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Old July 24, 2015, 05:06 PM   #1
Road_Clam
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K98 Mauser consistiantly shoots poor

So about a year ago I bought a used K98 Yugo 8mm Mauser which seems to be in great shape. Bore looks typical rifling looks good and the major dia looks dull and gritty. I've tried shooting PPU 198gr FMJBT's with 4350, 4064 , and W748 and my Mauser is shooting only about 3.5 moa average. The best I've shot so far is 1.5 moa but in no way can I claim consistency. I had this rifle disassembled and I noticed a PO did a hackenstein bedding job using devcon 2 part epoxy. My question is how can I differentiate between a rifle that is shooting poorly from a shot out barrel , vs. a rifle that simply needs to be accurized ?
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Old July 24, 2015, 06:03 PM   #2
Paul B.
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WE need more info. Is this rifle besides the hack bedding job al basically all original milsurp gun or has a DIY sporterization job of some type been done? Maybe something in the middle???
If it still has the original military sights, I'm not too surprised that accuracy isn't all that good.
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Old July 24, 2015, 06:38 PM   #3
wpsdlrg
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Check for excessive contact of the upper handguard against the barrel. Ideally, you want as little contact as possible. Also, the bayonet mount and the front most barrel band need not be excessively tight against the barrel. Can't speak about the bedding job, but bedding military-stocked Mausers can work very well, if done properly. Make sure that the recoil lug, which on the K98 is very small, is firmly bedded against the stock crossbolt. I would also check whether the tang is firmly bedded into the stock and can't move under recoil.
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Old July 24, 2015, 07:32 PM   #4
emcon5
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if it still has a full military stock and bands, try the things mentioned in this thread from gunboards: http://forums.gunboards.com/showthre...ussian-capture

or discussed on this site under "Bedding a Mauser action"

http://www.mausershooters.org/k98k/SC_tips2.html#bed
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Old July 24, 2015, 09:36 PM   #5
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Quote:
I noticed a PO did a hackenstein bedding job using devcon 2 part epoxy
Seems to me, you already know the source of the problem.

Grind out the surface of the epoxy bedding (Devcon should be fine, unless it was a "flexible" type epoxy) and re-bed.

Suggest you give that bore the once-over (or more as needed) with a good copper solvent. Probably never been done...get it down to the bare steel.
I've also had good results using JB Bore Paste to clean up badly neglected bores after copper removal.

After this thorough cleaning, it'll likely shoot like crap for a few rounds until a baseline of copper fills the imperfections in the leade and grooves- then it should improve (until it fouls too much again).

JMO...YMMV.
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Old July 25, 2015, 07:52 AM   #6
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Optics or issue sights?
The issue sights may not provide sighting consistency adequate to produce smaller than 3.5" groups.

The rough bore may or may not seriously affect accuracy but will likely increase pressures. Some careful use of an abrasive may slick up the bore and improve accuracy to boot.

The full length stock and handguard can cause accuracy problems regardless of other factors. Relieving pressure points or uneven stock pressure may help but is laborious and sometimes frustrating.

I have a couple of 8x57 Mausers and once bought a mixed lot of bullets. I tried the 125's(?) and 150's w/o usable accuracy. Finally tried Nosler 180 BT and WOW both rifles shoot quite well with that bullet. The 185 Remington CoreLokt did fairly well, also.
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Old July 25, 2015, 09:42 AM   #7
Road_Clam
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I had planned on doing a more quality bedding job anyways. I think I will also try some bullets in the 175gr weight to see how they shoot. I'd like to shoot my Mauser out to 600 yds but before I do I would like to get consistiantly under 2 MOA .
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Old July 25, 2015, 02:27 PM   #8
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I would check the crown. If it is out of round due to a bad cleaning rod it doesn't matter how good a bullet you use. If it is out of round the only thing to do is have the barrel recrowned or counter bored.

But speaking of bullets, PPU 198gr FMJ bullets are not exactly noted for extreme accuracy. Even with M80 ball in 308 I don't expect more than 3.0 MOA from even very accurate rifles.

I've had good luck with 185gr Rem with 45 gr of IMR4064. Easy on the shoulder and more than enough for deer. Easily under 2 minutes with two different Mausers.

Also remember that a consistent 1.5 minute group was "sniper grade" in WWII, so try to have realistic expectation.

