Junk in 40sw bbl, stumped

[popper]

40 SW 180 LTC max 231 load various lubes. 1st 2 shots were with 2 cycle oil. Left a grainy particle looking deposit (look like powder grains) at chamber end ~ 1/4" long, 1/8 wide. Same deposit still there after 200 rnds. Didn't come out with brush, most everything else did, including minor leading. Took ~ 10 passes (scrubbing) with chore boy to get it out. Eds red got the black residue out, no problem. Haven't used copper for > 2000 rnds. I have seen a few specks like this before but they came out easily. Any ideas?

[Wayne Smith]

"1st 2 shots were with 2 cycle oil" as lube?? What do you mean?

[popper]

Just used echo ashless cycle oil as CB lube. CBs are pure/tin. Looked down the bbl and saw this junk. Visual appearance is like a sparse streak of black sandpaper grains. No, I couldn't recover any when I used the chore-boy. Fired the other 198 rounds with various lubes. So much for the myth that firing known non-leading rounds will clean it out. I might try some COW blanks for the next trip. This is the most difficult junk I've ever had to clean out. All were on paper @ 7 yds, but no groups. I US clean the cases - doesn't always get them perfectly clean. Maybe it was primer residue or built up carbon deposit from previous loading? Just wondering if anyone has run into this problem before.

[groundsclown]

Just used echo ashless cycle oil as CB lube.

Just wondering if anyone has run into this problem before.

Not me but then again I use a proper lube & not 2 cycle oil.

[popper]

I use a proper lube & not 2 cycle oil Just doing some experimenting with results from extreme lube thread. I use this stuff on my sprue plate and have 2 15 yr old ryobi weed whackers that run fine using it. I shot another 48 of the same and bore condition didn't change much - so I don't think it is the lube. Another 100 with canola oil, 50 canola/carnuba, 100 with PB and no major changes in bore. Some leading but nothing I haven't seen before. My conclusion is whatever happened in the 1st 2 rounds spoiled the rest of the day.

[Dan Cash]

Since oil does not stick like bullet lube, I suspect you have some soldered on leading. Try several tight fitting patches wet with turpentine ( you should have to use a mallet to drive the rod through the bore). After patches, scrub with bronze brush or chore boy wet with turpentine then repeat the tight patch routine. If it is lead, you will see gobs come out pretty quickly.

Another approach is a tight patch soaked with Go-Jo hand cleaner. It does not seem to harm the bore but it surely brings crud out of the bore.

[popper]

I use kroil, kerosine and atf for cleaning, has always worked well. I used the bore brush, tight patches, wet patches and finally wet choreboy on a brush. Only the last worked with a lot of scrubbing. I've seen the micro lead bbs, plated lead and the black junk when using LLA, this was different. Just have to chalk it up as a mystery, if I see it again I'll pack up and go home. I usually carry a choreboy brush inthe range bag but it wouldn't have helped much this time.

[texassako]

You said it was an ashless 2 cycle oil. Is it TCW or API rated? TCW is for low temp engines like boats and can cause fouling and plug problems in hotter running engines. I bet the heat and friction did something similar in your barrel.

[popper]

Jasco-FC and ISO LEG-D rated synthetic, petroleum based small air-cooled high temp engine oil. I use it for sprue plate with no problems. If the lube, it should, I think gotten worse with the next 48 rounds, it didn't. Strange stuff happens.

[groundsclown]

another 100 with canola oil, 50 canola/carnuba, 100 with pb and no major changes in bore.

pb = ?

[popper]

Pure Pb with Sn added, an oops, I thought I had a bar of #2. Accuracy isn't great but OK. I do have a batch of the proper alloy also, but as I am testing lube and trying to eliminate a terrible flinch I developed (and it's too darn hot to cast more), I'm just shooting them up. PB is peanut butter and it does work. I'm looking for completely self purging lube. It only leaves a slight oil film behind. I'm looking for a 80 mesh peanut flour so I can try AC, rock drill, ZDDP oils. The nut absorbs oil readily and is hard enough for scrubbing but not so hard as to damage the bbl. It leaves the CB at the muzzle, doesn't get hard at -20F, doesn't get runny at 120F, doesn't contaminate the powder. The canola oil only provides no leading to 2000 fps, fastest I can go with 308, 30-30 & 40sw. It is a little messy hand applied but I've worked around most of those problems. My personal opinion is that was is OK for floors but goes semisolid just after a shot and accumulates . LLA/Recluse is good but still accumulates. My testing is 70-107F, this fall I'll try cooler weather. Enough of that. As far as this threads problem I guess I got some unknown contamiate in those loads, I'll wait till I see it again, if ever.

[groundsclown]

PB is peanut butter and it does work. I'm looking for completely self purging lube. It only leaves a slight oil film behind. I'm looking for a 80 mesh peanut flour so I can try AC, rock drill, ZDDP oils.

:veryconfu

360 views and I CANT be the only one thinking Jiff or Skippy belongs on bread and not a grease groove.
But hey. Whatever floats your boat.