Whitleys 260rem 30 degree improved

[BradY]

Correct me if im wrong, but I think the headspace works off the middle of the shoulder. So standard 260 is steeper angle but longer where this is shorter and sharper shoulder would work. That would be the only way I can see regular 308 NO GO and GO gauges would work.

 

[daj]

I agree. The headspace datum must be unchanged from the std 260, 243, 7-08 & 308 etc. for the 308 GO/ NO GO gauges to work, but the longer neck of the Improved 30 has to come from the shoulder. Does this forming happen during chambering of the factory brass/ammo?

 

[Raptor]

It would happen when you fire the case, it will then conform to the chamber.

 

[daj]

Raptor, if you superimpose the two case designs on a sheet of paper you will see that a std case will jam in the Imp 30 chamber at the neck shoulder junction. If you could fire this std case in this position, yes it would conform to the chamber just like forming the 260AI case. However, the case is too long to fit the chamber without some sizing of the shoulder into a longer neck.

Hopefully Robert will explain how and when the "slightly longer neck" is formed.

 

[rcw3]

If you use true "to scale" drawings you would see how factory 260 Rem brass goes into a 260 Imp 30Ëšchamber and comes out after firing with a slightly longer neck. A good picture is worth 1000 words but I don't have scale drawings to illustrate it and I am not game to post 1000 words on this subject although I know it to be correct since I do it every time I pull the trigger on a fire forming round.

Robert

 

[daj]

Thanks Robert. I didn't doubt for a second that it works as you claim ( I bought your sizing die and ordered a reamer a few weeks ago). I just could not visualize how you get the longer neck.

Do I need to be more alert for donuts with this design than with the std 260 in Lapua brass?

 

[jcampbellsmith]

I have the 40º version and have chambered several rifles with it. So far, no complaints. .....

A question, how well do the rounds feed from the magazine/floor plate? Thanks JCS

 

[rcw3]

Thanks Robert. I didn't doubt for a second that it works as you claim ( I bought your sizing die and ordered a reamer a few weeks ago). I just could not visualize how you get the longer neck.

Do I need to be more alert for donuts with this design than with the std 260 in Lapua brass?

I have not had issues with donuts with Lapua brass. Make sure a standard 308 Go Gage goes in the chamber easy (i.e. not a jam fit but not swimming in there either) and have whoever does your barrel then double check things with some new factory Lapua 260 Rem cases and make sure they go in easy (jam fit not necessary - but not swimming in there either).

The fire forming process also tends to pull the neck brass back slightly and pull a potential donut away from the neck/shoulder junction - so that's a good aspect of the forming process.

I also used a .090" radius at the junction of the neck and shoulder to leave a little more clearance there to help avoid potential donut issues (i.e. normal Ackley type chamber has a smaller .060" radius there).

The two barrels I have were done up as noted above and I have not seen any donut issues with using Lapua brass.

Good luck - you're bound to have fun with the cartridge - I sure do - I like it a lot - and the right fire forming loads using factory brass shoot very well and feed superbly too so you don't feel like your just burning up the barrel fire forming brass, you can do some real shooting with it while forming!

Robert

 

[Raptor]

Robert,
Have you tried preforming a case in the 260 30degree die as you do with the 6SLR and then shooting it in your rifle?? Or is this something you don't want to do??

Just curious if it would be more like shooting a load in a "Formed" case as in the 6SLR. Thanks!!!

 

[BradY]

Again correct me if Im wrong but the 6.5SLR is headspaced differently so that dimension case would be loose in the chamber where as the headspace for a standard 260 wouldnt be. Honestly, Robert is the one with the experience so if he says load standard 260 and shoot then I reckon he might have it right.

 

[daj]

Thanks for the handy tips and info, Robert, and thanks for coming up with such a great design. My 6.5x47L and 260R were great shooters but the Imp 30, for my money, has to be the best balanced S/A 6.5 out there. I'm looking forward to running it.

 

[nellie]

has an one got diagram of a 6.5-308 habu 30degree shouders I have rifle cambered in it but have no reloading resizing dies

 

[joejo]

has an one got diagram of a 6.5-308 habu 30degree shouders I have rifle cambered in it but have no reloading resizing dies

i have a diagram. let me dig it up. pm your email and i'll send it to you.