.30BR outside neck diameter unturned?

S

sambubba1

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I am having a .30BR built and my smith is using a no turn reamer. What is the OD w/o turning? Also, I have 100 cases that have been turned to .324 from a .330 neck. Will these cases have split necks from firing with the greater neck expansion? I hate to discard 100 Lapua cases.
 
There is absolutely no such thing as a no turn 30BR unless you have found a source for factory made 30BR brass [NOTE- IGNORE THIS NEXT NONSENSE 7.62x39 Lapua brass maybe???? Probably uses large rifle primers. ETA later in the day -DOH. Wrong case :eek::p ]. If you neck up 6BR brass the outside of the neck looks terrible. The inside looks worse. This is why you must inside ream and turn the outside.

I am not that familiar with blowing out the cases from 6mm to 30 but it still ends up with a donut on the inside.
 
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Ray is pretty much right. As close as you will get to a no-turn 30BR is probably a chamber with .333 or .334 neck. Neck thickness varies significantly with technique used to expand from 6mm to 30 cal. I would advise you to have a detailed discussion with your gunsmith before any work is done. At a minimum, you will have to turn the necks to a uniform diameter (thickness) & get rid of the donut.
 
.30br

The smith said he ordered a "no turn", whatever that means to him. Ray, offhand do you know the OD of .30BR case necked up from 6mmBR before turning? I will turn them anyway. Thanks for the quick response.
 
Thanks for the replies guys. This is what I needed. I will use an expander die to prep before neck turning.
 
Here's a pic of a Lapua case necked up with a Redding tapered expander that measures .3065. An expander of a different dimension will obviously be.... different:

brcase.jpg


You can see the 'donut' at the base of the neck...this material used to be the upper part of the shoulder of the 6BR case. This 'donut' measures .335. The area of unturned case neck immediately ahead of the 'donut' measures .331. The case neck i.d. is around .3050 after expanding up. It's also not round and not parallel to the outer neck.

For what it's worth......... -Al
 
If Lapua offered 30BR brass I can't imagine what the response would be like. As good as the Savage 6BR's shoot just imagine a factory 30BR with a 17 twist?
 
sambubba1 said:
The smith said he ordered a "no turn", whatever that means to him. Ray, offhand do you know the OD of .30BR case necked up from 6mmBR before turning? I will turn them anyway. Thanks for the quick response.
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That just doesn't even begin to make sense. "Whatever" is term never used in benchrest. And you will turn anyway????? what will you turn to? and Why? all you'll be doing is adding slop to you cartridge fit in a "no-turn, tight neck chamber" The reason for a no-turn chamber is that it is fitted to the neck of a cartidge that is formed and not turned. In a fitted neck chamber, you turn necks to the size needed so that they fit is right in your chamber.

Paul


Al whats up,???

I think you posted the wrong picture... Looks like a WarewulffPup before fire forming????
 
Sam

I just necked up a Lapua 6BR, and seated a typical 30 cal match bullet that measures .3085 on the base. The neck measures .3315 to .3325, depending on the wall thickness variation of the originolcase.

If I was going to build a no neck turn 30BR, I would go no smaller than a .335 neck.........jackie
 
I am getting confused. I talked to him while ago and he said he ordered a reamer cut so necks wouldn't have to be turned; he did not want a tight neck reamer. I thought I read somewhere on 6mmBR.com that there was such an animal and one of the well known shooters was using one and winning matches. Maybe I am thinking of the 6BR. I turn necks on both my 22BR and 6BR. I use Sinclair's oversized expander mandrels/die before turning. What's the concensus, turn or not if it is not a tight neck chamber? I would think there would be uneven neck wall thickness. You guys have forgotten more than I will ever know about this stuff. Thanks for your replies.
 
I don't think there's anyway around turning the necks on a 30 br if nothing else to just cut the doughnut off
 
I tell you what I would do in this situation. I would go get my stuff and take it to somebody else.
 
I sure wish

sambubba1 said:
I am getting confused. I talked to him while ago and he said he ordered a reamer cut so necks wouldn't have to be turned; he did not want a tight neck reamer. I thought I read somewhere on 6mmBR.com that there was such an animal and one of the well known shooters was using one and winning matches. Maybe I am thinking of the 6BR. I turn necks on both my 22BR and 6BR. I use Sinclair's oversized expander mandrels/die before turning. What's the concensus, turn or not if it is not a tight neck chamber? I would think there would be uneven neck wall thickness. You guys have forgotten more than I will ever know about this stuff. Thanks for your replies.
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people would quit trying to "get by" and would realize there is a certain amount of "WORK" that has to be done to be involved in the real "Benchrest" game. No free lunch. Get off your butt and do the work.
 
.3365 is what I had one done at for an upcoming gas gun project. The case measures .334 with a 155 Lapua seated in it. If you're going bolt action I'd consider .336 by virtue of the brass having thick as well as thin areas in the neck. Hope that helps.
 
David Halblom said:
people would quit trying to "get by" and would realize there is a certain amount of "WORK" that has to be done to be involved in the real "Benchrest" game. No free lunch. Get off your butt and do the work.
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David, no one needs a SA answer to an honest question. If you read my posts, you would have seen I turn necks for the 22BR and the 6BR already. I had no info or experience with a "no turn" reamer which this 'smith has. Neck turning has always been a given--just trying to learn something new to me. Not all of us have the answers to everything related to benchrest.
 
Sam

For what it is worth, I have cases that I blew out to 30BR, (as opposed to necking them up with a mandrel), and while the necks look reasonably decent on the outside, there is the mother of all do-nuts about 1/8 inch up from the neck shoulder junction. This, of course, is taken care of with neck turning.

If you use any bullet of length, it would get into that do-nut...........jackie
 
Don't do it.

crb said:
I tell you what I would do in this situation. I would go get my stuff and take it to somebody else.
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I agree. When I ask questions, and I'm not getting the right answers, You do not want this guy doing your work, as you will be redoing it again. No matter how cheap it is, it's money gone down the drain.

I shoot a .330 neck 30BR and most others that I know that shoot 30 br's are shooting the same.
 
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Obvious

Ok lets just ask the obvious,
If the Smith "ordered" a reamer that is a no neck turn, that sounds more like the expanded dimensions of a SAMI chamber that is so large that ANYTHING will fit.

Ask the smith "EXACTLY" what the neck size of the reamer is. That is the obvious question to which all answers must be derived.

The ENTIRE reason we turn necks is to make sure that the case seats EXACTLY center or concentric to the chamber.

If the chamber is so big that it is like a SAMI chamber and NOTHING ever has to be turned then it can never be guaranteed to be centered when loaded.

However if you are not going to compete then it does not matter so much.
But if your going to compete you may have just shot yourself in the foot.
Just my 2 cents
 
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