A short time ago a friend gave me four boxes of 7mmBR brass. The brass is brand new in rem box but I was told it can be changed to 6mmBR size but I am not sure how to do this. I was told to run the brass through a full lenght sizer die and all this did was to smash the case. could I please get some help or can't this be done? Thanks Alot Sevenfals
7MMBR to 6MMBRbrass
- Thread starter sevenfal
- Start date
If I understand your post you've already done this ^^^^^ and your cases collapsed. PM sent
hoz53
Gold $$ Contributor
I sized down 6br to 22br lapua no problem. I also have some Rem 7br that are sized to 22br but I didnt do these. How did you lube the case? They may need to be annealed. Did you try it without the decapng stem in the die?
Yes, but you only reduced the neck dia. by .020" ............. sevenfal is trying to reduce neck by .041" a monumental task in comparison
What possible effect could a de-capping stem have on reducing 7mm to 6mm ...... Just askin'
hoz53
Gold $$ Contributor
I know that.Yes, but you only reduced the neck dia. by .020" ............. sevenfal is trying to reduce neck by .041" a monumental task in comparison
hoz53
Gold $$ Contributor
The expander ball can get in the way at times. I always take the stem out when trying to form something.What possible effect could a de-capping stem have on reducing 7mm to 6mm ...... Just askin'
hoz53
Gold $$ Contributor
Did you get it to work?
jds holler
Gold $$ Contributor
I've been doing this for awhile now, and apparently have gotten lucky. My goal was to turn 7's into 22's.
Since I didn't even have a 6mm sizer die, I snagged a cheap 243 Win, neck sizer at the gunshow. Took it home and cut the base off of it to reduce the length to where it's shoulder would come to bear on the shoulder of the 7BR case. With this modified die, there aren't even enough exposed thread to use a locking ring, so the die is loose in the press. I do about half of the neck in one stroke, and then screw the die down and finish.
I think that the gentler angle of the 243 Win die is what allows me to do this without crushing the case?? I use Imperial lube and have done about 200 of these. The cases are unfired Remington. After this 7mm to 6mm step, I take them down to 22BR with another pass into the FL 22BR die. jd
Since I didn't even have a 6mm sizer die, I snagged a cheap 243 Win, neck sizer at the gunshow. Took it home and cut the base off of it to reduce the length to where it's shoulder would come to bear on the shoulder of the 7BR case. With this modified die, there aren't even enough exposed thread to use a locking ring, so the die is loose in the press. I do about half of the neck in one stroke, and then screw the die down and finish.
I think that the gentler angle of the 243 Win die is what allows me to do this without crushing the case?? I use Imperial lube and have done about 200 of these. The cases are unfired Remington. After this 7mm to 6mm step, I take them down to 22BR with another pass into the FL 22BR die. jd
hoz53
Gold $$ Contributor
That's interesting and a good tip. Thanks
7mm to 6mm in that case could be problematic...Forcing the 7mm neck into the 6mm opening is what collapses the shoulder. I have a 6.5BR die and that is a good middle of the road step to get there. If you can get the neck started down first, that would be the way to go. .277->.264->.243 works well. Some folks get the bushing die and different bushings to work their way down. Other folks use seating dies to get the neck started.
6BR brass is relatively cheap.....borrowing dies is an option....CH4D may even rent them.....Someone local to you may help...PA is too far from me to help, but you could mail your brass and I would be happy to size it for you.....you would need to pay postage both ways tho....
6BR brass is relatively cheap.....borrowing dies is an option....CH4D may even rent them.....Someone local to you may help...PA is too far from me to help, but you could mail your brass and I would be happy to size it for you.....you would need to pay postage both ways tho....
Are you listening Sevenfal? .................. This is an offer that will solve your dilemma. I wonder if Steve would also anneal the cases after converting to 6BR? They'll sure need it. ..................... There are some great guys on this Forum and Shaggy357 is one of them. If you have a no-turn neck type chamber Steve's help is all you need. A tighter neck may require neck turning as the 7 BR case walls will fatten after reducing to 6BR. ............. The neck walls on the cartridges I mentioned above fattened by .001" to .0015" measured with a Ball micrometer. This equates to .002" to .003" larger dia. of case neck..... Just a few things you need to consider.
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I really like the idea of even trading brass and since they no longer make 7MMBRbrass I would do a trade. The brass I have is brand new Remington and I Have 88 of them I will trade even up for 88 lapua 6MMBR brand new brass. If anyone is interisted send me an e-mail. also i'll pay shipping to you you do the same to me. thanks Sevenfal
Hi Dwight! ........... Feel free to use the Classified Ads here it will most likely be read by more people than this single Post. A sell or trade would be appropriate
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