at least +/- 1 thou is a fairly trivial tolerance to meet.

@@Wehra96 as someone that works as a machinist for the military, and have machined for medical also bores that tend to have alignment, or intended to have other moving parts inside them tend to be sub 1 thousandth tolerance, especially when pertaining to perpendicularity to the base datum, and towards the original post you shouldn’t be running a machine in auto that has not been warmed up properly, causes a lot of premature wear to the machine and wildly varying tolerances

@@johngarlick7115 i worked with hydraulics and parts relating to hydraulic low pressure motors i've worked with tolerances all the way down to +0 -0.003mm, +/-0.00039 inches or +/-0.01mm would be our standard tolerance for stuff meant to fit together while moving. tighter for smaller stuff. our machines were never shut off unless we needed to restart the NC and kept them running for 12-16 hours per day autonomously so a cold machine was never really an issue. We also had a lathe that was used for very high precision large stuff that was shut down over night and we pretty much just let the spindle spin for a few minutes before starting to machine the parts.

@@Wehra96 same thing we do bud s500 m3 for about 20-30 mins while the rest of the hydraulics run generally gets you where you need to be as far as everything being consistent, older machines may take a bit longer, or ones with ceramic spindle bearings as they don’t warm up easy on ceramic bearing equipped I have the guys run on the mid range rpm of low gear, then after 20 mins go to the mid range of high gear, and yeah tight tolerances can be a bear but once your there your there as long as you s+f’s are good and don’t chew your tools up. A lot of our important bores are +.0003 -.0000 so I feel you on those tolerances lol

@@Wehra96 ever run Siemens 840 controller ? If you use NX to program for them you can actually account for tool wear in a sub cycle based on cycle count, it’s under one of the volumetric comp menus

So by buddy has had problems with 2 separate BCG’s from Wilson. They did fix it but took them a little while.

I would second that motion.

@@rifleshooterchannel208 It's more likely that he actually does shoot but has so many different rifles in rotation round count's stay pretty low.

Rifle Shooter Channel ...yep, EXACTLY what I was thinking. I thought “autopsys” were for dead parts, NOT NEW..?

@@m118lr hence why the title says physical and not autopsy

Then dropped even more money on replacing the carrier keys

Sucks when others have more money doesn’t it?

Vaughn Westerby where did you purchase the LMT bolt from?

Sergio Armas Brownells but, it’s on backorder. It will take a while to get.

Check Titan defense located in Scottsdale, AZ

Thanks I’m thinking about getting an LMT bolt for my new home defense build. Lowers done, upper is a few paychecks out so having to wait to get one is ok. Loving this channel. I used to think I knew a lot about AR-15s, now I think I didn’t know shit.

TheK9COPPER thanks a lot for the tip! I’ve been waiting for a back order at Brownells for a month, l ordered today! Thanks again 👍🏻

Different runs can have different tolerances and even start and end of run can and typically do have different tolerances. When you have a CNC running, even taking into consideration of the temperature of the grease in the machine can affect measurments. Its especially the case with cutting tools if you are doing longer runs before checking tolerance; think of a drill running holes over and over, those holes will change the more it cuts and you have to offset or change the tool before it becomes an inssue. KAC has phenomenal QC and this blueprint session proves it out.

This is why we have tolerances. It''s impossible to produce any parts that are exactly identical.

Ultrasonic cleaner.

Yes sonic cleaner. They get ever single bit of dirt off stuff.

Where do you live?

I know right! I’ve torn my bcgs all down and checked them with what I could but not entirely due to not having all the go no go gauges. Great content here and it’s made me laugh when thinking about some of the other review and comparison videos I’ve watched before that really didn’t check or compare anything!

I think some might have come from Pacific Tool also..saw it in another vid BUT STILL not sure which came from WHERE

What combo do u run when suppressed?

