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View Full Version : Fireforming 6BRX brass...why 107gr bullets?



Steelringer
12-08-2012, 12:58 PM
Howdy,
I am about to start fireforming brass for my new 6BRX rifle. Anxious to see how this rifle performs for me. I am familiar with the process, but have one question. I see it is generally recommended to load a 107gr bullet into the lands. Is it really necessary to use this weight? Why not say a 60gr 6mm bullet?; I have more of these less expensive ones on hand. Appreciate the feedback.
S

alinwa
12-08-2012, 01:12 PM
I always prefer to ff with faster powder, which means lighter (or no) bullets. IMO fireforming with 107's will give lesser quality results.

I have good reasons for my preferences and thousands of measured rounds to back them up. If you want to "KNOW," test it yourself.

Please publish the results here if you take the time to test.
al

Steelringer
12-08-2012, 01:21 PM
Al,
That has been my experience too when fireforming my 6PPC brass, and am pleased with the results.
S.

vtmarmot
12-08-2012, 07:52 PM
The theory on using the long bullet seated into the lands, is that it will not allow the force of the firing pin against the primer to push the case forward until the shoulder hits the end of the chamber before the primer ignites the powder. If that happens, the theory goes, the case walls will stick before the base of the cartridge is forced back by expansion, resulting in a pronounced ring that may cause early case head separation. I have also seen (but not tried) a recommendation to wipe the case lightly with WD40 before fire-forming. I suspect all this is not necessary in a match-grade chamber, but in a really sloppy chamber like the one in my Mannlicher Commemorative 6.5x54 it probably is worth considering. I fired 10 new Norma cases in that and the ring is quite noticeable. I am certainly going to try something else before I compromise any more cases. I don't know why they put such a sloppy chamber in a modern rifle. The freebore is so long, however, that no bullet known to man will reach the lands. Very strange.

JEFFPPC
12-12-2012, 08:52 AM
I load whatever left over 6mm bullets I have to fireform for my 6brx. I have a hundred ready to go right now, used some old Serria 80gr.Single Shot pistol bullets, same thing I used last year. I lightly oil the cases to allow the overall case to stretch, not just the web. Have had excellant results.Seat the bullet out so it engages the rifling so when the firing pin hits it the primer ignites instead of the case just pushing forward in the chamber.

Steelringer
12-12-2012, 01:27 PM
Thanks for the info. guys. I understand the theory behind the process. My lighter bullets reach the rifling, so was thinking they should work as long as there is resistance for the cartridge to move. I'll keep the lightly lube idea in mind a well. Thx. I see that Hornady make a hydraulic forming die. Might just try that and compare both procedures. Just acquired a Stiller in 6BRX thru my friend LeftT :) and anxious to start on trial loads.

alinwa
12-12-2012, 10:59 PM
OK OK, some stuff....

#1, seating bullets long WILL NOT ensure consistent cases, altho it will oftentimes aid in ignition if headspace is over-long. "Seating long" DOES NOT hold the case back from the fore of the firing pin.

#2, oiling cases is a poor fix for a real problem, the problem of an over-long chamber. Lubing also WILL NOT "fix" the problem altho it will make longer cases first go-round and in extreme cases can avert a head separation.

The correct way is to set your cases for a crush-fit for fireforming.
al

JEFFPPC
12-13-2012, 09:27 AM
By "crush fit" I think you are referring to creating a false shoulder??? You may be correct, I do not know. What I do know is that to me the "proof is in the pudding" so to speak. I have used the above described method in several rifles over the last couple of years to the tune of around 1000 cases and have not lost 1 case .Are the cases consistent? Don't have clue, but I win. All I care about.Some of these cases are approaching 20 reloadings and still going strong.Some times there are more than one way to skin a cat.