Converting a Mauser to a 7.62x39


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Ruddie
March 13, 2011, 12:45 AM
I have a GEW 98 that is a little rough around the edges. I was wondering on yalls thoughts on converting it to a 7.62x39. I have a ton of ammo and figured it would give me a fun bolt action to play with.

Thoughts?

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ColtPythonElite
March 13, 2011, 12:50 AM
It would likely be cheaper to just buy a Ruger bolt gun to shoot your ammo in.

GCBurner
March 13, 2011, 12:59 AM
I've seen chamber inserts for converting a .308/7.62x51 Mauser to 7.62x39, but if yours is a 7mm or 8mm Mauser, it will need a new barrel. That's not going to be inexpensive.

Ian
March 13, 2011, 01:11 AM
I have an Arisaka converted to 7.62x39 by the Chinese. They used an SKS barrel. Took the original 6.5mm barrel, cut it off and threaded the stub to for the SKS profile. No modification to the bolt - it feeds, extracts, and ejects pretty reliably.

I would think you could also cut back a Mosin Nagant barrel and rechamber it.

Ruddie
March 13, 2011, 04:13 AM
I didn't know if it was worth it or not to convert the rifle. I have my Mosin Nagants and my 30.06 VZ-24 to play around with. I had skimmed through a couple of articles of people that had done it and was curious. I'll probably just leave it be and buy a 7.62x39 long rifle, whatever that may be. Who knows....

Smokey Joe
March 13, 2011, 03:00 PM
Ruddie--I agree w/the above posters who say that the conversion would cost more than it's worth. And more than just buying a 7.62x39 rifle new, in which to burn up yr ammo. BTW, CZ makes a nice little rifle in 7.62x39, all set to go.

On another topic, could you please explain what you meant byI have a GEW 98 that is a little rough around the edges.If it needs a stock, that can be done. If the stock just needs refinishing, that can be done. If the rifle is battered enough to be mechanically unsound, it hadn't ought to be shot at all, IMNSHO, in 8mm OR in 7.62x39.

dirtyjim
March 13, 2011, 04:24 PM
i've seen a few sr mausers converted & numrich even sells the barrel & feed kit for them.
as far as cost goes if you have the ability to do the work yourself it is not very expensive or difficult.
most of the 7.62x39 bolt rifles on the market use a .308 barrels instead of the .312 barrels.
just have pacific grind the reamer with a slightly longer lead for a .308 barrel.

parts would run $100-150 for the barrel, $200 for the reamer & gauges, & $30 for a blank extractor. you could rent the reamer & gauges to save some money but i prefer to buy them for use on future projects.

if you have a decent smith the job should only be slightly more expensive than a standard rebarrel job. having to fit the extractor blank and soldering a bushing to the boltface to reduce it down for the x39 casehead would be the main differences in the conversion from a standard rebarrel.
sr mausers have been made to feed with a magazine spacer and i'm sure with some tweaking a lr mauser could do the same. on .223 mauser conversion a ruger mini-14 mag is cutdown & solderedd to the floorplate and i think the same thing might work on a x39 conversion.

rbernie
March 13, 2011, 06:14 PM
The .472" breech face of the Mauser will be too large for the 7.62x39 and you'll likely have extraction issues unless you have the bolt/extractor modified. The barrel will need to be replaced, and the magazine well will need to be modified to reduce the box size. Even after that, there is no guarantee that the gun will feed reliably and you may wind up having to rework the receiver rails to adjust to the smaller case diameter of the 7.62x39 round.

It really will be cheaper to just buy a Ruger or CZ.

Phaethon
March 14, 2011, 12:00 AM
If it's a nice Gewehr 98, I wouldn't butcher it. I think a Mini-14 in 7.62x39 was always an attractive option.

