yes, when you blow out a case it will get shorter.

The shoulder blows out, where does that metal come from ?

Be careful working up loads for a Gibbs (or Ackley) type. ONce you get near max, pressure signs come up suddenly.

ZERMEL-Using 270 brass was my next step. I had the reamer neck built so I could use 270 & 280 brass if I wanted to. New Win. 30.06 brass is only 2.486" long. When fireformed it shrank to 2.467" which leaves a neck of only .217". Will the Cream of Wheat method cause less shrinkage?

Thanks,
Victor O.

Eldeguello-I'm using some real old 130gr. BT's (the kind that blow up if they hit a rib) for fireforming. I'm using H-4831 because I had some. I'm using 59gr. because that's 4 gr. less than the old Gibbs book says is max. plus I was shooting 60 gr. H4831 in my 270 Win.'s without any problems. Some guy on another web site says his 270 Gibbs shoots 150 gr bullets 3248fps with 66 gr. of IMR4831 and a 24" barrel. I'll be happy with an accurate 3000fps. I think this rifle is going to be a shooter. I'm breaking in the barrel while reforming. When I started shooting 5 shot groups they made one big hole. I'm an old hotrodder and I'm having a ball doing this. I've got to send my die back to RCBS so they can polish it out some. It's resizing the cases too much. I won't start working up a load until I get the die back. I'll post the results when I get through.

Later,
Victor O.