It happened to this guy about a year and a half ago...using Tula 308, repackaged as Herters ammo.
https://www.youtube.com/watch?v=TleMPyDq56s
https://www.youtube.com/watch?v=TleMPyDq56s
M1 Garand blowup
- Thread starter Erno86
- Start date
The mushroomed and flattened and pierced primers on his other cases are the giveaway that the wrong powder or wrong dose of powder got into these. From his report of more flash, I would assume it's the latter. The damage is typical for a case blowout without the gun letting go, but I hope the Cabala's gunsmith knew to check for lug setback and cracking just in case. before putting it back up for sale.
I don't see that the gun "blew up" or "separated violently". I see a gas escape from a broken case head causing the stock to split. That rifle might have excess headspace, which could cause the primers to back out and also to let the case back out enough to blow out. I also suspect that the cases have thin webs, something common in some foreign cases where the makers wanted to save money by using thinner sheet stock.
BTW, pierced primers are not the result of too heavy a firing pin blow, but of too light a one. If the primer is not supported by a heavy firing pin/hammer spring or the inertia of a heavy hammer/firing pin, it will blow out.
IMHO, that blown case should be a warning that when it comes to ammo, cheap is not always best. Most milsurp ammo is OK, since it was made under military control, but a lot of junk stuff has been imported that is of poor quality in many ways.
On the rifle, though, I don't see any obvious problems, but many so-called "tanker" M1's were built on "cut and weld" receivers, which have been known to have bad headspace, slam fires, and other serious problems.
Jim
BTW, pierced primers are not the result of too heavy a firing pin blow, but of too light a one. If the primer is not supported by a heavy firing pin/hammer spring or the inertia of a heavy hammer/firing pin, it will blow out.
IMHO, that blown case should be a warning that when it comes to ammo, cheap is not always best. Most milsurp ammo is OK, since it was made under military control, but a lot of junk stuff has been imported that is of poor quality in many ways.
On the rifle, though, I don't see any obvious problems, but many so-called "tanker" M1's were built on "cut and weld" receivers, which have been known to have bad headspace, slam fires, and other serious problems.
Jim
A pause for the COZ
New member
I can tell you with out a doubt. If I had a Garand. The only ammo I would run through it is ammo I made my self.
They would not be top pressure loads ether. They would be just right.
Be too afraid to hurt that gun.
They would not be top pressure loads ether. They would be just right.
Be too afraid to hurt that gun.
I would agree than any Tanker is suspect. This one showed up at the range, the barrel unscrewed itself. The receiver front is Springfield, but the back is Winchester. You can see how it was welded together.
I don't know if that particular round was overpressure, the case could have been defective and split through the case head. If the chamber was over length, that is the headspace was long, that could have caused the case to split exactly through the case head. Steel is not as ductile as brass, don't know if a brass case could have handled it. If a dry steel case is fired in a dry chamber, friction between the case and chamber causes the chamber body to adhere to the chamber wall. If the headspace is excessive, that would have put severe stresses on the sidewalls and the case head. You can see the stress through a case head on Varmit Al's web page. Dry cases in dry chambers put a load path directly through the case head. Given that the case was steel, and thus not very ductile, I consider this a possible explanation. Might have had a flaw in the case which aggravated things.
Now what is interesting to me, is that the Army/Navy used lubrication to prevent case head, case body ruptures for the 20 mm Oerlikon. The rounds for this automatic cannon were not merely lubricated, but heavily greased! And it turns out, the headspace was not standardized. As the book states, heavily greased cases prevented case ruptures when the gun had excessive headspace.
