Difficult 30-378 Weatherby Magnum

[bsimmons4]

I have a 30 378 weatherby mark v accumark that I am just getting into long range shooting with. I've had a hard time finding good loads for it, but finally found one: 210 vld berger bullet, 98 grains of H1000 powder , and seated my bullet 0.020 inches off the lands. MY PROBLEM is that I've had many of my cases start to dent right before the shoulder while shooting them. There is only about 1/8th of an ice of the bullet in the case besides the boattail, because I want my bullet close to the lands for better accuracy. My cases also have a black soot on them after being fired. Can anyone help?

 

[gohring3006]

I have a 30 378 weatherby mark v accumark that I am just getting into long range shooting with. I've had a hard time finding good loads for it, but finally found one: 210 vld berger bullet, 98 grains of H1000 powder , and seated my bullet 0.020 inches off the lands. MY PROBLEM is that I've had many of my cases start to dent right before the shoulder while shooting them. There is only about 1/8th of an ice of the bullet in the case besides the boattail, because I want my bullet close to the lands for better accuracy. My cases also have a black soot on them after being fired. Can anyone help?

The case is not sealing to the chamber. STOP shooting that load before you erode the chamber.... You need to seat deeper.

 

[bsimmons4]

Any ideas about how much a bullet needs to be seated in order to create a good seal between the case and the chamber?

 

[gohring3006]

At or around .308" of bearing surface. The 300 Win mag has less than .308 but not much less, and it can be quite accurate. I am intrigued by you saying you found a good load with only 1/8" of bearing surface in the neck. The runout would be horrible...
I would start at .308" and work backwards with seating.

 

[Lefty7mmstw]

mild loads will do this too... I'd stuff the bullet into the neck a bit more as others have stated, then up the ante on your charge until the denting goes away.
You could have a very bad day should a bullet not exit your barrel and you send another bullet down the bore. They are correct that the load needs to be fixed or is NOT shootable. Hodgdon shows a bit more for top charge than you are using; going to 104 grains h1000 on a 220 partition in the 30-378... You need a heck of a primer too... I hope you are using a 215 or wlrm...

 

[Dosh]

4, I'm surprised you got that close to the lands since the Accumark like all Wby calibers have a very generous freebore. The 210 VLD shoots well, but their 215's and 230's are awesome. That pic scares me.

 

[gohring3006]

I would say, the 1/8" isn't enough bullet in the case. And when fired, the primer launches the bullet, and the case doesn't have enough pressure to seal the chamber. Basically the bullet isn't in the case when the powder ignites...

 

[bsimmons4]

Thank you guys. This us very helpful. I'm going to seat my bullet at least .308" and go from there until denting stops. The 210 VLD was just long enough to touch the lands in the Weatherby. I also have the 225 hornady match that is longer yet and has no problem touching lands. I wanted to get a bullet close to the lands for optimal accuracy but I am seeing that the bullet must be seated deeper.

 

[bsimmons4]

Would you guys shoot that dented case in the gun with a proper load to pop the dents back out or ditch the case?

 

[gohring3006]

I would ditch it... It would be over worked in those areas, being dented then blown out that far...

 

[Deleted member 46119]

The case is not sealing to the chamber. STOP shooting that load before you erode the chamber.... You need to seat deeper.

+1 on that

 

[sp6x6]

I would be picking the heaviest bullet for that type round.230 Berger,also as others have said,in weatherby's you usually are not close to the lands and you can get accuracy.Ive had several Wbys.

 

[rsnell]

Buy the Burger reloading manual and follow it. If you still have questions, call Burger. The load you are using is not safe.

Bob

 

[FEENIX]

I would ditch it... It would be over worked in those areas, being dented then blown out that far...

I would be picking the heaviest bullet for that type round.230 Berger,also as others have said,in weatherby's you usually are not close to the lands and you can get accuracy.Ive had several Wbys.

+1!