Blue Dot users, your help is needed..

I think there have been some fair questions raised about Blue Dot use in the 223, and the "potential" for disaster theorized by some...

For folks that have used some of the Blue Dot loads that they have gotten from AR here, would you post if you have had success with them or experienced problems...

I'd really especially like to hear of those that have had problems ( and we are not talking complaints because it won't cycle your AR15 or your Mini 14)...

if problems exist out there, that I have not heard about, I think it is something that I should know about an honestly pull the blue dot loads that I have posted on AR here...IN ALL Calibers....

But I need feed back from those that have used them... and the more the better...

I get tons of emails about the successful uses experienced by others.. and haven't received any negative emails...

But if any of you gentlemen have experiences problems.. we need to hear about them!

We need to know if the load data put forth has flaws in it or not.. so we can either adjust them or pull them..

I share all the work for free, so there is no money made on doing this...but I want it to be safe for all concerned.. and that is the number one priority...

so all of you that can help, it would be greatly appreciated...

cheers
seafire

Zero bad experiences. Nothing but smiles for this safe, accurate, economical load.

I thank you for your experiments and willingness to share them

Seafire your timing in incredible!

Friday a fellow hunter and I were out on our first squirrel sufari this weekend and I had my frist bad happening with BD.

I was putting the DPMS .204 throu the paces with single foaded BD rounds to get the close ones before opening up with the fulltilt loads, when I has a lock up. The five rounds before this had no pressure signs at all.

The .204 upper was done for the day! I could not get the action to open no matter how hard I tryed.

Saturday I when to the gunsmith to see if he might be able to resolve this issue. Ten minutes of light hits with a soft faced hammer and it finaly came open.
Both the smith and I where amazed to fine the case was now belted!!!!! That right BELTED!!!!! Almost blow! Looking at the casing in my hand as I type this it make me wounder how close it was.

Just for the record the load was,
Hornady case
Win wsr primer.
14.0 gr Blue dot
32gr. Seirra Blitz King
C.o.l. 2.265

I pulled ten in the same box and they wieghed out to 14.0 .

I'll try to post a pictue of the case tomarrow as I'm on dial-up at home.

Seafire you know I realy liked the BD loads but intill I figure out what went wrong there on the shelf.

............338vt

338,

please keep us posted on this.. from what your gunsmith thinks may have caused it...

anyone with quickload, can they run a scenario and ascertain the potential pressure in this?

This was with a 204 chambering and in an AR...

I am going to assume that this was not an accidental overcharge... the 14 grains would eliminate a double charge scenario...

any AR smiths or experts out there that could weigh in on this??

