Excess pressure signs for AR 15 223 loads?

[bbowles]

Just started loading for an AR 15 223. Have loaded some for bolt guns but new to ar. My gun is a DD 16". I loaded up 3 different loads starting at min and load 1 round each at .3 grain increments to look for pressure signs and for velocity thru chrono.

Just wondering if what seems like more powder residue than normal (over factory loads) is excessive pressure?

My loads were (all were 2nd loading Lapua brass, 1st load for fire forming; CCI BR-4; bullets seated to 2.256" OAL):
Horn V-Max 50, Hodgdon CFE 27.3-28.5

Sierra Match 69, Varget 24.0-26.1

Sierra Match 77, Varget 21.5-23.9

All loads were good velocities at max load and none seemed to show any signs of excess pressure compared to factory loads. Primers not too flat (still have rounded edges), primers all backed out to .0005 below flush, no shiny rings above rims, primer pockets seem ok (haven't removed old one yet). Only odd thing is seems like slightly more powder residue on brass body. Not lots more but I would think when load approached max residue would get less.

Does all sound ok to you guys? Thanks and sorry for my rambling!

 

[mosquitoshooter]

Sounds good to me. I would think the hotter you go, the more sealed the brass would be to the chamber wall when it ignites and thus LESS soot. My Rounds with varget seem "sootier" than factory rounds as well. However, Velocity is exactly the same as factory rounds. i cant explain it. i am sizing to the same size as factory rounds too! I once had a way undercharged round due to a bad primer or something and the brass was black!! I think you're fine as long as the velocity is good as well as primer reading. I wouldn't worry

 

[bbowles]

Also, I full length size about .003 under full headspace.

 

[bbowles]

Been loading for Daniel Defense ar 5.56 chamber 16" barrel. Starting loading for this rifle about 6 month ago. About 500 reloads thru it. Mainly Sierra 69 match. Worked up to max with cci br4 primer, lake city 13 brass and AR Comp powder of 23.2 gr.

Think I am about at max for this rifle. Trying to learn pressures and knowing when to say when. 23.2 gr is max per Alliant website (new powder and very little info).

Had some light ejector ring marks with same load but Varget as early as 1.5 gr before max but NO other press signs. Max of 26.1 varget was about 2675 fps.

The max load of AR Comp shows no ejector rings or primer prob but prob about max. My thinking is each 0.3 gr incr brought 30 fps incr. At max load of 23.2 still only 30 fps incr and .0000-.0005 casehead expansion.

So took 2 past max at 23.5 and 23.8. The 23.5 load had 46 fps incr but still CH Expansion of .0000-.0005. The 23.8 load had 65 fps incr and .0005-.0010 CH Exp. stopped there.

So know last 2 is over max but think the 23.2 load will be ok. Am I hi king correctly? Btw none of the loads (even over max) showed any other press signs at all.

 

[bigedp51]

You have loading data for short throated .223 rifles and loading data for AR15 rifles with longer throats.

Each rifle will be different by chamber/throat, case capacity, bullet type, primer,etc. Published maximum loading data is a safe 'ball park" pressure, and your rifle will tell you a story as you work up your loads.

Below is pressure data gathered on a .223 bolt action rifle and a AR15 rifle using a strain gauge. Looking at the green bar on the far left you can see factory loaded .223 ammunition is loaded 6,000 psi below the maximum rated chamber of 55,000 psi. Now if you look at the far right blue bar you will see the military loads its ammunition very close to the maximum rated chamber pressure of 55,000 psi. Also note the .223 and 5.56 are "rated" for the same maximum chamber pressure of 55,000 psi "BUT" the throat differences cause the pressure variations.

Again any loading manual lists the "approximate" maximum for the rifle and components being used, and today the chamber and throat must be large enough to fit the cartridge and the company Lawyer into. My Savage .223 rifle has a longer throat than either of my two AR15 rifles and can be loaded much hotter than any .223 loading data.

 

[bbowles]

Big ed,
So...how do I measure throat? I have the length calculated to the lands.

What do you think about my loads and whether they are too much?

 

[bigedp51]

Big ed,
So...how do I measure throat? I have the length calculated to the lands.

What do you think about my loads and whether they are too much?

Your loading for this AR15 so the throat is what it is and you can't change it, I only brought up my bolt action .223 because it has a nonstandard throat. Meaning it is not the short throated SAAMI version.

Your brass will tell you when it has reached maximum pressure by the base expansion which you are tracking. BUT Lake City cases have a harder base web area and would show signs much later. Meaning each make, brand, hardness of brass will have a different "MAX" pressure point.

