I inherited a sporterized German mauser 98 from my grandfather a few years ago. After loading for it off and on for a couple years, I never could get it to shoot good groups consistently. So, I had the barrel scoped by my local gunsmith. He told me my barrel was shot out. Because of the sentimental value I decided to spend the money and have it rebarrled in 6.5- 284 Norma. After shooting some rounds for barrel break in, and some load development I started experiencing hard bolt lift randomly, but I wasn’t anywhere near max load. I also started noticing a burr on the side of the rim on the fire cases when the bolt was hard to open. Some how the brass is going in the ejector slot and getting rubbed off when I open the bolt. I took it back to the gunsmith, and the only thing he could come up with was the bolt and the receiver may have some slop in it. Has anyone ever experienced this or have any ideas what might be causing it?
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Gunsmithing Sporterized Mauser troubleshooting
- Thread starter Plcoffman910
- Start date
I don't know the answer to your question. But have one for you.. how do you rebarrel to a smaller diameter round? I assume your model 98 was 8mm how do you go to 6.5? Why did you choose 6.5 - 284 Norma instead of 6.5 CM?
Thank you
Thank you
Take off old barrel.
Thread on new one that has a smaller hole in it.
That would be a rechamber and possibly a set back. Wouldn't be beneficial to do in that case since the barrel was shot out. It's not the chamber that goes bad. It's the throat and lands / groove area that goes.
Ok I will take some more pictures this evening when I get home from work, but if your looking for other pressure signs I can’t see any. The primers look fine and no swip on the back of the case.
Take some comparative measurements at and above the casehead between your fired and sized brass if you have a mike.
Looks to me like you have a concentricity problem, your barrel threads probably are not concentric with the chamber. Firing forces brass into the ejector cut, opening the bolt shears that brass flow off causing hard bolt lift/opening. You mentioned the problem is intermittent, is it or is it not. Another thing, the case head looks stretched or is that just the camera angle. If you still own brass from the rifles previous chambering that my be worth a look as well, perhaps the same problem existed there, which would suggest bore bolt location issues with the action.
Try a different brand of ammo or brass. You may have a bad batch of brass that is too soft. That would result in a round primer but pressure signs in the case. Unlikely but possible.
Also, who made the action? Post some pics of it if you would.
Additionally, notice that the “only” thing your gunsmith could come up with was that there was some slop between bolt and receiver. If it wasn’t doing this before and is doing it now odds are it is something that he did that caused it. I would avoid using him again until you learn what happened to this rifle and whether or not it was his fault.
Gunsmiths are either the best or the worst people ever.
Additionally, notice that the “only” thing your gunsmith could come up with was that there was some slop between bolt and receiver. If it wasn’t doing this before and is doing it now odds are it is something that he did that caused it. I would avoid using him again until you learn what happened to this rifle and whether or not it was his fault.
Gunsmiths are either the best or the worst people ever.
Mausers are controlled feed are you feeding them all from the magazine? If you're forcing the extractor over the rim that could be contributing to the issue.
On the other hand it looks like the extractor is digging in the the rim as the bolt rotates. If the case head of the 6.5 284 is larger than the original cartridge the extractor should have been modified to accommodate it otherwise the extractor claw radius is too tight.
On the other hand it looks like the extractor is digging in the the rim as the bolt rotates. If the case head of the 6.5 284 is larger than the original cartridge the extractor should have been modified to accommodate it otherwise the extractor claw radius is too tight.
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I am using brand new lapua brass, which i guess could be a bad batch, but with lapua’s reputation I wouldn’t think so. Everything I have fired so far has been brand new and full length resized on a Redding type S die. One of the last tests I did I shot over a magnetospeed chronograph but did not shoot for group. I loaded 140gr Barnes matchburners with 51.4gr of RL 26, .020 off the lands. Max for that load is 54.1 gr at 2938 FPS. 1st shot was 2695, 2nd 2723, 3rd 2725, 4th 2704, 5th 2719. SD was 13 and ES was 30. The first 4 I had the bur issue and the last did not. The gun was originally barrel in 25/06 which I believe is a higher pressure round and I did not have this issue. I also took measurements of fired and non fired brass and every point was .001 to .0015 larger on the fired brass. Here is a picture of the markings. Thanks for the help
I would still take a look at the extractor to see if there is a sharp edge on the claw. Also the bolt face itself. The extractor was probably removed for rebarreling and a headspace gauge is really hard it could have kicked up a burr somewhere during checking.
