reforming 7mm/08 brass

[smokeater]

A friend gave me some 308 once fired brass and while sorting found some 7mm/08 brass mixed in. My question is: how much trouble is it to resize to 308Win and would it be safe and worth the time.
Also, when reloading military brass everyone says reduce from 2grains up to 10%. Is this reduction on all loading or off MAX load

[Mk42gunner]

smokeater, I saw your post last night and was waiting for someone that had actually done it to reply. Since they haven't (or maybe no one has done it), I will.

Forming your 7mm-08 to .308 should only take a pass in the 308 die with expander button. I will be very surprised if it takes much effort.

However, I wouldn't do it unless you have at least a couple hundred cases. I have seen way too many people blindly trust the headstamp with some one else's reloads to be comfortable necking up to a very similar round.

The reuction for military brass was started when the .30-06 was the military round, and a lot of it had thicker (less volume) brass. With 7.62 and 5.56, it can go either way.

Robert

[Outer Rondacker]

I have done 243 to 308 for an order years ago during the shortage. Takes one pass. I like to rub some lube on the expander. If I can make that jump with one pass you should be fine.

[dh2]

I have alway seem to get more life from brass when sizing down more than sizing up. but here you are only going up by .02 I don't see an issue with it.

[smokeater]

Fellow Members,
Thank You for your input. I have been reloading and casting for roughly 25yrs but have never reformed brass into another cailber. Each of you brought up good points. I didn't know if necks would have to be turned or if there was something else to look out for. I sincerely appreciate your responses. Looking online today seems like 30cal components are coming back and I found some 308 brass today so think I will forgo the 7mm/08 brass, only had 3 pieces but if I needed them I would have tried it.

[Winger Ed.]

I wouldn't have any problem doing it.
Since it was getting worked that hard a second time, I'd go ahead and anneal it too.
Going to a slightly larger size, neck thickness shouldn't be a problem since its getting stretched.

My new reloading books don't address it, but in the old days,
all of them said to reduce one full grain for the added thickness of military brass,
and it having a reduced inside volume/capacity.

I understood the reduction to be across the board, to get the listed speed in the data.
However; I would hesitate to do it for a minimum powder charge.
Since I never get up more than 85-90% or so of max. loads it was never really much of an issue for me.

[smokeater]

Winger Ed,
You bring up a good point. The majority of my reloads will be in the same area of load density as yours plus lot more will be cast bullet loads. Reason I asked was one place says reduce 2 grains, another says reduce 5% still others say 10%. Like you said, see no purpose in reducing start loads and maybe I'm wrong in my thinking but thought loads wouldn't require reduction until up in the 90 to 100% load density. I f that is wrong please say so, I won't be offended nor feel flamed. A person is never to old/experienced to learn.

[Blanco]

Send me that 7-08 brass and I'll send you back twice as many 308

[Winger Ed.]

f that is wrong please say so, I won't be offended nor feel flamed.

Nahhh bro...... We're good, as I'm sure you are with everyone here.

With my last job before I retired, I worked with a bunch of guys that were younger than my kids.
Just for the enjoyment of doing it,
I tried to teach at least one of them either a bit of 'geezer wisdom' or something every day.

That's a habit I've kept after I left them.
When guys here wade off into uncharted waters, I try to keep them from shooting their eye out.

Anyway:
All the stuff I post about is from my own experiences, and those of folks I've known over the years.
If someone finds it informative or entertaining-- great. If not, ahhh,,, that's OK too.

[smokeater]

Blanco,
Sorry by the time I saw your post I had already resized the three pieces of 7mm/08 brass to 308. Worked like a charm. Greastest resistance was getting expander ball into neck after that no more than resizing a 308. I would like Thank everyone for their input. It's nice to have a place like Cast Boolits where one can learn and everyone is friendly and helpful.

[MostlyLeverGuns]

Resizing 7-08 should be easier than 308 to 358 and that is done quite a bit. With 308, my experience is that many brands of cases weigh very close to LC and other military, about 180-185 grains on my scales- unprimed, my lots of Lapua, IMI, and Peterson 308 have been 180 plus/minus. I have found Winchester and a very old lot of Frontier are significantly lighter - 160 plus/minus on my scales. Top end loads developed in the Winchester weight cases do need to be reduced for the heavier cases while moderate loads don't create problems.

[CastingFool]

Just messing around, I've made 308 W brass out of '06, and 270. The reformed cases just sit unloaded on my shelf.

[Texas by God]

BITD- Back In The Day when the 7mm-08 was new, my brother bought a 788 (2.0 version). When we tried sizing .308s down, the necks were too thick causing high pressure. Our late( and missed) oldest brother studied the cases a bit and the next thing you know he was shooting his .243 shells in the 7mm-08. What do you know- perfect fire formed 7-08 cases that would not chamber in a .243 any more!
Thanks for rekindling an old memory!

Sent from my SM-A716U using Tapatalk

[Milsurp Junkie]

I have resized 243 and 308 brass to 358 winchester in a single pass w/out issues. 7mm to 7.62 mm isnt a problem.
Going from larger diameter to smaller, you will get thicker necks, and might need to ream tne necks.

[smokeater]

Thanks guys for the input. You guys make ignorance a thing of the past as long as someone ask and willing to follow your instructions/experience. Members on this forum represents a treasure of knowledge and wisdom if followed.

[dale2242]

I have a friend that has formed 308 into 7MM-08 without issue.
We bought our great granddaughter a 7mm-08.
I have more than enough 308 brass.
Since there is a number of 308 Win shooters in the family, I opted to buy 100 Starline brass for her to prevent any mix up in ammo.
If you or others in your family you load for have 308s I would stick with proper head stamped brass.

[Milsurp Junkie]

I didn't have a 308 or 243 at the time. I have a 308 now, but not worried about confusing a 358 winchester for a 308. I have a 243 H&R barrel, but I am going to send it off to JES to make into another 358 Win.

[smokeater]

Dale, I fully understand the concerns of sizing different than headstamp seeing as I have a 243 also. The brass for the 308 will be purposed mainly for cast boolit loads or reduced J word loads. This is my everyday woods walking exercise rifle. Like the credit card ads; don't leave home without.

[country gent]

Rule of thumb is sizing brass down it thickens and lengthens sizing up it thins and shortens. There is a set amount of brass in the case and it has to go somewhere being changed since the only opening is up the excess brass flows up and out thickening and lengthening. not enough and it shortens and thins.

[smokeater]

Trimming to 2:005" after resizing 7mm/08 to 308 amount trimmed was no greater than my factory 7.62x51. Just couldn't stand to throw the 3 or 4 pieces of pristine brass to scrap. Will not be a rountine project. Kinda neat knowing it is easily done.