Vaarok
March 14, 2011, 12:05 AM
Concur on all points- why butcher a Gew, buy something else and have two guns, and it's a huge pain in the ass. A rifle designed and built for X is not really the best thing to change into Y after the fact, not even if somebody makes a kit or you're handy with tools, it's just more effort than it's worth.

dirtyjim
March 14, 2011, 12:24 AM
A rifle designed and built for X is not really the best thing to change into Y after the fact, not even if somebody makes a kit or you're handy with tools, it's just more effort than it's worth

if that was the case there would be no custom rifles and everyone would be shooting generic store bought crap. it may not be worth the effort to some but some of us actually like building our own rifles. i don't see a 7.62x39 conversion as even a slightly difficult project
.
i think the attitude against building your own guns shows just how little skill is left in the general population.
i get real tired of hearing it'll cost as much as a new remchester or it will never feed from people who have never built anything.

Ruddie
March 14, 2011, 01:34 AM
[QUOTE=Smokey Joe;7164447]

On another topic, could you please explain what you meant byIf it needs a stock, that can be done. If the stock just needs refinishing, that can be done. If the rifle is battered enough to be mechanically unsound, it hadn't ought to be shot at all, IMNSHO, in 8mm OR in 7.62x39.

Keep in mind I bought this rifle for $50 from a pawn shop buddy of mine.
The barrel has been poorly spray painted with several coats of black paint.
The aftermarket sights are rough and the front sight post has been chipped off a bit.
After removing the bolt I noticed there were a couple of semi deep rust pits on the outer surface of the bolt.
The barrel looked as if hadn't been cleaned since WWI.
The trigger guard was rusted, pitted and deeply scratched in a few places.
I got an aftermarket stock with it that was cracked long ways down the buttstock. Not bad enough to not be used. It looks as if someone tightened the top buttplate screw too much.
I had to order both action screws.
I'll try to have pics of it today sometime.

gunplumber
March 14, 2011, 06:03 AM
It is a total disservice to say that the cost of a conversion such as this is as cheap as a new rifle OR that anyone can do it at home. A bbl vise and action wrench is not mentioned (oh yeah, I forgot about the standard pipe wrench.....) I have been in the biz over 20 yrs and never met a smith that would tell you a conversion such as this is cost effective. I get to do a lot of repair that "kitchen table" gunsmiths have worked on. They pay my salary on a regular basis. What about bluing the bbl? Drilling and tapping? Bolt forging or welding? Mag box work or changing the safety (for a scope). Feed rail and bolt face work for the novice???????? I don't think so...There is a reason I don't work on choo choo trains or the Space Shuttle

Shadow 7D
March 14, 2011, 06:55 AM
Zastava makes a mini mauser, as does CZ
the Zastava was imported by Charles Daley, I think either Remington or Winchester imports them now, they are based on the K98/M48 action.

dirtyjim
March 14, 2011, 07:12 PM
the problem with 85% of the smiths today is they are assemblers instead of actual gunsmiths.
they lack the skill & creativity to overcome small problems like reducing the boltface down for the smaller casehead, modifying the extractor and solving feeding issues so they price the work where no one would have them do it.

i've seen just as many botched jobs come from smiths as i have seen come from bubba & billy bobs kitchen table.

i have a mini-mauser in 7.62x39 but a fullsize 98 would still be neat.
i think if i was to do one i would do it on a shortened turk k kale then surface grind the receiver down to resemble a g33/40. i just happen to have a k-kale action in the corner and i need another project like i need a hole in my head.

HankC
March 14, 2011, 07:20 PM
Zastava makes a mini mauser, as does CZ
the Zastava was imported by Charles Daley, I think either Remington or Winchester imports them now, they are based on the K98/M48 action.
Mini Mauser is not true mauser action. It is push feed. Most recent importer is Remington (Rem 799). I have one and the extractor chipped only after no more than 60 rounds. I want to think it is a factory defect and not the norm, but they would not repair it under warranty. By the time I noticed it, I was 15 days passed the 1 yr warranty. Now EAA is the service center for these rifles.

