Kar 98k

[RyanJames170]

So I have a complex question here guys.
My kar 98k ended up getting some leading in the first 5 rounds and I think it’s probably due to a little pitting in the barrel and what I was wondering is what I should do, and can do about this.

Also dose 8mm mauser have a big variation on bore size? Like 303 British dose?

[HangFireW8]

I have a salt n pepper bore Turk that I shoot lead in all the time.

My secrets are...
Remove all previous fouling
Polish with Flitz, or whatever
Run a patch of your lube down before each session
Be generous with a quality lube
Put LLA on top of that

and finally

Accept that it will never be perfectly clean... At best, perfectly seasoned.

[TNsailorman]

My experience with mausers is that since they were made by so many countries with varying skill levels of workers makes them have variances in bores as well as other shortcomings. I have used military rifles since I was a teenager. I have found that a mixture of Kroil and J B's bore polish will not only clean lead but copper fouling better or as well as than anything else that I have tried . I clean the powder fouling out with either Butches bore cleaner, Hoppe's or CLP. Then I start working with the Kroil & JB to remover either the copper or lead. The JB will also polish the bore as well as clean it and I have found that over several cleanings the fouling slowly gets easier to remove because of a smoother bore, which you can actually feel as you run a patch down it. my experience anyway, james

[RyanJames170]

So you guys are saying to polish the bore and then coat the bore with some lube prior to shooting?
If so how would I go about polishing the bore?

Would running some gas checks help out with any possible issues?

[tmanbuckhunter]

Fire lap it with some PC'd cast boolits with 400grit lapping compound smashed into the grooves with a patch of that run down the bore, or use Tubbs final finish. It won't be perfect, but it will help.

[RyanJames170]

I’m not set up currently to do PC bullets so that option is kinda out.

[TNsailorman]

The Kroil & JB bore cleaner/polish that I mentioned use a cleaning rod and patches on a bore jag, Same as cleaning, just work the JB back and forth about 4 or 5 time for each shot you have fired. Refresh the JB when it appears to have worn off the patch. I don't recommend fire lapping. It will smooth the bore some when used correctly but at the expense of enlarging the bore. my experience anyway, james

[RyanJames170]

What your saying is to polish to bore via a snug fitting patch on a cleaning jag with JB bore compound.

I do have some fine valve grinding compound I could try, I don’t have any JB bore past though.

Would this work on rough bores too, I have a 30-06 that has either putting or just a rough looking bore.. I got the advantage of sizing bullets to .311 fir 30-06 so opening it up a lil would not be a issue with that gun.

[tmanbuckhunter]

I’m not set up currently to do PC bullets so that option is kinda out.

Do a standard boolit then and tumble it in alox after. Run a gas check when you do it.

The Kroil & JB bore cleaner/polish that I mentioned use a cleaning rod and patches on a bore jag, Same as cleaning, just work the JB back and forth about 4 or 5 time for each shot you have fired. Refresh the JB when it appears to have worn off the patch. I don't recommend fire lapping. It will smooth the bore some when used correctly but at the expense of enlarging the bore. my experience anyway, james

My experience has not been the same, but I don't fire-lap with anymore than 5 or 6 shots. If I can't get it clean in 5 or 6, then hand lapping it won't make it any better without removing the same amount of material.

[RU shooter]

So you guys are saying to polish the bore and then coat the bore with some lube prior to shooting?
If so how would I go about polishing the bore?

Would running some gas checks help out with any possible issues?

Are you shooting non gas checked bullets(plain base ) now and getting the leading ? You can shoot plain based or non gaschecked bullets but you will need to use a load that keeps the speed down around 1300 fps or less .

[waksupi]

I would say you could use another .001 on the diameter.

[Larry Gibson]

So you guys are saying to polish the bore and then coat the bore with some lube prior to shooting?
If so how would I go about polishing the bore?

Would running some gas checks help out with any possible issues?

Apparently you're not using GCs on a GC design bullet?

Before getting wrapped around the axle polishing the bore could you give us the specifics of the;

bullet (mould designation)
alloy
lube, sizing
powder/load

[RyanJames170]

The bullet mold I was using is the Lee 175gr mold
I was using a charge of unique that gave about 1480 FPS on about a BHN of 16-17

There was no gas check, and the size was as dropped at about .325 ish and the bullets were tumble lubed.

[RU shooter]

Try 8-9 grs of unique or 5-6 grs of Bullseye, red dot .w231 or similar with that same bullet if you gonna use it without the gas check

[Larry Gibson]

The bullet mold I was using is the Lee 175gr mold
I was using a charge of unique that gave about 1480 FPS on about a BHN of 16-17

There was no gas check, and the size was as dropped at about .325 ish and the bullets were tumble lubed.

