anyone do barrel lapping in Canada ?

mbogo3

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I have a re-bore that holds accuracy for a dozen shots then throws bullets. I believe it is cut rifled . I have used cast exclusively and this was happening then tried jacketed with the same results.It seems to foul quickly is there anyone that hand laps barrels and would this be beneficial? I don't have a bore scope BTW.
 
Read up on fire lapping.
I have done it with good results.
Before Precision Shooting closed its doors, Merrill Martin wrote that diamond paste did an even better job. I got some from eBay or perhaps Amazon.
It seems to work well, but I haven't used it much.
 
Get yourself a cheapo amazon borescope to see what you’re dealing with. If it’s minor you can try fire lapping or paper patching to smooth things out. If it’s rougher, casting a lead lap is something that can be done at home too.
 
Read up on fire lapping.
I have done it with good results.
Before Precision Shooting closed its doors, Merrill Martin wrote that diamond paste did an even better job. I got some from eBay or perhaps Amazon.
It seems to work well, but I haven't used it much.

I have a fire lapping set and tried to save a win .338 that the factory rifled with a chimp and a cleaver. Re-barreled it. I need a scope to see what the issue is. Don't want to FU the barrel.
 
Get yourself a cheapo amazon borescope to see what you’re dealing with. If it’s minor you can try fire lapping or paper patching to smooth things out. If it’s rougher, casting a lead lap is something that can be done at home too.

No point if you're only going to use it once.I'll find a smith somewhere with one.
 
I've had similar issues with barrels

I picked up a very clean looking Rem 700 barrel in 6.5x55 and it was a ''rebore'' done by Ron Smith on a worn out 223 varmint contour 24 inch tube.

It looked very smooth and shiney at the gun show and for $50 I was willing to take a chance that if there was something wrong with it, I could likely make it work anyway.

You want to talk about fouling, this was the worst fouling barrel I've ever had.

I contacted Ron Smith about it and he wasn't interested at all. I don't blame him, no one can predict what will happen to a barrel, once it's installed by an amateur.

Anyway, I cleaned that darn bore several times before I decided to "lap" it.

I lapped it with 000 steel wool, laden with "Motty's Bore Paste" mixed with a bit of very fine "Diamond Paste" the Red Grade. I use this stuff sparingly as it's quite aggressive and very expensive.

I gave it 20 strokes, all in one direction, pulling the jag off the end of the cleaning rod and reattaching it for the next pass.

This really made that bore shine and it did help to bring the fouling down, but not to the point it was useable IMHO.

So, I repeated the above process, but this time with 000000 steel wool.

What happened surprised me.

After wiping out all of the residue, I looked down the bore with my naked eye and saw little bits of steel wool, just small single strands and they were stuck on the edges of the rifling

The cutter Ron had used was sharp and left a very smooth surface on the lands and groove flats but left some burrs on the edges of the rifling that were quite pronounced when I finally broke down and bought a cheapy bore scope from Amazon.

I broke down and wrapped a very tight "alter linen" patch cloth, used for muzzle loading patches, heavily coated with coarse valve grinding compound. Not something I would normally even attempt but there wasn't anything to lose by this time, soooooo.

I gave it 50 passes one way, then with a muzzle guide gave it another 50 passes the other way.

I followed this up with another 20 passes, one way, with 000 steel wool, lubed with cutting oil for drills.

After all of this, I really wasn't expecting much but when viewed with the bore scope again, everything looked pretty good. I couldn't see one burr on any of the edges of the rifling.

That barrel shoots very well and I kept that rifle for a couple of years. Put 600+ rounds down it but found it to heavy to carry in the field for what I was using it for. The fellow that has it now, lives about 25km South of Cardston Alta and uses it from his back deck to take out the Coyotes that become to aggressive with his chickens and livestock. Claims he will never sell it.
 
Typically barrel lapping involves casting a lead plug on a jag within the bore and then inducing an abrasive grit working it back and forth throughout the bore. I have never done it but there are many out there who have. As with anything the more barrels you do the better at it you get...

A cast lead lap works the whole surface evenly compared to a patch lap or steel wool which attacks edges the most.
 
OP,
Purchase a few ounces of oil base 320grit silicon carbide lapping compound.

Wet the bore w/ jag/patch/solvent.
Dab some lapping compound (250-400grit) on a clean patch.
Apply the patch to the jag.
Push into the lead & short stroke back & forth stopping shy of the crown
Flip the patch on the jag & push it thru the bore.
Repeat again.
Wet patch the bore to clean out compound
Dry patch the bore

With a wet patch,push it into the bore 3-4 inches.

IF,you can NOT pull the wet/solvent patch back out of the bore you have more lapping to accomplish.

The rod/jag/patch combination is a push fit...not a pound it thru fit.

The "FEEL" of pushing the jag thru the bore will tell the tale.

A bore scope helps tremendiously.

I've lapped numerous rifle,shotgun,pistol barrels over the years....w/out any tennis elbow issues!!
 
Coincidentally this is a Ron Smith re-bore from 30-30 to 38-55 in a Marlin 336...……………………………………….. I have a NECCO kit
 
Lapping is done with a lap; polishing is done with a resilient backing. I have used lead laps and laps of 5 minute epoxy. Lead works best because you can bump it up as it loosens in the bore. I generally use a 320 or 400 grit compound and may finish with JB on a lead lap. A lead lap will cut the high spots and allow one to produce a uniform diameter. A resilient backing will perpetuate variations in dimension.
I have often thought that a polishing bob made with leather washers might be ideal to polish, but I've never taken the trouble to try it.
 
Typically barrel lapping involves casting a lead plug on a jag within the bore and then inducing an abrasive grit working it back and forth throughout the bore. I have never done it but there are many out there who have. As with anything the more barrels you do the better at it you get...

A cast lead lap works the whole surface evenly compared to a patch lap or steel wool which attacks edges the most.

Yes, I agree but it was the EDGES I needed to clean up
 
Lapping is done with a lap; polishing is done with a resilient backing. I have used lead laps and laps of 5 minute epoxy. Lead works best because you can bump it up as it loosens in the bore. I generally use a 320 or 400 grit compound and may finish with JB on a lead lap. A lead lap will cut the high spots and allow one to produce a uniform diameter. A resilient backing will perpetuate variations in dimension.
I have often thought that a polishing bob made with leather washers might be ideal to polish, but I've never taken the trouble to try it.

Your assessment/technique is Correct,
as I was attempting to keep the process simple

hint;
a Lewis Lead Remove rubber arbor & a felt bob works wonders.
 
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