Changing The Caliber On A Remington 700

[wrat]

Couple things if you go the insert route. The bullet is going to have a big jump before it gets to the rifling, maybe this is not a concern just wanted to bring it up.

Never seemed to matter to competition shooters, but it might this time. Now, of course, these were many years ago when the military competitions meant you had to use military caliber. So when the .30-06 went away, it had to be shot in .308. So that meant shoot a Garand with an adapter -- because a Garand with a .308 barrel is not a Garand -- or get rid of it for an M14.... which would invariably bring up yet another pointless debate about what's better than what.

You need to be careful that the insert does not come out when firing the rifle, this would create an excessive headspace situation, dangerous if the rifle was fire like this.

Has this ever happened ever in the history of these adapters, ever? Because I've only heard of them being removed with a broken case extractor. These operate nicely in semi-auto Garands, so I'd be very surprised if the comparatively gentle rigors of bolt action were to even jar one loose, let alone suddenly come out.

If you have some meat on the barrel shank I would cut off enough to clean out the 30-06 chamber with the 308 reamer. reset the headspace and redo the tennon as needed

Sure, probably the second-safest route, but also the route of most trouble and from which there is no return. Further, the barrel, stamped .30-06, is no longer labelled correctly, either. More changes.
Screwing in a new .308 bbl would be the best. But again, a lotta trouble for an experiment.


Wrat

 

[MontanaAardvark]

I did some research on these, and the story was that the Navy looked at this to convert Garands to the shorter 7.62x51 and said that the adapters came out and were therefore unsafe in a semiauto or full auto situation.

For a bolt action, where a user could take a quick look at each cartridge and see if the adapter ejected, that doesn't seem to be as big an issue.

In my case, I've kind of stepped back and started asking if I really want to convert my .30-06 to anything else. In particular, the guys at the 600 yard range I have access to, tend to use smaller cartridges like the 6mm BR. Another guy I was talking to on the shorter 200 yard range said he used something like .270 because it had good ballistics and was a bit easier on the shoulder for lots of practice.

Whether 6BR is a passing fad or a real advantage, I couldn't say.


Bob

 

[wrat]

Interestingly, the Navy shooting team were among the ones using adapters in competition. Oh well, there's the right way, wrong way, and Navy way. No idea.

6BR has a pretty good foothold. I don't have one, but I'd not call it a passing fad, either. Several groups and sites are dedicated to 6BR even now. But then several sites are dedicated to antique Macintosh computers, too, so maybe that's not such a great metric. Still in all, it's been used for decades and i've even seen AR pistols done in 6BR.

While I'm always up for a conversion or some good old fashioned gunsmithing of any type, you may be headed the right way on letting this go. And going 6BR? Not a bad decision, either. Put it this way, i've never heard of anyone saying "I'm gonna get rid of this 6BR as soon as I can." I've heard people say that about other calibers (.40S&W, 30-40 Krag, etc.) but never 6BR.

And since you reload, also, you'll shortly be working up 6BR loads for your particular rifle. They all do. It's a blessing... and a curse.

 

[MontanaAardvark]

When I became a COF (Certified Old Fart), a lot of things started looking faddish. Some of them obviously are, but not all.

As I say, the longest range I can get to without an overnight trip is 600 yards., and that's in the club I belong to. I'm sure there are nuances that matter at 1000 yards and beyond that don't matter at 600, or that matter a lot less. What got me started down this road was that our club had an "open house" where we were able to go check out everything available, and I got to shoot a guy's custom 6BR bench rest rifle. I know that he did all the hard stuff, but it was fun to hit 3 out of 3 in the center of the target at 600, 2 of 3 touching. It got me thinking of getting something more suited to 600 yards than my other rifles. I have a Savage Scout rifle in .308 (the original model) and it has a super trigger, but while that 6 BR rifle had a trigger that would fire if you started at it too hard, the Savage is more like a pound. Scout rifles are not intended for bench rest, and the 2.5x optic is useless to me at 200 yards, let alone 600. That got me thinking of a new rifle and which option to go after. .308 is a respectable long range round, but most folks seem to have gone to the smaller rounds for the reduced recoil.

I guess the only real reason to convert my .30-06 is to save a little cash. Changing to a .308 is just a barrel change. If I were to change to just about anything else, I'd guess that's a whole new rifle. Along those lines, I saw a guy hitting targets at one mile with an off the shelf Ruger American Predator in 6.5 Creedmoor. Pretty impressive for a rifle I can pick up for $400 locally.

 

[Herk]

The Remington 700 is a fine rifle, and available in either 308 Winchester (7.62x51mm NATO) or 30-06 Springfield (7.62x63mm). Conversion should be fairly straightforward by changing barrels and magazine followers and possibly tuning the extractor slightly. If you had an otherwise pristine 30-06 with a shot out barrel it might be worth it, but you're probably money ahead to just trade it for a similar rifle in 308 if that's what you really want. A new barrel will be about $350-400 by it self, plus cambering and fitting.

As others have mentioned, saying that the 308 and 30-06 are "ballistically identical" is not exactly correct. If you compare loading data you'll see that for a given bullet and powder, the max powder load for the 308 is about the same as the suggested starting load for the -06. And even then, the -06 generally outperforms it. When it comes to factory loads, the difference is even more pronounced. For example, comparing good old available anywhere "green box" Remington Express 150gr CORE-LOKT ammo the 308 has a muzzle velocity of 2820 fps and muzzle energy of 2648 ft-lbs while the 30-06 is 2910 fps/2820 ft-lbs. Now don't get me wrong, I'm not bashing the 308, it's a great cartridge. In fact, both the 308 and the 30-06 are popular for similar reasons. They are versatile, adaptable and widely available. They can be loaded to provide similar performance in a wide range of applications, but the 30-06 with it's larger case capacity has an inherent advantage.

