Clearing up alloy discrepancies

[Casull]

Can anyone help clear up this mess. My goal is 300 grain 454 casull @38,000 psi. The mud starts with the lee bhn tester saying for 35,000 psi i need a bhn of 27 but the lyman casting handbook says to use #2 alloy and thats a bhn of 15? Is it be possible to shoot a 15 bhn bullet at 38,000 psi even with a gas check. 15 to 27 is a huge difference when talking 38,000 psi.
Question 2: i hear that i dont want to use anymore then 6% antimony because that would make the alloy to brittle BUT the lyman 50th addition says to use linotype and that has 12% antimony? STOP CONFUSING the newbs! Damn BOOKS

 

[ReloaderFred]

A Bhn 27 bullet would probably be brittle. I've used Bhn 18 bullets in .44 Magnum, .41 Magnum and .357 Magnum and they work just fine. A gas check helps with gas cutting the base, and would be beneficial in the .454 Casull. These days, most of my casting is at Bhn 12, and I've run those pretty hot at times.

Bullet fitment to the cylinder mouths and bores is the important thing to consider when loading cast bullets in revolvers.

Hope this helps.

Fred

 

[243winxb]

The Lee bhn tester chart is for plain base cast bullet. Your using a gas check that protects tne bullets base.
I would think linotype is hard enough to prevent slump & skidding.

Your oven heat treated, water cooled should work well also.

Have your heat treaded bullets gotten harded since first cast?

 

[Texas10mm]

Did you read the book I linked you too?

 

[MEHavey]

I'm currently shooting Lyman #2/BH=15/gas-checked at 40-43,000psi
30 & 357 caliber both.
EX:

No problemmo

 

[Iwsbull]

Going to run some tomorrow that are about 12 bhn or so without a gas check but powdercoate. I plan on working up to about 1300-1400 FPS with them and gas check at the same hardness when pushing the velocity on up to upper 454 levels. If it works out and I get to go tomorrow I will try to post some results.
These are 320 grain hollow points so similar in weight to what you are running and air cooled cww.

 

[forrest r]

You're going to find that velocity with pc'd cast bullets is meaningless. You might as well throw the xxx bhn per xxx amount of pressure formula's out the window while your at it.

Plain based bullets cast from 8/9bhn range scrap and pc'd shot from a 10" contender. This is a 37,000+cup load doing 1300fps+.


That is nothing more than a blammo ammo plinking load. Same with these range scrap 8/9bhn bullets, 10-shot group @ 50yds with a 308w.


I see nose slump was brought up in a post in this thread. You don't have to worry about nose slump with pistol bullets. they have fat or flat noses. This bullet is an excellent example of nose slump, they're cast from a cramer 2 cavity mold using a 14/15bhn alloy.


The cramer #43 is a 186gr bullet and the hp version is 180gr. That 46gr of rl19 is a 45,000psi+ load and any time I got over 2200fps the sp bullet's groups started opening up just like the target pictured below.


More 40,000psi+ loads using the same 14/15bhn alloy in a 308w using the lee 160-tl 2r bullet that has a strong short nose, hence no nose slump.


The only thing you have to worry about in the size of the cylinders in relationship to the bore diameter. If you're cylinders are too small you'll end up with the bullets skidding destroying accuracy. Those 308w loads pictured above are from a 14/15bhn alloy. The alloy is made from 3 parts pure lead and 1 part mono-type.

Those 12bhn pc'd bullets should do fine.

 

[243winxb]

slump

This can be from slump or the barrel is sizing the bullet diameter down .003" or more. (For the reloader that likes to match the throat diameter).

 

[243winxb]

Skid

If there was no gas check, the bullet would be skiding as it leaves the muzzle. Accuracy would not be as good as a harder alloy.

Harder is better, no slump or skid in magnums.

 

[forrest r]

View attachment 893837 This can be from slump or the barrel is sizing the bullet diameter down .003" or more. (For the reloader that likes to match the throat diameter).