Good luck,
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Old July 25, 2015, 02:43 PM   #9
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I found that mine would not shoot the usual sS bullet, which has a rather small bearing surface well. You might try some FB softpoints, if you can afford it. I went to a 220gr cast bullet with 26gr of RL-7 which does very well.
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Old Yesterday, 09:24 AM   #10
Road_Clam
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So last night I did some research on Mauser bedding as suggested. I then began to give my rifle a close "interference inspection". I found out I have stock pressure at several points along the barrel including the bayo lug. So what I found out was that if I added shims to a total of .017" at the front of the action I am able to achieve about a .015" free float barrel clearance all the way down the barrel. I had to do a lot of stock sanding to achieve a consistent clearance , especially to the top handguard cover. So hopefully shimming the action and the Devcon bedding I should have some better accuracy. I'll take pics as I make progress. Thanks for all the help !
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Old Yesterday, 01:30 PM   #11
T. O'Heir
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"...shooting poorly from a shot out..." Slug the barrel. Hammer a cast bullet or suitably sized lead fishing sinker through the barrel with a 1/4" brass rod and a plastic mallet and measure it with a micrometer. 8mm Mauser should have a .323" groove diameter. Plus 2 thou, I think.
Also look at the rifling for clean and crisp edges.
Sounds like it's more likely to be that bedding job though. Inconsistent accuracy usually is the bedding.
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Old Yesterday, 02:34 PM   #12
Road_Clam
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Here's a typical 4 shot group , and this is actually one of my better groups. You can see how my shots are all over the place. I shot these at 100 yds and off my custom rest.



I got all the old crap epoxy removed from the stock and did a lot of finish sanding to get the barrel free floated. I used some high strength Devcon wear resistiant putty #11410 . Seems to be ideal for a bedding job , and I get it for free from my work !

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Old Yesterday, 03:36 PM   #13
wpsdlrg
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Devcon is great stuff. I've bedded every rifle (I've ever bedded) with it. Be sure to check that the recoil lug on the bottom of the receiver is firmly seated against the stock crossbolt. Add shims if necessary. Without that, you'll likely never get real accuracy.
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Old Yesterday, 05:35 PM   #14
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Not familiar with that type, only ever used the 10110 steel putty. As long as it's got near zero shrinkage it'll be fine.

Let us know if it helped.
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Old Yesterday, 07:36 PM   #15
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I can see part of your problem from the picture. There's no way you can achieve a solid cheekweld with the combination of low comb and "towering" scope mount. Fix that counter-productive combination and I'll bet your groups tighten right up.
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Old Today, 05:03 AM   #16
Road_Clam
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Quote:
Originally Posted by Mobuck
I can see part of your problem from the picture. There's no way you can achieve a solid cheekweld with the combination of low comb and "towering" scope mount. Fix that counter-productive combination and I'll bet your groups tighten right up.
Yes it looks to be an issue, however when I shoot this rifle I use a Blackhawk adjustable cheek pad which is not in the pic. It's not my hold or mechanics.
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Old Today, 05:12 AM   #17
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Since you've scoped the rifle, why not punch out the rear sight- that'll let you put some lower rings on and drop the scope down to where it should be.
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Old Today, 05:59 AM   #18
Mobuck
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With that much scope height above boreline, you have the potential for significant variations of POI due to the slightest(even un-noticeable) amount of scope tilt. Your group shows 2 pairs of two shots each close together but separated by a couple of inches. The target has no + reference lines to assure the crosshairs are being held consistently vertical.
I'm not so much questioning your shooting ability as pointing out what I see as a potential cause for the problem.
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Old Today, 07:00 AM   #19
tobnpr
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Cant error is typically more of a long-range issue- but you make a good point. Without a reference on the target, it could have a measurable effect even at such a short range- but he would have needed to be really canting the rifle.

One degree cant = five inches at 1000 yards:

http://www.accurateshooter.com/optic...int-of-impact/
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Old Today, 08:34 PM   #20
James K
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I hate to be the bearer of bad news, but that is a military rifle and 4" groups were considered acceptable. You might try other ammunition, and other bullet brands in your reloads and things might improve. But that rifle was not made as a 600 yard target rifle and it might be both frustrating and expensive to try to make it one.

Jim
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