27 RPM reloading dilemma

[pavementends]

The bushing die or converting existing 6.5 die to 270 will work with the mandrel. There are several folks who will either convert you current die to a bushing die or Forester used to offer a service to ream your current sizeing die to deliver any neck diameter you desired. Not totally sure on it being Forester but it was one of the major die makers.

 

[crystalgayleguy]

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

Graf and sons usually carries one bushing die for 6.5 wrpm

 

[fmuguira]

A Lee collet neck die can be used. Might need to build a little spacer to bump the collet if you can t find something in 6.5 caliber that is similar case length. ie: a 264 Win Mag collet die…. Btw, Lee collets are very reasonably priced.

Then a 6.5 rpm body die could be used every 2-4 firings once case needs bumped back a couple thousandths.

 

[fmuguira]

Just looked and 6.5 rpm is .040 longer to neck /shoulder junction than 264 WM.

So a .040 "washer/spacer" on top of your shell holder when you neck size in the collet will do the trick!! (Inside hole obviously has to be large enough for case to slide through.

 

[matthewsboy]

Have you considered going real crazy and shorting the case by .2" or something to easier seat longer bullets? Idk much about wildcatting but I do know that the case is pretty long…

 

[FEENIX]

Have you considered going real crazy and shorting the case by .2" or something to easier seat longer bullets? Idk much about wildcatting but I do know that the case is pretty long…

Why would you want to do that? The 6.5 RPM has the most case capacity in .473" cartridge and the OP is taking advantage of it. Depending on his action, he can have it throated longer.

 

[matthewsboy]

Why would you want to do that? The 6.5 RPM has the most case capacity in .473" cartridge and the OP is taking advantage of it. Depending on his action, he can have it throated longer.

Why I would personally want that would be to keep the spirit of the rpm series. It takes the Weatherby small mkv action and utilizes its full potential. By making a little sacrifice of powder I figured one wouldn't need to do anything wonky with super long bullets. However I do see that most people probably wouldn't benefit from this unless it was a factory cartridge.

 

[FEENIX]

Why I would personally want that would be to keep the spirit of the rpm series. It takes the Weatherby small mkv action and utilizes its full potential. By making a little sacrifice of powder I figured one wouldn't need to do anything wonky with super long bullets. However I do see that most people probably wouldn't benefit from this unless it was a factory cartridge.

Shortening it to your recommendation takes you back to .270 Win variants.

 

[matthewsboy]

Shortening it your recommendation takes you back to .270 Win variants.

I guess that makes sense because Weatherby has said that the 7mm rpm in testing was pretty much 280ai. I should have thought about that.

 

[FEENIX]

I guess that makes sense because Weatherby has said that the 7mm rpm in testing was pretty much 280ai. I should have thought about that.

As previously noted, the RPM has case capacity advantage. Below is my .270 AI next to 6.5 RPM.

 

[K.E.C. Darkside]

As previously noted, the RPM has case capacity advantage. Below is my .270 AI next to 6.5 RPM.
View attachment 622216

Big difference.
Would you have the case capacity for these two. Thanks.

 

[fmuguira]

Dang it… that photo makes me drool for a long barreled 6mm RPM to replace my 6-280AI ….

 

[FEENIX]

Big difference.
Would you have the case capacity for these two. Thanks.

I do not. If I have the time and remember it, I will do a quick H2O case capacity comparison when I get home.

 

[archeratlrg]

Bushing dies are being made f

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.

Bushing dies are being made for the 7mm RPM so you could pick up a set along with tge appropriate .277 bushing.