That's not bullet slump, it's compression. Myself I never shoot a bullet that's 3/1000th's oversized nor do I size a bullet more than 3/1000th's in 1 step.

WFN's/FN's/SWC's/RN's/short nosed pistol bullets don't slump, bullets with long bore riding noses or long pointed noses slump.

 

[Obturation]

A 15 bhn 360 grain gas checked bullet has taken all the pressure I can put to it. No problem.i think the velocity is the limiting factor, though I'm not sure.

 

[Iwsbull]

Tested without gas checks from 1111 to 1257 with about 2.5” groups at 25 yards at 1111 and 1170 groups almost identical. One more step up to 1200 and they grouped right at 1” after that at 1250 and 1260 ( point of diminishing returns) the groups went to 5+”. The first 3 groups were in .5 grain increments the last 2 were in 1 grain increments. I am looking to retest with the gas checks installed. Bhn around 12 straight coww powdercoated air cooled.
These are in a SRH 454 320 grain hp.

 

[Casull]

The Lee bhn tester chart is for plain base cast bullet. Your using a gas check that protects tne bullets base.
I would think linotype is hard enough to prevent slump & skidding.

Your oven heat treated, water cooled should work well also.

Have your heat treaded bullets gotten harded since first cast?

The Lee bhn tester chart is for plain base cast bullet. Your using a gas check that protects tne bullets base.
I would think linotype is hard enough to prevent slump & skidding.

Your oven heat treated, water cooled should work well also.

Have your heat treaded bullets gotten harded since first cast?

The Lee bhn tester chart is for plain base cast bullet. Your using a gas check that protects tne bullets base.
I would think linotype is hard enough to prevent slump & skidding.

Your oven heat treated, water cooled should work well also.

Have your heat treaded bullets gotten harded since first cast?

Is it ok to use only linotype? I hear i dont want more then 6% antimony and lino has 12%. no they didnt budge at all. I think my problem started when i melted my 5lb bar of superhard without fully knowing what i was doing. Im pretty sure i scraped antimony off the top of my pot thinking it was slag. PLUS the last ingot i made was thicker like oatmeal probably because it was most of my unmixed antimony. Then the ingot i grabbed to cast those bullets didnt have as much antimony as i expected. Im also thinking i have no arsenic in my mix.

 

[Casull]

The Lee bhn tester chart is for plain base cast bullet. Your using a gas check that protects tne bullets base.
I would think linotype is hard enough to prevent slump & skidding.

Your oven heat treated, water cooled should work well also.

Have your heat treaded bullets gotten harded since first cast?

Did you read the book I linked you too?

Yes i did. Is there a hard copy available?

 

[243winxb]

Casull So i made some really nice bullets for a 454 casull but my hardness readings seem all over the place. I test the same bullet a couple Different times and get different results 15-19. Then i tried heat treating them at about 475 for 2 hours then plunged in cold water. Now 18 hrs later my BHN is 15? one five thats the same as my 45lc’s from clip on wheel weights not heat treated. I must be doing something wrong but i cant figure out what.

https://www.thehighroad.org/index.php?threads/help-i-cant-get-my-bullets-hard.863580/

Shoot these with the gas check installed. Time to do some testing. And no, i dont think Rotometals Linotype is to hard. Just expensive.

 

[243winxb]