As RU shooter suggests.

I generally get better accuracy with GC designed bullets sans the GC at 1200 fps or less.

Assuming LLA lube as per Lee's instructions(?) so a bit softer alloy might work better. I most often use an alloy with 12 - 14 BHN with my PB'd 8mm cast bullets. You might try a GC with your load as I get excellent accuracy with a similar weight GC'd bullet in the 1500 - 1600 fps range.

BTW; I also often use LLA and TL my low end bullets sizing at .325 and get zero leading.

[yeahbub]

". . . getting some leading. . .' Could you describe the degree of leading you speak of? A slivery-grey frost removable with solvent and brush? I get this pretty commonly, but it doesn't get any worse over a string of shots. Heavy streaking and where in the bore? This could be an indication your boolit is "running out of lube" if it's toward the muzzle. An alloy hardness/pressure match-up to get a little obturation for a good gas seal is needed, but not so much that it overcomes the lube strength and crayons lead onto the steel.

Another alternative which expands the range of usable alloy hardness over a wider range of pressures is paper patching. No lead-to-steel contact and soft lead at full pressures is a possibility with experimentation and load development. I patch conventional unsized .30 cal. cast and size to .325 for the throat in an M48 I'm playing with. Works great. In fact, This is the only instance I can get good accuracy (3.5" at 100 out of the 8mm) with a cast spitzer copy of the 173gr match jacketed - historically, a bad bet for high speed. Paper patching from the heel to half way up the ogive lends bore support to more of the boolit's length than when bare, which shortens the length of the unsupported ogive. Normally, this boolit is limited to 1400fps or so before accuracy goes south, but in the 8mm and ..30's, I can crack it out there with loads intended for jacketed.

You haven't mentioned the purpose of your cast loads. Do you intend to hunt with them or are they just for plinking? A MV of 1480 should be within reach for plain base or unchecked boolits, but Larry G and RU may have an answer in going with lower pressure/velocities, at least for experimentation. I'm not sure what "a little pitting" means, but a little salt-and-pepper usually won't preclude accuracy when loads are kept within the limits of the alloy used.

[RyanJames170]

I think that it’s a combo of lube running out, and maybe to high of pressure/muzzle velocity with out the gas check, the bullets were just tumble lubed.

What I may try is getting the lead out, and running a bit patch of Alox lube down the barrel and then shoot it and see if it still leads. If it don’t I’ll try and actually put them threw the luber sizer once I get a 8mm die and add gas checks to them as well.

[yeahbub]

I think that it’s a combo of lube running out, and maybe to high of pressure/muzzle velocity with out the gas check, the bullets were just tumble lubed.

I think you're right. It's just a guess on my part, but it's a good bet that filling the lube grooves to capacity and adding a gas check (for another lube groove) will show much improvement. Lube is a noncompressible fluid and is hydraulically applied to the bore when engraving takes place and the lands intrude into the lube groove's volume. If there's also air in the lube grooves, the lubing action will be less positive, limiting velocities. It's been my experience that, for lower pressures and velocities like "cat-sneeze" loads, this works well, but if one desires greater horsepower for distance or hunting, more will be needed. For added insurance, you might size-and-lube, and tumble -lube as well. It's hard to have too much going for you. I've used this in carbine-length barrels with boolits that don't hold much lube and the "lead frost" effect toward the muzzle is reduced.

A word on paper patching. I found with PP'd that gas checks had little effect on accuracy and I don't generally use them. The paper covering the entire bearing length + of the boolit makes for an effective seal, and there's no exposed lead to suffer gas erosion/cutting from leaks on its way up the bore. A PP'd boolit can cover several liabilities common to shooting bare cast, my favorite being eliminating any lead contact with the bore. I am then free to pursue the accuracy I desire without having to adjust alloy hardness appreciably for whatever power level I need, hence, full velocity won't require linotype or monotype to accomplish. I can do that with air cooled or quenched WW's, as long as the ogive shape will withstand the acceleration. For hunting boolits with a short ogive and flat point, range scrap at 8 BHN driven hard works fine.

[HangFireW8]

I forgot to mention, gas check and size to bore diameter or a little more. I use gas checks, water quenched WW +tin or equivalent for all rifle except 45/70 and 444, for the straight wall big bores I have some plain base. The only time I have ever gotten leading is with minimal lube and long barrels. By long barrels I mean longer than K98k. The K98k has a modern standard barrel length for bore.

[ReloaderEd]

absolutely best answer I've seen. I use valve grinding compound which has done the job in any pistol, rifle, etc. I've had problems with.