Question About 6mmBR Norma vs. Remington

[GSPV]

Sometimes you need a small base die even with everything aiming for nominal 6 BR Norma dimensions and Lapua brass. I've got one. Had to go to the SB die. It's just a small chamber. Shoots great. Don't want to take a chance on rechambering

 

[GSPV]

If Remington is chambering it they still would have the 6 BR REM reamer that they made their 40X in. Jim Stekyl who worked for REM invented it shot Benchrest with it. I would want to make absolute certain what reamer they used. Longer brass in a short chamber wouldn't be good. Sorry but If it was mine I would want to be absolute certain. Matt

They are telling him that it's for Lapua brass. At that point, you have exactly the same confidence that you have coming from any other gunsmith.

And, of course, all the same double checking that you should do when any other gunsmith chambers a barrel for you is still called for.

 

[expiper]

we are all on the same page,,,just trying to save the OP some grief $$$$....it is amazing how many gunsmith$ say the reamer is for such and such brass or bullet (FB) when they have no reamer drawing,,,I always insist on a reamer drawing/print when dealing with PT&G (Kiff),,,,that way there is no confusion on what you have,,,,I think that every reamer that is shipped should have the print right in the box with the invoice,,,they had to tell the machine what to grind,,,they dont mind telling us how much we owe,,,,Roger

 

[rkittine]

I am going to send the Custom shop some Lapua Brass and I might take a ride up there when the weather gets a little better. Getting them on the phone is extremely hard. They did tell me not to waste my time looking at what is on the web site, which only shows this model in 6mmBR Remington and only with 1:12 or 1:10 twist. I e-mailed them and asked for a spec sheet showing that it is 6mm Norma BR along with confirming the other specs that we went over.

What would it cost me to get my own reamer? Would want it for the future anyway. Based on their back-log I have time.

Bob

 

[GSPV]

Reamer is $138. You'll also want a go gauge. With shipping and everything less than $200, I'd guess.

 

[jde650]

I have the berger loading manual. This is their quote. The 6mm Remington BR and Norma BR are exactly the same case but the Norma chamber is cut to allow for heavy long VLD bullets. Thus Norma will not chamber in the Remington 6mm BR because of the longer VLD bullets not the brass.
The base of the Norma brass is 0.4709, Base of Remington brass 0.4703. Both should be trimmed to 1.550.
I have a Norma 6mm brass I measured-brass length at 1.557.

Looks like most everybody is well informed according to Berger manual.

Jim

 

[GSPV]

The issue here is that no one knows the real dimensions of the chamber in Bob's current barrel nor of the reamer that the custom shop proposes to use in the replacement.

You can say 6 BR Remington, you can call it a 6 BR Norma, or you can call it George. it doesn't address the real question.

 

[jrm850]

This is an excerpt from a post on this topic a good while ago. I still have that original 6br reamer which is too small at the base for Lapua Brass. Y'all can take from it what you want.

The Lapua Brass is almost a full .002" fatter at the base than the fired Norma Brass and will not fit in my old bench gun chamber. In the attached photo the lapua brass is the one in front and you can see the scuff marks where I tried to press it into the chamber. The Norma brass behind it in the pic has been fired many times and still fits. Both have had the necks turned for clearance and trimmed to the same OAL. Remington Brass fits aslo but I don't have a piece to compare with. The Reamer is an Old JGS that just says "6mm BR Match".

 

[rkittine]

Greg is correct in that one. Tim, reading things like what you quoted is exactly why I was questioning all the input I was getting and the Custom Shop must have also read the same thing as they thought as long as they opened up the neck (2.71 for a no-turn neck) and lengthened the freebore, (.1150), they would have converted a 6mmBR Remington into a 6mmNormBR.

Herb Coates, a bench rest rifle builder here in New York, sent me two reamer drawings from Pacific Tool. One for the each chambering and it shows a number of differences, some minor and others a little more. Although overall case length is 1.5838 vs 1.5830 (Rem Vs. Norma - chamber diamension) things differ starting at the base. From these drawings though it would appear that the Remington Lower Dimensions are actually a little more open then the Norma, i.e. (Rem first vs. Norma)
.4738 vs .4700 then farther along the chamber
.470 vs. .4714
.4609 vs. .4609
.271 vs. .272
.2435 vs. .2435
There are also some differences in initial rim taper degree and spacing between the rim and the case body, but for a newbie dummy like me, it would look like a Lupa case would fire-form to the Remington dimensions rather then the other way around. BUT I want a real 6mmNormBR chamber and that is what I am negotiating with them now. Might be time for them to invest in a modern reamer. Based ion what JRM shows, it would be the other way around.

Maybe I should just go back to Skeet Shooting!

Bob

 

[GSPV]

My grandfather was fond of quoting Yogi Berra "Ya don't know till you know."

He also said "The worst measurement is better than the best assumption."