Neck differences

[SquirrelNuts]

I came across some .338-378 brass for really cheap and would like to neck it down to 30-378, which is what I shoot.

Will accuracy, point of impact, etc diminish with this necked down brass compared to the factory 30-378 brass?

Thanks

 

[britz]

I don't have any experience with necking cartidges down but I do know that it isn't a good idea to purchase used brass if you want to load for accuracy. You never know for sure how many times it has been fired, it will have come from different lots and it likely will be different brand even.

 

[kraky]

Only one way to find out...try about 10 rounds and see. I would say perhaps leave all others in the original caliber in case you aren't happy with the results. I'd be watching the primer pocket seating for looseness and would also be checking the headstamp area for extractor marks....this might tell you how hard they were pushed.
Also,,,,and I doubt it will be a problem make sure the brass chambers freely as it's likely the case necks will be a bit thicker than normal after being shrunk down. You might want to take an extra bullet with you to the range and after firing the first round with the new brass make sure that you can "drop a bullet" into the case mouth with ease.

 

[Buffalobob]

A few things to watch out for and to consider before you jump off the cliff into the water holding a concrete block. THERE MIGHT BE SHARKS IN THERE!!!.

Now then, having been a big weatherby fan for many DECADES I would just say that there are a few sharks to watch out for. First of all even though I do nto pay attention to my teyping a spelling I am a fairly decent engineer. The Wby shoulder is designed form a fluid flwo point of consideratain and nto from a structural streanght stand point. Downward pressure will defrom the double radius shoulder sooner than an angled shoulder. Wby (norma) brass is soft (although well formed) which further compounds the problem of the shoulder collapsing upon necking down. Even when it is not apparent to you that the neck is "not edxactly right " it probably is not right. This then need to "blow the case back out". Well by now the prinmer pockkets are getting a little on teh big side.

I would say that if you are gettign them for 30% of new price then you may be OK, but definitely keep them separated as "practice" rounds.

I have no expereince with the case you mention but I have dealt with the smaller cases and so you can take my adivec for waht you paid for it because that is about waht it is worth


Now then if any of teh anal engineers who can't get through loife if there is a typo can psot up their advice and we will see who knows their stuff.