The new 5.56x42(6.8 case) Yote Smoker barrel from AR Performance
75gr Amax 2.295" 20" barrel
31gr Lever =3246fps ave
31gr CFE=3225fps
28gr 8208=3148fps

55gr NBT............
32.5gr Lever=3525fps
33.5gr Lever=3588fps-max case fill
30gr 8208=3567fps
29gr N530=3598fps
29.6gr N530=3676fps

50gr Varmint Grenade
28.5gr N530=3703fps...max load.longer bullet, more pressure

70gr TSX should run 3250fps to 3300fps

ARP Yote Smoker Barrel

More to come.....

Interesting....

I can see using it for 75gr. But otherwise there isn't much reason for it on 55gr. That performance isn't far from a standard AR.
What's brass like to get for the 6.8? I always like wildcats but haven't strayed to far from the 556/300blk.

6.8 brass is easy to get, new or once fired.
22PPC dies will neck size and seat the cases.
Powders look to be in the same range as the 6.8 and 6.5G use so far.

I think I'm going to build one for the 75gr Amax and 62gr TTSX and 70gr TSX.
Harrison says the 70gr TSX should hit 3300fps, I think I can get it to 3400fps.
It will also run the 80gr out of a standard 6.8 mag.
Testing right now is going on with a 30gr trying to hit 4200fps.
I'm watching this one closely.

Im assuming to do one of these it would require a 6.8 lower and magazine.

Magazine and bolt should be the only difference

Yes 6.8 magazine, 6.8 bolt and .22 x 42 barrel

Very interesting.   Never used one of their barrels.  What is accuracy like.  Their barrels look really affordable

Groups of .25 to .5 MOA at 100 yards are being reported with multiple powders.

Very interesting.   Never used one of their barrels.  What is accuracy like.  Their barrels look really affordable

Your gonna make me spend some money

Damn, thats close to .243 ballistics on the 75 gr rounds. Interesting.

the 6.8 sample I saw was quite good .

FYI, unlike most wildcats that need specialized dies, the 5.56 x 42mm, which is how I labeled mine, uses standard Redding 6.8 bushing full length sizer dies with bushings.  You form by using several bushings to take the 6.8 case down to 5.56, I like to go in .010 steps so I use several bushings, then anneal, trim to final length, and from that point on just use the final bushing  (.245) to size.  You do not need to inside neck ream, outside neck turn only for accuracy but there is no need to thin the walls.  I ONT only because I like to squeeze every last drop of accuracy out of a round like this and that means consistent neck wall thickness.    
I use a Lyman M die to expand and a Hornady .224 bullet seat die to seat.  If I crimp, I use a Lee FCD which Lee only charges about $32 to make.  
So, you are not out a couple hundred dollars and six months wait to get your dies special made by Hornady or CH-4D, all are off the shelf except the LFCD.

Nice thing is, so long as you are not bumping the shoulder any, you can use the sizing dies and bushings on all 6.8 based rounds from the parent 6.8 SPC down to anything you want.  The same sizing die does it all so long as you leave the shoulder length and angle alone.

Cases for this 5.56 x 42 from ARP can be formed the same way.
The idea was to not have to purchase 4 or 5 bushings.
It is coming to light though that using bushing dies to reduce to neck size is the best way to go.
The shoulder is not pushed back on this cat either.
As well you dont have to neck turn but it will increase accuracy.

From his website:
The 5.56x42 is a 6.8 based wildcat we designed in 2008 to allow the use of the 75Amax at mag length.  3100fps+ is possible from a 20" barrel. 55gr Noslers will hit 3450 easy enough. 6.8 bushing dies are used  to neck the case down then trim them to 42mm(1.640) where the ogive of the 75 Amax will be outside the case mouth. 22ppc dies make it easy to neck down the first time and seat the bullets. Cheaper than having custom dies made.

4150 CMV  8 twist  5R.
M4 feed ramps, .850 dia. under the guard, .730 dia. in front of the gas block.
Rifle length gas system, .750 gas block, 2lb 13oz--NOTE these barrels have a 5/8-24 muzzle thread.
Melonite treated barrels have proven to near twice as long as stainless barrels and are just as  accurate.