To all you sub.22 caliber guys I've been trying to be as forceful as I can in saying the sub.22's spike pressure totally differently that bigger bores. Reduced powder charges of super high speed pistol and shotgun powders that attain more than greatly reduced velocities are unsafe! As I keep repeating, sub.22's are near all I shoot and they do "NOT" respond the same as bigger bores.
Further, I got into this Blue Dot craze issue several years ago when a fella on a site I frequent posted pictures of the eye they had just done surgery on after a reduced Blue Dot load in his .223 Contender catastrophically failed. They barely saved his eye.
I have talked to Ben Amonette at Alliant several times and he most definitely does not recommend Blue dot for the uses it is being touted for here.
This is not a personal issue and and the only dog I have in this fight is the safety of fellow shooters.
I will repeat one more time at the risk of sounding like I think I know everything which I most certainly do not. I have a large gun safe full of wildcat and factory sub.22 caliber rounds. Loading for them is about all I do and I'm retired so I do it a lot. Those that insist on trying to make one super fast burning powder fit all applications in the .17's and .20's are going to get hurt!
We are blessed with a plethora of fantastic powders suitable for any application in the sub.22's. If all you can afford is one kind of powder you can't afford this hobby and how the heck are you gonna afford the eye surgery, plastic surgery, prosthetic hands, law suits or worse? I can't make it any clearer than that! .17, .19, .20 calibers etc. spike pressure differently! Think about it. They have a much smaller escape route for the pressure to get out of before the pressure builds to catastrophic levels. To achieving near standard velocities with very small amounts of super fast powder can only happen one way, the pressure has to spike incredibly fast and give that projectile a ultra quick blast down the bore as opposed to the slower steady push of a slower burning powder. That means "HIGH PRESSURE".
If your car wouldn't run and you wanted to push start it by getting it up to 30 miles an hour would you rather have a car lean on your rear bumper and slowly accelerate to 30 or be rear ended by a pick up doing 60 miles an hour and get to speed in 2 seconds?
Like I posted on another thread. Take a great big lungful of air and blow it hard down a McDonalds drinking straw. How much pressure or force did it take? Now take the same big lungful and try to blow it real hard down one of those skinny little straws that come in a mixed drink, blow real hard! You'll damn near pop your ear drums. Now do those two respond to the pressure of your blowing real had the same? Of course not. Those two analogies are exactly what your looking at doing with Blue Dot in a .17 or .20 with anything but an "extremely" reduced load.
Personally I don't need 3 or 4 or 5 guys to come near blinding themselves before I listen to the techs that manufacture a powder about it's intended purpose, just one picture was enough for me. I sure wish I'd of saved the picture of that fella's eye! It was darn sure worth more than a thousand words.
If any of you fellas are considering for example Blue Dot in a .17 Fire Ball or such like and I've given you any reason to think about it PLEASE, call the techs at Hornady that make the .17 cal bullets and call Ben at Alliant who produces the Blue Dot. The calls are even free, the consequences of trying it and being wrong sure as heck aren't!
No disrespect intended in any way seafire but I have boo-coo small caliber experience and this needs to be said.

Interesting discussion. I shoot a lot of .222 Rem with a 50 grain bullet and formerly 11 grain BD, now 13 grain N110. Both behave quite similar, I have so far not made any bad experiences but no, it is definitely not a low pressure load, neither the 36 grain BD I use in the .338 WM with a 200 grain ballistic Tip.

There it *seems* that primer pockets open up even a little faster than with regular loads.

Well Doug,

based on your and hot core's post on the other thread, that is why i brought this thread up for those to post problems......

I hope they keep coming...

So far we have 112 views and ONE posted problem.. I do hope more come out...if more exist...it is important to hear it from those that have experienced problems...not "well I have a friend who..."

quote:

Originally posted by seafire2:
...I hope they keep coming...

So far we have 112 views and ONE posted problem.. ...

Well Seafire, I guess I'm on the opposite side of the fence again - I hope they don't keep coming.

I count 2 problems that probably would not have happened if the folks had been using an Appropriate Powder. Here is the count I see:
1. 338vt nearly Ka-Boomed his 204Rug AR. He is a very lucky individual.
2. The guy Doug mentioned nearly lost an eye following a Ka-Boom.

How many Ka-Boooooms does it take to get the message through???

Best of luck to you guys.

quote:

There it *seems* that primer pockets open up even a little faster than with regular loads.

There it is my friend, "high pressure"! High pressure is the only think that knocks primer pockets loose faster than they oughta. Were talking serious ballistic issues here and because a number of folks are doing it's starting to sound like casual experimentation but it's not, it's taking BIG risks to save money on powder consumption.
This is a good discussion however and I thank all for participating in a civil fashion.

No, I was not talking high but regular pressure, some people confuse reduced loads with low pressure loads. This is of course no true, the pressure just drops off more sharply over time than with slower powders.

I tried these "reduced" loads with several calibers and still use the .222 Remminbgton on the range and the .338 Wm plus the 9.3x74 for hunting. I did NOT experience any problems and checked all loads with Quick Load. They are completely on the safe side but not, I repeat, low pressure loads, only the velocity is reduced.

What we hear here from the DEVA institute is that most likely in all cases of blown-up weapons with reduced loads a double charge was involved. There is, at least for faster powders, just no other possible explanation.

