I have an old Rem. Sportsman 78, .30-06

[scpaul]

It's basically a 700 Adl with a cheap stock. I was wondering if it would be feasible to change it to a 6mm Rem? I haven't looked at the dimensions of the boltface. I'm more concerned about how it would feed having been an 06. If I did I'd probably look for a dessert used barrel since the feed thing and I've never been around a 6mm or a 243 very much. I don't remember firing either one. I'd rather the 6mm for the longer neck and could shoot 243 if I couldn't get 6mm.

 

[scpaul]

I just saw the post about bolt faces. I didn't see them before, they are a big help. I've still got the feeding question. Thanks

 

[Coyote Shadow Tracker]

JE Custom put out a Post years ago on Bolt Face Comparisions. I have it saved somewhere.

 

[Coyote Shadow Tracker]

Found this

Bolt face diameter's

@USAF Marksman The 33 Nosler has a 0.534 rebate rim diameter like the rest of the Nosler family, short mags, etc. A magnum action should work. The bolt face won't need modification but the feed rails and mag box probably will. https://www.nosler.com/33-nosler-1 Thanks for setting me straight...

www.longrangehunting.com

 

[scpaul]

I found the boltfaace thread after I originally posted this then edited it to reflect that I found it. I don't know where it went. After I found it my question was about being to use the feed area for a 6mm Rem. It is a Adl equivalent, it has a blind mag. I've modified a Savage 116 to a removable mag. and for this one if I don't have to I'd rather not. I did the other to get a 3.850 mag. to fit. The 06 and 6mm use the same boltface, the case length is shorter and the case diameter is smaller I believe so I don't know how it'll affect the feed. I'm thinking that I can have fun it with a long for caliber bullet and if I have a problem finding 6mm brass I can use 243. Ya'll's thoughts. Oh by the way, I want to use cheap/used parts until I see how I like it.

 

[KRP]

I wouldn't expect any major problems getting a 6mm Rem to feed from a 30-06 magazine.

If you are thinking you'll use 243 Win brass/ammo in a 6mm Rem chamber I suggest you study some case/chamber dimensions.

 

[sable tireur]

Many 6mm-caliber cartridges are used for various shooting purposes because they provide excellent accuracy and light recoil. Some of the greats are (from left) 6mm BR Norma, 24 Nosler, .243 Winchester, 6mm Remington, and .240 Weatherby Magnum.

.30-06 Springfield

 

[scpaul]

I always thought that you could shoot 243 on a 6mm chamber but not the other way because the neck was longer. I guess that's more info that needs to be verified before I repeat it. Thanks for the correction. I'd never seen them side X side. I see your point.

 

[scpaul]

KRP, I just pulled my copy of "Cartridge Conversions" copyright 2011 and looking and comparing the dimensions I'm thinking that the 243 fired in a 6mm Rem. chamber would work. When I fireform the brass for my wildcat it has to reform more than most of the dimensional differences than 243 to 6mm. Look at the measurements and see what I'm looking at. If I'm right, I don't know what the case is next to the 243.
Let me know what you see, Paul, Thanks

 

[KRP]

KRP, I just pulled my copy of "Cartridge Conversions" copyright 2011 and looking and comparing the dimensions I'm thinking that the 243 fired in a 6mm Rem. chamber would work. When I fireform the brass for my wildcat it has to reform more than most of the dimensional differences than 243 to 6mm. Look at the measurements and see what I'm looking at. If I'm right, I don't know what the case is next to the 243.
Let me know what you see, Paul, Thanks

I don't have that book so don't know what it shows. I'm sure you could work a piece of 243 Win brass so it would fit/fire in a 6mm Rem chamber. I don't know how you are going to make up for the difference in case length? You'll wind up with a piece of 6mm brass with about 2/3 of the neck missing at least.

https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

 

[scpaul]

I don't know which is right. The Cartridge Conversions shows the measurements are all close to the same. The biggest difference is 243 neck is .240 and the 6mm is ...., excuse me tha page flipped and I was looking at the .260 Rem. My mistake. You are right. I just went back and looked again and now I am confused. I'll sort it out tomorrow.

 

[Bret GRAVELINE Graveline]

Do not attempt to fire a 243 round in a 6MM chamber, the headspace is not the same, it most likely won't chamber, the 243 has less case taper, but that doesn't mean you can't close the bolt on a 243 cartridge you just shouldn't, the bolt face will not be a issue, if you incounter any feeding issues they will not be hard to correct, A spacer in ethier the front or the back of the magazine box will correct that, rem produced a 257 Roberts on the long action in the classic series, the Roberts and 6MM case are nearly identical, feeding was never a issue, the 78 will accept all 700 parts so adding a ADL or BDL stock and floorplate are options, as well as anything intended for the 700.

 

[scpaul]

I appreciate it. I know that virtually all 700 adl parts will interchange. It's for all intents and purposes a 700 Adl just with cheap furniture. That rifle has gotten more deer and done more ammo testing than anyone would believe. I cleaned the barrel and somewhat decoppered it and it took 30 or so rounds to tighten back up where it was. Copper is about the only thing holding the barrel together. It's hard to believe but it still shoots 1" or smaller groups at 100yds.
I've had about every caliber from 358 down except a 6mm. I've been told that they perform better than you should expect for that small of a caliber if I do my part.
How hard will it be to find a lightly used Rem.6mm barrel just so I can see if I like the caliber. I've also thought about a 35 Whelen but would like to go smaller and different. Thanks everybody, Paul

 

[Bret GRAVELINE Graveline]

Not hard at all, eBay has four listed right now, A couple have buy it now for 120.00, my big game adventures started in 1972 with a ruger 77 in 6MM Rem, a rifle I still have and will never part with, I filled a lot of deer tags with that cartrige, countless rock chucks and coyotes along with several black bear, one being a 7 footer, I like it enough that I have a ruger num 1 International in 6MM as well, makes a nice little woods rifle that our local blacktail are so fond of, I once used the 6 loaded with a 95 gr partition to take two blacktail bucks that were standing side by side, I didn't recover the bullet, I later replaced the Nosler slug with the early Barnes X 90 gr bullet, they no longer make the 90 gr but I purchased enough of them to get me through to the end as long as I point them at teeth or horns, these days a 257 Ackley serves as my go to deer rifle, but I'd get rid of that rifle before I let the 6MM go, its a fine round,