30gr CFE and 24.5gr 10x with the 75Amax at 2.295 shot around .6 today.

Not my results, I will keep updating progress reported for those interested.

New speed report in.

30gr Varmint Grenade over 4300fps with Alliant 10X
It hit 4423fps with Reloader 7

40gr Vmax @ 3968fps with 10X

Those 40 grain bullets are 22-250 velocity.   Awesome from an ar platform.   Ordered mine the other day and it shipped today.  U made me spend money.

Could you post some pics of the loaded rounds?

SAAMI pressure rating for 22-250 is 65,000psi.  All it takes is pressure to get a projectile going past Mach 4.  22-250 achieves these speeds with a 26" barrel, a .473" case head diameter, and 31-41 grains for max loads.

This is getting out of hand.

And does it have 22-250 barrel life and throat erosion issues?

Holy bat balls.  Those are 26" 22-250 velocities, with max charge weights on a gun with a much beefier barrel tennon and 6" more barrel, more case capacity, etc.  I'm just looking over 22-250 load data right now, and many of the loads you posted are beating or right at 22-250 speeds.  This is more insane than I thought.

Who knows!

One thing for sure you certainly don't work for Hornady.  If you did you would have tried to convince them that developing new power formulas would never work and they never would have developed the Superformance ammunition line.  You know that pressure thing again.    Funny how they figured that different powder formulation offered 100-200 fps increases in MV while still remaining with safe pressures.   Gosh how did they do that?

Powder blend formulation with a team of engineers specific to each caliber, not off-the-shelf hand loader powders, like we're seeing here.  This is straight unsafe, again from the same source who was banned from AR15.com for posting customer info, to include name and address as a form of revenge.  That's the mindset we're dealing with who is playing with fire pushing cases and chambers beyond the yield strength of steel.  Then accumulating a fanbase of novices who don't know the difference, filling them with BS like it was gospel, and circling the wagons on the insanity train.

People getting into wildcats and reloading need to know there are no free rides.

I guess I dont understand why some are against this 556x42.   If you dont like a particular barrel manufacturer I can understand that.   After looking at the ballistic data doesn't look like a bad round especially for the ar15 platform.   I personally kinda like playing with a wildcats.  My last was a 243lbc.  It shoots like a champ.  I did order one of these barrels and will build an upper.  Looking forward to it.

The 5.56 x 42 is a great round but I cannot for the life of me figure out why anyone would want to throw a 30 gr. bullet at 4300 fps.  The trajectory at long range is abysmal and the barrel life will be greatly reduced; it makes no since at all unless this is some sort of misguided big prick contest.
Even if 4300 fps is possible, with a 300 yard zero the 30 gr. bullet looses its steam quickly and the bullet drops 168 inches by 600 yards.  The 75 gr. AMAX at a comparatively snail's pace of 3038 fps, which is what I honestly get out of mine and is totally safe and barrel friendly, with the same 300 yard zero, the bullet drops only 53.1 inches at 600 yards.  So, what's the gain of throwing a 30 at 4300 fps?
It makes no logical since at all.

PD's at 100 yards = bloodmist

Your personal vendetta is not welcome in this thread sir

Exactly Bama
And I quote:
I can work up loads, test velocity and pressure in the back warehouse of the shop then when I find one with low spread apx 1 gr below max I head to the range.
People please do not listen to LR, he is on a personal vendetta against AR Performance and has been for quite some time.

True I guess, but at 150 yards, both bullets are going  about 2700 fps. The 75 a little less, the 30 a little more, and look at your cost in barrel life.  By 175 they are reversed, the 75s a little faster, the 30s a little slower.  Granted, out to 100 yards the 30s are screaming and as close to a laser as I guess you can get.  However, the down side is too much for me.  
Pardon me if I've missed it, but what is the accuracy of those 30 gr. pills?  I always see people list velocity but very seldom accuracy.  I know the 75s will put them into a half inch at 100 yards all day long with every load I have tried, and back in the day when my pasture poodle rifle was a .22-250, the light bullets back then, 40-45 gr, would not group very well.  And the .22-250 had the proper twist of 1:12 or 1:14 IIRC, but the 5.56 x 42 with a 1:8 twist, which is what mine has, is not ideally suited for extreme lightweight bullets.  It's great for heavies but a bit too fast for optimal performance from a 30 gr. bullet.  Honestly, at that speed and rotation, I'm surprised they hold together.  Hornady use to make a Super Explosive 50 gr. bullet and cautioned not to use them above 3200 fps, or something like that.  They worked fine in the .221 Fireball but out of the .22-250 at 3800 fps, they seldom reached the target.

