Reading through several posts I keep seeing the term plunk. "plunked a barrel" Any particular meaning to this as concerning the R51?
I'm pretty sure it means removing the barrel from the pistol and dropping a round into it to make sure it seats to the correct depth. It makes a "plunk" sound... Nothing to do with my user name, btw...
Plunkster,
Learned from IKlawason, when you reload, drop the reload into the breach
and if it goes :plunk", It will go bang!
And everything will be copacetic.
Blackie
Blackie:
I think that's what I said...
;)
Pat
Quote from: Xtratoy on January 07, 2018, 02:11:32 PM
Reading through several posts I keep seeing the term plunk. "plunked a barrel" Any particular meaning to this as concerning the R51?
As above stated. That is the basic
mechanics of the "plunk test."
To clarify, the
purpose of the plunk test is to make sure that hand loads are safe for that particular chamber. The fear is that a particular chamber might be at SAAMI minimum specs for the the distances between where the chamber ends and the rifling begins (called "Leade" or generically sometimes "free-bore"). There needs to be a tiny bit of space between the bullet (the "slug" in the loaded cartridge) and the beginning of the rifling. If the bullet contacts the rifling then when the cartridge is fired the the pressures in the cartridge will rise to dangerous levels and could lead to a case rupture and possible damage to the gun or even the shooter. Bad juju.
In a "plunk test" the cartridge is dropped or gently pushed into the chamber and then inspected to see if the bullet is contacting the rifling. Sometimes you can feel if the bullet is contacting the rifling. It might even stick and can not be pulled out by hand. Many hand-loaders will coat the bullet (coper jacketed) with black magic marker then drop the cartridge into the chamber and rotate/twist the cartridge therein. If the bullet is contacting the rifling, this will scratch off a circle of the magic marker.
If this happens the hand-loader will need to seat the bullets deeper (which can cause issues as well) or choose not to use those cartridges in that gun.
Some hand-loaders purchase a cartridge gauge to plunk their ammunition in. A cartridge gauge is a block or cylinder for that cartridge which is at SAAMI minimum spec. The hand-loader will plunk the cartridge into the gauge as a go/no-go instead of removing the barrel and plunking to the individual gun.
This test is particularly important to the R51. The collective experience seems to be that the chambers for R51 barrels tend to be at SAAMi minimum. There is at least one report that the Remington RP9 also has minimum spec chambers.
One of the commonly stated advantages of hand-loading is that the hand-loader can make ammunition tailored to that particular gun, which makes it more accurate and reliable. By plunking for that specific chamber, the hand-loader can make the cartridge exactly the right length, neither too long (dangerous) nor too short (impacts accuracy).
Peace favor your sword,
Kirk
Quote from: plunkster on January 08, 2018, 09:25:14 AM
Blackie:
I think that's what I said...
;)
Pat
Plunkster,
Sorry pardner, I thought I was addressing Xtratoy. Had a brain fart!
Blackie