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Seater die for 6BRA question

I’m just getting into the 6BRA and have seen some are having Harrell dasher dies cut down. I have a 6BR seater die and my question is can it be used to seat bullets in the BRA without any mods? I’m having a sizing die made.

Thanks for any help,
Jeff
 
The first time, yes. After fire formed, no. You’ll need a Dasher die, or something custom.

I had Sinclair drop shop a 6MM Wilson blank to a smith to “chamber”.
 
If your 6BR seater is the Wilson in line type it can be altered easily by the smith that has the reamer. If I remember it only takes .020" or so to get a fireformed case in there correctly.
 
Forster will modify one of their Dasher seaters for you. I had a friend do mine, a little differently. He took .090 off of the bottom of the sleeve so that the case pushes it up rather than the shell holder. Last night I used it to put together a dummy round that had a total runout of a little over a half thousandth, measured about .150 out on the bullet. Of course this would not have been possible if the sized case had not been very straight. That is another story.
 
I have it. I know Alex posted it in one of the threads, If you do a search i am sure it will pop up. I don't know how to get it to you via the computer. Sorry....
 
A standard Dasher inline Wilson seater will do the job with no modifications.. a fair few BRA shooters are using it.
 
Forster will modify one of their Dasher seaters for you. I had a friend do mine, a little differently. He took .090 off of the bottom of the sleeve so that the case pushes it up rather than the shell holder. Last night I used it to put together a dummy round that had a total runout of a little over a half thousandth, measured about .150 out on the bullet. Of course this would not have been possible if the sized case had not been very straight. That is another story.

What kind of runout were you getting from the Forster die before you modified it?
 
The die would not have fit the case if it had not been modified. It was made for a Dasher. I am using if for a 6BRA. Shortening the sleeve the additional amount so that the case pushes it up rather than the shell holder was a modification that I had suggested to a friend for a Redding competition seater, that imporoved runout of the loaded rounds. It puts the taper of the case body a little farther into the internal taper of the case, improving the fit. We did other things as well. One thing that I tried for this use was to set the die so that the ram could not go all the way to the top of its stroke, in an attempt to have better ogive to head of case consistency, but one dummy round is not enough to evaluate that. For the Redding seater, we set it to have the shell holder make contact with the bottom of the die body, enough for a very slight toggle. That is contrary to the manufacturer's instructions. I spoke with Redding and I think that their concern is that the body is not hardened and that customers might deform it by using too much toggle. We kept that in mind. There have been no problems.
 
The majority of guys that are using a BRA now had a dasher before so they are using unmodified dasher seating dies, as am I. I do not feel that the seating die is that important to runout. That comes more from sizing IMO. So quick and easy, just order a dasher seater. Or get a blank and have your smith ream it with the chamber reamer. He can also ream your BR seater. Whidden does have a copy of my print, which is similar to every other BR AI out there so if you like a threaded seater they can do it. Or like Boyd said, cut off the bottom of a dasher seater if you want a closer fit. A BRA/BRAI has its shoulder back .080" from a Dasher.
 
The die would not have fit the case if it had not been modified. It was made for a Dasher. I am using if for a 6BRA.

I'm using an unmodified Forster Micrometer Dasher die for seating 6 BRA. The brass fits, it just has space in front of the shoulder when seating a bullet. I was thinking of having Forster make me a new sleeve for the die.
 
What ever works for you... I know that the seater is not as important to concentricity as the sizing process, but my tests have shown that the modifications that we have done do have an effect. I will admit that BT bullets are less of a problem to seat straight. Last night I put a stock BR case in the modified seater and it fit just fine. By having the case push the sleeve, the the sleeve's shoulder angle centers the case's shoulder quite positively at the neck shoulder junction. The sleeve was cut off .090 to create a little clearance between it and the shell holder when there is a case in place. Of course you would not cut this much off of a Wilson Dasher seater. The mods that I mentioned were developed for flat base bullets in a PPC but there was no reason not to incorporate them for any application of a seater that has a full length sliding sleeve held down by a spring. Of course trimming the seater was simplified by my having a friend with a lathe, who builds rifles, shoots this caliber, and likes to try new stuff.
 
Got a dumb question on this process....

So when the brass lifts the sleeve and the seating stem is pushing the bullet won’t the seating depth be determined by your sleeve now and the consistency of your shoulders ?

Vs
Having the shell holder push the sleeve and base of rod and seating stem determine you BTO seating depth ?

Reason I ask is when sizing I get .001 variance in the shoulders (most times) and now my seating depth will fluctuate that much also

Or am I being to OCD ?
Or should I not get any variance in the shoulders?
 
Having the shell holder push the sleeve and base of rod and seating stem determine you BTO seating depth ?

The sleeve rides independently of the seater stem which does not move. The shell holder to stem distance determines seating depth. The sliding sleeve is just there to align the brass so the question is what approach aligns the brass the best.
 
I'm using a Redding 6BR Competition seating die for my 6BR Ack Imp. It works just fine. The base to bullet ogive never varies more than .0005 and my maximum bullet run out is less than .002. Don't know about other seaters but this one works perfectly . Maybe it's because of the sliding sleeve.
 

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