7mm whisper
02-14-2017, 06:46 AM
#6
Giant Nontypical
Join Date: Oct 2013
Posts: 9,230
Run them through a full length sizing die and then trim 1/1000th off the brass. Clean up the case mouths. Install primer and load with a minimum starting load and the cheapest 7mm bullet you can find (I use blems) and then take it to the range and fireform them to you chamber. Check length with caliper to be sure your case length is still good and then all you have to do is neck size to work up accurate loads.
02-14-2017, 03:50 PM
#7
Nontypical Buck
Join Date: Feb 2015
Location: Illinois
Posts: 3,695
As an add to Flag's post, make sure you are using a TRUE neck sizing die and not just an adjusted FL sizing die to do the neck. That way you aren't bumping the shoulder or sizing any more of the case. Personally, when I fire form, I use the cream of wheat method to fire form my cases. But that can be a little time consuming to find the right recipe of pistol powder load for proper sizing and shoulder forming. You should also learn how to anneal your case necks to prevent cracking/splitting and increase longevity of the case.
02-18-2017, 11:25 PM
#10
Nontypical Buck
Join Date: Feb 2015
Location: Illinois
Posts: 3,695
I've only seen the prints on the 7mm Whisper. The .221 parent case is the old .222. All the whisper rounds are of course designed for sub sonic loads but your 7mm can be loaded to a little over supersonic. What are your intents for the round. Hunting? Target? Is your firearm a rifle or pistol? Lets start from there and maybe we can work something up for you.