Either way, the 5.56 x42 is fantastic.  95% of what you can get out of a .22-250 in an AR, and there is certainly no shortage of accuracy.  While my barrel is not a H provided barrel, H did chamber my blank. At that time he did not offer completed barrels and mine is a stainless steel barrel so I imagine his Melonite coated barrels would withstand extreme speed a lot better than mine would over the long run.  If you get tired of playing with those lightweights, stuff in some Hornady 75 gr. AMAX and don't feel cheated at all.  Plus, as you will find, using the 42mm case instead of the longer 43 mm case makes stuffing those long-nosed AMAX in the magazine a lot easier without seating below the full diameter portion of the bullet or cutting out the front of the magazine.
It's a great round and I hope it catches on.  I like the 42 mm version better because I like the heavies, but the 43 mm version offered by others is a little less work to form (like trimming 1 mm is a big deal) and gives a little more case capacity for the lightweights but offers nothing over the 42mm case on the heavier bullets.

Heres where Im getting the info.
.22x42 ARP

Quote:
"30gr Varmint Grenade over 4300fps with 10x. First powder tested just to see how fast it will go.
4426fps with Re7"

40gr Vmax -3968 with 10X
He has not reported accuracy testing or claims yet on these, but we both know there will be a node in there someplace.

I have been following this cat and thought the hive here would like to know about it.
I'm going to build one as soon as my current project is completed.

HK I do love all the work you do on the 6.8 case and all the fluting etc you offer.
I have never heard anything but good reports about your products.
Thank you for all you do as well sir!

Disclaimer before someone brings it up:
I have NO affiliation to Harrison and have never met the man.
I do however have respect for all his work as well as how he does not hesitate to help others even if they are the competition from what I have seen.
There is only one guy that seems to have a problem with him.
I'm in retail and there is always a customer that you cant make happy that comes along, no matter how hard you try.

I was actually going to post something supportive, since this is really what the SCHV proponents were looking for back in the late 1950's, and one of the Army Ordnance Engineers proposed taking the 25 Remington and necking it down to .224, which is basically what this is.

Then I read the claimed mv's in the OP, looked at .22-250 26" barrel data, and red flags started flying.  There's a problem with the source of all this, in that he doesn't have the judgment and mental stability to put a safety factor into what he's doing, and likes to push things way beyond max in the AR15, then claim it's totally fine.

Maybe you'll get away with a few thousands rounds, or maybe the chamber will be stretched at a few hundred.  Who knows?  What's certain is that in order to achieve those speeds from a 20" AR15, rivaling 26" .22-250, you need pressures that exceed the safe working envelope of the AR15 by at least 12-15ksi, which is reckless, pure and simple.  Reckless behavior from someone with serious mental or substance abuse problems, both of which I genuinely hope he gets help for, but in the meantime, this is plain to see for anyone that understands the constraints of steel and AR15 dimensions.

I could see a 75gr A-MAX at 3000fps maybe, but you don't want to push to anywhere near 60,000psi with this case in the AR15.  It's just not sound over the long term, and a lot of people will get away with it for a while, call it good, and won't be the wiser.  Maybe throat erosion will hit beforehand, maybe not.

Run the 75gr A-MAX up to 3000fps and you're in much safer territory.  That would make an excellent load.

