30BR Bulge

[Doublejake]

What are you using for a full length bushing sizing die? Have you checked the neck run out before seating a bullet? -Al

It’s a custom Die by Sid Goodling.

 

[Rodney]

The lump, I assume you’re referring to the donut formed at the neck shoulder junction, will be cut away when turning the neck. If your neck is .0105, not sure how you are getting a loaded round dimension in the .326/.327 range. You should be around .329 or more. I noticed the bullet looked like a nosler varmageddon. Make sure the ogive makes good contact with the seating stem which will help keep things straight. I could be way off base, but just trying to help. I make my own 30BR brass myself and it’s not that hard once you get the process down. I actually used some peterson 7BR brass for my last batch and it’s working great. Peterson makes 6BR also. Might be easier to find than Lupua at the moment.

 

[wildcat3d]

How would one address the lump?

 

[Doublejake]

Do you have the part number for that? So it’s a 30 mandrel for the KM that will also Cut out the bulge on inside?

View attachment 1458763View attachment 1458763

 

[AlNyhus]

How would one address the lump?

When manually expanding, here's how I do it. After expanding to .30, the neck O.D. on a Lapua 6BR case is going to be right at .330...depends on the size of the expanding mandrel, of course. But let's use .330 as an example. The 'lump' is going to be right at .337. The first thing I do is straighten the neck.

-Use a bushing in your f.l. die that's .003-.004 smaller the the expanded neck O.D. of a case. If it's .330, use a .327-.326 bushing for example.

-Now size the case right up to the lump. You can adjust the lock ring, use die shims or a spacer of some sort under the bushing to do accomplish this. I use an 'o' ring under the bushing. What this step does is straighten the neck relative to the case body.

-Now expand the neck using your original expanding mandrel. The neck will be straight to the case body.

-Next I turn off the 'lump'. With .007 to turn off (.337-.330=.007) you can do this in one step. Adjust the cutter so you're not cutting the neck...better to leave a little 'lump' than cut into the neck. Don't worry about blending the cut on the 'lump' into the shoulder perfectly...this will be done in the neck turning process.

At this point, I'm ready to turn the necks. I don't do any math for neck thickness and have no idea how thick my 30BR necks are. All I want to know is what the neck measures across the base of a seated bullet. For clearance, .0025-.003 is what I use. I 'lead' the clearance by .0005 initially as they will thicken about that much after half a dozen firings or so. Then they'll settle down and not move. I've gone all the way to .004 clearance in testing with no loss of accuracy. Anything under .002 is not where you want to be with these .30's.

When turning, I use a plastic bowl large enough for my neck turner and fill it with rubbing alcohol. When a case comes off the turner, I put the turner into the bowl. This keeps the temp consistent. With a small soldering flux brush, the brass gets removed and dab of lube goes on the mandrel. Rinse and repeat.

After they're done, I stress relieve ('anneal') the neck/shoulder area and f.l. size them with a bushing .004 under what the neck with a seated bullet measures.

Having done literally hundreds and hundreds of 30BR cases over the years, this works for me. Other methods are good too. With this method, I can immediately do load work from the first firing.

Hope this helps. -Al

 

[wildcat3d]

Do you have the part number for that? So it’s a 30 mandrel for the KM that will also Cut out the bulge on inside?

No part number just this on their website,

• Add ".30 Cal Carbide Cutting Pilot" for$54.10each
  In stock
  .30 Cal Carbide Cutting Pilot quantity

 

[Doublejake]

When manually expanding, here's how I do it. After expanding to .30, the neck O.D. on a Lapua 6BR case is going to be right at .330...depends on the size of the expanding mandrel, of course. But let's use .330 as an example. The 'lump' is going to be right at .337. The first thing I do is straighten the neck.

-Use a bushing in your f.l. die that's .003-.004 smaller the the expanded neck O.D. of a case. If it's .330, use a .327-.326 bushing for example.

-Now size the case right up to the lump. You can adjust the lock ring, use die shims or a spacer of some sort under the bushing to do accomplish this. I use an 'o' ring under the bushing. What this step does is straighten the neck relative to the case body.

-Now expand the neck using your original expanding mandrel. The neck will be straight to the case body.

-Next I turn off the 'lump'. With .007 to turn off (.337-.330=.007) you can do this in one step. Adjust the cutter so you're not cutting the neck...better to leave a little 'lump' than cut into the neck. Don't worry about blending the cut on the 'lump' into the shoulder perfectly...this will be done in the neck turning process.

At this point, I'm ready to turn the necks. I don't do any math for neck thickness and have no idea how thick my 30BR necks are. All I want to know is what the neck measures across the base of a seated bullet. For clearance, .0025-.003 is what I use. I 'lead' the clearance by .0005 initially as they will thicken about that much after half a dozen firings or so. Then they'll settle down and not move. I've gone all the way to .004 clearance in testing with no loss of accuracy. Anything under .002 is not where you want to be with these .30's.

When turning, I use a plastic bowl large enough for my neck turner and fill it with rubbing alcohol. When a case comes off the turner, I put the turner into the bowl. This keeps the temp consistent. With a small soldering flux brush, the brass gets removed and dab of lube goes on the mandrel. Rinse and repeat.

After they're done, I stress relieve ('anneal') the neck/shoulder area and f.l. size them with a bushing .004 under what the neck with a seated bullet measures.

Having done literally hundreds and hundreds of 30BR cases over the years, this works for me. Other methods are good too. With this method, I can immediately do load work from the first firing.

Hope this helps. -Al

Thank you