These pressure signs are good to know, BUT what is really gained by pushing the limits? If you keep your chamber pressures around 50,000 to 52,000 psi your brass will last much longer and put less strain on the rifle. My practice loads for 100 yards or less are kept between 46,000 to 50,000 psi, my brass will last a very long time. I'm shooting 55 grain bullets with mixed brass with 25 grains of H335 and the paper targets die just as hard regardless of the velocity. I'm also shooting 69 SMK with 24 grains of H4895 which is an old favorite of Camp Perry shooters. (approximately 50,000 psi)

Bottom line, consistent accuracy is more important than top velocities.

 

[Clark]

I fired this in my old Colt AR15.
There is a flat primer
There is a primer crater
The case stretched in front of the web
There is an extractor impression.
There is an ejector impression.

I did this with 18 gr Blue Dot 35 gr Vmax which will alternately show no pressure sign on the brass and show 4100 fps and the other half of the time it shows like this pic, and 4200 fps.

There is no charge high enough nor low enough to cycle an AR15 with this powder and bullet. The pressure curve does not last long enough.

The biggest problem with AR15s and pressure is the bolt carrier slamming into the receiver. Without an adjustable gas system, all that can be adjusted is by changing the recoil spring.

The 223 case head is SAAMI registered at 55,000 psi, but will work well up to 75,000 psi, having a lot of safety margin.
The 270 case head is SAAMI registered at 65,000 psi, but will work ell up to 67,000 psi, having little safety margin.

When the case head gives, the primer pocket gets loose.

 

[bbowles]

Clark,
Wow! That looks scary. My cases look good as new except slight CH expansion of .0000-.0005 with my AR Comp load 0.3 past published Alliant website max of 23.2. And .0005-.0010 with 23.8 (0.6 gr past pub max). No CH marking other than what seems to be normal light swiping of Case headstamp at all charge levels (this seems normal compared to factory loads and Lapua brass loads).

Some say ANY CH expansion is too much. Zediker in his book, "Handloading for Competition", which is great book says first firing he thinks past .0015 is too much and .0005 on successive loadings is too much (if I interpreted it right).

This pressure thing is a hard one to deciper but I feel my loads are at or near max so will quit pushing any farther. I would like to stay at this max for my gun if safe cause it shoots GREAT (better than lower charges at least in this load and gun) AND want as much velocity as can for up to 700 yd shooting. It does help to have more velocity at longer range for range estimation errors.

 

[Clark]

This is a work up with Blue Dot and 35 gr Vmax, an erratic powder at high pressure in the .223 that works best around 35,000 psi


This is a work up with H335 55 gr, a powder that works well at high pressure.
From left to right:
unfired, extractor groove .329"
28 gr, extractor groove .329", 11% overload 69 kpsi Quickload
29 gr, extractor groove .329", 15% overload 80kpsi Quickload
30 gr, extractor groove .3295", 19% overload 92kpsi Quickload
31 gr, extractor groove .3320", 23% overload 106kpsi Quickload

We don't really care what the pressure is, we care about the effects of pressure on the weakest link in the system, the case head. The .223 case head in this case is failing somewhere between 29 gr and 30 gr of H335.
Maybe the primer pockets are not loose, yet, but I find the extractor groove expansion to be the best indicator for the limit on which to base a safety margin.
Somewhere between 29 and 30 gr the threshold can be found.
The safety margin is subtracted from that to find the max load.
For when he is writing a load book, Vernon Speer in 1956 said to subtract 6% powder charge.
But for an individual rifle, individual jug or powder, and with temperature insensitive powders, I subtract less than 6% for my hunting loads. Often I reduce by 4%.

 

[bigedp51]

Military cartridge cases are made to higher standards than commercial SAAMI cartridge cases. They are harder in the base to better withstand larger diameter and longer headspaced chambers. The loads above could prove extremely dangerous in weaker civilian commercial cartridge cases.

At AccurateShooter web site many of the competitive shooters will keep working up a load until they see ejector marks on the base of the case where the brass started to flow into the ejector and then back off the load one or two grains. All that is being done here is testing their lot of cases for brass hardness and pushing the pressure limits.

The H.P. White testing Laboratory states that the majority of catastrophic firearms failures are not caused by a single overpressure event. The majority of firearms failures are caused by a series of lesser pressure events that led to the failure of the firearm.

