6CM and the Doughnut

[hoverp]

does the 115 DTAC or the 107 vld class loaded to magazine length avoid the neck shoulder junction, i.e. the doughnut on the 6CM like the 6XC does?

just curious...not trying to start a war!!!

 

[mikecr]

Wouldn't it completely depend on YOUR magazine length?

 

[hoverp]

Ok, with that said, let me rephrase my question. For the guys shooting the 6CM in Highpower out of bolt guns does your magazine allow bullet seat depths that keep the full diameter of the bullet (in the longer VLD class of the 6mm) to NOT be in the neck shoulder junction?

Yes or No and what rifle are you shooting. any T2K owners out there shooting this round?

Thanks

 

[rcw3]

With a 6CM, at a normal 2.8" - 2.840" short action magazine length, even a Sierra 107 will have some of the bearing surface back in the case, and with a 115 DTAC, you will have about .070" more of the bearing surface back in the case.

Now you are using the word "donut" as if it's an accepted fact that there must be a "donut" in the brass at the base of the neck and shoulder junction. I cannot accept this as true and correct that there is always a "donut" there, as that depends on such things as what brass you use (at least is does with my 6CM). If I use Winchester brand .243 Win brass to make it, there is virtually no donut, but with Lapua brass there's a big donut.

Robert Whitley

 

[Dgd6mm]

Robert is correct, no donut with Winchester Brass. You will have a donut with Lapua Brass.

 

[rcw3]

FWIW - I also shoot the 6mm Super LR that I made up, and if you run that in something like a Tube Gun using the Accuracy International magazines, you can go around 2.880" magazine length. With the 6mm Super LR if you are over around 2.860" with a DTAC 115, the full bearing surface of the bullet is up in the neck of the case, so you can run them magazine length and all be up in the neck of the case with the bullet. The 107 Sierras are all up in the neck of the case at around 2.800" OAL with the 6mm Super LR so that has no issues keeping within a typical short action magazine length and keeping the full bearing surface of the bullet up in the neck of the case.
http://www.6mmar.com/Super_LR.html

Robert

 

[hoverp]

Thanks guys, I just wanted to know how the round was set dimensionally on this particular point.

 

[HPMike800]

Actually being able to fire 107's at 2.800 OAL is a very nice feature of the Super LR. I have a 0.090 FB chamber and depending how I set the bullet, there is little if any full diameter in the case.