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BR case neck thickness?

Good morning,

I am looking to start spec'ing a reamer for a 6 BR variant and have not yet been able to get my hand on brass to measure. Through site searches here I have found posts with mic'd thickness from over 10 years ago Blue/Brown box Lapua. What I am asking for here is some more recent measurements based on the following for Lapua, Alpha and Peterson brass measured with a tube or ball micrometer:

Brand of brass?
Lot number, if available?
Smallest and largest thickness found in your sample?
What does the case head measure on new your brass? (I added this as an afterthought).

Please, and thank you, Dale
 
Last edited:
[QUOTE="RedfootRanch, post: 38611917, member: 1306168"

Brand of brass? Peterson
Lot number? N055B
Smallest and largest thickness found in your sample? 0.0121”/0.0129” Measured 4 pieces at 3 different radial locations using a Mitutoyo ball micrometer.
[/QUOTE]
This is what I am am looking for!!
I appreciate it, Dale
 
My thoughts also. However, I see where a lot of folks are saying that the new blue box lapua brass is thicker and requires a larger neck than .272.
My thought for what it is worth is you need your "variant" case WITH the bullet you are going to use, seat the bullet and get that measurement to get a true "loaded round" diameter THEN spec your reamer. JMHO
 
Al, is this using the newer Lapua brass? It appears that they are making the neck thicker (at least for the 220 Russian), I've not been shooting that long to give good info so I'll let the pros such as yourself handle it.
So far, the only brass I've seen a change in is the 220r brass. The latest 6br brass that I have is still the same as it has been for several years now...since the "change". I can't imagine how one would be related to another caliber unless they did an across the board change, making it all bigger. I seriously doubt that or any logic with that notion.

I guess ultimately, we are at their mercy but it wouldn't make much sense to change things without reason. The 6BR stuff was "updated" relatively recently. I guess it was time for the same on their 220 brass. Sometimes we are our own worst enemy, changing reamer dimensions to a number that likely has little or no benefit, in the name of being closer, when realistically, we are shooting ourselves in the foot for no good reason. I've never seen a chamber neck too big in terms of accuracy. Brass life, yes but not accuracy.

With the 6br, all was good for many years with a 272 chamber neck. Then for whatever reason, people started changing reamer specs around brass that was what, a half thou or so thinner, but with the same consistency? A thou loose won't hurt a thing. So lets not jump off of any bridges just yet.

The move toward no turn ppc stuff was done when the brass was thinner than the new stuff appears to be. The problem is some spec'd reamers around that brass and for minimal clearance. If we had all gone a thou bigger, I don't think it'd show on the target and we wouldn't be having this discussion. Lesson learned, hopefully.
 
Al, is this using the newer Lapua brass? It appears that they are making the neck thicker (at least for the 220 Russian), I've not been shooting that long to give good info so I'll let the pros such as yourself handle it.
I just received this from another source "virgin lapua neck wall thickness 14.5 tho. Just measured. I’ll reply later with the lot number, smallest was 13.5, average 14, largest 14.5"

He added later the Lot # "LPT00898" which is a different format than I have of any Lapua brass in my records.
 
My thought for what it is worth is you need your "variant" case WITH the bullet you are going to use, seat the bullet and get that measurement to get a true "loaded round" diameter THEN spec your reamer. JMHO
I do understand what you are saying completely. If I only had some brass to do this with! I haven't found a source the has Lapua brand available at this time. I got off the phone less than an hour ago with Alpha and I have a sample of their brass coming. I will contact Peterson Monday for the same.

Once I have this in hand, I can get a 'true load round' number.
 
My unturned Lapua 6br brass necks avg at .0126 Lot # PO1188206/1261919. What I done when I had Manson do me a reamer was to get the brass first then measure. Safest way to go and get enough of the same lot to run the life of your barrel. JMO
To Add I also have some virgin Norma 6br brass and their necks avg .0123.
 
My unturned Lapua 6br brass necks avg at .0126 Lot # PO1188206/1261919. What I done when I had Manson do me a reamer was to get the brass first then measure. Safest way to go and get enough of the same lot to run the life of your barrel. JMO
Thank you for the input numbers. They are right in line with those I have received from other's regarding Lapua 6BR brass with the Lot # beginning with "P".

I'm within 30 miles of Manson and I spoke with them earlier today. Ray is back from S. Africa and should be back in the shop on Monday. I expressed to Blake I'd hold off on sending them my preliminary hard numbers until I got the neck numbers sorted to save everyone's time.
 

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