waksupi
12-08-2006, 09:08 PM
Since I play with the .358 Win quite a bit, I thought I would pass along some info on making the cartridges feed.
First off, anything based on the .308 cartridge, can be a problem for getting good feed in a bolt action. Add a wide meplate to it, and the matter worsen. The flame cut forces the nose over too far to the right with a wide nose.
Last weekend, I ran various nose configurations through the .358W, and invariably, it seems in every magazine full, there would be at least one failure to feed, from the left side position.
From past experience, I was loathe to do any grinding on the reciever rails, to allow for earlier release, permitting the cartridge to rise sooner, to reach proper alighnment.
Looking at my Mauser action, I saw at the left of the feed ramp, there is a small projection, that helps force the case too far to the right, causing the bullet nose to hang up on the shoulder of the barrel.
I polished this bump, and the feed ramp. That helped a little, and some of the slimmer bullets would then feed well. But, my goal was to be able to feed the Bator 358260.
I unbreached the barrel, and inserted a loaded cartridge in the chamber. It was clear I had more than enough web support. So, I took a large reamer, and deepened the chamber lead, by about .030. I then ground the barrel at a taper from the one to three o'clock position, keeping the surface intact at the reciever/barrel shoulder. This is a slopeing relief, from the barrel shoulder, to the bottom of the reamer cut. The action is an H ring, and may benefit from having the upper right corner smoothed out somewhat.
After polishing the surface, I re-indexed the barrel, gave everything a good cleaning, and loaded the magazine.
When fed ultraslow, the nose will still hang up just slightly. When I chamber one, with my usual speed, or slightly slower, the feeding is smooth. Fast chambering is very smooth.
So, these are some of the things I did to remedy my feed problem. If you want to try the same with a .308 based chambering, and don't have a barrel vise to remove your tube, you may be able to get a local gunsmith to spin it off for you, and do the hand work yourself.
I did cast up a batch of the 358260 this morning, got them sized, some lubed, and will most likely start serious load develoment on Sunday, assuming the fog lifts enough to see a hundred yards.
First off, anything based on the .308 cartridge, can be a problem for getting good feed in a bolt action. Add a wide meplate to it, and the matter worsen. The flame cut forces the nose over too far to the right with a wide nose.
Last weekend, I ran various nose configurations through the .358W, and invariably, it seems in every magazine full, there would be at least one failure to feed, from the left side position.
From past experience, I was loathe to do any grinding on the reciever rails, to allow for earlier release, permitting the cartridge to rise sooner, to reach proper alighnment.
Looking at my Mauser action, I saw at the left of the feed ramp, there is a small projection, that helps force the case too far to the right, causing the bullet nose to hang up on the shoulder of the barrel.
I polished this bump, and the feed ramp. That helped a little, and some of the slimmer bullets would then feed well. But, my goal was to be able to feed the Bator 358260.
I unbreached the barrel, and inserted a loaded cartridge in the chamber. It was clear I had more than enough web support. So, I took a large reamer, and deepened the chamber lead, by about .030. I then ground the barrel at a taper from the one to three o'clock position, keeping the surface intact at the reciever/barrel shoulder. This is a slopeing relief, from the barrel shoulder, to the bottom of the reamer cut. The action is an H ring, and may benefit from having the upper right corner smoothed out somewhat.
After polishing the surface, I re-indexed the barrel, gave everything a good cleaning, and loaded the magazine.
When fed ultraslow, the nose will still hang up just slightly. When I chamber one, with my usual speed, or slightly slower, the feeding is smooth. Fast chambering is very smooth.
So, these are some of the things I did to remedy my feed problem. If you want to try the same with a .308 based chambering, and don't have a barrel vise to remove your tube, you may be able to get a local gunsmith to spin it off for you, and do the hand work yourself.
I did cast up a batch of the 358260 this morning, got them sized, some lubed, and will most likely start serious load develoment on Sunday, assuming the fog lifts enough to see a hundred yards.