We have even a bullet manufacturer here who has published a complete book on reduced loads, most with Vihta N110, some with Unique: H&N.

I figure they wouldn't do it if it wasn't safe.

I forgot to mention that even Vihtavuhori recommends the use of N110 for reduced rifle loads.

Dirk,

thanks for the H & N web site link..

some of their posting with Unique and Trail Boss mirror my results also in the 6.5 x 55 and 8 x 57, 30/30 and 30/06...

quote:

Originally posted by 338vt:
Seafire your timing in incredible!

Friday a fellow hunter and I were out on our first squirrel sufari this weekend and I had my frist bad happening with BD.

I was putting the DPMS .204 throu the paces with single foaded BD rounds to get the close ones before opening up with the fulltilt loads, when I has a lock up. The five rounds before this had no pressure signs at all.

The .204 upper was done for the day! I could not get the action to open no matter how hard I tryed.

Saturday I when to the gunsmith to see if he might be able to resolve this issue. Ten minutes of light hits with a soft faced hammer and it finaly came open.
Both the smith and I where amazed to fine the case was now belted!!!!! That right BELTED!!!!! Almost blow! Looking at the casing in my hand as I type this it make me wounder how close it was.

Just for the record the load was,
Hornady case
Win wsr primer.
14.0 gr Blue dot
32gr. Seirra Blitz King
C.o.l. 2.265

I pulled ten in the same box and they wieghed out to 14.0 .

I'll try to post a pictue of the case tomarrow as I'm on dial-up at home.

Seafire you know I realy liked the BD loads but intill I figure out what went wrong there on the shelf.

............338vt

I'll wait for the pix but if the 'belt' that you mentioned is as I'm picturing it, it sounds like you had an 'out of battery' discharge. Maybe a case sizing issue?? If so, it would have been much worse with a 'full power' load.

Again, the assumption was made on the visual that I created from your text.

I had some pressure problems with my .338 WM when I first started loading and using blue dot. I got a few very flattened primers and a stuck case. I havent played around with blue dot in that rifle since. I wasnt going over the recommended load using 200gr bullets. I THINK I may have been too close or into the lands, is it best to back off the lands more with blue dot than you would with normal powder? I have used blue dot in my 223 rem and 243 win without any problems yet, but I havent done any extensive shooting so far with that powder in those guns.

quote:

Originally posted by 338vt:
... Just for the record the load was,
Hornady case
Win wsr primer.
14.0 gr Blue dot
32gr. Seirra Blitz King
C.o.l. 2.265 ...

Hey 338vt, I'm curious about a couple of things:
1. Was your Goal simply a Reduced Velocity, plinking Load, or something else?
2. Did ANYONE warn you to use Pistol Primers?
3. Did you use CHE & PRE to compare the Pressure to a Factory Cartridge?
4. Did you develop the Load starting with a lower level Load, or just go straight to the 14.0gr of Blue Dot with the 32gr Bullet?
5. Is the Headspace still OK on the rifle?

I'm sure glad you did not get hurt.

seafire
I will get the pic. up soon! No the gunsmith has no idea as the chamber is fine and headspaced prefect. The case in question is 1gr heaver then any others I've weighed so farbut that shouldn't have had that much affect on pressure.

I'm wondering if maybe the sun/heat had a hand in this.

DUK

Can you run Quick load with the above load and get back to use!!!

Hot core,

1 The goal was a cheap load for close stuff that wouldn't over heat my rifle in 40 rounds like the factory/normal handloads.
2 Yes!, even at 14.7 grains of db I still was well bewllow CHE of a factory round! 14.7 is as high as I went as accuracy was at 13.9 to 14.2 so I went with 14.0 as it shoot the best .212 for five at 100 yards Vel. of 3430 ES 13, S.d 8.

Starting load was 12.7 as you can't double charge the case from here!