Below from the H.P. White testing laboratory

The case capacity of the .223/5.56 can vary from 28.8 to 30.6 in grains of H2O, this can cause the chamber to vary 6,000 psi. In the above photos I see different dates on the Lake City cases and it make me wonder if the poster checked the case capacitiy of these cases before his test done "WITHOUT" pressure measuring equipment.

In over 46 years of reloading I have never had a single case failure due to excess pressure, I have never had a case head separation and the worst thing that has happened were split necks.

Pushing the pressure envelope is asking for trouble and only shortens case life, the life of the rifle and can injure the shooter. There is this thing called safety and not exceeding the design strength of your cartridge cases and the safety margin built into them.

 

[bbowles]

BigEd,
I was not going to respond as I have been reading your replies but they are all the saying the same thing. You even responded to some of my other threads. I surely appreciate any advice that I can get as this is what this board is about.

In essence, I believe you are saying that I should not push my loads or even try to find maximums for my guns. That I should not wear out my rifle or barrels prematurely. That I should save my case life and that I should be concerned with, above all, my own safety. And that I am, overall, a moron that knows nothing about anything. Maybe I am a moron but I am trying to become an accomplished loader. I get that my safety is far more important than getting extra 50 fps out of my loads. I even THINK you care for my personal safety. BUT assuming my loads are safe (if they are, which is what I am trying to determine) it IS NOT your place to tell me i should save my barrels, case life, etc. If I want to buy new stuff after I have wear them out, it is my choice. I appreciate your willingness to try to HELP me save dollars and protect me and my equipment.

My point is that I don't see where you are actually helping me answer the question I asked in the first place. And that is whether the signs and facts I provided in my original post indicate if i AM PAST A STOPPING POINT FOR SAFETY. You said before in prior threads that I have too many "toys" in my loading equipment. As long as I understand how they work and operate them correctly (which is what I am trying to learn) then it is my choice to spend money on "toys". I KNOW I don't NEED some of the equipment I have but I am a detail guy and love tech stuff.

I do have some understanding of technical equipment. I run a national level pulling tractor during the summer months too. This tractor puts out about 3000 HP with a triple turbocharged alcohol motor in it. I only say this to show I have a little mechanical background in tools and other high tech tools.

I am in no way trying to cause trouble! Just want to LEARN to understand technical loading procedures and dealing with load pressures. If I am PAST pressure limits in my loads I mentioned above then I surely want to KNOW to be safe. I know that different cases will bring different pressure levels. I only have used Lapua and LC 13 new unfired brass. Just trying to figure out if THIS load with THIS brass is still safe.

Hope we can be internet friends and continue this learning process together. Thanks!

 

[Clark]

I was in engineering for 30 some years and noticed a polarization among engineers into two camps, "Do it per procedures" vs "Get-r-done".

I can see some of that same dichotomy in the previous two posts.

 

[bigedp51]

bbowles

Right now at castboolits there is a poster by the screen name of "multigunner" handing out information. The problem is mutigunner does not cast bullets or even have a reloading press. Mutigunner simply reads postings in other forums and then passes this information off as his own in another forum. I know this because I caught him passing off word for word what I wrote in another forum and went back and checked his other postings The last time mutigunner reloaded anything was 1982 with a Lee loader and as I stated earlier he doesn't even have a reloading press. NOW let this sink in to your gray matter for a moment.

So now let me tell you point blank, you are asking faceless screen names and people you do not know and never met if something is safe.

The people in this forum are not holding your cases and seeing them first hand, and are making physic guesses with your written postings.

Anyone with two fingers and a computer can write anything they want on the internet and it doesn't mean its a safe accepted practice.

Below are the military milspec pressure requirements for commercial contract 5.56 ammunition made for the military. PLEASE notice the acceptable pressures are 52,000 cup or 55,000 psi. And you have someone here telling you is OK to take the chamber pressure up to 75,000 psi.

MIL-C-9963F
15 October 1976
SUPERSEDING
MIL-C-9963E
12 May 1970

MILITARY SPECIFICATION
CARTRIDGE, 5.56MM, BALL, M193

3.7 Chamber pressure.

3.7.1 Measurement by copper-crush cylinder.-The average chamber pressure of the sample cartridges, conditioned at 70° ± 2°F, shall not exceed 52,000 pounds per square inch (PSI). The average chamber pressure plus three standard deviations of chamber pressure shall not exceed 58,000 PSI.

