Bushing die question

[MOShooter]

Going to pick up my new bushing dies for my 6br tomorrow. For now I'm going to shoot new Lapua brass and not turn the necks. How do I determine what size bushing to get? What is the standard size of a non bushing 6br die? I bought the bushing dies with the hopes of turning neck at some point. But for now I want to keep things simple and not get in above my reloading skill level. I've read on here about measuring loaded rounds but I don't have any. Also with out turning the necks can I run that tight of tolerance?

Sometimes all these small details makes my head hurt.

 

[Immike]

I just happen to have a box of Lapua 6mm B.R. Norma brass. I checked out 2 cases and it was .013-.014 neck wall thickness. I don't have a 6br die to seat one but my best guess is. 13.5 x2 +243 = .270 The question I have is this a custom chamber and will that fit?

 

[22BRGUY]

Would suggest you buy a ball micrometer to measure the brass neck thickness for yourself on one side of the neck; multiply that number by 2 and add it to your bullet diameter (.243). That would be your loaded round neck thickness. Most shooters want at least a .002 clearance on all sides of the loaded round neck thickness for safety. Then find the actual chamber neck dimension from either the rifle manufacturer or the gunsmith that chambered the barrel and see if you will have safe clearance.
Best Wishes

 

[Lapua40X]

My 6BR Norma brass comes out of the box at .270. I'm currently sizing them with the .266 die and it's working fine. But your chamber neck dimensions may not be the same as mine so you'll need to do some analysis before making your decision.

 

[snakepit]

I use no turn Lapua 6BR brass. My numbers are: .266 bushing, .268 neck with bullet seated and .270 neck with a fired case. My recent reloads have been with a .267 bushing with the results being about the same as the .266 bushing. I have a standard Savage chamber. I jump my bullets.

 

[mikecr]

I've read on here about measuring loaded rounds but I don't have any

Seat a bullet in a case and cycle it through your chamber to make sure you have clearance. Measure this loaded neck, pick a bushing 2thou under it to begin.

 

[Milo 2.0]

I have a no turn chamber myself. I bought a .263 bushing at the recommendation of my smith, was upset when I measured my first dummy round, it was .2695 or so. I bought .266 & .267 bushings. Using either one of those I felt no tension seating a bullet, could literally keep seating the bullet deeper with the micro seater. Sold both of them, now I run the .263, just feels better, and no pressure increase from more tension, accuracy still there too.

 

[MOShooter]

I don't have the rifle yet. If all goes as scheduled I should receive it in the first part of Jan. It is a prefit criterion. I sent them an email asking some questions, about 3 weeks ago, and never got a response. I am want to get all of my brass prep done before it arrives.

 

[MarTay6]

I'm kind of in the same situation... have a Brux barrel being chambered in 6.5 Creedmoor at SSS, all I know is that their chambering reamer is a PTG reamer.... so I'm kind of stuck until I get the barrel, finish up the gun and can shoot some factory ammo through it, I guess.
Wes

 

[DCRYDER]

The neck diameter of the chamber has nothing to do with the resizing bushing. The loaded 6br blue box neck should measure around .2685, so a bushing around .266-.267 should be fine. If you turn your necks then you would need a smaller bushing.

 

[Area Man]

It has been my practice to run the Sinclair mandrel that came with their neck turning kit in and out of the neck before the first loading. This gives good neck tension for the initial loading and then you will have loaded rounds (and soon fired cases) to check dimensions. My mandrel measures 0.241".

 

[LCazador]

Use a ball micrometer to measure neck thickness if you have one. If you don't have one and you intend to neck turn in the future, it would be a sound investment now. Like some one said earlier, if you don't have a loaded round, measure the neck thickness multiply by 2 , then add your bullet diameter. From this subtract 2-3 thousands for proper bullet tension, to choose your bushing. If you have brass that runs 13-14.5 in thickness, use the lesser thickness to select your bushing, other wise you will not have enough bullet tension to hold bullets properly with the thinner necks. You'll have more tension on the thicker necks, something you deal with in a no-turn chamber. When you decide to neck turn, work with the thicker dimension first. In other words work from the .0145" dimension to slightly under the .013. Don't cut more than .0015-.002" at time, otherwise you'll loose the thickness consistency you are neck turning for! Standard dies oversize the neck, some as much as 8-10 thousands under! Ask for your chamber dimensions, regardless of who made the reamer, there can be many variations. You can also request a blue print of the reamer used, for your records.

 

[22BRGUY]

The neck diameter of the chamber has nothing to do with the resizing bushing. The loaded 6br blue box neck should measure around .2685, so a bushing around .266-.267 should be fine. If you turn your necks then you would need a smaller bushing.

This statement is absolutely correct but the OP did not mention if the rifle is a factory built or custom or new or old. I purchased a used 22BR at one point and did not know it had a tight neck .246 chamber. Had I not done chamber casting I may well have had an unsafe situation and I definitely had to turn necks. This case may well be different, don't know. Just trying to be on the safe side first.

 

[MOShooter]

It is blue box brass. I've got 200 pieces so it will take me a while to cycle through them. It's took about a year for us to go through the same number in our 308. After 3 firing I might send them off to be annealed.
The barrel will be chambered by the factory. I will try to contact them again for reamer specs. It would be nice to know the free bore.

 

[MOShooter]

Just as info. I called whidden gun works today. Their non bushing dies have a 263 neck.