I have found Quick Load to be very close in this round, at least with Re 17 and the 75 gr. AMAX.  QL does err often and often predicts higher velocities than you actually see but with the A max and #17, it has been spot on.
That said, when I run the numbers for the 5.56 x 42 with a case capacity of 35.3 gr. H2O and a case length of 1.640, both of what I use or have measured on my cases, if one uses a max load of AR-COMP with a charge of 32.4 gr, one can get 4284 fps at 54000 PSI. COAL is 1.977 inches which allows .225 inch of bullet in the neck; barrel length is 24 inches.  Fill is just over 100% so it is slightly compressed.  That is NOT over pressure since a lot of 6.8 loads I have found work in the 54K range, Hodgdon lists several loads at that level, so the AR and the case can take 54K psi.  The 75 gr. load I run is right at 54K psi, according to QL and the velocity is spot on with no pressure signs.
So, according to QL, the AR certainly is not being over stressed with a load tossing a 30 gr. BVG bullet at 4283 fps.  
While I am not interesting in doing it, there is nothing unsafe about doing so, at least according to Quick Load.  YMMV of course.

I don't intend to get between warring factions here, but I believe I understand the root concern with this round.

I also don't have all the facts and figures, but it's pretty obvious the limitations of the AR15 design in terms of strength are known.

The concern is the pressure that the barrel is being subjected to is (potentially) in excess of what it can safely support. Using an analogy, say a standard AR15/5.56 barrel is "safe" at the working pressure of 5.56. It is "safe" because the the strength of the steel, based on composition and diameter, is able to contain the pressure of the round it is intended for. Now take it to the extreme: reduce the outside diameter of the barrel in half at the chamber. You will almost certainly exceed the capability of the barrel to withstand the same pressure, and bad things will happen.

This has nothing to do with pressure signs from the fired casings. Those are not likely to indicate you are going to have a barrel or lug failure. This is why there is a minimum barrel diameter, and pressure is used to calculate what that minimum diameter can be.

Without having pressure test numbers, you can't know with certainty that what you are doing is safe. Since the AR15 barrel diameter can't get any bigger than it is where it attaches to the receiver, that (plus the bolt) is your strength limitation.  

One might want to go middle of the road with something like the 55 gr. Sierra BlitzKing.  According to QL, COAL of 2.200 inch, Re #17, a 34.0 gr. charge gives 54,000 PSI and a velocity of 3500 fps.  With a 300 yard zero, a 600 yard drop is a mere 58 inches, almost as flat as the 75 gr. AMAX leaving at 3038 fps, and to keep comparisons the same between the 30, 55, and the 75, reaches 2700 fps at 210 yards.
This a whole lot of cartridge wrapped up in a small and lightweight package.  Personally, I don't see what's not to love about it.

Im hoping to push the 70gr TSX to 3100 to 3200fps. Im getting 2940fps avg with 25grains of AA2230 @ 2.27 OAL from my 5.56 16in PSA barrel (Accurate 5.56 load data from the book).
That would be a heck of a hunting round from a .224 AR

People have been running the 6.8 case at 58000 for years now in the SPCII chamber.
None of the things you keep saying are happening.
The pressure spikes that caused the early problems were from a few factors.
1. .050 leade, which was just to short
2. 50:50 to 70:30 land to groove ratio from the .270 barrels, 40:60 to 30:70 does not have those issues.
3. Wrong cone angle
We have been over this countless times and you ignore it my friend.
How does a 5.56 take more pressure than a .223? A longer leade, yet you keep stating it does not make a difference in the case of the 6.8.

I cannot believe the mods allow you to openly talk crap about people, when they would shut down anyone else that does. You must have some great photos man.

You do realize there is a .044 difference between a 5.56 chamber and a 6.8 chamber.

So almost same diameter, just a bit less than the 5.56.

Are these numbers wrong as the max PSI for each loading? In a quick search I can't find apples to apples in pressure testing methods for both.

55,114 psi 5.56x45
54,000 psi  6.8

If the case diameter is the same, that means the chamber/tenon thickness is the same in an AR. If it's any thinner, it's directly related to case diameter.

54,000PSI must be safe with the 6.8 case (or, figured another way, with the thickness of the barrel tenon/chamber wall with that chamber cut in it) in the AR, so what pressure is the 5.56x42 running?