The Machine Gun Part V
Chapter 14 Birkigt Type 404 20-mm (Hispano-Suiza) Cannon
page 578
http://ibiblio.org/hyperwar/USN/ref/MG/I/
During war all that can be done is to install and make function as reliably as possible that which is issued. With the mounting of the 20-mm cannon in Navy, planes a series of malfunctions began that could not be properly corrected at the time because manufacture was at the peak of production. The slightest change would practically mean retooling. The most serious problem was the oversize chamber. There still remained considerable variance in dimensions between the chambers of the British and American cannon, even after the latter chamber was made one thirty-second inch shorter
Due to an outmoded agreement of long standing, everything above caliber .60 in the Army is considered artillery and the manufacture of the Hispano-Suiza cannon therefore came under this classification. In other words the production of this high-speed machine gun was done under artillery manufacturing tolerances. The resulting poor mating of parts, coupled with the inherent fault of all gas-operated weapons whereby the breech locking key in the receiver is immovable and the position of the gas port in the barrel is permanently fixed, made it impossible to adjust the relationship between barrel and breech lock to establish head space. Thus the most vital measurement in any automatic weapon was governed by chance in this instance.
An unfortunate discovery was that chamber errors in the gun could be corrected for the moment by covering the ammunition case with a heavy lubricant. If the chamber was oversize, it served as a fluid fit to make up the deficiency and, if unsafe head space existed that would result in case rupture if ammunition was fired dry, then the lubricant allowed the cartridge case to slip back at the start of pressure build up, to take up the slack between the breech lock and the breech lock key. Had this method of "quick fix" not been possible, the Navy would have long ago recognized the seriousness of the situation. In fact, this inexcusable method of correction was in use so long that it was becoming accepted as a satisfactory solution of a necessary nuisance.
I don't know if that particular round was overpressure, the case could have been defective and split through the case head. If the chamber was over length, that is the headspace was long, that could have caused the case to split exactly through the case head. Steel is not as ductile as brass, don't know if a brass case could have handled it. If a dry steel case is fired in a dry chamber, friction between the case and chamber causes the chamber body to adhere to the chamber wall. If the headspace is excessive, that would have put severe stresses on the sidewalls and the case head. You can see the stress through a case head on Varmit Al's web page. Dry cases in dry chambers put a load path directly through the case head. Given that the case was steel, and thus not very ductile, I consider this a possible explanation. Might have had a flaw in the case which aggravated things.
Now what is interesting to me, is that the Army/Navy used lubrication to prevent case head, case body ruptures for the 20 mm Oerlikon. The rounds for this automatic cannon were not merely lubricated, but heavily greased! And it turns out, the headspace was not standardized. As the book states, heavily greased cases prevented case ruptures when the gun had excessive headspace.
The Machine Gun Part V
Chapter 14 Birkigt Type 404 20-mm (Hispano-Suiza) Cannon
page 578
http://ibiblio.org/hyperwar/USN/ref/MG/I/
During war all that can be done is to install and make function as reliably as possible that which is issued. With the mounting of the 20-mm cannon in Navy, planes a series of malfunctions began that could not be properly corrected at the time because manufacture was at the peak of production. The slightest change would practically mean retooling. The most serious problem was the oversize chamber. There still remained considerable variance in dimensions between the chambers of the British and American cannon, even after the latter chamber was made one thirty-second inch shorter
Due to an outmoded agreement of long standing, everything above caliber .60 in the Army is considered artillery and the manufacture of the Hispano-Suiza cannon therefore came under this classification. In other words the production of this high-speed machine gun was done under artillery manufacturing tolerances. The resulting poor mating of parts, coupled with the inherent fault of all gas-operated weapons whereby the breech locking key in the receiver is immovable and the position of the gas port in the barrel is permanently fixed, made it impossible to adjust the relationship between barrel and breech lock to establish head space. Thus the most vital measurement in any automatic weapon was governed by chance in this instance.
An unfortunate discovery was that chamber errors in the gun could be corrected for the moment by covering the ammunition case with a heavy lubricant. If the chamber was oversize, it served as a fluid fit to make up the deficiency and, if unsafe head space existed that would result in case rupture if ammunition was fired dry, then the lubricant allowed the cartridge case to slip back at the start of pressure build up, to take up the slack between the breech lock and the breech lock key. Had this method of "quick fix" not been possible, the Navy would have long ago recognized the seriousness of the situation. In fact, this inexcusable method of correction was in use so long that it was becoming accepted as a satisfactory solution of a necessary nuisance.