Edit: received my new extractor. The original one that chipped appears to be a defect. The new one is definitely more robust.

gunplumber
March 15, 2011, 10:06 AM
Anyone that gets an honest quote from a reliable qualified smith will tell you that the cost of a conversion such as this is considerably higher than buying the rifle new. A few phone calls is all it takes; while you're talking to the man, get a list of the tooling it takes to do the work, then price those. If he's truthful he will also tell you that the conversion should NEVER be undertaken by someone without the proper training (which was the subject of the op in the first place). I would think just about anything can be done if you throw enough money at it but in this instance you will fastly approach a point of diminishing returns. Most folks that want this type of work will never do it to save money; it's done because they have their perfect rifle in mind and cannot find it on the shelf. Most guns today are more accurate than the average shooter and are available for a greatly reduced price compared to a conversion.

ball3006
March 15, 2011, 01:11 PM
As posted above, the bolt face is too big for that cartridge. Also, you will not get reliable feeding of such a short cartridge in a long action and large magazine box. Extraction would be non-existant because of the large bolt face. Just buy a handi rifle for under 200 bucks and go have fun......chris3

dirtyjim
March 15, 2011, 08:18 PM
asking the smith what his equipment cost is irrelevant, he must have the equipment to do a standard barrel job. the only thing he might not have on hand is the reamer & h.s. gauges if they are not a common caliber.

it seems as though a bunch of keyboard pounders with no smithing experience have thrown down the gauntlet on this conversion and i accept the challenge and my 7.62x39 mini mauser will have a bigger brother.

after about 30 minutes of playing around with some 7.62x39 ammo and couple of my parts guns i can already see this is going to be easier than i thought.
the extractor works as is & will work even better when i solder the bushing to the bolt face to reduce it down for x39 case head.
ejector needs about .025 added to it to work reliably, it will eject as is but not as good as i would like.
feeding will need a little work. left side feeds good, right side doesn't. a new follower might fix it but i'll probably just attach a shortened mini 30 magazine to the top of the floorplate and be done with it.
reamer is about two weeks out and the barrel will be ordered on friday.
total parts should come in about $400, i'm including the price of the reamer & gauges even though they should not be included in the price of a build because they are used on other projects as well.

Ian
March 15, 2011, 09:22 PM
The 7.62x39 has a rim diameter of 11.35mm, and the 8x57 has a rim diameter of 11.95mm. My converted Arisaka uses a 6.5 Jap bolt, which is designed for a 11.85mm rim, and extracts 7.62x39 very well. It will occasionally drop the round before ejecting, but it never fails to extract it. I would think that the additional .1mm difference from using an 8x57 bolt would not change things significantly.

Here's how the Chinese dealt with the magazine length:

http://www.thehighroad.org/attachment.php?attachmentid=135819&stc=1&d=1297026231

http://www.thehighroad.org/attachment.php?attachmentid=135820&stc=1&d=1297026231

Those two tabs block the tips of the rounds in the mag and prevent them from moving forward. The top round is free to move, though.

I've seen another Arisaka conversion that used a shortened follower and a block in the back of the mag - effectively shortening the whole magazine to fit 7.62x39.

Ignition Override
March 16, 2011, 02:34 AM
Phaethon:
My nice wood/stainless Mini 30 (Mini 14 in 7.62x39) needs no work.

gunplumber
March 16, 2011, 01:31 PM
ruddie:

Make a few calls to actual gunsmiths and see what they would charge for this conversion in finished form then you can post your findings here for us all to see. It goes without saying that misinformation runs rampant on a lot of forums. It was implied by one poster that anyone can do the conversion at home which is what I took exception to and still maintain. The listed parts and minimal tooling mentioned already approaches the cost of a new gun and you're just getting started. Obviously a gunsmith will have most if not all of the tooling but if you are not one, you will have to purchase, borrow or pay a smith to do the work you can't yourself. There is a lot of diff between sticking on a bbl and finished product. Even with a pre threaded , crowned and short cham bbl, you still have to drill and tap for a scope or drill and tap for irons plus the cost of the sights, blue the bbl (hopefully with the rest of the gun so it will all match) rework the bolt (unless you use irons) just to name a couple. I have been doing these conversions for 20 years in cals from 22-250 to 458 American on the 98 actions and I don't recall a single FINISHED product that cost less than a new Savage for instance. To say that the average person (not a gunsmith with tools) can do this at home is a appalingly incorrect statement. Trust none of us; research yourself and let us unknowledgeable "keyboard pounders" know...........hehe