To all intill I/we get to the bottum of this I'm going to call it as my fult not BD as in the upcomming pic./s I will inclued a case from the prev. shoot that day. You will see no pressure signs on it.

Will post pic. soon but first I must free up all bandwh. I can.

................338vt

Only took 1 hour 23 minutes and two new aa's!

Left is the belted case right is a fired case from the same shoot. All input is welcome!
............338vt

Is that the new 204 Hornady Magnum cartridge that was introduced at the 2008 Shot Show?

Kidding......

Man, that's wierd. I am glad you did not get hurt

I have never seen the Quick Load reports for BD in a 223. What does it say?

quote:

I'll wait for the pix but if the 'belt' that you mentioned is as I'm picturing it, it sounds like you had an 'out of battery' discharge

If it was out of battery I would think the shoulder would have moved forward to fill the chamber as well. Looks to me like the shoulder hasn't moved.

quote:

Originally posted by ramrod340:

quote:

I'll wait for the pix but if the 'belt' that you mentioned is as I'm picturing it, it sounds like you had an 'out of battery' discharge

If it was out of battery I would think the shoulder would have moved forward to fill the chamber as well. Looks to me like the shoulder hasn't moved.

It looks like maybe the case head end of the chamber was somehow reamed oversize and high pressure fire formed the case head to the chamber.

338 VT,

Thanks for posting those.. I made copies of them and am sending them off to a couple of gunsmith acquaintences and see what they think...

I'll try to also get it to a local smith I know that specializes in ARs....and get their feed back...

After seeing that, I am wondering if it is not a bolt cycling issue... did you let the prior shot try and cycle the bolt, and it didn't do it comopletely and then the second round that blew, completed the cycling and a little more, since the bolt was not in the right position from the first shot...

on ARs, I state that the bolt must be cycled manually.. is that something that you did?

I am just glad you weren't hurt and then glad it didn't screw up a new firearm...

quote:

Originally posted by The Derek:
I had some pressure problems with my .338 WM when I first started loading and using blue dot. I got a few very flattened primers and a stuck case. I havent played around with blue dot in that rifle since. I wasnt going over the recommended load using 200gr bullets.

How much powder did you use? I shoot 36 grains BD with a 200 grain Ballistic Tip, according to the primer it seems to be still OK. I have to check again what QuickLoad says about the pressure, if I remember it well it was not far from maximum.

Using a Ruger 77 I do feel safe, it is a load I used to shoot quite a lot of pigs and roe deer.

Hey 338vt, I'd encourage you to switch to the Pistol Primers to add a small Safety Valve. I've used Reduced Loads since the `60s and have given them a lot of thought over those years.

Normally the Pistol Primer will "Pierce" and blow a bit of Primer Brass back at those of us using Bolt Actions, but it wouldn't get to you in the AR. And of course, re-develop the Loads.

Heat could very well be the problem if the Load is already too close to an UNSAFE MAX.

Real glad to see no more Serious Problems.

Case neck too long?? Did you take some measurements? Wierd. I have seen similar from an AR bolt not closing completely due to nasty, gunked-up lug recesses.

seafire,
Thanks! I will whate for your/ the gunsmith's responce.

DUK,
14.0 gr Blue Dot Hor. case, WSR prim., 32gr. Seirra BlitzKing.

Hot Core
I might go with pistol primers, but I have 25,000 Small rifle, 200Small Pistol

Ramrod
That's what I thought!

Smokey
Thats what the Smith there was thinking
I'm glad I didn't get a hurt as well, I'm left handed and might have had casing in my right eye!!!!
To all
I've loaded and fired 1000's of BD loads will no i'll affect. This is the only close call I've had EVER!, with any load!

