FIRE FORMING 6BR TO 30BR

[borderghost]

Looking for some information on fire forming 6BR to 30BR. I read that guys are using 6mm barrels and putting in a 30BR chamber , then firing the round loaded with a 6mm bullet. can you use pistol powder and a wax plug to form the cases , do you have to make the 30BR neck longer with a reamer to allow the brass to flow forward, would this method get rid of the donut caused by the shoulder junction of the parent 6BR case, is there any advantage to having a longer neck this way compared to sizing up with a mandrel and removing the donut .I am ordering prepped brass from a member on here , but would like to make my own with this method if it is a good method , I do have a lathe and reamer for 30BR , have just purchased a BAT action and have a carbon fiber stock ,and 2 new barrels , winter project to have this BR for next spring. any infor on this subject would be great.
Thx

 

[GeorgeSpringer]

I size 6BR Lapua brass with a tapered expander (K&M) neck turn due to the .330" chamber neck, load and shoot them. I neck size the fired cases to .324 and trim to length and continue to shoot them. YMMV but this works for me. GS

 

[gunsandgunsmithing]

The method of necking up won't do away with doughnuts. They are a result of the thicker brass in the shoulder becoming part of the neck when it's expanded up. They can be minimized or even eliminated when neck turning by turning slightly into the shoulder.

 

[dedogs]

I've had best results with gunsandgunsmithing's method but I would add that I make sure the bullet is jammed (.010) when fireforming. I also lube the cases very lightly with light synthetic oil. YMMV. dedogs

 

[Dusty Stevens]

What will the donuts hurt? I neck up, turn, and fireform with a jammed bullet- usually foulers at a match. Not sure if I have donuts or not (could care less)

 

[dedogs]

Dusty is right about the donuts probably not causing any concern as you will probably never seat the bullet anywhere near the donut. For myself I take them out with a K&M inside neck mandrel. Cant say it helps as I have never compared them to cases with the donut left in.dedogs

 

[JarheadAZ]

My smith made me a no-turn 30BR barrel by chambering it with a 6BR, then cutting the neck with a .30-'06 reamer. We were trying to get a 30BR out of a contract overrun/cull M-14 barrel that cost us nothing.

The barrel successfully chambered and fired 30BR ammunition, but it never was a star. There was concern about donuts, and issue was addressed by partial length neck resizing, leaving the suspected donut region fully expanded.

The fired brass/primers exhibited no high pressure indicators. It was believed that the expanded portion of the neck provided a better centering effect on the chambered round's neck. The cases were necked up with a homemade two-step expander mandrel.

The rifle was fired with 125gr SMK's, 125gr Pro-Hunter, and 135gr SMK's. It demonstrated acceptable hunting level accuracy, but was not competitive. Scoping the bore revealed awesomely atrocious tool marks.

Greg

 

[P1ZombieKiller]

or do it this way and save powder and bullets. While not perfect for your chamber, you can most certainly fire form them in a single firing as foulers in a big match or shoot in a small club match and fire form them all in one day.



https://youtu.be/6s2CPnJkFxw

 

[JarheadAZ]

My fireforming takes place as the first loading cycle in the brass' intended use. I don't see any real value to not putting the brass into use as soon as the case attains the proper configuration. My brass' accuracy rarely varies from the fire forming to the next loading. IMHO, the case fully expands to conform with the chamber well before the pressure curve reaches a peak. If I'm wrong, then I'm wrong. It's still practice. Even then my next loading cycle is performed on fire formed brass.

I appreciate the quest for perfection. But I don't lose sleep over imperfection since it seems to be the prevailing condition anyway.

Greg

 

[P1ZombieKiller]

My brass' accuracy rarely varies from the fire forming to the next loading.

This maybe a true statement depending on your "PURPOSE" for the caliber. For my hunting 308, I would not hesitate to put brand new brass and stuff it with my receipt, and take it to the field and hunt deer. After all, it just needs to shoot "MINUTE OF DEER".

However my 30br (as with most of my customers) is a benchrest caliber. While others may not use their 30br for the same purpose as I do, most of my customers demand perfection.

When a brand new "constructed" 30br case is created, it is not "properly formed" to your specific chamber. It is close.... sometimes very close, other times not. It all depends on your specific chamber.

While I have taken new virgin 30br cases and shot them in local club matches, they shoot "good enough". My expectation for those cases are not the same as those I have completely fireformed.

