Question about channels in face of 1906 20ga VH

[Bruce Day]

I think as a general rule, Rem Parker stocks are a little thicker in the wrist than say 1910 Parker Bros stocks. Whether it was done to reduce stock wrist fractures, I don't know, and it would be only speculation. I am not aware of any Parker factory or Rem notes about the increased size.

[Phil C]

Here are a few pictures of what happens when a primer is pierced. Fulton converted to a 454. Unfortunately what was a beautiful proffesional job in all other aspects, turned into a mess because the firing pin was too long. I purchased this gun which had never been test fired evedently. I took it to a friend whom is a Gunsmith. He took it to the test tunnel down stairs and told me to wait, as the policy was others can not be down there when he did test firing. I heard the report and a few minutes later he came up and said the gun blew up. If not for him wearing glasses it would have been serious as the glasses where horribly pitted. Needless to say one call to the company I recieved it from, and my money was refunded.

http://i557.photobucket.com/albums/s...lton454003.jpg
http://i557.photobucket.com/albums/s...lton454005.jpg
http://i557.photobucket.com/albums/s...lton454001.jpg

[Autumn Daze]

I have a Meriden/Remington transition skeet gun with a straight grip that is slim as slim can be. Maybe late Remington guns are thick wristed but this one sure ain't.I just measured the circumference of the wrist as I shot this gun today. It measures 4" in circumference.

Funny we should be talking about pierced primers....Today a my local club one of our trapshooters pireced a primer on a factory loaded Winchester AA 1 1/8oz. load of 7 1/2 shot in his Remington 1100 trap gun. Split the stock right above the wrist...Pretty bad too....

[Richard Flanders]

My 1887 Remington hammer 12ga pierces a lot of primers, but just barely. It has strong mainsprings and maybe someone made the firing pins a bit more pointed, tho they don't really look it. I've never had any ill effects from it other than a bit of blacking around the piercing. This blowing wood off a stock is new to me. Never heard of such a thing. It seems to me that the older paper shells, especially the ribbed Remingtons, have much heavier metal on the striking surface of the primer so maybe the older guns had strong springs for a good reason??

That .454 Fulton looks like an extreme case of long firing pins. Jeez. I bet that guy wears more than just glasses when he test fires anything from now on.

[Jim P.]

Irrefutable evidence, Phil. Thanks for the photos! This has been very instructive for me.
Jim

[AmarilloMike]

What are the physics of a pierced primer causing that damage? I just don't see it. I had a sixteen Flues that pierced primers but no damage. I thought the problem with a gun that pierces primer was blowing the products of primer burn (crud) into the action through the firing pin hole and gumming things up.

Not challenging, just trying to understand.

Best,

Mike

[Bruce Day]

Think of it like being in your car with your bird dogs after giving them a lot of steak trimmings or they found a dead deer.


The one pierced primer I saw had a hole all the way through, so obviously the expanding powder burn gas will blow back through the hole into the action through the firing pin or hammer nose hole. Like the dog, some goes out the front, some goes out the rear. Not very scientific explanation I suppose, but if necessary, I suppose some of us, like me, Flanders or Austin could provide a formula for rate of gas expansion, Bernoulli effect, venturi effect, momentum of ejecta, and other parameters.

[Richard Flanders]

This is a matter of basic physics. It's just a matter of how large a hole gets pierced. If it's a large hole there's a lot of pressure from the powder ignition, 11,000psi in some shells, and hence volume of air that can backfeed through the primer into the gun. It's the combination of the primer and the powder ignition that does the damage. A tiny hole and not much happens. Remember it's ps i, as in "inches". Pounds per square inch. The more square inches of hole, the more volume of air is going to get through. The PSI remains the same regardless but the hole size controls the volume of air that can pass through. A little hole lets a little through, a large hole lets a lot through. The holes my Remington makes are pinholes of approximately .2mm so the leakage is minimal. That .454 looks like it punched the primer clean through and into the shell so it's not at all surprising the amount of damage. It probably punched the hole in the bottom of the primer pocket clean out to the diameter of the firing pin.

[Dean Romig]

And, of course, once the thin metal of the primer has been breached it is only a matter of miliseconds during which time the hole becomes larger.

[Richard Flanders]

Roger that Dean. I'd have to wonder if the gunsmith who converted the Fulton didn't put the coil spring off the front end of a '66 GMC pickup in for a hammer spring on that thing. It looks like it might have driven the primer anvil right into the powder charge.