As I said, all fault fall on me intill I/we find the anwser!
Thanks All!!!
.................338vt

338VT
The bolt face on an AR fits against the back of the barrel with only about .015 or so clearance not counting the small forcing cone. If the bolt is closed and locked there is no where for the brass to expand and create a "belt" such as you have on the case in the photo, even with the forcing cone. The only way to do that is for the bolt to be not locked. The neck on the bad case looks longer than the one on the good case also shown in the photo. Is it possible that the bolt closed, chambered the round, but not quite because the longer neck prevented the bolt from locking? It was said before that the blue dot would not cycle the bolt, but it looks like it started to come back some which could create the belt.

Hard to say from the photos alone, but it does look suspiciously as if the bolt was not fully closed when the primer ignited.

quote:

Originally posted by Stonecreek:
Hard to say from the photos alone, but it does look suspiciously as if the bolt was not fully closed when the primer ignited.

There is just no radial metal support in that area weither it is a short chamber with the barrel not screwed down or metal removed from the barrel in that area. I have similar cases but the buldge ,if you will, is much closer to the extractor groove. They were not Blue Dot happenings. roger

quote:

Originally posted by Stonecreek:
Hard to say from the photos alone, but it does look suspiciously as if the bolt was not fully closed when the primer ignited.

Speaking with one gunsmith friend, he was of the same conclusion...He said the belt on the case indicated that right away...

If a Blue Dot load did that, one can imagine what might have happened with a load that had more recoil....

some one else I know with a strain gauge was going to look at testing the pressure on the 14.5 grain load with a 40 grain bullet with a small rifle primer.. and 13.5 grains with a 55 grain bullet...

He doesn't have a 204 to test tho...

There may be another possibility with respect to 338's problem.

As Clowdis alluded to, there is very little chance of a round going off if the bolt is not locked up.

Given that, the chambered round, after being struck with the firing pin and going off would have had to have moved back out of the chamber the distance shown. The only way this would have happened, I think, is if the pressure in the barrel built to the point that the bolt was cycled and started to move back. The only way I can figure this happening is if there was an obstruction in the barrel BEYOND THE BARREL GAS PORT.

The pressure built in the barrel as if the bullet was past the gas port (but wasn't) and started to cycle the action. The bolt moved back some until the pressure built to the point the rear of the case sealed at the rear of the chamber. At this point the case behind the rear edge of the chamber expanded until the obstruction and the bullet were forced out of the barrel.

What had me perplexed for a time was why the shoulder was not blown out. After thinking for a while I have a theory. With the neck and shoulder pulled away from the forward end of the chamber, the neck/shoulder may not have expanded and sealed, and therefore would not have expanded the shoulder. The pressure would have been the same on the inside of the neck/shoulder as the outside and so would not have been blown out.

You would think the rear of case would have seperated completely, but if the obstruction and bullet exited the barrel at just the right time it turned out as shown.

Not sure of anything, but I am having a hard time figuring out any other possibilities.

Jim

PS: If you study the way the ARs are built and lock up, you will see quickly the bolt has to be locked up for the firing pin to ignite the primer. I can't for the life of me see how the round could have fired before the bolt was locked up. It is quite a good system IMO.

quote:

Originally posted by seafire2:
[QUOTE]Originally posted by Stonecreek:

If a Blue Dot load did that, one can imagine what might have happened with a load that had more recoil....

I guess I don't follow you on this one, John. Are you relating recoil to the case deformation? Kindly explain. roger

Talked to another Gunsmith today after work. From what he said it sounds like the case was to long and cripped into the bullet as the action closed. Causing the high perssure to fourm the head of the case to this new look. The case (belted) is 1.860 I think 1.850 is max the other in the above photo is 1.840 which is the trim to lenght.

He also said that the action was closed for the round to do this otherwise I would have had case failure and eye surgery.

I'm going to put the fired case back in the chamber and see if it will close ,but first I'm going to have to file the burrs off to get the bolt head to rotate closed. Be right back!

.................338vt

quote:

Originally posted by Hot Core:
[QUOTE]Originally posted by 338vt:
... Just for the record the load was,
Hornady case
Win wsr primer.
14.0 gr Blue dot
32gr. Seirra Blitz King
C.o.l. 2.265 ...

