Reaming die blank for making seater die

[BuffaloBill]

I didn’t find in a search just now, any discussions on how to best chuck (and dial in) a die blank for the reaming process. I imagine a true bore alignment system would be handy for this. I don’t have one of those, but do have this fixture I made for pistol barrel work (that I’ve yet to actually use). It’s got 1/2-20 setscrews:



Or do people typically rely on their standard 4-jaw chuck jaws to achieve sufficient alignment, only dialing in the upper end of the pilot hole? I’m guessing not….(?)

In my case am looking at a Newlon micrometer seating die blank, having a 0.2362 pilot hole, and will be using a JGS 6BRA Wheeler #1 HSS reamer.

For the last few barrels I’ve chambered, I used inboard & outboard spiders to align the barrel to read as close to zero runout as possible at two bushing positions (over the depth of the chamber) using a Grizzly rod, then drilling so I can reach in the hole with an indicator to confirm the throat area is running true. Then taper-boring and reaming. Ideally, would I follow these same steps when reaming a die blank?

Given how closely spaced the spider screws (in the above pictured fixture) are, I imagine achieving perfect alignment is that much trickier compared to inboard/outboard spiders spaced 20” apart?

I didn’t find a print on the Newlon site to help me understand the 0.2362 pilot hole vs the seating stem diameter & hole depth. I assume the precision pilot hole is deep enough such that my reamer’s pilot bushing will be supported the whole way in? I have never reamed a die blank before.

The longest leadtime component I’ve ordered for this build is a Borden action (@10 months), so I have plenty of time to think about/sweat over this! All advice is welcome and appreciated.

 

[LVLAaron]

Here's how I do it. I use the same jig for actions. I cut aluminum split rings to fit the action or die, in this case.

 

[BuffaloBill]

Aaron,

That’s a nice idea, the split rings. Sounds better than having setscrews bear against die threads.

 

[LVLAaron]

I've been happy with it.

 

[Jonnyofalltrades]

Ok, so I understand that most 6mm bores will be around .236", so your reamer pilots will be in that size range.
However, is this not for an inline type seating die? As in, the bullet and seating stem are inserted from the top? Will that section be reamed to .243" afterwards?

Sorry, just a stupid question from the unwashed masses.

 

[LVLAaron]

For a wilson 6mm seater, the seating stem will be .243

 

[linebaugh]

Your cat head is how I plan to do mine. 4 jaw is prolly good enough but an extra 20 mins of set up for perfection is prolly worth it.

 

[X Count]

I've been thinking about the same problem. Reckon I'm gonna make up a dummy bar with a 7/8 female thread on one end. Screw the die into the thread and use the lock ring to hold it in place.

Suspend the bar between inboard and outboard spiders and dial it in like a barrel. If you wanna get fancy use hollow bar and run front flush cutting fluid.

 

[LVLAaron]

I've been thinking about the same problem. Reckon I'm gonna make up a dummy bar with a 7/8 female thread on one end. Screw the die into the thread and use the lock ring to hold it in place.

Suspend the bar between inboard and outboard spiders and dial it in like a barrel. If you wanna get fancy use hollow bar and run front flush cutting fluid.

A shot out 1.25 straight barrel would work well.

 

[Kurz]

In my case am looking at a Newlon micrometer seating die blank, having a 0.2362 pilot hole, and will be using a JGS 6BRA Wheeler #1 HSS reamer.

Everyone will have some sort of clever solution and their own method of completing this work.

If you are reaming a threaded die blank for use in a reloading press, what effect will all this attention provide when you just screw that reamed blank into the press threads?

 

[Doug Beach]

I use brass set screws against the die threads. I suppose you could still damage the threads, but I haven’t managed to yet.

 

[BuffaloBill]

Everyone will have some sort of clever solution and their own method of completing this work.

If you are reaming a threaded die blank for use in a reloading press, what effect will all this attention provide when you just screw that reamed blank into the press threads?

Assuming you’re a proponent of in-line seating dies, yes, I can appreciate the benefit they offer of having the case fully inserted in the die before bullet engagement with the neck.

I’m not opposed to making the switch to in-line dies & arbor press, but would like to see first, where runout measures using a reamed threaded die in my co-ax press. Using the spring loaded Whidden seater die on a 6Creedmoor, my bullet runout usually measures 1-3 thousandths (annealed cases, bushing sizing and a single pass expanding mandrel). Maybe this will be a step backwards?

 

[AlNyhus]

If you are reaming a threaded die blank for use in a reloading press, what effect will all this attention provide when you just screw that reamed blank into the press threads?

Which brings us to the simple beauty of a rubber 'o' ring and a loosey-goosey press.

Good shootin' -Al

 

[BuffaloBill]

Well…..I talked myself into trying an in-line seating die. Looking over the Wilson die blank reaming instruction sheet, they state the pilot hole being 0.245”. They state no tolerance spec however. I don’t happen to have a set of bushings covering that area. I could purchase a whole set of 6 or 9, etc. but don’t see myself likely to use them again.

So I messaged Wilson from their website, asking if they would be so kind as to identify the specific bushing size to match the die being shipped to me. I also offered a suggestion that they consider selling as an optional item, the bushing with their die blanks. I did get a reply but it wasn’t helpful and didn’t make sense to me. Perhaps the answer came from a non-technical employee?

For those of you who’ve used Wilson die blanks in the 6mm category, is their hole diameter spot-on such that a 0.2448 bushing is the ticket?

Aaron, I see you’d mentioned in an earlier post, that the hole was 0.243. Is that what your’s measured, or did you mean to type 0.245?

Below Is the reply I received from Wilson:


Hello Bill,

Thank you for your inquiry,

We recommend reaching out to whoever is the manufacturer or your reamer,

The manufacturer of your reamer will best be able to suggest which size to use for this.

Please let us know if you have any further questions.

Thank you,

LE Wilson Support

 

[LVLAaron]

The stem is .243 on the money. So the hole is probably 244. You don't need a bushing. Don't overthink it.

 

[TylerFromMS]

If you’re using a Manson reamer, grab you a roll of wax paper.

 

[WSnyder]

I used to use a bell chuck (same thing as the action truing chucks shown above but the old school name) but I've gone simpler. I just use a set-tru collet chuck. Dial in where the end of the case would be, pre-bore and ream just like you'd do with a barrel. I don't use a bushing when pre-boring with a taper or step bore. Both Wilson and Newlon dies cut pretty freely and more so the plain steel.

 

[BuffaloBill]

OK guys, will taper bore like I’ve been doing on chambers, and go bushing-less this time….

It will be done with a JGS reamer but will have wax paper on hand.

Thanks for the advice.

 

[LVLAaron]

If you’re using a Manson reamer, grab you a roll of wax paper.

Why do you say this? Do you feel the mansons are more prone to runout?

 

[TylerFromMS]

Why do you say this? Do you feel the mansons are more prone to runout?

Chattttttttttttttter. It made a cool ass pattern though. Also chattered on Giraud pilots. PTG and JGS have not.

The Manson cuts crazy good though, so I’m not talking bad about the product at all.