7mm-08 brass info needed

[GRUMPA]

I'm thinking about converting these from 308 brass but there's some info that I just can't find and I'm not going to be paying for new brass at a $1ea plus shipping.

What I would like to know is the base diameter of NEW brass. The spec calls out the base diameter at .470 for the 7mm-08 and I've been reading where actual NEW brass measures .468. I just need to be certain of this.

Another thing is the weight of the case itself, I don't have any here although I know I did at 1 time and I'm thinking I sent them off to a member that requested some which I do frequently.

[pjames32]

I've just run them thru the 7-08 sizer die. Lube well and check length and load. My loads were not max so I did not adjust the load. If your loads are max you probably need to back off a little.

[kevmc]

Base dia. ???
.370 ??? or did you mean .470"???
OD of new RP 7-08 case just above rim is .466" for 3 I just measured....

Lube.. FLsize in 7-08 dies...check case oal and load....

[376Steyr]

Base diameter or neck diameter? I converted a batch of .308 Federal Gold Medal cases to 7-08 and needed to turn the necks on them to be safe in my rifle. A dummy round with an unturned neck had a larger diameter than the neck of a fired case from my rifle.

[GRUMPA]

It's the base diameter of I'm after and yes even though I had the dimension right in front of me I still wrote it down wrong.

I'll go change the OP

[Pepe Ray]

GRUMPA; - - -FYI
I don't know when it began ,but many new cases are smaller than published info.
When R-P first came out with the 6.5 x 55 Sweed, I purchased a case of ammo. As you know we've been warned for years to not use 30/06
brass to make the Sweed as the Sweed case was several thousandth LARGER and consequently a remanufactured cartridge would be UNDERSIZE
and therefore unsafe. BULLPOOP!! The new Sweed ammo was ALL '06 size. Then W-W and Fed. produced the same stuff. Only Norma produced a case
more in keeping with the published dimensions.
I've never concerned myself with the differences since then. NOR with the 7.7 mm Jap which fell into the same myth.
Pepe Ray

[MarkP]

SAAMI drawings are max cartridge dimensions with a minus diametric tolerance listed, chamber drawings are minimum chamber with a plus diametral tolerances.

A cartridge with max dimensions will have a slight amount of clearance in a true minimum chamber.

[GRUMPA]

This is the primary reason I asked this question in the first place.

http://castboolits.gunloads.com/showthread.php?152056-HELP!-7mm-08-Case-sizing-difference

Seems this person was having a bit of a problem.....

[mac60]

GRUMPA - I have some R-P hs 7mm-08 brass (it's several years old - never sized). I measured 3 of them with a 1" micrometer and all 3 were .466". I'd be happy to send you a few if needed.

[GRUMPA]

Base diameter or neck diameter? I converted a batch of .308 Federal Gold Medal cases to 7-08 and needed to turn the necks on them to be safe in my rifle. A dummy round with an unturned neck had a larger diameter than the neck of a fired case from my rifle.

It was the base diameter I'm after. And looks to me like my thoughts on it was accurate. Most of the time I ream the necks, I do that on most of what I convert. My theory behind reaming is why produce something average when all it takes is a few seconds to produce something better.



SAAMI drawings are max cartridge dimensions with a minus diametric tolerance listed, chamber drawings are minimum chamber with a plus diametral tolerances.

A cartridge with max dimensions will have a slight amount of clearance in a true minimum chamber.

That part of the drawings I'm familiar with. What happens is.....let's say....gets a new to them rifle. They get cases from me and at times they hang up in the chamber. Any idea how hard it is to tell them the issue lies in the chamber and not the cases they just got.


GRUMPA - I have some R-P hs 7mm-08 brass (it's several years old - never sized). I measured 3 of them with a 1" micrometer and all 3 were .466". I'd be happy to send you a few if needed.

I may request those, for right now though I'm toying with the idea in my head which of course acts like a completely unorganized file cabinet.

[mac60]

I understand that - I suffer from the same condition. If you would like a few just let me know. I made 100 from some .308 win. brass - I don't really understand this, but from .30 cal. to 7 mm seems to me to be such a small reduction - I had to turn necks. I'm using them in a mod. 200 Stevens rifle in 7mm08 and have not had a single problem with them.

[karlrudin]

I'm thinking about converting these from 308 brass but there's some info that I just can't find and I'm not going to be paying for new brass at a $1ea plus shipping.

What I would like to know is the base diameter of NEW brass. The spec calls out the base diameter at .470 for the 7mm-08 and I've been reading where actual NEW brass measures .468. I just need to be certain of this.

Another thing is the weight of the case itself, I don't have any here although I know I did at 1 time and I'm thinking I sent them off to a member that requested some which I do frequently.


Here is the SAAMI specs for 7-08Rem. The only brass I use in my 7-08 IS 308. These are identical with 2 differences. The diameter of the neck and the overall length of the case. They both use the same cartridge headspace gauge for checking. In my rifle, Savage 110 with Shilen barrel, the small amount of neck length that you loose in the conversion has never cause me a problem. With gun itself or the accuracy. When you convert from 308 to 7-08, you final cases will end up being approximately 2.010. Whereas a factory 7-08 will be at 2.025 minimum. I full length size 308 in a 7-08 die, trim to 308 minimum, turn the necks down to .003 under max neck diameter. Run them through my 7-08 neck sizing die, then start to load. My cases, which I bought a bulk box of 250 cases, are Remington brand. My case weights avg 166-168 grains. Hope this helps.122928
122926

[GRUMPA]

When I convert the 308 Mil brass into 260Rem the second thing I do is measure the case, first is to clean them. I was shocked to learn the length of the case varies more then I expected. I get anywhere from 1.995 to 2.050 for the case length and separate the short ones and work with the cases that measure 2.020 or longer. I work with the Mil brass more than anything since it's a cheaper case and I can get a lot of them.

In the past I've had folks ask me to do these, but at the time I was busy doing other things. Getting geared up to actually convert these is another matter....

[too many things]

I tried a few 308 cases and had problem with necks wrinkle . Mid way has rem new brass for about $50,100-- so I got 100 and that will last rest of life