Hot Core & 338vt,
I have QL load, give me the following info on case/weapon:
I don't know much about the 204 case, it is a 222 Mag case necked down to 204 caliber? My old QL does not have the 204, but has 20/222 or 20/223 or 20/222Rem Mag case.

BBL length=total overall bearing surface length=
Case length=

The only 204 bullet I have is Horn 33gr Vmax.

Checking the 20/222 case with 14.0grs BD shows the following:
Horn 33gr Vmax bullet=
COL=2.265"
Psi=46407 psi
Load ratio of 75.1%
Velocity= 3317fps
BBL Len = 21"

20/222Rem Mag shows the following:
Horn 33gr Vmax bullet=
COL = 2.265
Psi=41832
Load Ratio=69.8%
Velocity=3249 fps
BBL Len=21.0"

20/223 shows the following:
Horn 33gr Vmax bullet=
Col= 2.265"
Psi=39275
Load Ratio=68.1%
Velocity=3273 fps
BBL Len= 21"

Provide the new info and I'll rerun the info and post the results.
Don.

Hey nvreloader, I don't have a 204Rug, so I can't help you on capacity, or what it is made from.

Just as a point of information about Quick Load,(which I also do not have) there has been some discussions in the past on the Reloading Board concerning strange, unexplainable, obviously WRONG data provided by it for some Cartridges. I don't have a link to it, nor do I remember if it was Pistol/Revolver Cartridges, Rifle Cartridges, or both.

That said, the "guesstimate" QL provides might be relevant for this Cartridge - I just don't know. However, once we get outside the Normal Powder Ranges for a Cartridge, I'd have even less faith in a Pressure which is a Software Guesstimate. I do have "Load From A Disk" and it is fun to play with, but I am very cautious about it's Guesstimates too.
-----

Hey 338vt, I appreciate your candid response about "why" you had chosen to use the Rifle Primers. Hopefully you will now realize how important it is to use the Pistol Primers.

Back years ago when I first mentioned folks should be using Pistol Primers with "ANY" Reduced Load, it was simply based on first-hand experience. Over the years I've had a few Loads that did not create a Ka-Boom, but now as I look back, I don't know why they didn't.

Obviuosly I won't be coming around beating folks over the head who choose to use Rifle Primers with these Loads which get "Past or too close to" a normal Peak Operating Pressure. But, I really don't want any of you to get hurt or damage firearms due to something so simple.

Best of luck to all you folks.

QL's author says that the program's model does not work very well with large, cylindrical cases. I don't think that there is that much difference between a .204 Ruger and a .222 remibgton Magnum which would explain such difference in pressure.

From what I have read the .204 was used in a self-loading gun, to me an out-of-battery ignition is the only plausible explanation. Have a friend who wrecked two (!) AR-15s with regular .223 reloads, these were complete KA-BOOMS, not what had happened here.

Duk your right about not much difference in the Triple Duce Mag and .204 for capacity as the .204 is made off the .222Mag case with the shoulders changed a bit.
There is a great deal of difference however in how they handle equal pressures. 50,000cup escapes with a lot less resistance and at a totally different rate of speed from a larger hole than it does a smaller hole. Smaller calibers spike pressures completely differently than larger calibers.

A re-introduction first. I used to post here fairly often, but wandered off long enough to have my member name purged - thus explaining my current low post count.

Now, a couple of observations.

I'm a fan of Blue Dot loads since beginning my own research on the concept of much-reduced loads. I stumbled across the work of James Calhoon and never looked back. Only recently have I found Seafire and his work. I can confirm that Clahhon's work and my own (done independently) match with Seafire's in every way. You can believe what Seafire claims.

With regard to comments about "never fail" traditional methods of judging pressure, I can categorically say that things like case expansion and primer appearance are no better than reading chicken entrails. Denton Bramwell's scientific analysis completely discredits them - especially case expansion. See these articles, please: LINK

The "belted" round from the AR is beyond my experience base, except that I have had one almost exactly like it from a .223 bolt gun, using a well-known and much-used published load of H-335. Weighed charge, BTW. Scared the poo out of me, and caused me to pull the other 99 of 100 loaded rounds in that batch. NO anomalies found. No explanation found, either.

