Borescope of lube deposits.

[BRatigan]

Here are some pictures of lube deposits left in the bore of my M73 357 Mag Sporter. I am working up loads using different alloys, so the weights and hardness vary. My first attempts leaded badly where I tumble lubed by itself with BHN 12 alloy. I decided to overlube the bullets and change powders, so I tumbled in Xlox, then sized to .358, then lubed in my Lyman 45 using a .3595 die and Carnauba Blue from White Label and then tumble lubed again in Xlox. Of course, I let the Xlox dry after any coat was applied. My powder of choice is HS-6 with this experiment at 7 grains, bullet weight was 174 grains BHN 11.8. That mix produced a fairly close ten shot group at 50 yards so it's a good start.

Now after the range session I needed to see what leading if any was present in the bore. I ran the scope down her and found zero lead accumulation. Some unburnt powder, just a couple of grains really left behind as I used Small pistol primers not magnums. The coolest part for me was to see blue lube deposited throughout the bore in thin streams. I had a lube star also at the muzzle crown. I was very happy with that result. This lube combo might smell like crayons but is clean and works very well over a 24-inch barrel. Fine tuning the powder charge will tighten things up. The numbers were also pretty good with average fps at 1251, ES at 56 and SD at 15. No signs of pressure. I think I can achieve 1350 fps.

The second picture is the throat area where the blue lube is as well. The above lube is awesome for me. Cleaning my rifle was a snap.





After a careful look at previous targets I came to the conclusion that I will size to .3595. That sizing in previous loads was actually superior to .358 for my gun. The group sizes were very small at that dimension. I firmly believe that lube in the proper amount and type had the biggest impact on not leading the barrel. I already had the groups but was not providing enough lube and I went down a size thinking it would help. Better fit was at .3595. Groups shrunk. BHN of 12-15 is the hardness. Next batch should prove out and get me a solid consistent load at 174 grains. I'll keep my powder charges consistent.

[stubshaft]

Neat

[georgerkahn]

Interesting, to say the least, that you, "and Carnauba Blue from White Label and then tumble lubed again in Xlox"! I have never thought of lubing (re-lubing?) lubed bullets, and I will surely file this trick away. I have used/enjoyed performance of the blue lube Magma (Star people) purvey: perhaps the same stuff?
Congrats on your results; and, thanks for the tip!
geo

[AnthonyB]

georgerkahn; the Magma blue and White Label Carnauba Blue aren't the same. The WL blue is softer, but you are the third person in recent weeks to share stories of success with the Magma version. I've a large quantity of it acquired with a newly purchased Star with air cylinder and have been pondering filling it with the WL blue but may try the Magma after all the good publicity!
Tony

[TD1886]

The lube sounds close to LBT Blue bullet lube.

[243winxb]

I double lubed for this test. Maybe its the lube? A lube star should be on the muzzle in 50 shots or less.

[TD1886]

I double lubed for this test. Maybe its the lube? A lube star should be on the muzzle in 50 shots or less.

Unless I missed it what was the velocity of that load? I use to shoot 10.0 grains of Unique with a 240 grain cast bullet.

I swage shotgun slugs, Foster type, for my 20 gauge BPS Browning with a rifled Browning barrel. They are full bore size not put in a plastic wad. I lube so I devised a way to knurl them I spread a very thin layer of lube with my fingers over the knurling and I do say it's minimum lube, but yet is leaves a lube star, if you want to call it that, on the muzzle as the muzzle is very thin as you can imagine. It's wet and I'm happy with it and I'm not getting any leading. The alloy is close to pure lead, but it's hard to get pure lead unless you buy it.

[243winxb]

No chronograph. Sold it back in the 70s. Sky screens were new then. The older ones had cardboard with a copper wire running thru it to trip the timer.
Used to load all 296 maximum loads. Me & gun getting old. The m29-2 was back to S&W for barrel set back, misc parts replaced. The 10 gr of Unique are a little easier on both of us.

[TD1886]

No chronograph. Sold it back in the 70s. Sky screens were new then. The older ones had cardboard with a copper wire running thru it to trip the timer.
Used to load all 296 maximum loads. Me & gun getting old. The m29-2 was back to S&W for barrel set back, misc parts replaced. The 10 gr of Unique are a little easier on both of us.

Thanks and yeah that 10 grains of Unique is kind of a standard mid range load for the 44 Mag. My Unique load for my 357 Mag is 6.0 grains with a 150 grain bullet.

[georgerkahn]

No chronograph. Sold it back in the 70s. Sky screens were new then. The older ones had cardboard with a copper wire running thru it to trip the timer.
Used to load all 296 maximum loads. Me & gun getting old. The m29-2 was back to S&W for barrel set back, misc parts replaced. The 10 gr of Unique are a little easier on both of us.

You bring back memories -- both good and bad. My first chrony was an Oehler that had four Nixie tubes -- vacuum tubes with dots at top end -- only one of which stayed lit on each of themto enable determination of velocity. One had to write down which dot was lit, and then look up on a chart/table to determine actual bullet speed. Mine used paper, but it probably pre-dated copper wires as it was similar to a more modern printed-circuit board -- solder adhered/embedded to the paper, which was roughly the same thickness as standard NRA target paper.
A couple other fellows owned the same chrony, and my "job" was to ("government job at work" -- shhhh!) melt solder in to bridge the holes. I still recall using an Ungar soldering pencil plugged into a Variac to control temperature -- jussssst enough to melt the solder without melting through or burning holes. I recall the paper burned at a hair above 450*F (233*C) so the repair was kind of a real challenge for me. I did NOT have 100% success ) The Oehler batteries, too, were heavier than the proverbial dead minister as well as quite costly. Another fellow had fire extinguisher/alarm maintenance in his job description, so a Jerry-rigged truck battery plus a series of 1 1/2 volt ADT alarm batteries gave us power at the range. NO printer there, or at the time, even at home.
The good ole days....
geo

[TD1886]

The chronograph to have is the Labradar. It does is all except pressure testing. It also tells you the BC as far as you want to know.