The Lee Factory Crimp Die applies a radial crimp by means of a collet. I use it to maintain consistent neck tension and see no increase in indicated total runnout.
Your rifle is most likely a JC Higgens Model 50 sold by Sears. I used a 50 to convert to a 338 WM for my elk rifle and it has the "FN Action-Made in Belgium" on the left side of the receiver. I'll give you $300 for it right now. No better action to use for a custom rifle. The trigger was the FN...
Redding 7STW dies set $35
W-W 7STW new brass, 50 pc, 2 bags $35 each
50 bulk W-W 7STW new brass $30
all prices do not include shipping......will ship USPS Flat Rate
SS 26" standard weight Rem 700 takeoff barrel in 7RUM. Bought for a canceled project. I was told it was a new takeoff barrel and it looks it. $100 plus shipping.