Originally Posted by alcesgigas
I'm building an Edge on a M70 action. It's soon to be barreled and chambered so now's the time to address this conundrum: Some of the hand loads, admittedly from individuals as applied towards their specific rifles, show COALs up to 4.00. These shooters are no -doubt purposely loading to these over-COALs to set their (ULD, VLD) bullet ogives a tested length that shoots best in their rifle (s). Kevin Wyatt of Wyatt's states that 3.85 is max length for the M70 using his MBE-8 magazine box. Is it possible to begin the rifling at a shorter length than normal (unknown what SAAMI chamber specs are for the Edge) so as to work from this--3.80--COAL? I'm thinking that there's enough powder capacity to begin testing at the usual lesser-than--maximum and work up to similar velocities with the same bullets as say a "normal" COAL?
When building a rifle for a specific bullet you run the risk of it not liking that bullet and you are
I recomend chambering to SAMMI specs. and tuning the load to the rifle. I am one of those people that have no fear of free bore. In fact I like it because almost any bullet can be made to shoot
very well and pressure is not an issue so most of the time higher velocity is achieved because of it.
Accuracy is also not an issue with free bore as long as head space is minimum (.000 to .001)
I am in the process of testing a new cartrige and it has .100 thousandths of free bore and durring
break in it was shooting 5 shot groups .381 and after break in it had dropped to .171 5 shots @ 100
yards. These are fire form loads and and the cases are being expanded from 115 grains capacity
to 122.3 grains. (an increase of 7.3 grains) and these loads are magazine length( 3.810 COAL).
So my advice would be to chamber to a SAMMI standard and work up loads for the rifle.
J E CUSTOM