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
Sinclair Concentricity Gauge
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="TRexF16" data-source="post: 2376041" data-attributes="member: 108912"><p>You don't want the RCBS NECK EXPANDER plug for bottleneck rifle cartridges - it's for straight-walled pistol cases.</p><p></p><p>RCBS dies, by their design, actually give you some good options that you would not have with, for instance, Redding (and I really like Redding so that's not a slam on them).</p><p></p><p>I like using a Lee universal decapper, so if you have one (or can spring for the $16.50 best price on Amazon) use it first, before FL resizing/shoulder bumping with the RCBS decapping rod removed. If you have another set of RCBS dies for a smaller caliber, you can just put that decapping rod in your FL die and go ahead and size/bump and deprime all in one step, but leave the necks unexpanded.</p><p>From here reinstall the original, correct for caliber, expander ball. Use its adjusting screw to retract it almost all the way up into the case (since you don't need it to deprime). That, BTW, is the thing Redding die design doesn't allow - they won't retract the expander ball as far up into the die body. The idea is that you will now run your FL sized (but not yet neck-expanded) case back up into the die and expand the neck on the up-stroke. The right height for the expander ball is such that you can push the neck completely over the expander ball without the case mouth entering the portion of the die that sizes it down. Only run the case as far into the die as required to run it over the expander ball, then bring it back out. Your cases may turn out straighter if you leave the decapping rod lock nut loose so the expander ball "floats", and centers itself in the case neck (this, BTW, often helps get straighter cases even if you're just doing the traditional FL sizing and depriming in one pass). By setting the expander ball as far up in the neck as I described, you can pick up more support for the case walls, reducing runout. But mostly it helps because you are fully supporting the case head against the shell holder and expanding on the up stroke, not just pulling the necked-down case over the ball, as normal FL sizing does.</p><p>Another technique that may or may not make even straighter cases, is to deprime first with the Lee die, then install the RCBS die set to FL size/bump, but with the expander ball drawn up even further into the die. You set it so there is just enough clearance for the case mouth to pass over the expander ball and enter the neck of the die. Let the decapping pin "float" for this. Then, as you withdraw the case from the die, the neck gets expanded on the pull stroke (which I know I said was "bad" just above) BUT, while both the case walls as well as the case neck are still supported.</p><p>To know if the steps above are doing you any good or not, you need to have a way of testing how straight your cases are when the process is complete - like a concentricity gauge. But those in a nutshell are two ways to get straighter cases with an RCBS FL sizing die.</p><p>Perhaps others have some additional tricks with RCBS dies they can share but those are the only ones I know that <em>only</em> require the small investment in a decapping die.</p><p></p><p>Hope that wasn't too hard to follow, and it helps.</p><p>Rex</p></blockquote><p></p>
[QUOTE="TRexF16, post: 2376041, member: 108912"] You don't want the RCBS NECK EXPANDER plug for bottleneck rifle cartridges - it's for straight-walled pistol cases. RCBS dies, by their design, actually give you some good options that you would not have with, for instance, Redding (and I really like Redding so that's not a slam on them). I like using a Lee universal decapper, so if you have one (or can spring for the $16.50 best price on Amazon) use it first, before FL resizing/shoulder bumping with the RCBS decapping rod removed. If you have another set of RCBS dies for a smaller caliber, you can just put that decapping rod in your FL die and go ahead and size/bump and deprime all in one step, but leave the necks unexpanded. From here reinstall the original, correct for caliber, expander ball. Use its adjusting screw to retract it almost all the way up into the case (since you don't need it to deprime). That, BTW, is the thing Redding die design doesn't allow - they won't retract the expander ball as far up into the die body. The idea is that you will now run your FL sized (but not yet neck-expanded) case back up into the die and expand the neck on the up-stroke. The right height for the expander ball is such that you can push the neck completely over the expander ball without the case mouth entering the portion of the die that sizes it down. Only run the case as far into the die as required to run it over the expander ball, then bring it back out. Your cases may turn out straighter if you leave the decapping rod lock nut loose so the expander ball "floats", and centers itself in the case neck (this, BTW, often helps get straighter cases even if you're just doing the traditional FL sizing and depriming in one pass). By setting the expander ball as far up in the neck as I described, you can pick up more support for the case walls, reducing runout. But mostly it helps because you are fully supporting the case head against the shell holder and expanding on the up stroke, not just pulling the necked-down case over the ball, as normal FL sizing does. Another technique that may or may not make even straighter cases, is to deprime first with the Lee die, then install the RCBS die set to FL size/bump, but with the expander ball drawn up even further into the die. You set it so there is just enough clearance for the case mouth to pass over the expander ball and enter the neck of the die. Let the decapping pin "float" for this. Then, as you withdraw the case from the die, the neck gets expanded on the pull stroke (which I know I said was "bad" just above) BUT, while both the case walls as well as the case neck are still supported. To know if the steps above are doing you any good or not, you need to have a way of testing how straight your cases are when the process is complete - like a concentricity gauge. But those in a nutshell are two ways to get straighter cases with an RCBS FL sizing die. Perhaps others have some additional tricks with RCBS dies they can share but those are the only ones I know that [I]only[/I] require the small investment in a decapping die. Hope that wasn't too hard to follow, and it helps. Rex [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Sinclair Concentricity Gauge
Top