Hello from Germany,
tried a reduced load with Lovex D060 that is similar to 5744. Got load data from a friend.
Case: Remington, Primer: CCI 200, Bullet: S&B 147grs FMJ, 24,0 Grains Lovex D 060.

6 Shots were absolutely fine. The seventh sounded strange. I could hardly remove the case from the chamber.
A double load of powder is because of volume not possible. Any ideas what have happened?






Regards, Hubertus

Welcome!!

That load is only using around 54% of the case capacity. MY GUESS is the powder laid on the side and the primer ignited across the top of the powder. Making a HUGE pressure spike. Due to the much larger surface area.
Per QL that load should only generate 13-14,000psi

Welcome to AR. Powders that fill the case closer to 100% have less ignition problems. Good luck.

quote:

Originally posted by Alex Hubertus:
Hello from Germany,
tried a reduced load with Lovex D060 that is similar to 5744. Got load data from a friend.
Case: Remington, Primer: CCI 200, Bullet: S&B 147grs FMJ, 24,0 Grains Lovex D 060.

6 Shots were absolutely fine. The seventh sounded strange. I could hardly remove the case from the chamber.
A double load of powder is because of volume not possible. Any ideas what have happened?

You got what is known by some as detonation. It is on the continum that includes a squip (a bullet stuck in the barrel).

If you increase the powder charge, the problem will go away. Also, if you haven't already done so, make sure there isn't a bullet stuck in the barrel.

quote:

Originally posted by ramrod340:
Welcome!!

That load is only using around 54% of the case capacity. MY GUESS is the powder laid on the side and the primer ignited across the top of the powder. Making a HUGE pressure spike. Due to the much larger surface area.
Per QL that load should only generate 13-14,000psi

Exactly. That is why loading manuals list minimum as well as maximum loads.

I don't think that's what happens at all. In my opinion with a reduced load the following happens:

1. Not enough pressure is present to get the powder to burn optimally.

2. The bullet hesitates on entering the rifling which causes pressure to build up to a more optimal one. Since the bullet has to start again from a stuck or semi-stuck position, much more pressure is required.

I had a similar thing happen in a 454 Casull. The powder fill of the case was plenty to eliminate the possibility of powder being ignited across the top of the powder. At my firing the round, the cylinder was almost locked up. I had no more problems after increasing the powder charge. And no, it wasn't an over charge as I individually weighed charges as I loaded the cartridges.

I've also worked with some Blue Dot 308 Winchester loads. There wasn't much difference in velocities between powder in front, in back and in between. Blue Dot loads, by the way, don't come close to filling a 308 Winchester case.

5744 can do strange and wonderful things in a bottle neck cartridge.
One of two things happened:
1. charge was not correct/double
2. charge detonated.
This happens with reduced loads and has been written about since the last century.
5744 is not the powder I would use in the .308

For reduced loads look at H4895 and check out the Hodgdons website and or their reloading manual.
It is potentially dangerous to reduce some powders lower than recommended charges.

Detonation ? nope does not happen, cannot happen reloading propellants are low order "explosives"
They deflagrate ( burn) and do not detonate.
fundamentally two different mechanisms.

The phenomenon of catastrophic pressure peaks associated with low density loads are commonly and erroneously referred to as detonations or as a SEE ( secondary explosion effect) which is also strictly not correct. SEE refers to the rapid deflagration of dry wood dust when combined with oxygen and then ignited by a spark ( as recently seen in the disastrous Burns Lake Wood mill fire in BC Canada)

One of the features of low load density propellant ignition is an initial increased rate of deflagration ( also inconsistent) and subsequently rapid phase change leading to a steep and sometimes catastrophic overpressure in the chamber. The reason for this lies in the direct environment surrounding the grains of powder.

This is less useful in terms of supplying force to propel the bullet than a high load density load. High density loads also raise peak pressure but burn rate follows burn rate laws and are consistent.

Have no experience of this powder at all.

But, we have been loading reduced loads in practically all calibers - from the 223 all the way to the 700 NE.

Our powder of choice is HERCULES UNIQUE. works like a charm in everything.

We have also used several pistol powders like GREEN DOT with no problems at all.

In very large cases, like the 577 T.Rex. I use anything between 30-50 grains of UNIQUE, topped by a few grains of KAPOK.

In smaller cases like the 308 Winchester - where loads can be from 12-30 grains of powder, no filler is used, and we have never had any problems at all.

Saeed:
Ah yes what you are using is a very fast burning powder as a reduced load ( choice for this purpose) but the problem comes when you use low density loads of slow burning propellants in overbore cartridges ! Different ball game !

