A dear friend of mine has a Ruger M77 chambered in 6mm Remington and is having a devil of a time finding ammo or brass for it.

My question to you fellow reloaders is, what case could be formed into a 6mm?

Seems like a good choice would be a 7x57 casing.....what do you think?

If so, is it a one pass through the 6mm die and trim to length sort of thing or is there much more to it?

Randy

6mm is a great round. It's also known as the .244 Rem. So you may want to look for brass so stamped.

Necking down from 8x57/.323, 7x57, /.284, .257 Roberts/.257 to 6mm/.243 will definitely require trimming and turning the necks. The larger the case mouth, the more work will be required. If possible, I'd look for .257Roberts brass, if I could find it.

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213th FBINA

CH4 covered it well concerning staying with 57mm cases (though there is a 9x57 cartridge as well, but not common).

You can also make cases from 30-06, 270 Win, 280 Rem and other longer cases. More to trim off but do-able.

Or buy 6mm Remington ammo and shoot it for practice - and to acquire the cases.

I saw Hornady 6mm Remington cases on the shelf at a local dealer fairy recently, though I don't recall at present how long ago.

The 6mm Remington is a fine cartridge that deserves more use than seen. It is generally better-behaved reloading than the 243 Winchester, as well as giving higher velocities.

I did some, but years back. Necking down 7x57 or even .270 using 6mm dies works fine. Followed by trimming and neck turning. Simple enough to do if you have the tools.

Yep, 6mm rem brass and 244 rem brass are the same. Barrel twist was changed, Rem 700's in 244 rem had 1 in 12 twist and wouldn't stabilize the heavier bullets used for deer, rem 700's in 6mm rem have a 1 in 10 twist to allow it to compete with the Win 243Win.

I've had at least five rifles chambered in 6mm Remington over the last forty years or so. I would have to check my old notebooks to be sure, but I don't recall one rifle that I handloaded for that would get book velocity with 100 grain bullets, though sometimes I'd get close.

I still like the cartridge but there is almost no performance difference between it and the .243. There should be because of the greater powder capacity, but it appears the .243 might be a bit more efficient design. My current 6mm is a Cooper. It shoots very well even if I can't quite get the velocity I like.

My "The Home Guide to Cartridge Conversions" by George Nonte,Jr says: use 30-06, reduce neck to 6mm, trim to 2.250" length, set shoulder back until case will chamber. fire form. neck reaming may be necessary. My book is dated 1967 so I'm sure newer cartridges have been developed from the '06 case that are shorter.
SWCA 892

A lot of work with '-06 brass and you'd better have a stout press. I wouldn't neck ream any case neck. Outside neck-turning works better, but I've never done this conversion. Regardless, neck work will be required as they will be too thick.

Before I'd use '-06 brass, I'd wait till I could find righteous 6mm brass. The other suggested brass already mentioned here for conversion - .257 Roberts, 7x57 Mauser, etc. may be just as hard to find as 6mm, but they would be slightly easier to work with if you go that route. If you've never done conversions, brass capacity will often vary considerably and should be measured and compared with regular 6mm brass before handloading as you may have to increase or decrease suggested powder charges.

Not a beginner project but fine for the experienced handloader.

Randy - Here is a link to loaded 6mm Rem ammo. Might be the best way for your friend to gather brass. I have shot and reloaded quite a bit of PPU in .308 win, and I have found it good stuff.

PPU 6mm Rem 100gr Soft Point 3100 FPS Rifle Ammunition 20/box

Larry

Be extra cautious when handloading PPU brass. It's good brass, as good as any other. My only experience with this brass was in 7mm Remington Magnum. The brass was 14% heavier than comparable Winchester brass. Powder charges had to be adjusted because of the reduced internal capacity. However, all PPU brass may not be like the 7mm RM brass. Just something to keep in mind.

The conversions difficulty and effort depend on the brand of equipment you have. I once converted 500 30-06 brass to 8x57 for a friend with an MG 34.

1) Fl size in 30-06 die (de-cap at same time)
2) FL size in 8mm FL Die or 8mm trim die
3a) Optional: Cut off almost 1/4" of neck on band saw or other equipment
3b) Trim to length. My Forrester trimmer has neck reams I can use at the same time.
3c) Ream or turn neck thickness to.015+/-
4) De-bur case mouths
5) load as normal.

Optional: run through 7x57 die, and if desired then through 244Rem/6x57 die.

If using Military Brass; start with a 5 to 10% reduced charge on test loads to check capacity issues.

