30BR reamer with .328 finish neck

[borderghost]

I am having a 30BR reamer made , I turned a bunch of the Lapua blue box 6BR brass to .010 and have noticed that a lot of the necks do not clean up . looks like it would take maybe a .001 more off to clean them up . is there any problem with making my reamer a .328 instead of the .330 that is common or just turn the extra .001 off and go with more clearance on the loaded round . any comments would be appreciated on this.

 

[bugman]

Before you start changing anything, are you sure these necks that don't fully clean up are really 0.010? I am not saying it isn't possible, but I have not run into any blue box that would not fully clean up at 0.010.
If you ARE correct, then I would not turn them all the way down to 0.009 because that .001 thinner neck would translate into .002 more in total chamber clearance.

 

[borderghost]

will check again , I use a PMA neck turner set at .010 from PMA with a carbide mandrel , will load some with just bullets and check loaded round , thx

 

['Freak]

“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.”

Shouldn’t all that be happening in a .30 caliber barrel (bore) and not in a barrel with a 6mm bore?

&&

“I am having a 30BR reamer made, I turned a bunch of the Lapua blue box 6BR brass to .010 and have noticed that a lot of the necks do not clean up . looks like it would take maybe a .001 more off to … ”

Are you turning necks still in their original 6BR configuration, or already mandrel expanded up to .30 caliber?

 

[gunsandgunsmithing]

“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.”

Shouldn’t all that be happening in a .30 caliber barrel (bore) and not in a barrel with a 6mm bore?

&&

“I am having a 30BR reamer made, I turned a bunch of the Lapua blue box 6BR brass to .010 and have noticed that a lot of the necks do not clean up . looks like it would take maybe a .001 more off to … ”

Are you turning necks still in their original 6BR configuration, or already mandrel expanded up to .30 caliber?

A few people are fire forming them in a 6mm barrel, yes. It works but I don't care for that method much, only because of the "possibility" of someone or some youngster..managing to close the bolt on a loaded 30br round. It wouldn't take much effort at all with light neck tension.

 

[SmokinJoe]

The best forming method I ever used was to chamber a worn out 30 cal barrel with a special reamer which was ground to give a 1.580 chamber OAL. I then loaded new 6BR Lapua cases with a very fast burning powder and seated a 1/4" poly ball on top. After firing, you end up with very straight cases with length of approximately 1.550 - 1.560. You then trim, run in your expander mandrel & turn. This yields the best 30BR brass you will ever make and gives you the option to chamber with a special reamer that has a 1.555 OAL, about .040 longer necks than you get using a mandrel to go from 6m up to 30 Cal.

Like Mike above, I was aware of the method whereby a special reamer is used in a 6mm barrel and a loaded 6BR round is fired to open the brass to 30 Cal, but I also had reservations about the advisability of doing it that way. Murphy is always in charge, you know.

 

[borderghost]

The best forming method I ever used was to chamber a worn out 30 cal barrel with a special reamer which was ground to give a 1.580 chamber OAL. I then loaded new 6BR Lapua cases with a very fast burning powder and seated a 1/4" poly ball on top. After firing, you end up with very straight cases with length of approximately 1.550 - 1.560. You then trim, run in your expander mandrel & turn. This yields the best 30BR brass you will ever make and gives you the option to chamber with a special reamer that has a 1.555 OAL, about .040 longer necks than you get using a mandrel to go from 6m up to 30 Cal.

Like Mike above, I was aware of the method whereby a special reamer is used in a 6mm barrel and a loaded 6BR round is fired to open the brass to 30 Cal, but I also had reservations about the advisability of doing it that way. Murphy is always in charge, you know.

I took a used 6ppc barrel and ran a 6BR reamer in , then took a .330 chucking reamer and ran it in till I have a OAL of about 1.560 , I could have went about .015 longer , I use a full case of pistol powder with a full neck of paraffin wax and fire , I am the only using this barrel for fire forming and have it well marked as that , ( to stay away from Murphy ) makes perfect cases with nice long necks , just when I am turning the necks to .010 they do not seem to clean up completely , still a few marks where the cutter has not reached , just wondered if this was normal or maybe the batch of cases that I have . Is there any harm to have a reamer with a .328 neck compared to .330 . would the necks be to thin at .326/.327
thx