Dutchman
07-05-2015, 07:11 AM
For informational purposes I'm copying this from the Swedish military firearms forum @ gunboards.com pertaining to shooting the Ag42b rifle.
Shooting the AG42b Ljungman Rifle - What Ammo?
The information on lubing m/41 ammo for the Ag42b came first from the forum co-owner, Anders, in Sweden. As he was sergeant in the Swedish army his information is first hand and unquestionably accurate. He performed this protocol under orders. Everywhere else on the internet mimics this original information. That this procedure was done is known and why it was done is known (slow burn rate in m/41 ammo).
Shooters of AG42b TODAY and tomorrow need not mimic this archaic method to get perfect function. Its important to know the practice was officially sanctioned and for what reason. But as shooters today of vintage military rifles we need to use modern methodology if we're going to shoot these rifles. The variables that come from lubricating cartridge cases can lead to variable results. Its important, always has been important in [gunboards] forum, that we disseminate accurate information and safe information.
From this point forward the topic of lubricating cases for use in the Ag42b will be for historical information only and will not be presented as a viable means of gaining superior function. Any topics that deviate from this directive will be deleted or edited at the discretion of the forum owner/moderators.
Why?
The Ljungman is very ammo-specific. It does not have an adjustable gas port or valve as the Hakim or Rashid or FN49. The ammo has to be tailored to the rifle. Same as many other semi-auto rifles such as the M1 Garand. Shoot slow powder in the Garand and you'll be buying a new operating rod.
Some Ljungman owners have followed an old recipe by modifying the gas block with a screw to adjust the gas in some way mitigating this situation greatly. There use to be a detailed photographic presentation here by a former forum user but in the several moves by gunboards.com that valuable information has evaporated into the cosmos. While we strive to maintain a "no modification" religion, if you will, this has been one modification that we agree will obviate our conviction to do no harm to our vintage rifles. But not every Ljungman owner will feel confident in messing with his valuable rifle. The Ljungman is no longer a $180 rifle. They can easily touch $800. With that in mind those shooters who choose to experiment with ammunition should know that the Ljungman can be rather fragile and can easily be destroyed by such experimentation.
What has been diagnosed as "firing out of battery" in a Hakim was actually found to be excessive gas port pressure ripping the rim and head portion of the cartridge case as it was extracted from the chamber. The result was not pretty. The gas blast was directed down into the magazine, which was completely destroyed. The center triggerguard screw attachment interface with the stock is very weak and in this particular case it destroyed the stock. By virtue of its design features the rifle was repaired and put back into shooting condition but the owner never really trusted it again. The Ljungman can be afflicted by the same condition this Hakim suffered. I was eye witness to this event and was hit by debris when the magazine exited the rifle. The shooter suffered minor cuts and bleeding on his left forearm.
In the split second of firing, the gas pressure within the cartridge case pushes outward in all directions obturating the cartridge case to the chamber walls. This is a designed feature of most semi-auto firearms. The function of the weapon depends on this aspect of the cycle to slow the rearward push against the bolt as the cartridge case expands and then contracts. If you remove that aspect you greatly increase thrust on the bolt and strain on the receiver and associated parts. You have successfully made your Ljungman function with m/41 ammo but at what price?
Below is the gas block on the Ag42b. It is pressed very tightly onto the barrel and for all intents and purposes cannot easily be removed to modify.
http://media.fotki.com/1_p,rrtbgktktsdftrgxwfqbfsgtwfb,vi/rbrdtgggsxwdkttwrwtxrfgbbsgss/4/28344/9895637/043b-vi.jpg
http://media.fotki.com/1_p,skbksgwrdbqdrwqxwfqbfsgtwfb,vi/wfqwttbkqxrrrrdwtrs/4/28344/9895637/ag2-vi.jpg
Shooting the AG42b Ljungman Rifle - What Ammo?
The information on lubing m/41 ammo for the Ag42b came first from the forum co-owner, Anders, in Sweden. As he was sergeant in the Swedish army his information is first hand and unquestionably accurate. He performed this protocol under orders. Everywhere else on the internet mimics this original information. That this procedure was done is known and why it was done is known (slow burn rate in m/41 ammo).
Shooters of AG42b TODAY and tomorrow need not mimic this archaic method to get perfect function. Its important to know the practice was officially sanctioned and for what reason. But as shooters today of vintage military rifles we need to use modern methodology if we're going to shoot these rifles. The variables that come from lubricating cartridge cases can lead to variable results. Its important, always has been important in [gunboards] forum, that we disseminate accurate information and safe information.
From this point forward the topic of lubricating cases for use in the Ag42b will be for historical information only and will not be presented as a viable means of gaining superior function. Any topics that deviate from this directive will be deleted or edited at the discretion of the forum owner/moderators.
Why?
The Ljungman is very ammo-specific. It does not have an adjustable gas port or valve as the Hakim or Rashid or FN49. The ammo has to be tailored to the rifle. Same as many other semi-auto rifles such as the M1 Garand. Shoot slow powder in the Garand and you'll be buying a new operating rod.
Some Ljungman owners have followed an old recipe by modifying the gas block with a screw to adjust the gas in some way mitigating this situation greatly. There use to be a detailed photographic presentation here by a former forum user but in the several moves by gunboards.com that valuable information has evaporated into the cosmos. While we strive to maintain a "no modification" religion, if you will, this has been one modification that we agree will obviate our conviction to do no harm to our vintage rifles. But not every Ljungman owner will feel confident in messing with his valuable rifle. The Ljungman is no longer a $180 rifle. They can easily touch $800. With that in mind those shooters who choose to experiment with ammunition should know that the Ljungman can be rather fragile and can easily be destroyed by such experimentation.
What has been diagnosed as "firing out of battery" in a Hakim was actually found to be excessive gas port pressure ripping the rim and head portion of the cartridge case as it was extracted from the chamber. The result was not pretty. The gas blast was directed down into the magazine, which was completely destroyed. The center triggerguard screw attachment interface with the stock is very weak and in this particular case it destroyed the stock. By virtue of its design features the rifle was repaired and put back into shooting condition but the owner never really trusted it again. The Ljungman can be afflicted by the same condition this Hakim suffered. I was eye witness to this event and was hit by debris when the magazine exited the rifle. The shooter suffered minor cuts and bleeding on his left forearm.
In the split second of firing, the gas pressure within the cartridge case pushes outward in all directions obturating the cartridge case to the chamber walls. This is a designed feature of most semi-auto firearms. The function of the weapon depends on this aspect of the cycle to slow the rearward push against the bolt as the cartridge case expands and then contracts. If you remove that aspect you greatly increase thrust on the bolt and strain on the receiver and associated parts. You have successfully made your Ljungman function with m/41 ammo but at what price?
Below is the gas block on the Ag42b. It is pressed very tightly onto the barrel and for all intents and purposes cannot easily be removed to modify.
http://media.fotki.com/1_p,rrtbgktktsdftrgxwfqbfsgtwfb,vi/rbrdtgggsxwdkttwrwtxrfgbbsgss/4/28344/9895637/043b-vi.jpg
http://media.fotki.com/1_p,skbksgwrdbqdrwqxwfqbfsgtwfb,vi/wfqwttbkqxrrrrdwtrs/4/28344/9895637/ag2-vi.jpg