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
Size for bushing to neck size
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="rscott5028" data-source="post: 497300" data-attributes="member: 24624"><p>If your loaded DIA is 0.291, then your case wall thickness is about (.291-.264)/2=.0135. </p><p> </p><p>So, I'm guessing you neck turned relative to new Lapua brass which usually runs ~.014-.015". I usually turn mine down to about .013-.014" just to clean up the high spots. </p><p> </p><p>I just checked a couple of 3 times fired pieces of un-turned Norma 6.5x284 brass and they measured .293 loaded and .297 fired. So, it appears my chamber neck is cut about the same, but the necks are slightly thicker on the Norma samples that I happened to measure which resulted in .004" expansion vs .006". </p><p> </p><p>Regardless, you've hit on one of the trade-offs between better concentricity and even neck tension vs working the brass. ...hence, tight neck reamers for avid competitors. </p><p> </p><p>I've been using a bushing that's ~.002" under sized rather than .003". Others may be better qualified to speak to that. But, I think you can count on about .001" of spring back and you need about .001" for neck tension. </p><p> </p><p>In any case, you're likely working it a lot less than a standard die would be doing for the same piece of brass. </p><p> </p><p>-- richard</p></blockquote><p></p>
[QUOTE="rscott5028, post: 497300, member: 24624"] If your loaded DIA is 0.291, then your case wall thickness is about (.291-.264)/2=.0135. So, I'm guessing you neck turned relative to new Lapua brass which usually runs ~.014-.015". I usually turn mine down to about .013-.014" just to clean up the high spots. I just checked a couple of 3 times fired pieces of un-turned Norma 6.5x284 brass and they measured .293 loaded and .297 fired. So, it appears my chamber neck is cut about the same, but the necks are slightly thicker on the Norma samples that I happened to measure which resulted in .004" expansion vs .006". Regardless, you've hit on one of the trade-offs between better concentricity and even neck tension vs working the brass. ...hence, tight neck reamers for avid competitors. I've been using a bushing that's ~.002" under sized rather than .003". Others may be better qualified to speak to that. But, I think you can count on about .001" of spring back and you need about .001" for neck tension. In any case, you're likely working it a lot less than a standard die would be doing for the same piece of brass. -- richard [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Size for bushing to neck size
Top