Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Reloading
reworking brass
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="flashhole" data-source="post: 513381" data-attributes="member: 21375"><p>I don't own either but I can give you a few things to look at so you can make a self determination.</p><p> </p><p>You are going from a 7mm to an 8mm neck diameter. That means you will be thinning your neck when reforming. I like to go the other way (larger diameter to smaller diameter) and turn the necks if needed for uniformity and fitment to the chamber. It's not a big change so you should have adequate neck wall thickness to give good neck tension on a loaded round. You can actually calculate how much it will be thinned if you know how to determine the area of a circle and have a micrometer to measure neck wall thickness on the original case.</p><p> </p><p>I will assume the shoulder on the 7mm is further forward than the 8mm reform so reforming would push the shoulder back reforming to 8mm dimensions. This would require trimming the case to the proper length but is a good situation to be in.</p><p> </p><p>If the shoulder is further back on the 7mm you will want to adjust your die so you leave a bit of the neck (neck/shoulder junction) unsized so it acts as a false shoulder giving you proper headspace when fireforming the loads. This is a trial and error process if you don't have a cast of your chamber. Partial size it and see if it fits in your gun. If not, adjust the die down a bit more and try again. </p><p> </p><p>A caution here is if the case needs to stretch more than ~.010" during fireforming you may not want to reform at all because it will thin the web too much. That could create an unsafe situation and cause the case to rupture.</p></blockquote><p></p>
[QUOTE="flashhole, post: 513381, member: 21375"] I don't own either but I can give you a few things to look at so you can make a self determination. You are going from a 7mm to an 8mm neck diameter. That means you will be thinning your neck when reforming. I like to go the other way (larger diameter to smaller diameter) and turn the necks if needed for uniformity and fitment to the chamber. It's not a big change so you should have adequate neck wall thickness to give good neck tension on a loaded round. You can actually calculate how much it will be thinned if you know how to determine the area of a circle and have a micrometer to measure neck wall thickness on the original case. I will assume the shoulder on the 7mm is further forward than the 8mm reform so reforming would push the shoulder back reforming to 8mm dimensions. This would require trimming the case to the proper length but is a good situation to be in. If the shoulder is further back on the 7mm you will want to adjust your die so you leave a bit of the neck (neck/shoulder junction) unsized so it acts as a false shoulder giving you proper headspace when fireforming the loads. This is a trial and error process if you don't have a cast of your chamber. Partial size it and see if it fits in your gun. If not, adjust the die down a bit more and try again. A caution here is if the case needs to stretch more than ~.010" during fireforming you may not want to reform at all because it will thin the web too much. That could create an unsafe situation and cause the case to rupture. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
reworking brass
Top