3.7.2 Measurement by piezoelectric transducer.-The average chamber
pressure of the sample cartridges, conditioned at 70° ± 2°F, shall not
exceed 55,000 PSI. The average chamber pressure plus three standard
deviations of chamber pressure shall not exceed 61,000 PSI.

So to answer your question its your face next to the receiver when you pull the trigger, so how stupid and gullible are you to ask questions of strangers you have never met?

Your answers are in the reloading manuals, in reading your primers and measuring case head expansion.

You have some very good toys to play with, why don't you read and learn how to use them before taking advice from strangers and getting your face blown off.

 

[bigedp51]

I was in engineering for 30 some years and noticed a polarization among engineers into two camps, "Do it per procedures" vs "Get-r-done".

I can see some of that same dichotomy in the previous two posts.

The dichotomy of your posting is you are saying its safe to load the .223/5.56 cartridge to proof pressure testing levels.

And the problem is some new inexperienced reloader might believe your stupidity.

And as I said anyone with two fingers and a computer can write anything they want or "rewrite" what they have read somewhere else.

I invite everyone to read the link below and then ask yourself "WHY" would you trust anyone wanting you to fire a proof pressure testing cartridge every time you pull the trigger. ("Get-r-done")

55gr 223 loads - 223 / 5.56 / 9mm reload central database

SMALL ARMS SAFETY
EXAMINATION AND TEST PROCEDURES
June 1988
H. P. WHITE LABORATORY, INC.

SMALL ARMS SAFETY*EXAMINATION AND TEST PROCEDURES, Feature Articles- FirearmsID.com

 

[Clark]

The dichotomy of your posting is you are saying its safe to load the .223/5.56 cartridge to proof pressure testing levels.

And the problem is some new inexperienced reloader might believe your stupidity.

And as I said anyone with two fingers and a computer can write anything they want or "rewrite" what they have read somewhere else.

I invite everyone to read the link below and then ask yourself "WHY" would you trust anyone wanting you to fire a proof pressure testing cartridge every time you pull the trigger. ("Get-r-done")

55gr 223 loads - 223 / 5.56 / 9mm reload central database

SMALL ARMS SAFETY
EXAMINATION AND TEST PROCEDURES
June 1988
H. P. WHITE LABORATORY, INC.

SMALL ARMS SAFETY*EXAMINATION AND TEST PROCEDURES, Feature Articles- FirearmsID.com

Is that what you really want to post, to convey, "I wouldn't do that."?

The big time engineering consultants always phrase things to be polite, correct, and helpful. When they disagree with someone, they own their own limitations.

 

[bigedp51]

Is that what you really want to post, to convey, "I wouldn't do that."?

The big time engineering consultants always phrase things to be polite, correct, and helpful. When they disagree with someone, they own their own limitations.

Your stupidity didn't deserve a polite answer, and the firearms industry has already come up with a "SAFE" working pressure. Answers like yours are what get people hurt or killed when reloading and YOU need to find a new hobby and stop giving out bad advice. And telling anyone that 75,000 psi is a safe working pressure puts you squarely in the moronic class of reloaders. The OP is reloading a gas operated AR15 rifle that wasn't designed to shoot your 75,000 psi proof pressure rounds and 20,000 psi over the rated working pressure of this firearm and cartridge. So how does a electronics engineering consultant get to know more than the firearms industry when YOU don't even have the pressure measuring equipment to come up with any safe answers.

Evaluating Pressure Signs in Reloaded Cartridge Brass « Daily Bulletin

Detecting Excessive Pressure in Cases « Daily Bulletin

RELOADING TIP?Use Shell-Holder to Monitor Case Expansion « Daily Bulletin

TECH TIP: Check Your Cases for Signs of Over-Pressure « Daily Bulletin

 

[Clark]

Your stupidity didn't deserve a polite answer, and the firearms industry has already come up with a "SAFE" working pressure. Answers like yours are what get people hurt or killed when reloading and YOU need to find a new hobby and stop giving out bad advice. And telling anyone that 75,000 psi is a safe working pressure puts you squarely in the moronic class of reloaders. The OP is reloading a gas operated AR15 rifle that wasn't designed to shoot your 75,000 psi proof pressure rounds and 20,000 psi over the rated working pressure of this firearm and cartridge. So how does a electronics engineering consultant get to know more than the firearms industry when YOU don't even have the pressure measuring equipment to come up with any safe answers.

