Converting a 30-06 to another .30 calibre

[Valentin16]

Hello to all you rifle lovers and gunsmiths,

I love my bolt-actions as much as the next guy, but I also have preferred calibres. My question is, what other cartridge can you modify your 30-06 rifle to shoot. Bear with me - I will not be doing the work but an experience gunsmith will. The rifle is a new CZ 550 American, bought it and never fired it in the four years I have owned it, and as it turns out, I do not care for the 30-06 cartridge. Either I sell it, or modify the chamber whilst keeping the barrel if possible.

Is my idea at all even possible? All ideas are welcomed.

[762xIan]

bought it and never fired it in the four years I have owned it, and as it turns out, I do not care for the 30-06 cartridge

Is this due to prior experience with the .30-06 round? I mean, if you never fired this rifle, how do you know it isn't a tack-driver? If you don't reload, the huge popularity of the .30-06 round will give a person the advantage of more factory loads available than probably any other round.

Either I sell it, or modify the chamber whilst keeping the barrel if possible.

Not much you can do chamber wise...the .30-06 case length is 63mm, which is pretty long, 300 win mag is a hair bigger than .30-06, but there may be a safety issue if you have to remove too much metal to convert it to that.

Re-barreling the rifle or selling it is probably your best bet.

[bricktop]

For as much time and money you will be putting into getting it re-chambered, I would just get a fresh, cut-rifled barrel (like a Brux, Rock, or Obermeyer) and have it cut to whatever you want. There are many options for a long-action with a 473 bolt face. An interesting one would be a 284 Win. 7mm bullet popularity seems to be on the rise. With the long action, you're not restricted to the max. magazine length of the ~2.850 short action, letting you set the bullets out (if the chamber permits) and get the most of the round.

I bought a barrel here: http://www.bugholes.com/barrels.php and am waiting on the threading/chambering from a local smithy.

[oblivionboyj]

I am not a gunsmith, and I have not accomplished the following modification...

I was looking into a Garand a while back, and I had a long conversation with a machinist at a gun show who had a couple of nice Garand recievers for sale.
He told me that making a Garand into a 308 Garand was a simple matter of removing enough material at the rear of the chamber (in the barrel you will use) to fit the 308 cartrige rather than the 30-06 (which aparently are dimentionally the same in diameter, and only differ in length).
He said that after you got the barrel back onto the reciever, and timed correctly, that you just put a plug in the magwell to take up the difference in the size of the round.
He really made it sound pretty easy if you have the skills.

Find a good gunsmith and get a quote, I am sure it is a doable mod.
Good luck

[dk99358]

Depending on barrel thickness, bore it out to either 338-06 or 35 Whelen.


Dale

[Tomcat088]

I am not a gunsmith, and I have not accomplished the following modification...

I was looking into a Garand a while back, and I had a long conversation with a machinist at a gun show who had a couple of nice Garand recievers for sale.
He told me that making a Garand into a 308 Garand was a simple matter of removing enough material at the rear of the chamber (in the barrel you will use) to fit the 308 cartrige rather than the 30-06 (which aparently are dimentionally the same in diameter, and only differ in length).
He said that after you got the barrel back onto the reciever, and timed correctly, that you just put a plug in the magwell to take up the difference in the size of the round.
He really made it sound pretty easy if you have the skills.

Find a good gunsmith and get a quote, I am sure it is a doable mod.
Good luck

It's possible that the modification could be made, but it's not quite how the machinest presents it; notice that he isn't necessarily a gunsmith, there can be a significant difference. Technically, it's not about removing material from the rear of the chamber. The chamber is the area that is cut into the barrel that contains the brass. The barrel has to actually be "set back" so that a portion of the barrel where the threads and that area, is removed. This allows you to basically get to a place where you can rechamber the barrel, and since it has the same bullet diameter, it is possible. The .30-06 has some body taper to the cartridge, and is a different diameter than the .308 as you get closer to the neck. So you can't just lop some off of the rear of the barrel, thread it, and throw it on the rifle. The barrel would have to be rechambered for sure, which isn't necessarily difficult for a gunsmith, but it does take time and has to be done EXACTLY right. I'm not familiar enough with all the minute details of the garands to say for sure that it can or can't be done, or without a huge headache. It should be mentioned that the contour of the barrel, tenon length, and lots of other things come into play. Depending on the dimensions of the bottom of the action and how garands feed, some material may have to be taken off or added in the bottom of the action. It's very easy to screw this up and not have a rifle feed consistently and reliably. Blocking off the action isn't difficult, but it also has to be done right, and is one of those things that can be screwed up and effect reliability. The other thing that would concern me and that would probably need some tweaking is the gas system. The .30-06 operates at different pressures than the .308. The Garand's action, and the holes that bleed off gas to cycle the action were designed for the .30-06 and it's pressures, etc. So in changing propellants, how many grains of that powder, optimum burn length for that powder, and pressures, but keeping a long action, with the same heavy mass on the bolt and all the gas system; things could get a bit tricky. I'm not trying to say that what the machinist told you is completely incorrect, but I don't think it's quite as easy as what he thought it was. Simply chambering a barrel has lots of little nuances to it, much less all the other things that come into play with this rifle. After all the time, headache, still having a long action, etc, it might just be worth the headache and time to buy an M1A.

