98 mauser shooting problems

[dirty-06]

howdy i have an oberndorf 98 mauser chambered in 308 norma magnum and i loaded up some 165g hornady bullets took in out and was clover leafin my shot group. i went and took it out today and at 100yds with the same ammo the bullet was hiting the paper sideways.73111 what would do this? i cleend it and it did the same thing but with every other bullit powder combo i try i get bout a 6" group

[Sergeant Earthworm]

strange that you were getting clover leaf groups before and suddenly it went to ****. sounds to me like a damaged crown, improper headspace, or bullet seating depth are possibilities. also possible that the barrel is shot out or the load is way too hot. could be a combination of these or other factors.

[waksupi]

Check scope mounts. Probably the culprits. If not, had you taken the gun apart? Incorrect tension on the screws on re-assembly can also cause accuracy problems.

Oops, just caught the keyhole thing. Wrong size boolit.

[uscra112]

Badly fouled bore ?

[Sergeant Earthworm]

that would have to be a seriously fouled bore.

some years ago I had a rifle that keyholed, cause was a damaged crown. a gunsmith worth their salt should be able to tell right away and with the right tools the fix (if that is the problem) is not terribly difficult.

[swheeler]

howdy i have an oberndorf 98 mauser chambered in 308 norma magnum and i loaded up some 165g hornady bullets took in out and was clover leafin my shot group. i went and took it out today and at 100yds with the same ammo the bullet was hiting the paper sideways.73111 what would do this? i cleend it and it did the same thing but with every other bullit powder combo i try i get bout a 6" group

An 8mm Oberndorf that was rechambered to 8-338(8mmPMM) Does it have the stepped military barrel? Bullet is undersized or riflings are missing.

[fouronesix]

Clean the bore completely first then slug the bore to get some idea as to dimensions and groove depth. Could very well be badly worn and "right on the edge" for standard Jbullet shooting- especially with "mag" type loads. I could easily visualize at least some wear to the lands and maybe a lot of wear or erosion right in front of the throat. The bullet could easily be skidding the first few inches of the lands before getting up to full rotation. Add to that a few rounds of fouling and it could be skidding even farther down the bore. All just guessing here but those are the things that come to mind given the rifle/barrel/results.

[FLINTNFIRE]

So I read it is a 308 norma mag. Another poster mentions an (8mmPMM) , is it the original stepped barrel or is it rebarreled ?
I guess I am wondering if you have found out the reason yet.

[roberto mervicini]

Hello Dirty-06
If you or some one cut a new chamber for the 308 Norma Mag on a 8mm 98 mauser barrel and fire the new cartridge with it, the results you are experiencing is normal.... .308 (7.62mm) bullet in a barrel that is .323 (7.92mm) it can't be accurate, the bullet will not stabilize, tumble and could be hitting the target sideways. If you kept the original 8mm barrel either military or commercial then you should recut a new chamber 8mm x .338win mag. and the problem will be corrected.

[Wayne Smith]

Hello Dirty-06
If you or some one cut a new chamber for the 308 Norma Mag on a 8mm 98 mauser barrel and fire the new cartridge with it, the results you are experiencing is normal.... .308 (7.62mm) bullet in a barrel that is .323 (7.92mm) it can't be accurate, the bullet will not stabilize, tumble and could be hitting the target sideways. If you kept the original 8mm barrel either military or commercial then you should recut a new chamber 8mm x .338win mag. and the problem will be corrected.

Or, now that you have fire formed brass, simply load an 8mm (323) boolit in your cases and see how they shoot. You probably now have an 8mm Norma Mag!

[roberto mervicini]

Or, now that you have fire formed brass, simply load an 8mm (323) boolit in your cases and see how they shoot. You probably now have an 8mm Norma Mag!

Yes this is one option provided the trout is ok for the 8mm bullet, assuming he had re-chamber with a 308 norma mag reamer this rifle has no trout for the 8mm tip. Also he need to fine a reloading die for the 8mm x 308 norma mag.

20 plus yrs a go I re-chamber a Brno ZG47 from 8mmx57 to 8mm x 338 win mag. Since already own few 8x57 rifles, this wast was the easy and inexpensive way to proceed. The rifle turn out very accurate with a flat trajectory .
I reload with 338WM brass, neck down to 8mm, my gun like 200 grain tip Speer spitzer and or Nosler partition over a healthy load of IMR 4831, never bother to check the fps, may be one day I will get curious and put it over the Crony.
At the time a tooling company in Ohio made the reamer and the reloading dye for me, if interest I could look up the name and address and post it provided they still in operation.

7336173360

[Char-Gar]

Take a good look at the loads that keyholed as they are not the same as the first batch. Look for undersized bullets....

[swheeler]

yes this is one option provided the trout is ok for the 8mm bullet, assuming he had re-chamber with a 308 norma mag reamer this rifle has no trout for the 8mm tip. Also he need to fine a reloading die for the 8mm x 308 norma mag.

20 plus yrs a go i re-chamber a brno zg47 from 8mmx57 to 8mm x 338 win mag. Since already own few 8x57 rifles, this wast was the easy and inexpensive way to proceed. The rifle turn out very accurate with a flat trajectory .
I reload with 338wm brass, neck down to 8mm, my gun like 200 grain tip speer spitzer and or nosler partition over a healthy load of imr 4831, never bother to check the fps, may be one day i will get curious and put it over the crony.
At the time a tooling company in ohio made the reamer and the reloading dye for me, if interest i could look up the name and address and post it provided they still in operation.

7336173360

nice wood!

[fouronesix]

Since it was brought up, who in the world would run a 308 Norma Mag reamer into an 8mm bore? Then somehow forget to mention it or it gets passed along as a 308 Norma Mag.... Then 30 cal bullets cloverleaf one time out. Then keyhole the next??? Whew, I'm missing something here. I'd think slugging the bore would answer that question.

[roberto mervicini]

nice wood!

Thanks swheeler, Honduras rosewood .

[swheeler]

Beautiful!!!!!!!!!!

[dirty-06]

sorry its been so long i dont get on much. it was one of the mausers that where sporterized in the 50's to 30-06 and came by the boat load by sears and montgomry words and others. then befor i got it some one changed the bolt and remed out the barrle to 308 norma. i cleened it. with rem oil but looking for some copper lead salvents. it did the same thing but 15 shots later it was shooting strait again but in about a 7" group?????? shot the same ammo out of my dads 308norma mauser and it shot decent so ikd. next step is to bring it to a decent gunsmith. i live in wyo. so we dont have much humidity but my guns sit in a rack under my window and i left it opne one night and it rained lightly and drips wher on my gunz when i got up to shut the window. could this be it? but none of my other rifles be afected?????i also slugged my bore it came out at .306 ish wasnt a very good slugging. 73462

[FLINTNFIRE]

Well that answers the question as to caliber , and bore .

[roberto mervicini]

........... i live in wyo. so we dont have much humidity but my guns sit in a rack under my window and i left it opne one night and it rained lightly and drips wher on my gunz when i got up to shut the window. could this be it? but none of my other rifles be afected?????i also slugged my bore it came out at .306 ish wasnt a very good slugging. 73462

I do not think the rain could cause the problem, is not worst than hunting in a rainy day.........
Once I had a problem with a new Browning .338 out of the box first box of ammo perfect than start to spread big time, change the ring, still no good, I was planning to replace the stock regardless, don't like plastic, I fit it in a nice thumbhole laminated with glass bedding and post and still didn't work ....I never taught changing the scope since good quality and also brand new.... it was the scope.