I tried this with a 460 Weatherby built on a 602 , had me a hangfire and then blew the case ! the bolt held but the stock and floor plate came unstuck in a big way !

quote:

Originally posted by Rapidrob:
5744 can do strange and wonderful things in a bottle neck cartridge.
One of two things happened:
1. charge was not correct/double
2. charge detonated.
This happens with reduced loads and has been written about since the last century.
5744 is not the powder I would use in the .308

I use 5744 with cast bullets in a .308. Never had a problem. Yet.

Laboratories have tried to replicate what is commonly known as detonation (unsuccessfully as I understand it) but even if they were able to produce detonation, apart from a damaged case and sometimes damaged rifles, the evidence of what actually occurred has gone i.e. the powder is burnt and the bullet ejected from the barrel.

A precursor to detonation (we'll call it that for convenience) are delayed fires, some are only just perceptible, others a real definite click bang. These only ever seem to occur with light loads of slow powder.
There is no reason why when a primer flashes the powder should not ignite and burn other than there is too much airspace for a powder that requires fuller containment to allow each granule to assist the next to ignite. Faster powders are not coated with so much retardant to regulate burn speed and ignite extremely easy.

I believe the movement of the bullet into the barrel leade by the primer before light loads of slow powder properly ignite is the cause of the pressure spikes but of course nobody can prove that as in all cases of detonation where the rifle and case have held together the bullet is not in the barrel or if it is it won't be in the leade area where it most likely was when the detonation occurred.

In reloading for various odd European cartridges and also with cast bullets in my 404 where I have tried lower loads of slower powder I have experienced delayed fires. Sometimes a wad over the powder has cured this although I have backed away from these loads usually.

I have never had any problems when using light loads of Unique, Bullseye and now my favourite for cast loads in my 404, Vectan AS shotgun powder (also recommended by Vectan for light loads in rifles). No wads needed and never a hint of delayed firings or pressure spikes.
IMR or H4895 seems to be a powder recommended as better suited to lighter loads in most cartridges.

quote:

Laboratories have tried to replicate what is commonly known as detonation (unsuccessfully as I understand it) but even if they were able to produce detonation, apart from a damaged case and sometimes damaged rifles, the evidence of what actually occurred has gone i.e. the powder is burnt and the bullet ejected from the barrel.

The part about laboratories not being able etc. not true.

There are ample "scholarly article" references to the problems related to ignition and burn rate problems in low density loads. It is only in the world of internet discussions around this subject that confusion exists.

Vented closed bomb deflagration experiments ( as opposed to non vented ) show the trends in pressure relationships very well.

As I have said before, these are not detonations ! not even intermediate explosions ! The rate of the process is too slow and fundamentally we have two different processes though both have deflagration as part of the process.

in low explosives we have deflagration followed by state change.

in detonations we have shock wave propagation followed by deflagration. In the former the process os slow enough to be useful to do work with, the latter is destructive !

Alf I am recognising that it is not true detonation but for want of a better word detonation is the one commonly used, not just on the internet, to describe this phenomenon.

As far as I am aware from various articles I've read, laboratories have not been able to replicate this phenomenon in sporting rifles. Many advanced reloaders (those playing around with different powders, bullets and loads not necessarily out of a manual or tried and tested by someone else) at one time or another will have experienced delayed fires which according to some, are a possible precursor to having a 'detonation' event.

I have experienced delayed fires numerous times and have witnessed others too but never have had a detonation or witnessed one.
Maybe it is just a very narrow band of circumstances coming together that will create such an event, I don't know.

I would have thought that had laboratories been able to replicate such an event, preferably several of them, and had in place specific measuring devices then we would not be debating this as it would be a well documented phenomenon whereby we would know exactly the set of circumstances to avoid.

As far as I am aware this is not the case. All the information on the phenomenon of delayed fires and detonation is quite airy fairy with no definitive answer i.e. we don't know if it is a powder thing, a primer thing, a bullet thing or even a case thing, or a combination of one or more of these things.

Seems to me we are spending a lot of time on "Semantics".

No matter what you call it no matter what actually causes it too small a charge of often too slow (or simply wrong) powder can give you a pressure event. Or if you are lucky a hang fire(my choice), delayed ignition or what ever you want to call it. If you are lucky it is a hang fire if not a huge pressure spike. And yes it will not cause you an issue every time. If you are lucky it is only the case you lose. But could be FAR worse.

For me you want a slow or low recoil load go with a powder designed for the job or a load that has been checked by someone other than a shade tree or internet listing.