My fireformed match brass needs to shoot "MINUTE OF 10X".

When you expect your gun to shoot groups .100" then you need the best of the best. When you expect your gun to just hit paper.... then you don't need to put as much time or effort into things.

 

[Scarab]

I would be a little bit careful jamming a bullet in a virgin 30br case, many times i have found that using the K and M expander will leave the necks off center with the body of the case a significant amount. Out of the 1000+ 30br cases i've made i have had 18 of them pierce a 205 match AR primer, 3 of them stuck in the chamber and one i dont want to talk about!!! I now jump my virgin br cases with the front 1/2 of the case lubricated to allow the brass to flow and resize in the chamber with out sliding back and smashing the bolt face.

 

[JarheadAZ]

We were experimenting with a .30 cal chambering in order to evaluate the effect of the larger diameter on a for-score target. The barrel and chamber were far from ideal to begin with. COF was 40rd for score on four bulls at 250yd, with bench and prone scored separately in a semi-sorta-F Class format. This was a club match with no outside certification.

As mildly suspected it was never gonna be a a producer of screamers, so some of the more extreme efforts were spared. Appropriate expectations were realized with no shed tears. The predominant emotion was some sincere gratitude toward a couple of friends who donated their skills and time to a duffer like myself.

So I ask some leeway in judging such efforts against full blown BR accuracy expectations. Even so, the barrel and brass performed at about 5 points shy of a winning score of around 197 out of 200. It was competing against everything from factory varmint rifles up to and including BR built custom 6.5x47's and various flavors of 6BR.

The experiment failed, and the rifle's previous 28" L-W drop-in 260 Rem Long Range barrel now resides where the experiment once rested.

For deer, I use a Mod 70 .30-'06 I bought used in the mid-1990's, which took 4th in the NJ State Sniper Matches in 1997; more than good enough for the likes of me.

Greg

 

[danyboy]

I made a 12ga x 30 BR insert. Fill 6BR brass with 10 gr. of Unique, cream of wheat to 1/8"-1/4" from edge of neck, neutral shoe polish to cap it off. Small Winchester pistol primer. Shoot in a 45 gal. plastic barrel in garage. No inside donut this way as opposed to using k & m expanders plus hardly any runout, couldn't be any more concentric.

 

[762plinker]

to a SEVEN year old thread wow

 

[JEFFPPC]

I would be a little bit careful jamming a bullet in a virgin 30br case, many times i have found that using the K and M expander will leave the necks off center with the body of the case a significant amount. Out of the 1000+ 30br cases i've made i have had 18 of them pierce a 205 match AR primer, 3 of them stuck in the chamber and one i dont want to talk about!!! I now jump my virgin br cases with the front 1/2 of the case lubricated to allow the brass to flow and resize in the chamber with out sliding back and smashing the bolt face.

Not sure I agree. The case dry will expand and grab the chamber walls, not smash back. A lubed case will not grab the chamber walls.

 

[LVLAaron]

to a SEVEN year old thread wow

 

[Scarab]

Not sure I agree. The case dry will expand and grab the chamber walls, not smash back. A lubed case will not grab the chamber walls.

A lot has changed in seven years! I now could care less and shoot fire forming rounds for score

 

[wildcatter]

For me a lot has changed in 3 years for my fireforming methods.

I no longer waste bullets powder and barrel fireforming any brass. I use bullseye pistol powder, corn cob polishing media that's old, and bar soap to cap the load.

I use 14 ish grains for my 6 and 257 Ackley brass, 4 is grains for BR and PPC size cases. I create no heat firing off dozens of rounds, keeping the barrel cool.

I believe I am smoothing any roughness in barrel from machining very gently using the polishing media which is gentle on brass and harmless to steel.

I don't wast my bullets or over stress any brass doing this. It has worked great, and for any body expanding or neck expadding on new brass the way I will go forward from now on.

Neck turning will be done after forming and is much more accurately done in this order. I also use the K&M turning tool with the inside carbide dognut cutting mandrel.

Simply neck downs of a parent case I will simply use dies in small incriments to get the job done. Then determine the amount of neck turning needed as the necks thicken as they are reduced in diameter.

Never ending change thru the years has improved and made my loading techniques not only more efficient, but easier year after year. Thank th Lord I don't use the procedures I did 7 years ago, let alone decades ago!