2 dogs
Buckeye
I got another real interesting job in the other day. My client complains his Toklat 454 Ruger with 340 grain bullets has sticky extraction (I forget how fast they were going but I'm pretty sure you couldn't get them going any faster, will amend this later) with maximum loads. His gas checked cast bullets were .453" diameter and he was not seeing any leading. He wanted to know if I would polish his chambers to see if that would ease his full cylinder extraction issues.
When the cylinder arrived, I was a bit surprised at how well the cylinder was already polished. I would call it a high 400 finish. That is pretty slick for a factory gun. About the only ones that are better are the FA's and the old Colt Python Royal Blue guns. However, when I measured the throats, I was surprised to find that they were all a bit over .455".
Hmmm, he is running a .453" bullet at maximum velocity through a .455" plus throat and not getting any leading from gas blow by? Well, there was also a bit of soot on the chamber walls. My theory is that a 340 grain 45 caliber bullet is pretty long for caliber. That means the ogive of the bullet might well be past the forcing cone and engaging the rifling while the base of the bullet is still in the throat. So, when the bullet starts to compress from the front the gas has to go somewhere so it is not only escaping the barrel cylinder gap but coming back around the case as well until the base of the bullet starts to upset and cuts the gas flow off and seals the throat and thereby preventing total loss of the bullet lube and leading of the bore.
Hey, I don't know everything. But I blocked off the throats and polished the chambers to a higher finish. I checked and sure enough this madman indeed had some 340 grain 45 caliber gas check bullets on hand. So, I sized them .455" and am sending them off to my client. I am tossing this out here in advance to see if my thinking is right and if I got this cat skinned right or not. We should know something back from my client in a week or two.
If anyone else is shooting locomotive derailing loads through their Toklat and experiencing hard extraction I would like to hear from you.
When the cylinder arrived, I was a bit surprised at how well the cylinder was already polished. I would call it a high 400 finish. That is pretty slick for a factory gun. About the only ones that are better are the FA's and the old Colt Python Royal Blue guns. However, when I measured the throats, I was surprised to find that they were all a bit over .455".
Hmmm, he is running a .453" bullet at maximum velocity through a .455" plus throat and not getting any leading from gas blow by? Well, there was also a bit of soot on the chamber walls. My theory is that a 340 grain 45 caliber bullet is pretty long for caliber. That means the ogive of the bullet might well be past the forcing cone and engaging the rifling while the base of the bullet is still in the throat. So, when the bullet starts to compress from the front the gas has to go somewhere so it is not only escaping the barrel cylinder gap but coming back around the case as well until the base of the bullet starts to upset and cuts the gas flow off and seals the throat and thereby preventing total loss of the bullet lube and leading of the bore.
Hey, I don't know everything. But I blocked off the throats and polished the chambers to a higher finish. I checked and sure enough this madman indeed had some 340 grain 45 caliber gas check bullets on hand. So, I sized them .455" and am sending them off to my client. I am tossing this out here in advance to see if my thinking is right and if I got this cat skinned right or not. We should know something back from my client in a week or two.
If anyone else is shooting locomotive derailing loads through their Toklat and experiencing hard extraction I would like to hear from you.