To the OP, I'll see if I can offer some insight into this. To answer the question that you asked, depending on what you want to do with the rifle, YES, it is theoretically possible to do. Also depending on what you want to do, it may not be practical, or feasible in terms of cost. I would like to ask you a question, and I'd like an honest answer. I'm not asking this to flame you, but so that I can better understand what type of modifications or chambering you might want. What exactly do you have against the .30-06, or why do you "not care for it"?

The reason that I ask is because the .30-06 is kind of at a "peak" in terms of performance and trade offs. Honestly, it would be silly to go to a .308 because you'd be "downsizing", and getting less performance from the rifle, and still stuck with a long action. The reason that most people like the .308 is because it has good performance and comes in a short action, with a short bolt throw, and plenty of kinetic energy in a .30 caliber bullet. The .30-06 betters that performance by a bit (not a ton, but some), but it goes to a long action to do it. If you go to a .308, you're going to lose velocity, and still be stuck with the long action and the long bolt throw. The only reason to build a short action caliber on a long action is basically because you want to use very long bullets (like VLD's or similar designs), and long throat them, but still be inside of magazine length. Because you don't know the specifics of modifying the rifle, and are asking for advice in caliber selection as well, it's unlikely that you have any need or desire to go with something like what I just mentioned. The .30-06 will got through barrels a bit faster than the .308, but the .30-06 still isn't overbore and isn't a "barrel burner". So you're going to give up velocity, and not get substantially more barrel life. Unless you're competing with the rifle, you probably won't ever shoot out a barrel in either caliber. There's just really no reason to "downsize" and go to something like a short action caliber like the .308 or even smaller. It would require a lot of gunsmithing including probably opening up the feed ramps, setting the barrel back, blocking off the magazines. You wouldn't ever be able to go with just factory magazines, all would have to be modified to accomodate the shorter cartridge.

That means that the only real practical direction to go would be "up", meaning to the magnums (.300 Winchester Magnum, Remington Ultra Magnum, etc). Some people like this idea because they want a "big gun", but notice I said the "idea". In terms of practicality, it's not all that practical either. The bolt face wouldn't be large enough and would have to be switched out, or opened up to accomodate the larger cartridge base. The barrel would have to be rechambered so that it could accomodate a larger cartridge. Depending on the tenon length (area where the threads are), barrel contour (how it tapers), new cartridge's chamber dimensions, and other factors, it may not be practically possible. Depending on what cartridge you'd want to go to, there may not be enough material in certain areas of the barrel to accomodate it. Even if it was possible, you'd be going to a cartridge that would be flatter shooting (a plus), but that has more recoil (a minus), and would would go through barrels faster (a minus). Again, if you aren't shooting it a lot, you probably still wouldn't run through a barrel, but it's still worth mentioning. The cartridges would be less effecient in terms of powder, and would cost more to reload (if you do), per round. For most people's needs, magnum cartridges just aren't necessary and don't fit their "needs". This is also coming from someone that shoots a magnum cartridge regularly, at least every few days, lol.

So again, what you're asking about IS possible, but it's just quite impractical. I don't know the exact specifics of all the little details of the CZ to tell you everything that would need to be done, or how it would be done. I'm very familiar with some of the modifications needed on some actions, which is evident in my sticky in the gunsmithing section about modifications for precision rifles. There may be some things not possible because of the CZ design, or that may be possible but even more impractical. The other thing that could be difficult is finding a gunsmith that would be able to do it. It's not a common modification that most smiths in the US would do, and so it may hike up the cost even more, which is already expensive. It might be quite difficult to find parts to do some of the modifications as well. If you wanted to go to some other caliber (not .308) and use the action, you might have some other options that wouldn't be quite as modification intensive, in terms of changing the action, bolts, etc. They'd still also be more expensive because you'd have to buy a different barrel and still have all the gunsmithing done.

Basically what you're talking about won't get you much more performance, and may give you less. You'll end up spending what most people would consider to be quite a lot of money. It could easily be $500 or more, depending on what you wanted done and by who. For that kind of money, you can keep the rifle you have and buy another one and have 2 rifles. If you like the CZ and just want it in a different caliber, I suggest that you just sell the rifle and buy the caliber that you want. You probably won't take a big hit since the rifle has never been fired and has probably just been stored away. I just doesn't seem like a smart move, and you'd probably be better off just selling the rifle. So what is it that you have against the .30-06 again?