Finger, eyes etc doing grow back.

Thru the years I've experimented with loading a large # of fast burning powders in bottle necked cases. Never had this problem. Of course I used graduated dowels to make sure there were no double or different charges. Seafire's Blue Dot loadings are a good example of non harmful occurrence.In fact using some of his Blue Dot loads I tested for powder position sensitivity and found NO real difference.
In at least two of the cases Alex shows the primers have backed out about .003". I'm not sure what relevance this has to his problem but it sure is there. roger

I might suspect the flame jumped the powder also. I have had that happen years ago thinking I could use a light powder charge in a 7 mm Mag to blow out some case's. Shooting at the ground the shot was violent, didn't think that should happen. Before shooting anymore I talked so a gunsmith in town Told him what I'd loaded and he told me about what happened. He suggested before fining point the barrel up to settle the powder in the bottom of the case and fire with the barrel up. Eliminated the problem. Everything I've read has always said to use a powder that fills the case well. I use very little fast powder's in my gun's shooting jacketed bullet's. I have two I shoot cast from and using light loads of fast powder, I stuff a quarter sheet of toilet paper in on top of the powder to keep the powder against the flash hole.

Might be just me, but your primer's seem to be all over the place. They should be set to the bottom of the primer pocket, couple might have made it but they all didn't. If they were then it looks like they were back out on firing and there wasn't enough pressure in them to re-seat them.

For many year I used a reduced load to demonstrate to students the effect of powder position and the requirement for the SAAMI Twist prior to pressure testing. As I recall, the load was 6.5 grains of Unique behind a 125 grain bullet in a 38 Special case. It was fired in a 10 inch Contender chambered for 357 Mag. Five shots with the powder positon to the front would consistently give 1100 fps and 18K psi. Five shots with powder to the rear would give 1400 fps and 28K psi. Most students didn't notice my clumsy gun handling that left the powder in the desired position before the shots.

The late Ballistician Emeritus Robert McCoy of Aberdeen Proving Ground once mentioned in a private conversation that he was scared of reduced loads. He could not reproduce the high pressures every shot, but often enough. His recipe for reduced velocity loads was to use a fast powder with the total charge containing no more energy than required to instantly convert all propellant into a gas at maximum permitted chamber pressure. From that point he had a chamber full of gas and it was just an airgun.

The writer Rick Jamison once made the comment that you have not finished your load development until you had a full case of powder.

Ken Oehler

quote:

Rick Jamison once made the comment that you have not finished your load development until you had a full case of powder

I've done some Blue Dot load testing with powder forward and powder powder back. The cartridge was a 308 Winchester with 110 grain bullets.

Powder forward:

Blue Dot charge: 16.0 grains
Group size: 0.818 inches.
Average velocity: 1,977 fps
Extreme spread: 29 fps

Powder back:

Blue Dot charge: 16.0 grains
Group size: 1.132 inches.
Average velocity: 2,068 fps
Extreme spread: 30 fps

So, I would conclude that Blue Dot is positional. No signs of high pressure were encountered.

I use powders specifically made for reduced loads that are impossible to double charge and not position sensitive. Sr5791, H4895, Trail Boss, etc.

Sadly SR4759 is no more. Gladly I have enough to last me 10 years of shooting my .458, 35 Whelen with Cast bullets. AA 2015 works in both of those as well so there are option.
Just a question: has anyone read Elmer Keith's work on Duplex loads and tubes that delivered the primer charge to the front of the powder instead of the back? Conclusions there from?

quote:

has anyone read Elmer Keith's work on Duplex loads

No but I've read Rocky Gibbs. I came to the conclusion it was a royal pain in the a$$.

ramrod 340:

Yes I have, I have the defence technical reports on the work they did on the 30-06 using duplex and triplex loads as well as shifting the point of ignition forward in the case by welding a tube in the case over the flash hole and then shifting the point ignition.

quote:

Originally posted by ramrod340:

quote:

has anyone read Elmer Keith's work on Duplex loads

No but I've read Rocky Gibbs. I came to the conclusion it was a royal pain in the a$$.

And IIRC, other than the educational value, not even worth the time or effort.

Don't we have some artillery rounds using the tube ignition Alf or have they went away?

Fury01
Yes there was but there is basically 3 types of ammo used in cannons, Fixed ( case and projectile as a single unit) semi fixed ( case and projectile can be separated to change charge in field) and separated where the projectile is rammed and separate from the bagged charge.
The ignitors for each obviously different.

