Very hard bullets

[megasupermagnum]

I was getting minor leading when shooting PB cast bullets in my 327 federal. The alloy was unknown, but relatively soft, around BHN 10-11. I tried lighter loads, and I had to go to very low pressures to stop it. I decided the alloy was just not up to the 40k+ psi loads. I cast and water dropped from the mold Lyman #2, except I couldn't get the last bit of Linotype in the pot. It turns out a Lee 20 pound pot is more like a 15 pound pot. The alloy ended up closer to 90/5/4 lead-tin-antimony. I air dropped some 30 cal bullets with it, and they come out 14-15 BHN, as I expected. The 32 cal bullets that I water dropped seem to be 25-27 BHN :shock:. That's not a bad thing, but I expected 18 maybe 20. I repeated the tests 2 more times on different bullets and got the same result. This was measured with the Lee hardness tester. Has anyone else gotten results like I did? I was casting in single digit temps, the water was probably just above freezing.

[mehavey]

You are effectively shooting Lyman #2 (90/5/5) ...
and low/low-mid 20's @ water drop is normal.

Before you go all superhard, though, try your loads normal/air-cooled/BN15
(I assume you're gas-checking them?)

[megasupermagnum]

No, these are plain base, and I am shooting them as such. I should have mentioned, I shot about 250 of these hard bullets through my brand new Henry over the weekend, and there was very little crud. What little there was, came out with just a handful of passes of a bore brush.

[sigep1764]

I might try softer boolits than Lyman no 2, but maybe harder than the 10bhn boolits. I doubt boolits that hard are obturating. Also you didn't mention what lube you were using or if you slugged the barrel or what you are sizing them at? What do the cylinder throats measure or is it strictly the rifle this boolit is used in?

[mehavey]

OK. (no GC)
Still... I'm running same Lyman 44Mag Max load (20gr/2400/250gr-Lyman 429421#2 plainbase/sized .430/50-50lube/very high 30's ksi)) through both my 4" Mountain Gun/1250s and my 20" Marlin/mid 17s.
Clean as a whistle with both.

Try it. Lyman#2 is remarkable stuff as-is.

[megasupermagnum]

I think I will try Lyman #2 air cooled. Currently, I'm running these bullets in both a Ruger LCR and Henry carbine. I've also fired them in an SP101, not owned by me. It is supposed to be 120 grains with COWW, but come out about 116 grains with Lyman #2. I've found 6.5 gr Bluedot to be the safe limit, but have gone to using 5.8 due to having to seat deeper for the rifle (not that case capacity is the issue). I started with Lyman orange magic lube, didn't like it, and quickly switched to Canaruba Red. I've been using it on all my bullets with good results since. The throats on my LCR are all right around .3145"ish, and bore was a touch over .312". My Henry has a throat of about .315", and the bore is a 5 groove. I used some shim stock and found it to be about .310". When I first got the mold, I sized to .313", and got decent results from the handgun. The next batch I went to .314" and have stuck with that size. Accuracy was not good in the rifle, but I had a blast shooting steel with it. This weekend was the first time shooting it, and I was getting about 2.5" groups at 50 yards from a rest.

[sigep1764]

Just asking, but with a throat of .315, is it necessary to seat deeper for the rifle?

[mdi]

OK. (no GC)
Still... I'm running same Lyman 44Mag Max load (20gr/2400/250gr-Lyman 429421#2 plainbase/sized .430/50-50lube/very high 30's ksi)) through both my 4" Mountain Gun/1250s and my 20" Marlin/mid 17s.
Clean as a whistle with both.

Try it. Lyman#2 is remarkable stuff as-is.

Wasn't the OP 327 Fed? Or did I miss a thread drift? I have had far fewer problems with leading with my .44 Magnums than most other calibers I cast for...

[megasupermagnum]

Just asking, but with a throat of .315, is it necessary to seat deeper for the rifle?

I needed to shorten the OAL so it would cycle through the action, no other reason.

@mdi, I think he was just saying he has run plain based bullets at pressures near as high as I was, and had no leading. I am shooting the 327 federal.

Next time I cast, I'll try air cooled, and see how they do.

[mehavey]

Wasn't the OP 327 Fed? Or did I miss a thread drift?No thread drift. The topic was high-speed plain-based hardness req'd in the high 30's ksi regime

A 44Mag -- plain-based at 37,000psi using Lyman#2 in both short and long barrels -- was used as example to say the OP should consider trying standard air-cooled #2 before going more exotic.

[mdi]

OK, I see. I guess it's kinda like using my Toyota PU as an example on a Ford sedan thread...:bigsmyl2:

I'm not an expert but I believe the caliber of the lead bullet, even if similar pressures, has a different effect. My 9mm (35k PSI) will lead much more readily than a 44 Mag. (36K PSI) at the similar pressures...

Not trying to start a "discussion" just my opinions.

[mehavey]

Which is why I could also point to my 32-20 running 1,900fps with#2 (GC'd & a carbine to be sure)
https://thefiringline.com/forums/showpost.php?p=6385377&postcount=1

But real point was to get the OP to try standard #2 before necessarily moving to higher hardness.

[megasupermagnum]

Well, I've already shot hundreds of these super hard bullets, with decent results. I will try air cooled for the next run. I was mostly surprised at how much water quenching hardened them. Maybe in the future I can get away with water quenched 94/3/3 or some other cheaper alloy. I do like the tin rich alloys. I liked 20-1, but Lyman #2 casts like a dream.

[mehavey]

It's a delicate dance between soft enough to obturate fully to the groove base, the pressure rise max/slope that does that w/o gross base damage, and hard enough to still hang on to those grooves as that pressure and speed both build.

[pls1911]

Gas check bullets alone will eliminate many of the variables discussed above.
Aside from assuring the bullet base remains good and true by being protected from pressure/heat gas cutting, the crimped check is even tighter in the bore which will virtually eliminate stripping in the bore in all but the very softest metal. The check also cleans the bore every shot. You get SOOooo many benefits from so little extra effort.
Depending on many variables, a gas checked bullet cast from any alloy close to #2 should shoot fine up to 1800-1900 fps, after which a harder bullet is preferred (by alloy or heat treatment)
At nominal non-magnum revolver level pressures and velocity 750-900 fps), your plane base bullet should probably shoot fine if properly sized and lubed.
My comments are based on 38/357 in pistols and rifles, and 30/30 in competition and many other calibers, rifle and pistol.
More importantly, my comments reflect mistakes I've made over the years.