[Tomcat088]

Depending on barrel thickness, bore it out to either 338-06 or 35 Whelen.


Dale

Hmmm, I'm curious on if you think this would be practical to do, especially when he also left open the option to just sell the rifle. Do you think it's practical? I think it would be pretty time consuming, and may not give the best results to completely re-rfifle a barrel, and then probably also have to have it recontoured and stress relieved, and then rechambered, just go to to one of the cartridges mentioned. At that point I'd think you might as well just buy a nice aftermarket barrel with the desired bore diameter, chamber it, and go on.

[Valentin16]

It's possible that the modification could be made, but it's not quite how the machinest presents it; notice that he isn't necessarily a gunsmith, there can be a significant difference. Technically, it's not about removing material from the rear of the chamber. The chamber is the area that is cut into the barrel that contains the brass. The barrel has to actually be "set back" so that a portion of the barrel where the threads and that area, is removed. This allows you to basically get to a place where you can rechamber the barrel, and since it has the same bullet diameter, it is possible. The .30-06 has some body taper to the cartridge, and is a different diameter than the .308 as you get closer to the neck. So you can't just lop some off of the rear of the barrel, thread it, and throw it on the rifle. The barrel would have to be rechambered for sure, which isn't necessarily difficult for a gunsmith, but it does take time and has to be done EXACTLY right. I'm not familiar enough with all the minute details of the garands to say for sure that it can or can't be done, or without a huge headache. It should be mentioned that the contour of the barrel, tenon length, and lots of other things come into play. Depending on the dimensions of the bottom of the action and how garands feed, some material may have to be taken off or added in the bottom of the action. It's very easy to screw this up and not have a rifle feed consistently and reliably. Blocking off the action isn't difficult, but it also has to be done right, and is one of those things that can be screwed up and effect reliability. The other thing that would concern me and that would probably need some tweaking is the gas system. The .30-06 operates at different pressures than the .308. The Garand's action, and the holes that bleed off gas to cycle the action were designed for the .30-06 and it's pressures, etc. So in changing propellants, how many grains of that powder, optimum burn length for that powder, and pressures, but keeping a long action, with the same heavy mass on the bolt and all the gas system; things could get a bit tricky. I'm not trying to say that what the machinist told you is completely incorrect, but I don't think it's quite as easy as what he thought it was. Simply chambering a barrel has lots of little nuances to it, much less all the other things that come into play with this rifle. After all the time, headache, still having a long action, etc, it might just be worth the headache and time to buy an M1A.

To the OP, I'll see if I can offer some insight into this. To answer the question that you asked, depending on what you want to do with the rifle, YES, it is theoretically possible to do. Also depending on what you want to do, it may not be practical, or feasible in terms of cost. I would like to ask you a question, and I'd like an honest answer. I'm not asking this to flame you, but so that I can better understand what type of modifications or chambering you might want. What exactly do you have against the .30-06, or why do you "not care for it"?

The reason that I ask is because the .30-06 is kind of at a "peak" in terms of performance and trade offs. Honestly, it would be silly to go to a .308 because you'd be "downsizing", and getting less performance from the rifle, and still stuck with a long action. The reason that most people like the .308 is because it has good performance and comes in a short action, with a short bolt throw, and plenty of kinetic energy in a .30 caliber bullet. The .30-06 betters that performance by a bit (not a ton, but some), but it goes to a long action to do it. If you go to a .308, you're going to lose velocity, and still be stuck with the long action and the long bolt throw. The only reason to build a short action caliber on a long action is basically because you want to use very long bullets (like VLD's or similar designs), and long throat them, but still be inside of magazine length. Because you don't know the specifics of modifying the rifle, and are asking for advice in caliber selection as well, it's unlikely that you have any need or desire to go with something like what I just mentioned. The .30-06 will got through barrels a bit faster than the .308, but the .30-06 still isn't overbore and isn't a "barrel burner". So you're going to give up velocity, and not get substantially more barrel life. Unless you're competing with the rifle, you probably won't ever shoot out a barrel in either caliber. There's just really no reason to "downsize" and go to something like a short action caliber like the .308 or even smaller. It would require a lot of gunsmithing including probably opening up the feed ramps, setting the barrel back, blocking off the magazines. You wouldn't ever be able to go with just factory magazines, all would have to be modified to accomodate the shorter cartridge.