If the chamber wall/barrel tenon thickness is the same between the 6.8 and 5.56x42, then pressure has to be the same to be safe.

http://www.americanrifleman.org/articles/2013/3/4/223-remington-vs-556-whats-in-a-name/

http://ballistictools.com/articles/5.56-vs-.223-myths-and-facts.php

Difference between 5.56 and 6.8 chambers is actually .046", but regardless, that's quite a bit of thickness when you look at it, with significant consequences for chamber pressure.

It amounts to half that when looking at wall thickness.

Keep in mind that 5.56x45 NATO even before M855 was pushing the limitations of the barrel and bolt on the AR15/M16, resulting in pitted, cracked, and broken bolts, and fast chamber wear.  They addressed this, not with a total re-design, but with metallurgy, coatings, a very specific chrome-lining process, and a very stringent QC process starting from steel selection to every machining and heat treating process, followed by HPT loads, MPI, and shot-peening.

Even with all that, 5.56 still breaks bolts, shears lugs, cracks cam pin holes, and wears chambers.

When you take the 5.56 NATO military guns and use that as a benchmark, but don't have access to the TDP, don't follow any of the specs for the military rifle and carbine components, then ream out a larger chamber, reduce the wall thickness, use a stainless barrel, a different alloy for the bolt, manufacturing processes for the barrel extension that are all over the map even within the manufacturer, to include nitriding the extension until it's extremely brittle in acute angle dimensions, then push into 5.56 pressures with a fatter case, there is only one thing that can happen.

The life of the system will be reduced.  By how much can only be determined with pyramid testing, or theoretically set based on the known yield strengths of the steels.  There was an excellent article on all this recently in American Rifleman, and I was surprised to see it there.  They went over stress-risers, hydrogen embrittlement, pyramid testing, steel life, surface fractures, and included insights from a major manufacturer on all this.

How does this apply to the discussion?  I have spent well over a thousand dollars on barrels from AR Performance, all on 5.56 or .223 Wylde pipes, thinking they would be solid performers.  Keep in mind this was years ago, like 2009-2010. They were all nitrided.  When I went to polish the feed ramps on one of them, the edge of the ramps literally chipped like glass, which I have never seen before.  One of my buddies who is an aerospace and medical device engineer, as well as a gunsmith that put himself through two different gunsmithing schools while doing his engineering degree, looked at the barrel.

I also called the nitriding shop Harrison referenced in this discussion on another forum.  The conclusion from everyone other than Harrison was that this extension had been nitrided after being sufficiently hardened during the normal process by which one hardens an 8620 barrel extension, and that by nitriding it after that, it caused the acute angles of the feed lips to through-harden.

When I took my Cratex bit to it (a rubber bit impregnated with light polishing elements), it immediately fragmented like glass or obsidian, it was that hard.  Keep in mind that I have polished untold numbers of AR15 barrel extensions over the years, and never seen a one of them behave like that.  He also stated in that thread that he sends out barrels with the extensions partially torqued when having them nitrided, which is genuinely retarded.  I don't know why anyone would do it that way, other than an attempt to cut corners, while leaving room for bad things to happen.



Now think about that acute angle embrittlement that is going on.  Now take a thinner chamber wall, and the two revolutions of threads that are engaged with each other.  What kind of angle do you have on threads, acute or obtuse?  That's right, they're acute.  The guy is not only clueless, but has a disregard for safety, which can been seen with practically everything he touches.  Never satisfied with leaving reasonable pressures alone, he has to push off into excess of 60,000psi, with an unsound pressure-containment system, with who knows how much caustic salt residue in the barrel extension and barrel tennon threads.  I mean, his website frequently has told customers to clean the salt residue from the barrels themselves.  If the customer has to clean the caustic salt residue from his bore and chamber, was it ever cleaned from the barrel extension threads where it really can cause a problem?

AR Performance Salt Bath Residue


It would be interesting to see why the 800 series bolts and extensions were pulled, for example.

This doesn't mean the .224 x 30 Remington isn't a viable cartridge-to the contrary.  Just be aware that there are people who know only enough information to be really dangerous in this industry when it comes to pressure-containment systems.  Most shooters won't see any problems because they don't shoot a lot, but when you factor in semi-auto, we have the capacity to see problems much sooner.

