27 RPM reloading dilemma

8x68s · Dec 4, 2024

Having a reamer made to create a .270 caliber version of the Wby 6.5 RPM. I have a 6.5 die set but I'm wondering if mandrel-ing to .270 (which I did to make dummies) is too much neck stretching for case durability. Without having specific dies made up (excessive cost and time) what options do I have for getting my neck size correct?
Thanks for your input!
Greg

Poor_choices · Dec 4, 2024

Are you thinking of sizing the brass down in a 6.5 RPM die every time, then using the mandrel to open the neck? That would be a lot of stress on the brass.

Maybe you could get a 6.5 RPM bushing die, then just have the die modified to accommodate the larger neck diameter of the .270 version. It would only be a small amount of material to remove, and anyone with a lathe should be able to handle that. Then you would just need to get the appropriate size bushing.

Mikecr · Dec 4, 2024

Mandrels should work fine in steps. Anneal the neck-shoulder junctions well beforehand, and use a neck lube.

7mm man · Dec 5, 2024

I am super interested in seeing how this whole thing turns out. What barrel twist are you going with? Bullets you plan on shooting?

K.E.C. Darkside · Dec 5, 2024

What a neat idea. Yes a mandrel will do it.
Chamfer the inside of your brass to help the mandrel get started, wax lube, your good to go. The reason I mention chamfer is sometimes new brass has rough edges on the inside and outside of the mouth.
Bushing dies, easy peasy.
8twt to use 170 Berger's or mono's.

liltank · Dec 5, 2024

Poor_choices said:
Are you thinking of sizing the brass down in a 6.5 RPM die every time, then using the mandrel to open the neck? That would be a lot of stress on the brass.

Maybe you could get a 6.5 RPM bushing die, then just have the die modified to accommodate the larger neck diameter of the .270 version. It would only be a small amount of material to remove, and anyone with a lathe should be able to handle that. Then you would just need to get the appropriate size bushing.

A bushing die is a great idea as long as none of the shoulder dimensions and case length hasn't changed. There is no need to ream the neck of the bushing die. They are already overbore to accommodate the bushings and allow different neck diameters.

Rosebud · Dec 5, 2024

All of this will turn into more money and time than if you had gotten the proper dies to begin with.
Every time you try to do stuff on the cheap, especially in this arena you loose.

can1010 · Dec 5, 2024

not sure if there are any bushing dies available for the 6.5 rpm but whoever is threading and chambering your barrel can bore a standard die to except a bushing it isn't that hard and plenty of standard dies available. that will be the quickest and cheaper than custom dies.

Mike D Texas · Dec 5, 2024

liltank said:
A bushing die is a great idea as long as none of the shoulder dimensions and case length hasn't changed. There is no need to ream the neck of the bushing die. They are already overbore to accommodate the bushings and allow different neck diameters.

This is not always true. They are usually very close to appropriate diameter for caliber to keep the neck in alignment for the bushing.

I have a 6.5 SAUM and later built a 300 SAUM and I was unable to use the 6.5 SAUM bushing die to size the 300 SAUM using the correct bushing size for it. Same with a 300 and 338 Norma Improved that I have.

matthewsboy · Dec 5, 2024

Why go with a 6.5rpm necked up instead of a 338rpm necked down?

FEENIX · Dec 5, 2024

can1010 said:
not sure if there are any bushing dies available for the 6.5 rpm but whoever is threading and chambering your barrel can bore a standard die to except a bushing it isn't that hard and plenty of standard dies available. that will be the quickest and cheaper than custom dies.

On my last wildcat build (.338 Thor), I had custom sizing and chamber reamers made. My GS made me a custom hydraulic and sizing dies out blank dies. The sizing die was sent out for hardening. He used the chamber reamer and .338 WM seating die to customize my seating die requirement.

Wildcatting always involves additional costs and time. The cost of the custom reamers cannot be avoided, but the cost of dies and the wait time were cut by more than half, and best of all, starting it right from the get-go eliminated frustrations.

FEENIX · Dec 5, 2024

matthewsboy said:
Why go with a 6.5rpm necked up instead of a 338rpm necked down?

Not with RPM, but I have done both, neck or neck down; the process is the same; it just depends on what tools/equipment the OP has to accomplish the task.

can1010 · Dec 5, 2024

FEENIX said:
On my last wildcat build (.338 Thor), I had custom sizing and chamber reamers made. My GS made me a custom hydraulic and sizing dies out blank dies. The sizing die was sent out for hardening. He used the chamber reamer and .338 WM seating die to customize my seating die requirement.

Wildcatting always involves additional costs and time. The cost of the custom reamers cannot be avoided, but the cost of dies and the wait time were cut by more than half, and best of all, starting it right from the get-go eliminated frustrations.

he won't need a custom sizing reamer any 6.5rpm sizing die can be converted to a bushing die by any quality smith and still be cheaper than a custom reamer alone.

FEENIX · Dec 5, 2024

can1010 said:
he won't need a custom sizing reamer any 6.5rpm sizing die can be converted to a bushing die by any quality smith and still be cheaper than a custom reamer alone.

I never said he needed it. I was sharing what I did on mine.

27 RPM reloading dilemma

8x68s

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Poor_choices

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Mikecr

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7mm man

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K.E.C. Darkside

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liltank

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Rosebud

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can1010

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Mike D Texas

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matthewsboy

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FEENIX

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FEENIX

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can1010

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FEENIX

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