@@jonengelbird7051 Depends. Usually I'm running Springco Blue Spring with Colt H2 Buffer. Sometimes I'll run Springco Blue Spring , Car Buffer and BRT Tuned 0.73 gas tube . I run 13.X Mid Lengths. Also quite a fee variables that depend on what combo or setup I use . If using Gassy Can than might wanna go with BRT Tuned Gas Tube . Flow thru type can you'd might wanna run Springco Blue with H Buffer . If using A5 System then Springco Green with A5H2 or A5H3 . The way it was explained to me is A5H2 Buffer is equivalent to Standard Car H buffer and A5H3 ould be same as Car H2 Buffer. For the most part Springco Blue Spring with Colt H2 buffer is what I use . Weaker 223 55g FMJ ammo might Short stroke when using this combo non suppressed . For Carbine Length Gas system I usually run Springco Red with Colt H2 because the action is way more violent .

AK47...

@@madeintexas1213 he was asking about a bolt carrier group.

@@YukarisGearReviews I think he was saying an AR47 is stupid. For the most part I agree with him. CMMG prolly makes the best components for AR47s. There are no good mags out there for them. No Duramag and pro mag are not good. I’d just go with an AK. Proven for that round.

Yes he stated and showed he was replacing the keys

I think he said the gauges had .001" in between them. Your hair is .004". I'm not sure the efficacy of checking those diameters in .001" increments. At that point you are LITERALLY splitting hairs. Maybe you would want to know if its .005" out of spec. A clearance fit where two parts can freely move typically has at least .002" to .003" unless you have perfectly ground surfaces. Lower than that and AIR has a hard time even getting past.. Im not sure what you learn discovering that your carrier is .001" oversized. EDIT: Id be hard pressed to find many if any features on the original AR drawings has a +/- .001" tolerance. I love the videos, but I think some of this stuff is overboard. You could measure most this stuff with telescoping gauges and a pair of calipers; spending a lot less; and having to store dozens fewer amount of tools. Those precision ground gauges are ideally used when checking production quantities where you can't take the time to measure it or have people that don't know the measurement; they are just paid to stick the gauge in the hole and put it aside.

@@LeCafeRacer So I would be interested in the tools that you are talking about, simply because the issue with the tools to measure the exact tolerances are expensive? Don't they require annual certification? Training? Great feedback!

Back in those days +/-.001 would be a cake walk. As a machinist for over a decade, I have come across many prints from the 60’s and 70’s that had tolerances of +/-.00025”.

Not an expert myself so take what I say with a grain of salt, but from what I can tell is these parts are made of stainless steel, so you shouldn’t see anything magnetic.

@@TheChad138 ah, so hints of magnetism would point to low quality/cheap, unsafe material like basic iron?

@@itsthorondil7608 just watched another video of his and he said it’s not a big deal if using brass cased ammo, but if you use steel or bimetallic cased ammo it would leave shavings and could mess things up.

@@TheChad138 Some stainless like 18-18/304 do have slight magnetic properties while others, like 316, do not. They also have different resistances to chemicals. 304 will rust when introduced to chlorine while 316 doesn't. Not sure what barrels are typically made of off the top of my head. I just sell fasteners, so have some knowledge.

Only the carrier, not the bolt.

AO has DOD contracts. They are g2g. Geissele bcg (not enhanced) are just rebranded AO precision bcg.

Both. As a rule they make excellent quality products, but they charge a huge premium for their name.

They’re one of the best manufacturers for AR15/AR10 parts. The quality of their products is insane.

Lmt enhanced bolt?

Two examples of quality companies are in this video.

Hard to beat FCD

Sionics, Forward control designes, BCM, Geissele, Daniel defense, Lantac, SOLGW, LMT, KAC

@@madeintexas1213 basically Microbest bcgs are very good

Steel-case ammo can apparently leave metallic particulates that accumulate over time in the bolt or upper receiver. Magnetized parts can pick up and retain these in critical areas with limited clearances - I believe the area of particular concern is the firing pin channel.

@@jaeger1447 interesting

I have about a dozen broken bolts in my shop.

500 bucks they better be perfect.