That means that the only real practical direction to go would be "up", meaning to the magnums (.300 Winchester Magnum, Remington Ultra Magnum, etc). Some people like this idea because they want a "big gun", but notice I said the "idea". In terms of practicality, it's not all that practical either. The bolt face wouldn't be large enough and would have to be switched out, or opened up to accomodate the larger cartridge base. The barrel would have to be rechambered so that it could accomodate a larger cartridge. Depending on the tenon length (area where the threads are), barrel contour (how it tapers), new cartridge's chamber dimensions, and other factors, it may not be practically possible. Depending on what cartridge you'd want to go to, there may not be enough material in certain areas of the barrel to accomodate it. Even if it was possible, you'd be going to a cartridge that would be flatter shooting (a plus), but that has more recoil (a minus), and would would go through barrels faster (a minus). Again, if you aren't shooting it a lot, you probably still wouldn't run through a barrel, but it's still worth mentioning. The cartridges would be less effecient in terms of powder, and would cost more to reload (if you do), per round. For most people's needs, magnum cartridges just aren't necessary and don't fit their "needs". This is also coming from someone that shoots a magnum cartridge regularly, at least every few days, lol.

So again, what you're asking about IS possible, but it's just quite impractical. I don't know the exact specifics of all the little details of the CZ to tell you everything that would need to be done, or how it would be done. I'm very familiar with some of the modifications needed on some actions, which is evident in my sticky in the gunsmithing section about modifications for precision rifles. There may be some things not possible because of the CZ design, or that may be possible but even more impractical. The other thing that could be difficult is finding a gunsmith that would be able to do it. It's not a common modification that most smiths in the US would do, and so it may hike up the cost even more, which is already expensive. It might be quite difficult to find parts to do some of the modifications as well. If you wanted to go to some other caliber (not .308) and use the action, you might have some other options that wouldn't be quite as modification intensive, in terms of changing the action, bolts, etc. They'd still also be more expensive because you'd have to buy a different barrel and still have all the gunsmithing done.

Basically what you're talking about won't get you much more performance, and may give you less. You'll end up spending what most people would consider to be quite a lot of money. It could easily be $500 or more, depending on what you wanted done and by who. For that kind of money, you can keep the rifle you have and buy another one and have 2 rifles. If you like the CZ and just want it in a different caliber, I suggest that you just sell the rifle and buy the caliber that you want. You probably won't take a big hit since the rifle has never been fired and has probably just been stored away. I just doesn't seem like a smart move, and you'd probably be better off just selling the rifle. So what is it that you have against the .30-06 again?

I would like to ask you a question, and I'd like an honest answer. I'm not asking this to flame you, but so that I can better understand what type of modifications or chambering you might want. What exactly do you have against the .30-06, or why do you "not care for it"?[/QUOTE]

Tomcat-
You seem to really know your stuff, and that is good as you have raised some great pointers. First, I'd like to mention that downsizing was not my intention, but merely to upsize. To answer your question: after reading about 308 being the child of the 30-06, practically eliminating its parent as an "all-around" hunting cartridge, I thought well, I have enough of other "all-around" cartridges. Plus, the ballistics between the the 308 and 30-06 are unbelievably close in factory loads (I do not reload, yet). I basically saw the 30-06 as wothless and overkill for medium game. After shooting my buds Rem 700 in 30-06, well, needless to say the recoil seems worse than my 300 Win mag. Truthfully, I think I was hoping to turn it into a 300 Win mag or 300 H&H mag.
On the flip side, I will either sell it or just add a muzzle brake and use it for heavier game. You and the others have persuade me to forgoe any majour modifications.
Thank-you

[Valentin16]

Is this due to prior experience with the .30-06 round? I mean, if you never fired this rifle, how do you know it isn't a tack-driver? If you don't reload, the huge popularity of the .30-06 round will give a person the advantage of more factory loads available than probably any other round.



Not much you can do chamber wise...the .30-06 case length is 63mm, which is pretty long, 300 win mag is a hair bigger than .30-06, but there may be a safety issue if you have to remove too much metal to convert it to that.

Re-barreling the rifle or selling it is probably your best bet.

762xIan-

What I think I have against it is probably foolish. The foolish is that 308 has such similar ballistics in a smaller package and is not "overkill" to medium game. And there's the recoil that seems greater than my 300 Win mag. I thought to upsize to maybe a mag in 300 Win or 300 H&H. I will just leave it alone or sell it unfired.

[Valentin16]

Hmmm, I'm curious on if you think this would be practical to do, especially when he also left open the option to just sell the rifle. Do you think it's practical? I think it would be pretty time consuming, and may not give the best results to completely re-rfifle a barrel, and then probably also have to have it recontoured and stress relieved, and then rechambered, just go to to one of the cartridges mentioned. At that point I'd think you might as well just buy a nice aftermarket barrel with the desired bore diameter, chamber it, and go on.

Because you mates know your stuff, and there is more to it than I thought, well, I am to keep it as it is or sell it. Unsure.