VERY strange BSA problem.
- Thread starter Why not?
- Start date
Tried putting a 7mm/.284 bullet into a fired case, and it won't even begin to slide in, so it certainly isn't going to chamber a loaded round with one in it. The easy answer? A rechamber to 280 Remington.
Ted
I read an article ( still have it somewhere) in Guns & Ammo by Ross Seyfried about paper patching jacketed bullets. Seems he had a .275 H&H mag with a bore diameter of .292", when at best it should have been .288". He paper-patched regular .284" bullets and got enough accuracy for hunting purposes at least. I'm not sure if .005" would give you enough room for this trick, or you could try patching .264" bullets.
Johnn Peterson
CGN Ultra frequent flyer
- Location
- Chemainus B.C.
Back home, and pushed a slug all the way through from the muzzle to the chamber.
Here's the answer, Gentleman.
Unfortunately, cutting and turning a new crown on this barrel isn't going to change anything when the smallest diameter of the grooves are a tad over 0.282 inch diameter.
The barrel is bright with sharp rifling, and has all the proof marks and 270 W calibre roll stamp. Evidently it is a [7mm barrel that was inadvertently chambered in 270 Winchester.
![U], and made it all the way through the process.9f5u8B.jpg](/forum/proxy.php?image=https%3A%2F%2Fi.imgur.com%2FjSomehow%2C+a+%5BU%5D7mm+barrel+ended+up+in+the+270+rack%5B%2FU%5D%2C+and+made+it+all+the+way+through+the+process.9f5u8B.jpg&hash=05050738a19c71e1cfd15b61d8000c56)
I can understand this happening because BSA chambered rifles in 7X57. I have had two of them in the past.
Tried putting a 7mm/.284 bullet into a fired case, and it won't even begin to slide in, so it certainly isn't going to chamber a loaded round with one in it. The easy answer? A rechamber to 280 Remington.
Ted
And
, back to post #4.
- Location
- Southern Vancouver Island
I may have told you of the guy who had a rifle which didn't shoot well and was causing all sorts of frustration. One gunsmith advised him to take the rifle, wade out into a pond, close his eyes, spin around and throw the rifle into the pond. The important thing was to keep his eyes closed, spin around a couple more times and walk out with his eyes still closed. This way, he would never see that rifle again and his troubles would be over.
I guess a tight 280 will probably work better than a loose 270.
I guess a tight 280 will probably work better than a loose 270.
You did tell me that story, and it's a good one.
The crazy thing about this whole deal is that I should have checked the bore with a slug right off the bat. If I had been hearing about this problem instead of experiencing it, that would have been one of the first things I would have suggested, but didn't because it was a factory barrel, not an aftermarket one that someone had installed. The bore is bright with sharp rifling and no loose spots, and the proof marks and calibre stamp are all there.
Everything looked right..... Paradigm is a wonderful thing.
Ted
The crazy thing about this whole deal is that I should have checked the bore with a slug right off the bat. If I had been hearing about this problem instead of experiencing it, that would have been one of the first things I would have suggested, but didn't because it was a factory barrel, not an aftermarket one that someone had installed. The bore is bright with sharp rifling and no loose spots, and the proof marks and calibre stamp are all there.
Everything looked right..... Paradigm is a wonderful thing.
Ted
I would do exactly that if they would chamber, but the chamber neck is too small in diameter. Nothing wrong with a 7mm-06 for a hunting rifle.
That was part of the mystery. Fired cases look and measure perfect.
Really thought I had found the answer when the gap under the rear base was discovered.
Ted
And
Yep, and you were right! I just couldn't imagine a BSA factory barrel being incorrect.
What really got me was that a 270 bullet measuring .277" will just barely slide all the way trough a normal 7mm barrel. I have done that a few times. This one would not let a 270 bullet enter the muzzle. Tried that in this rifle, and the slightly undersize bore would not allow it to enter. So, I just assumed it was a 270 barrel.
Again, paradigm is a very powerful thing. Never assume anything!
Ted
My luck I'd trip over it on the way back to the transportation.
Johnn Peterson
CGN Ultra frequent flyer
- Location
- Chemainus B.C.
When you started relating some of the issues you were dealing with,
I vaguely recalled, from YEARS back, a very similar set of circumstances a friend had to contend with. Guess my long term memory is still working and glad to hear you found the problem. What steps do you plan on taking for a solution?lol I was thinking the same thing...
Crown is always the first place to look. Over zealous rifle cleaning with steal rods from the muzzle will do it every time, especially on leaver actions. A quick way to check is to put a loaded cartridge in the muzze. I've see where it in all the way to the brass, not good. Also I've seen the bullet didn't sit square in the muzzle, it would touch on two points a rock back and forth definitely not touching all lands at the same time.
One final observation before sending this rifle away. The diameter of the slug pushed through the barrel is 0.282 inch. That is the depth of the grooves in this barrel.
The grooves in the slug measure 0.270 inch. That is the diameter of the bore.
The barrel started out the right size, but apparently the barrel maker got distracted and cut the grooves five thousandths too deep.
It should make a decent 280 Remington.
Ted
The grooves in the slug measure 0.270 inch. That is the diameter of the bore.
The barrel started out the right size, but apparently the barrel maker got distracted and cut the grooves five thousandths too deep.
It should make a decent 280 Remington.
Ted
