Over all case length on fire formed dasher cases

[digrazir]

I bought a used 6 dasher with 500 plus fire formed cases mostly fired once some twice. I know the brass was fireformed out of 2 different rifles chambered using the same reamer. All the brass is mixed into one pile. My intentions are to full lenght size the brass before using. No problem chambering. I measured the the unsized shoulders and they are pretty close. I then noticed some of the brass has been trimed. I have groups of cases that are 1.560, 1.550 and 1.540. My question is should I trim them all to the shortest length or cull the shortest ones? Thx in advance Ray

 

[ridgeway]

What is the chamber length? I have a 1.555 chamber and trim to 1.545

 

[digrazir]

I don't know the length of the chamber. I am going to have to order a 6 mm chamber length insert from Sinclair. Ray

 

[benjamin199]

I trim all of my dasher brass to 1.545" I did get one set of lapua brass that ended up being around 1.535 after fire forming, both lengths shoot well in my rifle. If it were me, I would trim them all to the same length in your rifle.
Ben

 

[digrazir]

Ben, after reading your post, I realized none of these cases had been trimmed. They varied in lenght because there were different lots of brass used during the fireforming process. I am pulling 200 cases out that I can trim to 1.550. Those 200 cases will keep me busy shooting until winter sets in. Thx to all for your help Ray