I suppose it ultimately boils down to what you want at the end of the day. If cheap is your priority, buy a set of dies and some 30-06 brass. The -06 will do anything a 308 will do, plus a bit. If you want a field rifle, either cartridge can be loaded to reliably take down just about anything that walks in the lower 48 states. If you want a target/range rifle, again, both have good target load data. I'm not a big fan of the insert chamber adapters. A floating head space adapter will never be as consistent as a properly reamed solid chamber. Eliminating inconsistencies, however small is key to target shooting. For a field rifle, assume anything that came come loose/jam/fall out will do so, and never at a good time. Also, brass that has fire formed to a slightly non-standard adapted chamber may not feed well in other guns, reducing the interchangeability advantage.

But, if you are looking to do a barrel change project, or custom build, the Rem 700 is a good choice. Plenty of goodies out there. The 6BR Norma or 6.5 Creedmore would be about the same hassle as a 308 conversion.

 

[Tozguy]

Thanks, DPB. I'm interested mainly because they are ballistically virtually identical and I have another couple of rifles in .308. Fewer kinds of ammo to inventory. I've been thinking of making a long range .308 gun and since the 700 is such an established platform, I'm guessing there are lots of parts available for it.

Around here, the longest range I can get to without an overnight road trip is 600 yards.

Wrat, if the difference is the 8mm length between 51 and 59, would I just cut that off on the lathe? This where I don't have a clue. I've heard of chamber reamers before, and I thought this is what they're for. Shorten the barrel by 8mm and then run the chamber reamer into it.

(I know. The worst words in the world are "all you gotta do is"...)

Just a few thoughts;

1. Not sure that a conversion to 308 will simplify your reloading or reduce your ammo inventory. Each barrel is different and for best accuracy, loads should be tailored to the individual barrel even if they are all 308s. You might also find that one bullet will work great in one barrel and not in another (are twist rates and bore diameters all the same?).

2. Converting a barrel to a shorter cartridge requires a set back, including turning a new shoulder and extending threads. Then a reamer to cut a a complete new chamber. You would probably want to match headspace as closely as possible to your other barrels.

3. Before proceeding, try chambering some dummy 308 rounds in the 30-06 as is to determine if there will be any feeding problems to solve.

 

[Tozguy]

I did some research on these, and the story was that the Navy looked at this to convert Garands to the shorter 7.62x51 and said that the adapters came out and were therefore unsafe in a semiauto or full auto situation.

For a bolt action, where a user could take a quick look at each cartridge and see if the adapter ejected, that doesn't seem to be as big an issue.

In my case, I've kind of stepped back and started asking if I really want to convert my .30-06 to anything else. In particular, the guys at the 600 yard range I have access to, tend to use smaller cartridges like the 6mm BR. Another guy I was talking to on the shorter 200 yard range said he used something like .270 because it had good ballistics and was a bit easier on the shoulder for lots of practice.

Whether 6BR is a passing fad or a real advantage, I couldn't say.


Bob

6BR is not a passing fad. As you saw for yourself it has superb accuracy, low recoil, less expensive bullets than 30 cal.

Converting your 700BDL to a true 600 yd bench rest rifle would require more than a barrel conversion. It has been shown many times over that a good used bench rifle costs less in the long run than converting a standard 700. If you can rub shoulders with some serious competitors you might be able to pick up a superb 600 yd.rifle. Its resale value alone will make it a bargain.

What you mentioned above about an off the shelf Ruger shooting accurately at a mile is amazing. It must have been a very large target. It should be worth $400 to you to see if you can duplicate that level of performance.

 

[MontanaAardvark]

6BR is not a passing fad. As you saw for yourself it has superb accuracy, low recoil, less expensive bullets than 30 cal.

Converting your 700BDL to a true 600 yd bench rest rifle would require more than a barrel conversion. It has been shown many times over that a good used bench rifle costs less in the long run than converting a standard 700. If you can rub shoulders with some serious competitors you might be able to pick up a superb 600 yd.rifle. Its resale value alone will make it a bargain.

What you mentioned above about an off the shelf Ruger shooting accurately at a mile is amazing. It must have been a very large target. It should be worth $400 to you to see if you can duplicate that level of performance.

I'm sorry I didn't see this last week when you posted it. I thought I had this board setup to email me if I had replies.

Anyway, due to the comments others have made and that you raised, I've decided it isn't a good idea to go down the road of converting the 700 to another caliber. As for now, I'm reading what I can get my hands on about getting started at 600 yards. Our club requires me to attend a once-a-month orientation before I can walk up and use the 600 yard range, so I'll use that opportunity to try to get some more information and meet some more people. I could spend more time trying to minimize my errors at 200 yards, too. I notice guys on the shorter range working to perfect their loads before they move to the longer range.

 

[bob308]

you can change the barrel. there is a chamber sleeve that will let you use .308 in the .30-06 barrel. they made them when the .308 became standard military load in the 50's. the navy converted their m1s that way. there was a plastic block that went in the action to prevent some one trying to load a bloc of 06 rounds. I think you would do fine if you loaded it one at a time.

I rebarreled my m1 with a .308 barrel it works fine and does not have the plastic block.

 

[drhall762]

The adapter you are looking for to go from .30-06 to .308 is interestingly enough The Naval Ordnance Bushing. Properly installed they work fine. Shot many rounds through a modified M1 at the NRTC in San Diego some decades ago.

Having said that, they haven't been produced since the 1960s. If you could find one it would probably cost you more than simply having your rifle rebarreled.