I still stand by the assessment that pushing into .22-250 territory with a smaller case, less chamber wall, and nitrided barrels is a recipe for bad things to happen.  You can call me every name in the book, but I genuinely don't want to see anyone hurt, regardless of how reckless they are with firearms.  Those of us that have seen people push the limits know what this looks like when it finally fails.  Sometimes "just" a ring will develop in the chamber.  Often times bolts will shear a lug or two.  When things do let go, the AR15 handles them better than bolt guns, but blood has been drawn by people with more bravery than brains.

Ok, so SAAMI pressure is 60,000 p.s.i on 5.56, according to that article.

SAAMI spec for the 6.8 is 54,000 p.s.i.

6000psi reduction by losing .044" in chamber/tenon thickness.

If you run the hoop stress calcs for a .442" chamber diameter, and an AR15 barrel tennon relief cut that has been run off a production line, and consider that stainless steel will be used by a good portion of people, you're looking at 53,000psi as a working pressure for the 6.8 and any wildcat based off of it.  The SAAMI data for it is overrated by 2,000psi.  The reaction to that statement is usually, "Who are you?  You don't know what you're doing."  Yeah, I haven't heard anyone claim Remington knew what they were doing when they submitted the cartridge for SAAMI either.

Keep in mind, Remington had arbitrarily determined that they could reach 2800fps with a 115gr once other people started taking notice of the 6.8, and weren't happy with mediocre performance.  This was done without even running any chamber dim calcs, just off-the-cuff in a conversation.  Because of all the excitement, people were willing to put logic aside and make assumptions in short time constraints, in order to build momentum and say "yes", when they should have been saying, "let us run the engineering and see".

Things you need to know when calculating the pressure containment system.

Yield strength of the steel you are using
Dimensions of the chamber area, to include the most narrow external dim, as well as the internal dim of the chamber opening
You also will be using a thick wall hoop stress calc, not a thin wall like Harrison things I have.  Thin wall is for soda cans and sheet metal, things like that, not chambers.
Take the nominal minimum, in the case of the AR15 and most barrels, it is the relief cut at .735" and subtract the chamber inside diameter.  That gives the difference, which is both halves.
Divide by 2 to get one wall thickness.

.735" - .422" = .313"
.313" / 2 = .1565"

Enter the desired chamber pressure, and see the hoop stress indicated.  Compare against the yield strength of the steel alloy being used, considering what temp it was heat-treated at.  If the barrel manufacturer doesn't get it right, it makes a huge difference in the yield strength and ductility.  You can see these specs on Crucible's data sheet for 416R.

Lassen Gunsmithing Hoop Stress Calculator

Crucible Steel 416R Data Sheet

Also keep in mind that you need a factor of safety.  You don't run pressures to the theoretical yield of the steel and call it good.  There has to be a safety factor to compensate for variances in materials, metallurgy, pressure loads, and what happens if variances stack on you.

For example, your charge averages 52,500psi, but batch-testing shows that some of your charges have hit 55,400psi.

When your extension was torqued in place, someone used 180ft-lbs instead of 120-150 because the wrench hasn't been calibrated in ages, was made in China, and doesn't give accurate readings.

The heat treatment of your barrel was toward the edge of acceptance because a new technician was being trained that day, millenials and all.

You go to shoot in extreme heat, or extreme cold.  416R is rated to -40, with as heavy as a barrel feasible being recommended for cold temps by metallurgists. I shoot in a lot of cold temps every year, so this is a major consideration for me and some militaries.

You have already shot several thousand rounds through your barrel.

All these things can stack on you and cause a major failure.

SPCII is 58,000

Show us a failure in a SPCII chamber or a 6.8 based cat.

But thanks, with the 6.5G's even thicker case I think everyone should turn theirs in for 100 bucks
The 7.62x39 owners as well.
Not to mention that huge bolt face, scary stuff.

Seriously, 6.8 barrels are proofed to 70,000 psi.
Thats why you dont see failures

Why not just state that it's 65,000psi?  You haven't let physics get in the way before, why handicap it at 58ksi?