SlamFire1
March 16, 2011, 03:40 PM
I have a 8mm Mauser, converted by the Israeliís to 308 Win.. Does not feed reliably. I converted a 7mm Chilean Mauser to 308 Win and it feeds reliably.

Flip a coin, might work, might not.

I would not bother with it. Too much cost and you wonít get your money out of it.

gunplumber
March 16, 2011, 04:05 PM
Slamfire 1

If you don't have a short follower and mag box spacer you can obtain the kit from Sportsmans Guide. The mag spacer is scwed or epoxied to the rear of your mag box to limit cart shifting. Just cut down the spacer to size needed to allow the cart into the box without excess fore and aft play, replace the spring and follower with the new shorter one and I would think it should not need anything further. Just a thought.....

BrocLuno
March 16, 2011, 07:34 PM
Hey Gunplumber, nice to see you over here. For those of you that don't know, this is a good reliable smith. He refinished my Savage 99 in Metacol years back and it's been doing just fine since :)

I'd be taking his word on the amount involved. But, that aside - I do think that early SR Mausers are good candidates for a custom 7.62x39 bolt gun. I just wouldn't look at the project in a dollars and sense way. I'd be more inclined to look at the overall build as a decent project to get a very unique rifle. If it's done right, it should feed and fire just fine :)

Ohio Gun Guy
March 16, 2011, 07:47 PM
The cugir factory makes a machine that will dispose of 7.62x39 quite nicely. ;)

dprice3844444
March 16, 2011, 07:52 PM
nef handy rifle in that caliber single shot.

gunplumber
March 16, 2011, 07:54 PM
BroncLuno:

Thanks for the welcome pard. I don't have near as much time to play on the box as I used to. I finally found me a 99 in 300 Sav to restore. It's gonna be nice when I get it done. Glad to hear yours is still limpin along.........

Ruddie
March 17, 2011, 01:08 AM
Gunplumber-
I love to work on things but know my limits. If I did decide to convert the gun, I wouldn't even try to. Plus I do not have the right tools to do the job. As fun as tearing into a gun with a pipe wrench and power drill sounds, I think I'll pass. I have to support my local gunsmiths... Since I'm getting mixed opinions on the conversion, I'll probably just let it be. I still want another rifle that shoots that particular caliber, just not a SKS. I've had one and I didn't like it. I know different models are better/ worse.
I guess I need to rather buy some 8mm ammo or sell the rifle.
Thanks to all who posted. It helped me.
I still have the 30.06 VZ to play with after its fixed. I still can't believe someone shot the gun with something in the barrel.... Someone is lucky to still have a face...

dirtyjim
March 17, 2011, 11:52 PM
here are a couple pics of what i've come up with so far.
i have the magbox, spring & follower from a 7.62x39 mini-mauser installed inside the military magwell. the box will be moved all the way forward when its permanently mounted to the floorplate. where it sits now it would need approx .030 shim added to the follower where the arrows are for the right side to feed right. magbox, spring & follower are right at $35.
http://img.photobucket.com/albums/v36/dirtyjim/sporters/762x39%20sporter/762x39lrmauser1.jpg

http://img.photobucket.com/albums/v36/dirtyjim/sporters/762x39%20sporter/762x39lrmauser2.jpg

http://img.photobucket.com/albums/v36/dirtyjim/sporters/762x39%20sporter/762x39lrmauser5.jpg
i'll make the bushing for the bolt face this weekend & solder it on, once thats done the extractor should hold the casehead securely to the bolt face.
http://img.photobucket.com/albums/v36/dirtyjim/sporters/762x39%20sporter/762x39lrmauser3.jpg
i'll order the barrel blank tomorrow, barrel will end up around 20" long & profiled similar to the win featherweights.

