statjunk

Hello guys,

Got a bit of a problem here. I just seated my first 300 WM bullet at 3.6" and it was able to go into my bolt action rifle no resistance what so ever. The Lyman reloading book says that the max length for this cartride is 3.34".

I will have to back it up to just about 3.34 to get it to go into the magazine. What is the issue here? Do I have too much headspace in my rifle? Should I just make it just long enough to fit it into the magazine?

Also if someone can just discuss this issue in general that would be great.

Thanks

Tom

bigcountry

Well, in general, most magnums have some freebore. My 300RUM's max COL to fit my mag was 3.65" but I would need to load to 3.82" in one, 3.75" in another to reach the lands. My STW same thing. Win mags I have had usually don't have that muchfreebore but yours sounds like it does. Weatherby's have over 1/2" sometimes. Its the way they are designed. So you have only one choice if you want to use it effectively for hunting. Load to fit your mag. Shoot it and see how it does. Its a luxury to be close to the lands, but surely not a must.

So there was a guy in another forum that had a 300RUM built same time I did. He said he was having a custom throat where he could reach the lands in 3.6". Well, it didn't turn out so perfect. It was accurate, but he had to throw away any commercial reload data. He had trouble reaching the starting load without pressure signs in some cases.

Oops, meant freebore.

Solitary Man

No, headspace is not the problem. You have excess freebore in the barrel it sounds like to me. Freebore is the portion of the barrel just in front of the chamber that is not rifled. You're probably just going to have to load 'em up so they'll fit in your magazine and not worry about it. Or else load 'em up longer and shoot your rifle single shot style.

statjunk

So am I to interpert that as the closer your bullet is tothe lands, the higher the pressure it will generate? Does this also mean that you will be getting higher velocities with less powder or is it just the opposite?

Tom

Solitary Man

Yes, quite possibly, but not necessarily.Seating your bullets so that they actually touch the lands is where you can really get into trouble if you're not careful.

Not that I know of.

statjunk

So if I were to have work done to my rifle to shorten the freebore would this mean that I could get the same ballistics out of a 300 WM with less powder? Approximately how much does an operation like this cost?

Tom

bigcountry

If you graphed it, it would be a bathtub curve. Closer you get to the rifleing the higher pressure, but deeper you seat the bullet, less room for powder and higher pressure, somewhere in the middleis lowest pressure, highest velocity.

bigcountry

Absolutely not, quite the opposite.Readthe story above about the guy who shorten his freebore.You would have reach the pressure limit way before you reach your velocity potential. Thats why roy weatherby started the whole freebore thing. To get max veloctiy but stay within pressure guidelines. Bullets in "magnums" are getting a running go.

Also know this, you shorten the freebore too much on a magnum, you might be able to shoot factory ammo again without going over pressure.

Solitary Man

I think it would be a waste of money. Shoot it like it is.