This is madness.

Show me a failed 6.8 SPCII chamber or barrel from over pressure.
You cannot, all you do is talk about conjecture and elude to an instance from an old SAMMI chamber you once saw.

I am actually very careful, I pull loads that exhibit any signs of over pressure.
But this thread is not about the 6.8, its about the Yote Smoker.
HK has already stated that the stated speeds are within pressure tolerances, are you also calling him a psycho druggie?

You still aren't even spelling SAAMI correctly.  You see how this can affect credibility?

I'm saying the speeds listed in the OP are off the charts, especially when you look at .22-250 speeds from a 26" barrel and compare them to the 20" barrel speeds advertised in the OP.

Something is going to give.  It's fine if you keep the pressures down.

From your methodology, I think you don't have a reliable way of measuring or assessing pressure.

So what PSI does the 5.56x42 run on the upper range of the loads?

Unless I'm missing something, what would pressure signs from brass tell you about the pressure the barrel is capable of withstanding?

7.62x39 SAAMI pressure is 45,010PSI. That follows the logic of reducing pressure while reducing the thickness of the chamber. Or, conversely, as pressure increases, chamber wall thickness is increased.

Big-Bore already posted he thinks the pressures are within limits and he is another barrel supplier.
Yet you continue.

As to spelling I'm at work and typing fast between handling things. I haven't really been question about credibility by anyone but you, or when you start it by your group of followers.
Do you not realize that when you cannot win a debate this is the direction you take it?
Like every time.
Like when you posted that stupid pic from 3 years ago with a backward rear sight trying to discredit me.
Yea that was the first AR I ever built and I was a bit excited.
Your MO as in Modus Operandi is to demean and discredit people, then cry foul if they do it back.

As I have never had a primer pop out, a case head separate - not even slightly, a case head ever have brass flow, a case neck ever crack or anything else pressure related happen I would say I am doing just fine.
I have never had a squib load, never an overcharge nada zip nothing.
I inspect every step of the process, I weight each and ever round when completed.
I never do anything but case prep with having a beer, and that rarely, as in 1 beer.
When I get near the top I work up .2 or .3 grains at a time.
I consider myself damn careful.
You have no idea of my methodology sir, nor anything about me.
Keep your personal opinions to yourself, stick to facts .

You've been spelling SAAMI "SAMMI" since you've been on the board.  Hand loaders need to pay attention to detail, so that's why it sticks out to me.  Just an observation.

This isn't about winning a debate.  That will never happen with people who refuse to understand applied physics.

The point of my posts is to illuminate what not to do when it comes to hand-loading, especially when one doesn't understand the limitations of pressure containment vessels.

One of the most important things a person can do when starting hand-loading is to get a competent mentor.

The internet has changed things a lot, in that way more information can be shared than ever before.  If someone understand applied physics as it relates to hand-loading, then this is a great thing.  If one has latched onto someone with a blatant disregard for safety, who has bad judgment because of a personality or mental problem, then it can be disastrous.

The real source of all this is Harrison, who blatantly disregards safety, and pushes the 6.8 and variants based off it to extremes, then says how he regularly does it, yet doesn't even know the meaning of pyramid testing until he reads about it after the fact.

Since he came at time when the 6.8 hit a major wall in its development with the irresponsible SAAMI submission by Remington, he is seen as a hero among those who bought into the 6.8 speshul forces advertising campaign.  Not wanting to ever question a pillar in the 6.8 story, everyone else becomes an enemy who questions the claims being made by him, echoed by those who take what he says at face value because he's a barrel supplier.

Being a barrel supplier does not competent one make, and the learning curve has been steep with him.  This is why those of us who have a pretty developed filter cock an eye when we see 26" .22-250 velocities from a 20" AR15 with less case capacity, and less support around the chamber.  Does that make the least bit of sense to you?  Not trying to be argumentative for the fun of it, just thinking out loud what comes to mind when I see Mach 4+ speeds from the AR15 from a 20" barrel with .224 caliber pills. Call me a healthy skeptic.