Evaluating Pressure Signs in Reloaded Cartridge Brass « Daily Bulletin

Detecting Excessive Pressure in Cases « Daily Bulletin

RELOADING TIP?Use Shell-Holder to Monitor Case Expansion « Daily Bulletin

TECH TIP: Check Your Cases for Signs of Over-Pressure « Daily Bulletin

Ed,
You are entitled to your opinion.
But I think i know what I am doing and telling the truth.
If someone wants to know what real pressure signs are in an AR15, I know.
I think I am being truthful and helpful and polite.

 

[bbowles]

Wow! Are we having fun yet?

BigEd, I SIMPLY asked for some opinions as to the info I provided that I am seeing with my loads. I described details of case condition and CH expansion numbers and SIMPLY asked for some opinions. At least Clark gave me some opinions and I thank him for that. If all you want to do is quote one technical research piece after another I guess this is an open forum. Again I am simply asking for some opinions from some guys to help me decide ON MY OWN what is safe for ME.

I was raised old school and was taught that "if I don't have anything nice to say then don't say it." There is no reason to call people stupid! I am trying to learn an art so I won't be stupid.

I DON'T NEED TO BE TOLD THAT I CAN'T TRUST EVERYTHING I READ ON THE INTERNET.

I have read and reread 3 manuals that I own. I have talked with Sinclair tech people several times. That doesn't make me an expert. Since everyone is probably scared (including me) to ask anymore questions about this I seriously doubt I will get any help on this topic.

I even talked about what I read in Zediker's book to discuss his idea of pressure signs. We all have to decide on our own how we see things but would have been nice to have had a nice civil, informative discussion on my original question. But I imagine that can't happen for fear of being called stupid. Any ideas or opinions (or even if bogus info from someone who knows nothing) are just things that we all can sort through to decide what we think is right.

I really am sorry that I started this thread! Really enjoy this sight but the fun is gone when you have to fear being land blasted for questions (even unintelligent ones, ha). I once heard the only "dumb" questions are the ones we don't ask. Guess that is not always true.

Thanks to any of you brave souls that want to give me your opinions as to my questions.

 

[bbowles]

Wow! Are we having fun yet?

BigEd, I SIMPLY asked for some opinions as to the info I provided that I am seeing with my loads. I described details of case condition and CH expansion numbers and SIMPLY asked for some opinions. At least Clark gave me some opinions and I thank him for that. If all you want to do is quote one technical research piece after another I guess this is an open forum. Again I am simply asking for some opinions from some guys to help me decide ON MY OWN what is safe for ME.

I was raised old school and was taught that "if I don't have anything nice to say then don't say it." There is no reason to call people stupid! I am trying to learn an art so I won't be stupid.

I DON'T NEED TO BE TOLD THAT I CAN'T TRUST EVERYTHING I READ ON THE INTERNET.

I have read and reread 3 manuals that I own. I have talked with Sinclair tech people several times. That doesn't make me an expert. Since everyone is probably scared (including me) to ask anymore questions about this I seriously doubt I will get any help on this topic.

I even talked about what I read in Zediker's book to discuss his idea of pressure signs. We all have to decide on our own how we see things but would have been nice to have had a nice civil, informative discussion on my original question. But I imagine that can't happen for fear of being called stupid. Any ideas or opinions (or even if bogus info from someone who knows nothing) are just things that we all can sort through to decide what we think is right.

I really am sorry that I started this thread! Really enjoy this sight but the fun is gone when you have to fear being land blasted for questions (even unintelligent ones, ha). I once heard the only "dumb" questions are the ones we don't ask. Guess that is not always true.

Thanks to any of you brave souls that want to give me your opinions as to my questions.

 

[bigedp51]

bbowles

You are the one asking questions.

And you are the one without the practical experience on the subjects you are asking about.

And yet you want to pick and chose your answers.

So go ahead and "Get-r-done" and load them to 75,000 psi.

And one more thing, the cases below were not loaded by Lake City Army Ammunition Plant because the brass failed its quality control inspection. These rejected cases were loaded by Federal and someone here wants you to load them to 75,000 psi after they failed inspection and he says "he knows what he is doing".

And bbowles you are the same person who didn't have his dies adjusted correctly and couldn't figure out why you were not sizing the entire neck of your cases. You have some nice new toys to play with and you still do not know how to use them. And on top of this you are the one asking the rookie reloading questions. READ your books and manuals, they will tell you how to adjust a reloading die and NONE of the manuals will tell you to load to 75,000 psi.

I do not mind answering questions but like I said in your other posting, I said "28 postings later and your dies are not any closer to the shell holder". Your neck wasn't being sized all the way and YOUR light bulb had not come on after all the answers given to you. And then you want to question the people giving you the answers and come up with smart remarks like you made above.

