300 Weatherby Brass problem

[Mudduck]

I purchased a used 300 Weatherby Mark V and have been assembling reloading components for it. Got some once fired brass that I full sized using a new forster full length die. I decided to try it in the rifle to see how it fits.

The brass slides in smoothly right up until I get to when the bolt slides down and locks. At that point I have to give it an strong push for it to move that extra bit so it will slide down and lock.
I have not worked with belted magnums before but when full sizing it appears that .125 above belt doesnt get sized ( I just switched to a Coax)

Measurements
Full Length of brass after sizing is 2.827 and length to top of shoulder is 2.393
When I eject the sized brass out of the rifle chamber after closing it there appears to be a fine line around the shoulder at 2.333 or 2.315
Would it be correct that my problem is that I need to bump back the shoulder or an I not resizing far enough down?

Hornady manual gives a different length to the shoulder???? ( misprint? or do they size their brass differently?) see comparisons
Hornadys 9th manual
Full length 2.825
length to shoulder 2.384

Noslers reloading 7
Full length 2.825
length to shoulder 2.298

Speers manual
Full length 2.825
length to shoulder 2.298

 

[636andy636]

Try some new brass. Sounds like your cases are bulged just in front of the belt. Common issue with belted mags. You can get a bulge busting system but I'm not sure where you can order one

 

[hookedonblacktail]

I would try bumping the shoulder back more as a start, sometimes the ram really has to cam over to size enough, my 300wsm is like that. I think I've read some guys file the top of the shell holder down a bit, I've never tried it myself

 

[Dogleg]

Sounds like rifle the cases were fired in first has a sloppy chamber. First make sure that you are actually full length sizing. Screw the die in til it contacts the shell holder plus 1/2 turn. There shouldn't be any light gap between the shell-holder and die when its at the highest point. There is enough variation between dies that just trying a different set sometimes works. Do you know anyone else that shoots that caliber? Its a bit of a long shot but it happens.

I've had some luck with small based dies on belted cases that didn't want to fit a different rifle. I don't know of one for the .300 Weatherby though. Depending on how many cases you have it might be worthwhile to get one for a .300 Win and cut it in half. The Willis collet tool is made for sizing closer than a FL die, and will work if you have enough brass to justify the cost. I've got one, and have used it on a salvage operation like yours.

Or you could just get some new brass.

 

[Mudduck]

Sounds like rifle the cases were fired in first has a sloppy chamber. The Willis collet tool is made for sizing closer than a FL die, and will work if you have enough brass to justify the cost. I've got one, and have used it on a salvage operation like yours.

Thanks - I double checked that I was full sizing properly but the same problem continues ..... so I have a Willis collet die on the way ... I will post an update once it arrives
Im also going to purchase some new 300 ammo later today

 

[Kirk930]

I just bought a Willis collet die for bulged .257 Wby cases, as I had the exact same problem you described. Cases were bought once fired.

Works exactly as advertised. Make sure you use lube!

What is nice about the die is that one end is a "go/no go" gauge, so it's easy to tell if a casing requires this extra sizing step.

 

[c-fbmi]

I made up a washer in the lathe and attached it to the bottom of an old die I reamed out to solve this exact problem with that 1/8" of belted mags, ahead of the belt, which will expand and does not get sized by regular FL dies. I have run into it many times. It is only very slightly radiused on the bottom, just enough not to shave brass and I set it up so that it bumps hard to the belt, I think I made it .510 or .511, anyway it works 100%.