the conversion can be done and it will cost less than a new savage or ruger and will be much more interesting.
gunsmiths or assemblers as most of them really are aren't the only ones with the skill and equipment to do a barrel swap or these types of conversions. in fact i would have to say the garage builders are doing a lot more interesting conversions and swapping just as many if not more barrels than the gunsmiths are.

Otis is DaMan
March 18, 2011, 07:10 AM
dirtyjim, what would be your cost, your invoice to convert Rudie's weapon as described ? Not your expenses, your invoice. Be sure to include profit. :)

snake284
March 18, 2011, 08:14 AM
Man that is no joke. My friend on another forum just finished a project of converting a 799 Remington action to a wildcat build on a .204 Ruger case, about the same as a .222 Remington case with a different shoulder angle and a .257 Barrel. The other forum named it the .257 Scooter after the one whose brain child it was who died shortly after the rifle was finished from lung cancer. His handle in the forum was scootertrash and he was a very knowledgeable bench rest shooter and prarie dog hunter. Anyway, the guy that did the actual mechanical work is a hell of Mauser Mechanic and the conversion dealt him a many a trick and problem he had to overcome. One was the firing pin hole in the bolt was too big and it blew primers. So the bolt had to be sent off to someone that deals with this that Scooter knew about, who actually put a bushing in the hole to reduce its size. Stuff like that was a real PIA for him. But being the mechanical genius he is, he overcame it all and built the rifle. Infact he took it hunting and killed deer with it. He had it honking on with a 100 grain bullet at 2800 FPS. Not bad for that little case. Anyway, this is to illustrate problems you might encounter on a build like that.

snake284
March 18, 2011, 08:16 AM
Try to find a Mini Mauser in 7.62X39. It will end up as cheap or cheaper and a lot less headache.

gunplumber
March 18, 2011, 01:03 PM
bbl 150.00, reamer 80-100.00, blue 165.00, going to use glass? add for bolt forging or welding, drilling and tapping, new safety and proper fitting.........and the beat goes on...................boltface alterations........well of course everyone can do that.........(correctly).........add price of go, no-go.......mag box alterations????......shoot yeah fellas......., I defer to snake and Otis on this one........my brain seems to have hit a slick spot...........all in fun.

BrocLuno
March 18, 2011, 01:23 PM
So I have to ask out of curiosity, if you were starting with another old 762 rifle like an 06, would there be enough safe metal in the chamber area to set the barrel back far enough to rechamber for this round? Say a beater P1917 that has been thoroughly bubba'd? That would save the cost of a new barrel?

gunplumber
March 18, 2011, 05:10 PM
There is a big diff in a 7.5 rate of twist and a 10 so bullet selection would be important, to start. The 06 cart is just shy of an inch longer and the shoulder is .441 where the base of the other is .445 or so. I don't have a P17 here to check and it's been a while since one was in but if memory serves, most chamber areas are not not long enough in fac form for this to work. It could be that they are out there with bbls good enough to warrant the work but not many I would think. Good question tho....

gunplumber
March 18, 2011, 07:26 PM
After a bit of searching I find that we have 10 sq.TPI for a length of .800 on the shank of the Pattern 17. The 7.62x39 is .830 shorter than the .06 so if you had a bbl cyl long enough on the 17 to remove the entire shank and prob the other .030 to the neck it would work. Then there would have to be enough shoulder to make suf contact, the wood would have to be replaced or prob reworked. I don't recall the contour on a 17 being long enough in the cyl to allow that much cutting and rechambering.