From my saved stuff-
Water drop harding alloy needs 2% antimony. Grain-boundary strengthening or Hall-Petch strengthening makes the bullet harder. The more antimony the faster the bullet will reach it full hardness level. Smelting produces many different metals. Swaged or cast, dont matter, heat treating/water drop still works if antimony is in the alloy. Its a proven fact oven treating gives more balanced harding from bullet to bullet, then just droping from the mould. Large amounts of tin is not needed or wanted in water dropping. For air cooled 2% tin is needed for velocity over 900fps. Why > Lyman>
Quote:
While antimony is used to harden the bullet, the mixture of tin is critical, for while antimony mixes with lead in its molten state, it will not remain mixed when it solidifies. If tin were not added, we would have pure antimony crystals surrounded by pure lead. A bullet of this type , while it feels hard , would certainly lead the bore and eliminate all potential for accuracy.. In a lead-tin-antimony mixture, the antimony crystals will be present just the same, but they will be imbedded in a lead-tin mixutre. As the bullet cools the tin will form around the antimony-lead keeping your bullets from leading the bore.
Obturate simply means to fill or plug. Cast bullets take the rifling by a process called swaging, same as a jackted bullet. This is why all cast bullets are sized groove diameter or .001" or more larger. Lyman #2 alloy will work with any cast bullet. No water dropping needed.

 

[forrest r]

FWIW:


Those bullets pictured above are the lee 160-tl-r2 bullets. The pc'd bullet shot that 10-shot 1 1/2" 2679fps group @ 100yds pictured in post #7. I did head to head testing with those bullets pictured above, traditional cast/lubed vs pd'd. Both bullets were cast with the same alloy, same gc's, same sizing die, same mixed brass, same powder, same reloading dies, same rifle/shooter/etc. This is what the traditional cast/lubed bullets did.


As you can see the traditionally cast/lubed bullets were slower than their pc'd counterparts. The 37gr load blew out/opened up. The chronograph #'s looked good so I re-tested that 37gr load using bullets that were lubed with the lbt blue (pictured above) along with adding a coat of 45/45/10. 45/45/10 is a mixture of Johnson's paste way and lee tumble lube.By adding the exta lube the groups tightened up considerably.


What the bbl looked like after those 2600fps loads using traditionally lubed bullets.


The alloy I use for those rifle bullets is a 14/15bhn alloy. It is made from 3 parts pure lead to 1 part mono-type.

Mono-type ='s 9% tin 19% antimony

The end result of the 3 parts lead/1 part mono-type alloy is:
2.25% tin 4.75% antimony

That alloy is way under the lyman #2 alloy of 5%/5%

The hardest alloy that I use for anything is that 3parts lead/1 part mono-type (2.25% tin 4.75% antimony)

The bullet design, the size of the bullet, and the bullet's rpm's are the limiting factor. I've tested the same bullet with pure mono-type, 1 part lead/1 part mono-typre, 2 parts lead/1 part mono-type. It didn't matter, started getting over 2700fps and bad things happened.

 

[Casull]

From my saved stuff-
Water drop harding alloy needs 2% antimony. Grain-boundary strengthening or Hall-Petch strengthening makes the bullet harder. The more antimony the faster the bullet will reach it full hardness level. Smelting produces many different metals. Swaged or cast, dont matter, heat treating/water drop still works if antimony is in the alloy. Its a proven fact oven treating gives more balanced harding from bullet to bullet, then just droping from the mould. Large amounts of tin is not needed or wanted in water dropping. For air cooled 2% tin is needed for velocity over 900fps. Why > Lyman>
Quote:
While antimony is used to harden the bullet, the mixture of tin is critical, for while antimony mixes with lead in its molten state, it will not remain mixed when it solidifies. If tin were not added, we would have pure antimony crystals surrounded by pure lead. A bullet of this type , while it feels hard , would certainly lead the bore and eliminate all potential for accuracy.. In a lead-tin-antimony mixture, the antimony crystals will be present just the same, but they will be imbedded in a lead-tin mixutre. As the bullet cools the tin will form around the antimony-lead keeping your bullets from leading the bore.
Obturate simply means to fill or plug. Cast bullets take the rifling by a process called swaging, same as a jackted bullet. This is why all cast bullets are sized groove diameter or .001" or more larger. Lyman #2 alloy will work with any cast bullet. No water dropping needed.

View attachment 894422

thank you for this information. I remelted my last batch after i realized i had to mix it better. Ill cast again and to the loudium (range) to do some shooting then ill be able to work with solid info