Several years after I did the batch of 8x57 I made 200 7x57 for myself using all one lot of Winchester Commercial once fired brass. I went as far as uniforming primer pockets and flash holes. These were loaded to 275 Rigby data and shot better than Hornady's 275 factory ammo in my Ruger No.1! (3 shot at 100yards 3/8" groups)

Ivan

In the last few years I've used the same techniques to make 800 brass for 300 Blackout (7.62x33) from 223 and I've made about 400 brass for my C-96 in 30 Mauser (7.65x25)! These formed necks are so long, you really must cut the off, I use a tabletop band saw.

The Donnelly book recommends using .270 brass for 6mm Rem. conversion. That would be slightly easier to work with than .30-06, still a good bit of work though.

I have some 6mm/284 from a custom built rifle which is gone. Could this be used for this?

I think the .284 case is too large in diameter.

If 270Win is easier than 30-06, then 25-06 should be easier yet. Much closer to 6mm bullet diameter.

25-06 brass is currently hard to find - I use it to make 6.5-06. Not wanting to wait until I found 25-06 brass, I picked up a box of loaded ammo and pulled the bullets. I could have used easily attainable 270 or 30-06 brass, but I don't want to trim and turn the necks. 257 and 264 is so close, I could probably seat the bullet without running it through the sizing die.

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213th FBINA

I had 4 bags of new Hornady 6mm brass at the Billings Gun show. Sold it to cheaply just to get it gone. I may have a few(about 80?) Rem once fired out in the garage. Have to look. Even if you nake it from 270 or 257...you should ream/turn the necks. You can make so muxh from 30-06...All acording to how much work you want to do. I've even made 22 Varminter from it...before it was made legitimate

Yes; I was only stating what was in the Donnelly book.

When I began shooting the .25-06 in 1965, it was a wildcat cartridge. It wasn't legitimized until about 1969 by Remington. Virtually everyone used .30-06 brass (GI brass and ammo was very plentiful and cheap then).

It was surprisingly easy to form brass in one step by running the '06 brass through the .25-06 size die. Seldom was a case lost or damaged. I'm pretty sure the case necks in most instances should have been neck-turned for safe clearance, but few handloaders neck sized or had even heard of the procedure at the time. I don't recall whether or not neck trimming was necessary.

Way back when, I formed many .25-06 cases from .270 with no problems. As well as 6.5x55 cases. The latter worked fine, even though the base diameter of the .270 case was a little smaller than the 6.5x55 case. I have also formed many 7x57 cases from both .270 and .30-'06 cases. Were I forming 6mm Rem cases today, I would start with .270 or .30-'06 cases mainly because they are easy to get, but there are many other possible starting case choices.

It is a good idea to have both a case trimmer and a case neck turner if you plan to form your own brass. There also case neck reamers, but outside neck turners are preferred. Donnelly's case conversion handbook is a valuable resource for those interested. I have no idea if it is still in print.

I have a lot of 25/06 brass around but no longer have a 25/06. If you should decide to go that route PM me and I will gladly work something out to give you some.

I think Donnelly died a number of years ago; don't know if the book is in print but used copies should be available. Perhaps the best of the conversion books is Ken Howell's "Designing and Forming Custom Cartridges For Rifles And Handguns" originally published in the mid-'90s, but I don't know about current availability.

Barnes & Noble and Amazon still list Donnelly as being in stock. I have not seen the Howell book.

I was in contact with Donnelly not long after his book was published. At that time, he already had plans for an updated edition. I can't remember when he died and don't know if the new book was ever completed or published. Perhaps what is available now is a second edition (?)

I've seen more than one report stating that his book contained numerous errors. I think it would be incredibly difficult to put together such a massive work containing so much detailed information and so many figures without mistakes. The book is still worth having as a reference source.

Remington Brass 6mm Remington Bag Of 50 For Sale | Reloading Brass Store

shows they have 6mm Remington brass

I have 3 rifles in 6mm and an XP100 I rebarreled to it

Buy loaded ammo ? 6mm Rem Ammo | Cheap 6mm Rem Ammunition - AmmoSeek.com 2023

That site appears to be a scam. They have brass that's been unobtainable elsewhere. When I put Lapua 222 Remington in the cart, they wanted a $100 minimum. I did that and the only payments are Zelle, Cash App or bitcoin.

Run away, run fast.

My copy of Donnelly has a 1987 copyright, so it must be a first edition, althogh it does not say that. It also has an inscription to someone and is signed by Donnelly. Those shown at Amazon and B&N have a completely different cover design than mine. Probably corrected and updated. While it is not in any way a reloading manual, it does have some reloading data. Sort of like COTW, also not a reloading manual, contains some reloading data.

BTW, if you have a nearby Ollie's store, they have COTW and the last two editions of Gun Digest for $10 each. At least the one near me does (or did). https://www.ollies.us/home.html?trk_...1003+Book+Item

Sorry, my bad if that is the case