dirtyjim
March 19, 2011, 11:40 PM
dirtyjim, what would be your cost, your invoice to convert Rudie's weapon as described ? Not your expenses, your invoice. Be sure to include profit
around $375.00 without bluing. if the customer was to finish the metal to a 320 grit i could rust blue for right at $100.


mag box $18.50
follower $12.00
follower spring $6.00
barrel $43.00 (i'm not sure if the shank on this barrel is large enough to be re threaded for a lr but it will work on a sr or a turk k-kale. i'll know when it shows up, if its to small add another $45.00 for an a&B blank or a couple hundred for a krieger, lilja etc. if you got deep pockets.
$20.00 to make & install the bushing on the bolt face to reduce it down for the x39 case head. i made about 20 of these today.
$45.00 to drill & tap the receiver for scope mounts.
i get talley style bolt handles for $5.00 and accu-tig welds them on & finishes them for $40.00. i'll do my own handles but for anyone else it would go to accu-tig.
D.T. safety or forged left side safety $25.00 installed, forged right side safety $30.00 installed.
shipping on parts & bolt handle approx $35.00

stocking would be up to the customer but i have a very good stockmaker local that i get extremely good deals from.

Try to find a Mini Mauser in 7.62X39. It will end up as cheap or cheaper and a lot less headache.
i have a 799 in 7.62x39, i also have one in 22 hornet & one in .223. they were all bought as project rifles and the barrel action is the only thing worth keeping on them. the remington stocks used on them are the worst excuse for a stock i've ever seen on a production rifle.
i'll have around another $1200-1500 in each of them before i'm done with them.

So I have to ask out of curiosity, if you were starting with another old 762 rifle like an 06, would there be enough safe metal in the chamber area to set the barrel back far enough to rechamber for this round? Say a beater P1917 that has been thoroughly bubba'd? That would save the cost of a new barrel?
i cant think of any offhand that would have a long enough shank.

gunplumber
March 20, 2011, 12:54 PM
It seems obvious to me that your ability far exceeds the average person with regard to gun work and can only come thru experience and much time learning or with training; not to mention the tools like a lathe, welders and torches etc. Everyone should be greatly impressed; at least I am. But you list the cost of this work at 475.00 with blue and WITHOUT stock. What did your 799 in this cal cost?

HankC
March 20, 2011, 07:32 PM
I converted 2 small ring mausers into 7.62x39. Both work fine even with original extractor. One conversion, I simply use a spacer block and AR follower/spring for the mag box. While having mausers in different calibers (8mm, 308, 7.62x39), I always worry that control feed can feed a 7.62x39 in a larger chamber and allows a round fired.

leadcounsel
March 20, 2011, 10:00 PM
Militaries convert thousands of rifles only because they have millions of stockpiled rounds so it makes economic sense after investing in the tooling and skilled labor... doing it for one rifle makes zero economic sense. Sell it or trade it for one that you want.

dirtyjim
March 21, 2011, 12:33 AM
my 7.62x39 rem799 was around $450 , but it was bought as a project rifle. it along with my other two 799's will be extensively modified. i'm going to rework the bottom metal to an in the bow release drop box style like i did on my .223 rem799. weld on a scaled down oberndorf style bolt handle, quarter rib with sights scaled to the rifle. extended tangs, square bridges cut for talley rings, mill the left side of the receiver similar to the g33/40 and ad the thumb cut to make it more mauser like. the stock will be typical pre-war british style. even with me doing the majority of the work my 799's wont exactly be cheap.the stocks will be turned by a friend after i'm done with the patterns.


i've always tried to get people to at least try to do some of their own work.
my lathe was $450 on craigs list, i spent my early 20's in a machine shop so i already knew how to run a lathe, mill, surface grider and grind & sharpen all of my tooling.
my rust bluing setup cost about $200, half of it doubles as a crawfish & turkey cooker.
my welders came from pawnshops, along with a lot of my other tools.
i learn by doing and i've botched a few things but i always did it better the next time.
having the tools & thec patience to find deals on parts has allowed me to build some very nice customs for very little money.

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