But never a single problem with Blue Dot Loads in 22 Hornet, 221 Fireball, 223, 219 Zipper, 30-30 or 308. I use an RCBS Chargemaster and funnel each weighed charge, then immediately seat a bullet. Zero chance of double-charge.

It's good to be back here. Howdy, y'all!

quote:

Originally posted by Rocky Raab:
...With regard to comments about "never fail" traditional methods of judging pressure, I can categorically say that things like case expansion and primer appearance are no better than reading chicken entrails. Denton Bramwell's scientific analysis completely discredits them - especially case expansion. ...

Hey Rocky, Welcome Aboard. denton is an idiot.

Needless to say I strongly disagree with your totally incorrect post, simply based on actual first-hand experience. Your hero denton was laughed off this Board because of his lack of knowledge - concerning anything dealing with Reloading.

Since you seem to think denton is such a wise Reloader, I would appreciate it if you would explain how his thoughts in The World's Most Ignorant Reloading Suggestion, are SAFE, intelligent and show even the most minute understanding of Basic Reloading.

I look forward to your answer.

quote:

Originally posted by pdhntr1:
There may be another possibility with respect to 338's problem.

As Clowdis alluded to, there is very little chance of a round going off if the bolt is not locked up.

Given that, the chambered round, after being struck with the firing pin and going off would have had to have moved back out of the chamber the distance shown. The only way this would have happened, I think, is if the pressure in the barrel built to the point that the bolt was cycled and started to move back. The only way I can figure this happening is if there was an obstruction in the barrel BEYOND THE BARREL GAS PORT.

The pressure built in the barrel as if the bullet was past the gas port (but wasn't) and started to cycle the action. The bolt moved back some until the pressure built to the point the rear of the case sealed at the rear of the chamber. At this point the case behind the rear edge of the chamber expanded until the obstruction and the bullet were forced out of the barrel.

What had me perplexed for a time was why the shoulder was not blown out. After thinking for a while I have a theory. With the neck and shoulder pulled away from the forward end of the chamber, the neck/shoulder may not have expanded and sealed, and therefore would not have expanded the shoulder. The pressure would have been the same on the inside of the neck/shoulder as the outside and so would not have been blown out.

You would think the rear of case would have seperated completely, but if the obstruction and bullet exited the barrel at just the right time it turned out as shown.

Not sure of anything, but I am having a hard time figuring out any other possibilities.

Jim

PS: If you study the way the ARs are built and lock up, you will see quickly the bolt has to be locked up for the firing pin to ignite the primer. I can't for the life of me see how the round could have fired before the bolt was locked up. It is quite a good system IMO.

Certainly not an expert,but pdhntr1 sounds like he's on to something.
I don't believe the barrel was plugged, I believe that the Blue Dot pressure curve way too abrupt for use in an AR.
These systems are basically ballanced for powders in the H335,IMR4895,Re15 etc range.

I understand this rifle is a .204, but whoever designed the upper still ballanced the carrier vs gas port location and diameter.

I'll bet my last dollar that he didn't ballance it for Blue Dot.

I believe an out of battery discharge if even possible would have been catastrophic.

I believe this was a timeing issue.

Why just once, instead of every time ???

Again, not a gunsmith, just one guy trying to give the experts something to consider .

Covey16

I'm glad you looked forward to it.

That hint of Denton's would make me cringe, too. But it has nothing whatever to do with his qualifications as a scientist, statistician and test engineer. If you cannot argue against his premise about case expansion, please don't drag in some spurious ad hominem attack.

Can you find mathematic fault with him?

I ask because (in your words) I strongly disagree with your totally incorrect post, simply based on MY OWN actual first-hand experience.