Short BTO 7stw brass

[Willie]

I recently picked up 120 pieces of Nosler STW cases at range. It appeared to be once fired. Once I got it back home, I deprimed and cleaned, then checked base to ogive. To my great surprise, I found it averaged 2.440". That was .020" shorter than my target BTO in my custom 7 STW.

My question is: Can I salvage that brass for safe usage in my rifle, as I am leery about early case separation if fired in my chamber?

My plan is to anneal, expand neck to 30 cal, then neck size to .282" leaving a false shoulder on brass, then fireforming to my chamber.

At the price of Nosler 7stw brass, it seems to worth a try to salvage this brass, but being fired, at least once already and still .020" under my chamber bto dimensions, I am being cautious.

 

[hogpatrol]

Base to ogive?

 

[Zero333]

I recently picked up 120 pieces of Nosler STW cases at range. It appeared to be once fired. Once I got it back home, I deprimed and cleaned, then checked base to ogive. To my great surprise, I found it averaged 2.440". That was .020" shorter than my target BTO in my custom 7 STW.

My question is: Can I salvage that brass for safe usage in my rifle, as I am leery about early case separation if fired in my chamber?

My plan is to anneal, expand neck to 30 cal, then neck size to .282" leaving a false shoulder on brass, then fireforming to my chamber.

At the price of Nosler 7stw brass, it seems to worth a try to salvage this brass, but being fired, at least once already and still .020" under my chamber bto dimensions, I am being cautious.

You mean Base to DATUM....

Yes you can salvage the brass....

You will have to load some bullets long so they jam in the rifling and support the case while it blows forward when fired.

Or...

You can do the false shoulder neck. Expend the neck to 30 cal. Then size the neck back to 7mm only far enough so it just barely fits in the chamber,. A kinda very tight fit. So the 30cal portion of the neck supports the case when it blows out when fired.

Edit: You can do the false shoulder neck thing with Cream of Wheat forming method.
That would be best in my opinion. Saving barrel life and form the brass better.
Some fellas fire cream of wheat forming brass in their garage !

 

[Zero333]

I think when forming the brass in the chamber it might be better to use a very light bullet with a faster powder instead of a heavy bullet with slower power.

The faster powder snaps the brass into shape better. The slower powders might not do it on the first try.

This is just a theory.

 

[Willie]

Sorry, Guys! Yes, I meant base to datum. Brain farts are a common occurrence nowadays.

I think when forming the brass in the chamber it might be better to use a very light bullet with a faster powder instead of a heavy bullet with slower power.

The faster powder snaps the brass into shape better. The slower powders might not do it on the first try.

This is just a theory.

Yeah, I'll try a faster powder. Hadn't thought too much about getting better results from a lighter bullet. It was just a surprise to find base to datum on fired brass to be 20 thou short of my chamber & wondering who would have shot 120 rounds from a STW, in one trip to range.

I'll go the bullet route, as I have a forming barrel with same reamer. I figured this would work out okay, but it never hurts to use the brain trust here, to double check. Many thanks.

 

[Zero333]

Sorry, Guys! Yes, I meant base to datum. Brain farts are a common occurrence nowadays.

Yeah, I'll try a faster powder. Hadn't thought too much about getting better results from a lighter bullet. It was just a surprise to find base to datum on fired brass to be 20 thou short of my chamber & wondering who would have shot 120 rounds from a STW, in one trip to range.

I'll go the bullet route, as I have a forming barrel with same reamer. I figured this would work out okay, but it never hurts to use the brain trust here, to double check. Many thanks.

Only Problem I see with using the lighter bullets is that the freebore will most likely bee to long to jam them in the rifling. Thus the false shoulder is the only option.

If you can find a "lighter" bullet that can reach the rifling and use the false shoulder together with the jammed bullet, that would be best. But just a false shoulder will work. Sometimes it has to be fired more than once to get the shoulder formed 100%.

Luckily you're not trying to form much. Moving the shoulder 0.020" forward should be no problem whatever method you choose to use.

 

[FeMan]

That’s quite a find! Since barrel wear in an STW is around $1 per shot by my experience and calculations, I’d try the cream of wheat method.

 

[Willie]

That’s quite a find! Since barrel wear in an STW is around $1 per shot by my experience and calculations, I’d try the cream of wheat method.

That's why I have a fire forming barrel. I have been been forming brass from Nosler 8mm RM brass. Got a large supply for less than 1/2 price of the Nosler 7stw cost. Got 1200 rds from first barrel before it lost accuracy, by never shooting it hot. Current barrel is nitrided, but it will be interesting to see if nitride bath will extend it's accuracy life.

 

[4xforfun]

OK...so ..check me if I am wrong, but....Isn't the STW a BELTED case?

Just load and shoot.

Tod