My sporter 98, man makes me sad even saying that, had/has the same issue. See if you can get good groups with it. Mine shoots ridiculously well, it will stack 5 130 grain eldms in to a pretty solid single hole. with the loose tolerance in my bolt and receiver, along with a pretty ugly extractor that I think still carries with it angry curses from nazis, I get torn up rims. My heavy bolt lift I fixed with some gentle lug lapping that made sure my bolt face was more square with the chamber and I think fixed any issues I might have had with pressure. I'd look there, disassemble your bolt and see if it is rough on the claw extractor. Could use a stone on it to flatten out any burs on the back face of it. How does it feed? Does it pick up rounds from the mag easy? Then I'd use a little lapping compound on the bolt lugs till the bolt falls like warm butter. That's what I'd do, or take it to a different smith with your torn up cases. If you're anything like me that'll take to long though and you'll diy it haha.
Sorry I thought you were asking for the rim diameter not the base. I don’t think the claw is high enough to touch the case head.
I’m going to take a sharpie and mark up a case so I can find out exactly where the scrape is occurring and then go from there.
You can see in the picture that the crescent is well below the case head so it should have nothing to do with it. I also fired a couple more rounds this evening with sharpie on the rim and I can tell it is the right side of the right raised part of the ejector slot so I filed it down a little. After seeing this I know the brass is not flowing into the ejector slot. Either the bolt is miss aligned and pushing on the brass and it pulls up the bur when I open the bolt after firing or the case is sticking in the chamber and when I open the bolt it pulls up the bur. I wont be able to shoot any more till later in the week to see if that helps.
That makes perfect sense due to the direction of the bolt rotation and that the extractor tension pushes the case in it. That ejector slot is a cutting edge. Adjusting the extractor tension may fix the problem or modify the bolt face. I don't think it's the chamber, if the chamber were misaligned you should see a slight jog in the case head alignment of a fired case.
I don’t think so, because when the bolt is closed the extractor claw is not opposite of the ejector slot any more. They are 90 degrees from each other. The claw stays on the side and the ejector slot is on top.
Yes that is also what I found when I did my research. Someone told me that it was made post war, probably by slave labor and the tolerances where not as good.
Produced post war by slave labor...uh huh.
Germany produced more weapons of all kinds in 1944 than any other time during the war, and even at this late stage they were still producing good quality items for the most part.
All military 98 Mauser(and most commercial) actions are a bit loosey goosey compared to other types, it has nothing to do with poor quality/tolerances, it's by design, they will function anywhere in the world under the most adverse conditions that would cause other designs to fail miserably.
Germany produced more weapons of all kinds in 1944 than any other time during the war, and even at this late stage they were still producing good quality items for the most part.
All military 98 Mauser(and most commercial) actions are a bit loosey goosey compared to other types, it has nothing to do with poor quality/tolerances, it's by design, they will function anywhere in the world under the most adverse conditions that would cause other designs to fail miserably.
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It didnt do it before, thus it is a new part (barrel) causing the problem or you have an issue with tolerance stacking. Tolerance stacking should not affect it in this way. I tend to agree with satterlee that the chamber is misaligned. Look at the angle the cartridge sits at on the bolt face.
I would think if the chamber was misaligned it would do it all the time. The case doesn’t look straight with the bolt in the picture because of the way the claw holds it. It has some slop. When the case is inserted in the chamber and the bolt is locked the case should straitened itself with the chamber and the bolt face. The gun smith that put on the barrel told me he lapped my lugs but told me you can’t true up the bolt face on a Mauser.
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