The object in each though to give a smooth ignition cycle. Ignition abnormalities and problems again a topic well published !

Thank you Alf.
best regards.

quote:

tried a reduced load with Lovex D060 that is similar to 5744. Got load data from a friend.
Case: Remington, Primer: CCI 200, Bullet: S&B 147grs FMJ, 24,0 Grains Lovex D 060.

Guten Morgen,
let´s go ahead and look more closely at your load and what we can see regarding the cases:
The first ones look fine, no pressure signs, the primers are nice and still rounded and do not protude but seating depth seems to be not uniform. There is a bit of soot on the exterior of the two closest to the really dirty one.

The dirty damaged one has some marks from the extractor on the side of the case but I dont see - apart from the clean areas - a real impression of the bolt face. It is missing its primer.

Now, you are using a reduced load of DO60 / AA5744. Lovex does not list any .308 loads with their powder (they are a little bit on the light side reloading data) but AA promotes the almost identical 5744 as "reduced" with minimal loads of 29,4gr for a 110gr bullet or 25gr for the 168gr - the minimum load for the bullets you used should be somewere in between...

So, reduced load, sooty cases, primer seating depth not uniform. I´d venture out and say you ain't got a high pressure problem, you might have a low pressure one.
In low pressure, you are lacking an even burn, most of the time the case does not anneal completely to the chamber and does not get pushed back all the way against the bolt face, thus protuding primers after firing (see cases 1&4 from the left in the 1st picture) and if the burn is even slower, your primers get pushed out and you get gas leakage. With some rifles the dirt and primer sitting next to the lugs will be enough to make them hard to open.

Please check the size of your primer pockets as well as the case head expansion. If both are within normal parameters with the blackened case, chances are that you are suffering from a low pressure event. In that case, more powder and a nice factory crimp might help.

A cornucopia of maybes, all good advise..If I fired 6 round with mild primer reaction as in your pictures, that would suggest that particular case had an oversize primer pocket from a previous load probably..it happens..

The other signs are what confuse me, the primers don't agree with each other, not that it can't happen, but normally doesn't.

a crack as opposed to a normal boom is a sure sign of high pressure or rather higher pressure, but when you combine several signs of high pressure together, its time to stop and give it considerable thought. Primers are a poor indications of pressure and this may be a good example.

Just off hand thinking, I would dare make a declaration without gun in hand and being at my reloading bench under which condition I could figure out the problem without a doubt.

It has to be high pressure when case has flowed into the extractor like that. A few of the first cases did not get enough pressure to press the primer back into the seat.

So both high and low pressure and some exessive headspace. What pressure would that load give if the bullet didnt move?

Alf,

I haven't read any lab studies and would appreciate a Clancy-esque narrative, from the viewpoint of the spark in the primer.

It would be nice to hear how that spark went on to produce the blown primer and ruined case in the 308.

Light load explosions:

In April of 2012 there were two wood mill disasters ( massive explosions) in British Columbia. One in Prince George and the one at the Babine Forestry Products in Burns Lake. In both there was loss of life and multiple injuries. ( The Burns lake explosion and fire impacted us directly as it falls within my health authority ) WCB Ruled both the result of a process that is seen in firearms as light load explosions.

This occurs when there is a rapid simultaneous ignition and burn off of a combustable particulate matter suspended in air in this case simple dry wood dust.

In the case of a low load density cartridge using a "fast" propellant the same conditions can occur.

In a low density load often using fast burning propellants a large proportion of the load is ignited at once and as the particles are relatively "suspended" in air a rapid often catastrophic burn off occurs with pressure spikes up to 4 times that of normal density load.

"Detonation ? nope does not happen, cannot happen reloading propellants are low order "explosives"
They deflagrate ( burn) and do not detonate.
fundamentally two different mechanisms."

Yes it will, even if unconfined:
http://www.dtic.mil/get-tr-doc...Doc.pdf&AD=ADA491715

This is why the BPCR Quigley Match restricts the use of 5744

Thank you for that reference:
Given the content of that paper and what I have been taught.

I will state again ! you will not get a detonation with smokeless using a standard off the shelf primer as igniter in our ballistic application ! The speed of phase change does not meet the minimum velocity limit to be classified as a detonation.

The studies cited in the referenced paper all used high explosives as initiators.

True, but nitrocelluose has a detonation velocity of about 7300 meters per second and when the conditions become "abnormal" it can raise holy hell.
This situation looks like a severe overload to me.