I keep looking at your postings, then your comments and wonder if you should be in a "special education" reloading forum. You question the very people who give you the answers and then want to debate the issue. If you think you have all the answers then why are you asking so many questions. And if you think the polite answer is the correct answer you have a lot to learn.

Cartridge Pressure Standards

Reloading for Semi-Autos and Service Rifles
(also in Sierra manual)
exterior ballistics

 

[bbowles]

Big Ed,
I did get my prob with sizing die. A nice man helped me out thru PM since was hard to solve with all the bickering. No idea where all the federal load stuff is from my question. Since I have only used Lapua and LC13 brass. AND. I never said anywhere that I am loading to 75k pressure.

Simply loading to about manual specs and trying to decipher pressure. And where is my smart remarks? Showed my wife this complete post and all she could do was laugh. It is very childish.

I am sorry that I have made you so mad at me and obvious from my earlier thread that you never liked me or my rookie toys. Since we don't "play well together" I will try to refrain from any further responses. Sorry it had to come to this but I will have to do my learning elsewhere.

Btw was READING zediker book again when you chimed in once again.

Good luck to you BigEd in all you do. Wish you a happy and prosperous life!

 

[Graham]

Excess pressure signs for AR 15 223 loads?

.223 brass fired in an AR doesn't always reliably show signs of excess pressure.

Sometimes the primers flatten, but other times they don't.

Often you won't be able to tell that the loads are too hot until you start blowing primers.

Increase .2 grains until you blow a primer, then back off by half a grain.

 

[bbowles]

Graham,
I sincerely want to thank you for a very good and civil response. That is something I understand. I have yet to blow a primer on any of my first 700 loads on this AR. But I did experience slight ejector ring on max varget load with lapua brass and backed off that load about a grain.

Not seen any pressure signs yet on this AR Comp load but feel am about max and will quit at 23.2 gr.

Thanks again for the info.

 

[bigedp51]

Big Ed,
I did get my prob with sizing die. A nice man helped me out thru PM since was hard to solve with all the bickering. No idea where all the federal load stuff is from my question. Since I have only used Lapua and LC13 brass. AND. I never said anywhere that I am loading to 75k pressure.

Simply loading to about manual specs and trying to decipher pressure. And where is my smart remarks? Showed my wife this complete post and all she could do was laugh. It is very childish.

In 28 replies to your question you never moved or adjusted your resizing die closer to the shell holder and someone had to PM you to get it through to you what you were doing wrong. All you had to do was follow instructions and lower the die and you still wanted to debate the subject. Your not stupid, your just thick headed and over think everything.

This is what was so frustrating, "YOU" never adjusted your die during 36 replies to your posting.

And you told us your die was 1/8 of an inch from touching the shell holder.



"No idea where all the federal load stuff is from my question. Since I have only used Lapua and LC13 brass".

Guess what brass is inside the Federal boxes.

Now guess why the military gets rid of this brass and Federal loads and sells it?

Your problem bbowles is you are so inexperienced you do not know who to believe when you ask a question. The answer to this is read more until you understand what you are doing and not confusing yourself. It shouldn't take 36 replies and you "NOT" adjusting your die lower to size the case properly. The tallest shell holder in the Redding competition shell holder set is .010 taller than normal with the die touching the shell holder. And your die was 1/8 of an inch from touching the shell holder.

 

[bigedp51]

.223 brass fired in an AR doesn't always reliably show signs of excess pressure.

Sometimes the primers flatten, but other times they don't.

Often you won't be able to tell that the loads are too hot until you start blowing primers.

Increase .2 grains until you blow a primer, then back off by half a grain.

Port pressure governs when the bolt starts moving to the rear and high port pressure can cause the primer to be forced out of the primer pocket due to pressure still being in the barrel as the bolt moves rearward.(the primers won't be crimped) So what are you telling bbowles to blow the primer out of the primer pocket and jam the trigger group or rupture the primer and score the bolt face?

Question: what is 55,000 psi and what does "shall not exceed 55,000 psi mean?????????

 

[Graham]

Excess pressure signs for AR 15 223 loads?

So what are you telling bbowles to blow the primer out of the primer pocket and jam the trigger group or rupture the primer and score the bolt face?

Question: what is 55,000 psi and what does "shall not exceed 55,000 psi mean?????????

Answer: Not knowing when 55,000 PSI is exceeded simply restates the problem.

Spare us the drama: The world won't end should he accidentally blow a primer.