My only experience with a 308 Garand was many years ago. A person at the range had a FTF problem and found his op rod bent. He was shooting 150gr factory ammo.
IMHO, I would not own one in 308. I am no real expert on Garands and don't claim to be. What I do know is there are significant pressure differences between the 308 and the 30-06.
IMHO, I would not own one in 308. I am no real expert on Garands and don't claim to be. What I do know is there are significant pressure differences between the 308 and the 30-06.
brasscollector
New member
Garands should never be run at max pressure anyway. Loads for M1's should be approx 200-300 fps slower than commercial loads. Pressure at the gas port is what is important and the pressure curves between 30-06 and 308 may differ enough to make the 308 garands more sensitive. Just my .02
The Garand was type classified in 1936. Both the Garand and the M1903 used the same ammunition, an ammunition that was required to go 2700 fps or so, with a 150 grain bullet. The velocity was a requirement, the bullet had to go that fast, pressure was a not to exceed. It turns out powder improved from 1903 to 1936, so issue ammunition had pressures closer to 30,000 psia than 50,000 psia. Most of the 1930's figures I have seen indicate 30-06 service rifle ammunition was around 40,000 psia. Now I believe that the Garand mechanism could handle much higher pressure, but it is hard on the operating rod. I recently talked to a USMC rifle team veteran, he shot Garands in the late 50's. After a shooting day at Camp Perry, he would disassemble his Garand in the hut, and bend his operating rod so it would stop dragging on the lower ferrule! Bent operating rods were common with issue ammunition. It will be worse with high pressure commercial ammunition.
The 42,000 psi figure is nice to know, but it is port pressure that matters for the oprod. Hence the burn rate guidelines for powders used in the Garand.
Too slow a powder can be just fine on chamber pressure, but way too much on port pressure. Generally folks get into trouble with the Garand action with too slow a powder, not too fast a powder although you can run into trouble either way.
Jimro
Too slow a powder can be just fine on chamber pressure, but way too much on port pressure. Generally folks get into trouble with the Garand action with too slow a powder, not too fast a powder although you can run into trouble either way.
Jimro
Can't speak for M1 tankers but I do have a Korean era M1. I wouldn't think of putting anything but surplus or my M1 specific hand loads through it. I recently fired off some Herters 7.62x39 I bought years ago from Cabelas in my AR. This repackaged Tula was over pressured compared to all other brands used or made. It was quite noticeable and resulted in flattened primers and stuck cases. Never again will I buy Herters/Tula ammo.
Jim Watson
New member
Anybody know the pressure of the M1 load which was GI when the M1 rifle came out? A 173 boat tail at 2650.
"I also suspect that the cases have thin webs, something common in some foreign cases where the makers wanted to save money by using thinner sheet stock."
This is I suspect, the real issue. My first outing with a homebuilt BM59 (modified Springfield Garand receiver) was with Tula 308, since it was during the Ban Panic and that was all that was to be had without digging up all the reloading stuff (I was shooting GP11 exclusively, otherwise), and had two case failures in a single box of 20 (I got through 12 before stopping).
A low-pressure (i.e. non catastrophic, but very smoky) blowout/crack halfway around the case at the extractor groove! No excuse for a cartridge which is supposed to be solid that far back to blow out less than 1/8" from the breechface; only explanation is these are basically steel "balloon head" cases of the type abandoned in this part of the world over a century ago. To save a modicum of steel.
Dangerous garbage.
TCB
This is I suspect, the real issue. My first outing with a homebuilt BM59 (modified Springfield Garand receiver) was with Tula 308, since it was during the Ban Panic and that was all that was to be had without digging up all the reloading stuff (I was shooting GP11 exclusively, otherwise), and had two case failures in a single box of 20 (I got through 12 before stopping).
A low-pressure (i.e. non catastrophic, but very smoky) blowout/crack halfway around the case at the extractor groove! No excuse for a cartridge which is supposed to be solid that far back to blow out less than 1/8" from the breechface; only explanation is these are basically steel "balloon head" cases of the type abandoned in this part of the world over a century ago. To save a modicum of steel.
Dangerous garbage.
TCB