I use AA5744 in black powder 45/70 cartridges, Accurate Arms claimed the powder was designed to be used in large cases, such as the 45-120. It should not be air space sensitive. My data shows exceptional extreme spreads and standard deviations in the large 45/70.


45/70 Martini Henry 26" Shilen Barrel

405 LRN 26.5gr AA5744 R-P cases WLR
29-Apr-04 T = 80 °F

Ave Vel = 1294
Std Dev = 14
ES = 40
Low = 1274
High = 1314
N = 15
Group Size Very . good

405 LRN 27.0gr AA5744 R-P cases WLR
24-Mar-04 T = 70 °F

Ave Vel = 1284
Std Dev = 23
ES = 80
Low = 1263
High = 1343
N = 12

405 LRN 27.5gr AA5744 R-P cases WLR
15-Apr-05 T = 75 °F

Ave Vel = 1363
Std Dev = 25
ES = 97
Low = 1298
High = 1395
N = 20

Group Size good offhand at 100 yards



Winchester BPCR M1885 30" Badger barrel

Ladder Sights: 5 graduations per 1/4 inch major.
1/4 inch major is 25 MOA, 1 grad is 5 MOA, 1 Veriner is 1 MOA

405 LRN 27.5gr AA5744 R-P cases WLR trimmed 2.085"

29 May 2010 T = 89 °F

Ave Vel = 1324
Std Dev = 9
ES = 26
High = 1338
Low = 1312
N = 6



M1873 Springfield Trapdoor 1884 rebuild

27" sight radius

405 LRN 27.5gr AA5744 R-P cases WLR trimmed 2.085"

14 Aug 2014 T = 78 °F

Ave Vel =1302
Std Dev =11
ES = 26
High = 1315
Low = 1289
N = 5

First round 15.5" high, rest, 19.5 to 23" high at 100 yards

Ballistic calculator: 100 yd zero, 25" drop at 200 yds, 82" drop at 300 yds


405 LRN 27.5gr AA5744 R-P cases WLR trimmed 2.085"

Heavily greased with Lubriplate 130A

14 Aug 2014 T = 78 °F

Ave Vel =1346
Std Dev =15
ES = 38
High = 1371
Low = 1333
N = 5

At lowest rear sight setting, two bullets 22", one @ 24", one @ 26.5", one @ 30.15"
at 100 yards


It did not fair badly in the 30-30, though it is my opinion that it was over pressure near 2100 fps with a 170 grain bullet.

Marlin M336 microgroove barrel, 30-30 Win

170 gr Hornady FBFP 23.5 grs AA5744 wtd lot $17.00 W/W cases CCI200 OAL 2.550"

1 Feb 2014 T = 60 °F

Ave Vel = 1910
Std Dev = 29
ES = 58
High = 1939
Low = 1881
N = 3


170 gr Hornady FBFP 24.5 grs AA5744 wtd lot $17.00 W/W cases CCI200 OAL 2.550"

1 Feb 2014 T = 60 °F

Ave Vel = 1978
Std Dev = 10
ES = 19
High = 1985
Low = 1966
N = 3

group 1 3/8" X 1.0"

170 gr Hornady FBFP 25.5 grs AA5744 wtd lot $17.00 W/W cases CCI200 OAL 2.550"

1 Feb 2014 T = 60 °F

Ave Vel = 2063
Std Dev = 17
ES = 33
High = 2083
Low = 2050
N = 3



170 gr Hornady FBFP 26.5 grs AA5744 wtd lot $17.00 W/W cases CCI200 OAL 2.550"

7 Feb 2014 T = 41 °F

Ave Vel = 2116
Std Dev = 28
ES = 75
High = 2153
Low = 2078
N = 10

group : 3 1/4" X 4 1/2" blown irregular group


I think you got more powder in the case than you expected. This powder is fast burning, add a few more grains, and, I think that is what your problem was.

After going back and looking at your spent cases I can unequivocally tell you what happened! You got lucky!!! roger

I found a webpage that downs a PDF with reloading receipts for the powder you are using https://explosia.cz/en/product...n/reloading-powders/. It shows a starting weight with a 147g bullet, of 41.7 g to 44g. I think where you got into trouble is the powder is already for reduced loads in large capacity shells, at the given weights.

"D060- High density, double base, tubular propellant similar to Accurate 5744 designed primarily for .45-70 Government,.45-120 and .50-90 Sharps cartridges and for reduced loadings (in) all calibre rifles."

You then reduced it even more (to near half) leading to the powder ignition possibly being unstable at such a low volume/weight. If you want to use this powder, use the commended loadings. If you a more reduced load, check out Trial Boss.