE to see an Aero tested

Love the threaded pins. It takes the angst out of my builds. Im not a pro and I have scratched a lower before getting the pins in.

As always, great vid and I have learned something new.

These are absolutely _fascinating_ videos just to watch! Sadly firearms are heavily restricted in my country, but thankfully looking at them is not (yet)!!!

I use a lot of automotive plastic panel removers. I have some flat ones and some that have a nice bend for moments like that selector. I use them on cars first and when they get beat up I shape them and use them on smaller stuff like this. 🤙🏾

Great job! I wish I would have watched this before I put my first rifle kit together!

Hi Chad. I hope you read this. I have had oversizing issues with my KAC lower as well. Mine is a non-ambi like this one except it was most certainly not sold as a blem. I have my suspicions that the company KAC has outsourced these lowers to are doing a very poor job, so I do not blame KAC in any way directly. However, I will try to bring this to their attention and my case as well.

Thanks for this informative video, learned some things.

I’d love to see you do a physical on a BCM blem upper receiver. Love the videos.

I have a 20-year-old Rock River lower that has a tight magwell, but it's a cool one because they did it on purpose so that GI mags wouldn't rattle around in the reciever. I can't use gen one p mags and gen 3 mags can sometimes require a shake to come free. Everything else is perfectly in spec though and the upper to lower lockup is solid.

I had this exact same problem with a non-ambi SR-15 lower last year purchased in the fall. Mine was not as severe as this case. I contacted knights they sent me a brand new lower with no hassle. It was not a blem lower but they treated me very well. Just my .02

Thanks for the video,Steel is had to beat,My M1 was made in 43 and still sending rounds down range.

FYI: a small string also is good for pulling levers if you don't have a plastic tool. Loop it around and pull. Tip is used by guitar and electronics techs to pull stubborn, and often rare knobs without causing damage..

Props to your wife for the camera work. I kept thinking you had three hands.

I had the buffer retaiing pin on my palmetto ar-9 pretty much in EXACTLY the same condition...it came loose when i took it to the range putting my weapon down for the day, completely mangled the spring too. Had to mortar it to eject the last 9mm round and clear the weapon for transport..such a simple mistake and something i now know to look for.

Good video. Knowing is half the battle.

Some cheap 3M Bondo 357 spreaders cut down would also help you remove safety's like these with out scratching anything .

This might have been the blems that was offered a few weeks ago on gundeals. I don't recall the vendor, but I remember the disclaimer was possible cosmetic issues , enlarge holes and undersize magazine wells.

I thought I new a lot about ar’s I followed man

I rebuilt M61A1 Vulcan's for the USAF and their nomenclature for the "split pin" is spring pin, and the "spiral" pin is what they called a roll pin.

Just noticed the Sriracha hot sauce bottle repurposed as a lube bottle. I do the same! Lol

Another great video !

Check out the KNS Precision bolt catch pin. It does not require a roll-pin and utilizes a C - clip to retain.

Incredible video!

Love these videos hope you do an armalite rifle soon

Great video

This makes me feel lucky with the "blem" receivers I've built so far, but after watching this video I don't think the savings is worth needing this much extra attention. Let's hope this is an extreme example.

KAC really needs to get their QA/QC together- there are MULTIPLE problems with that lower.