kombi1976,
I'll see if I can put it together.
Imagine an empty case chambered in your rifle, with the breech closed, as if you were going to fire. If you could see inside, you would see a space or gap between the case mouth and the beginning of the rifling.
This gap is the throat. And, this gap stays the same, once the rifle is built.
The rifling will allow a bullet to protrude out of the case only a certain amount. This means that the rifle will accept cartridges that are no longer than the distance from the rifling to the bolt face(maximum C.O.L.)
All of this is pretty much meaningless to the folks who shoot factory loads. But, the handloader can vary the C.O.L as long as he doesn't go beyond the maximum C.O.L. If you go beyond the maximum C.O.L., the bullet is jammed into the rifling and pressures will soar, creating an unsafe situation.
Per rifle, only a certain amount of the bullet is allowed to protrude out of the case because of the maximum C.O.L. Now, within any caliber there are several bullet weights. Some are shorter, some are mid-length and some are longer. Since the cartridge can't be longer than the maximum C.O.L., the extra length of the longer bullets must protrude down into the case and this extra bullet length takes up space inside the case that could be used for more powder.
Now, back in the late 1800's/early 1900's the world was making the change from long, heavy, slow bullets to shorter, lighter, faster bullets. Some of the rifles that were made during the "long, heavy, slow" period were built with long throats.
The M96 Swede is one of these, along with some others. The original load for the M96 included a 156g RN bullet and in order to get full powder space the rifles were built with long throats so that more of the bullet would be outside the case rather than inside the case. This left more room for powder.
After years of handloading, most handloaders would probably agree that most bullets shoot better when seated less than .010" from the rifling. In a rifle that is long-throated such as the M96, it just isn't possible to seat the shorter bullets this close to the rifling because a certain amount of the bullet must be inside the case in order for the case to hold the bullet securely. This means the shorter bullets must be seated further from the rifling and sometimes this isn't good for accuracy.
This is why I want my custom M96 built with a shorter throat that would enable me to seat 120g bullets at .005 off the rifling. With the current long throat I can't do this. I can still shoot the long 156-160g bullets from the shorter throated rifle, but I will lose some powder space. I have a M70 Featherweight that is also throated long and if I want I can shoot the longer bullets from it.
A long throat doesn't prevent the use of short bullets, but if the short bullets have to make a long jump to the rifling, the accuracy may suffer.
I hope this is clear!
Buffalogun
