Missouri Bullet Company - 357 question

[mattsh]

I have looked at MBC and their 357 offering of 158gr SWC. The site says that they are BHN of 18. According to the LEE manual the bullet will be able to withstand about 23,000 psi.

For all of you that have loaded this bullet, will it withstand higher pressures than that?

I ask because 23,000 psi seems to equate to the starting loads of Bullseye, Herco or 2400 which will only give you 800-1000 fps. [using the Lyman 49th edition 160gr as a reference]

I know on paper the LEE manual says that BHC of 18 gives you the ability to use up to 23,000 psi. But what is the reality? I would like to get about 1200fps. Is that realistic with this 158gr bullet from MBC?

 

[freakshow10mm]

The BHN will tell you what pressure it takes for the bullet to obturate. If you meet that threshold, it will obturate.

 

[mattsh]

So does that mean it is ok to go above that pressure?

 

[Quoheleth]

Personally, I haven't been able to push it much beyond those pressures. When I used AA#5's starting load (I don't remember...it's listed in Lee's manual), my barrel was pretty thick with lead. A dozen rounds and I had keyholing, flyers, all sorts of fun. IIRC, Universal was similar. I posted a similar question a year or so ago and got answers about size of bullet, bullet lube, smoothness of barrel, crimp - just about the whole gamut, including what did I eat for breakfast that morning.

So, I dug through the manual and looked for a powder that gave decent velocity with lower pressure.

The powder de jour I am liking right now with his bullet is Titegroup - I believe [read: CHECK FOR YOURSELF!] the max is 5.0gr which, per Lee and cross-checked with the website, gets it near the 1100fps and that 23K pressure line. It shoots clean, is what I call a "light" magnum, and is highly accurate. I use this load in my Ruger GP161 to pop clay pidgeons on the 50-yard berm at my range. No chrony, so I can't tell you the velocity on the load, but I can tell you it's a pleasant load to shoot. A bit of smoke, a nice bark (not "crack"), and dirt flies 50 yards away.

Q

 

[243winxb]

Maximum pressure for 18 BHN is 25,596 PSI to obturate , so you want to stay under that. To do this you will need to use slow burning powders that produce less pressure. Hodgdons websites list 2 cast types of bullets and there pressures. Alliant 2400 is a good choice, 13gr should shoot well with a 158gr cast lswc bullet. Lyman #2 alloy is listed at a BHN of 15 , so my guess is you should be OK, as this alloy hardness works well at most velocities/pressures for cast bullets. Not sure that going my PSI is totally accurate. The lube used is a major factor, as is powder choice.

 

[Ben Shepherd]

Alliant 2400 is a good choice, 13gr should shoot well with a 158gr cast lswc bullet.

Agreed.

That should prove an accurate load for you. It's also one that is in magnum territory but not one that is full snort or abusive on guns. Use a firm crimp, otherwise it'll burn a little dirty.

 

[freakshow10mm]

Maximum pressure for 18 BHN is 25,596 PSI

That isn't maximum pressure, that's the pressure it takes to obturate. There is a difference.

 

[Landric]

For those of you who are curious about what freakshow10mm means, obturation is when the base of the bullets expands to fill the bore and prevent hot gasses from passing the bullet at it travels down the barrel. When hot gasses pass the bullet they cause melting, which is often the source of leading. Hard bullets loaded to too low a velocity/pressure cause leading just as much as soft bullets loaded to too high a velocity/pressure.

 

[loneviking]

You don't really want to push lead rounds over 1,000 fps anyway, as the gun is really going to take a lot of cleaning to get the lead deposits out. What the number is telling you is to find a slow burning powder and use a light charge.

 

[TurboFC3S]

Good topic, I was just wondering this myself ... what are the good powders to use with 357 and lead.

 

[Gryffydd]

You don't really want to push lead rounds over 1,000 fps

I regularly shoot lead bullets over 1400fps with little or no leading and excellent accuracy. They can be pushed a lot faster than that too.
You have to:

• Use bullets sized to match your bore
• Have properly sized cylinder throats
• Use cast bullets of the proper hardness

After that it's all gravy. Gas checks can come in handy past 1500fps.

What the number is telling you is to find a slow burning powder and use a light charge.

Light charges of slow burning handgun powders tend to be inconsistent in ignition, especially H110.

 

[freakshow10mm]

You don't really want to push lead rounds over 1,000 fps anyway, as the gun is really going to take a lot of cleaning to get the lead deposits out.

Negative. I've shot bullets in rifles over 2,000 fps with no leading and little clean up. I routinely shoot 10mm lead to 1300fps with zero cleanup beyond a single pass with a Boresnake.

What the number is telling you is to find a slow burning powder and use a light charge.

No, the lead is telling you to use a slow powder. For the 357 use #7, #9, #2400, Blue Dot, etc. Light charges are not recommended for lead.

 

[243winxb]

Lyman #2 Alloy & Obturate

Who is right here. Missouri Bullet Company-

Lyman #2
6Sb2Sn92Pb Antimonial Lead

From Lyman-

Q: What is the composition for #2 Alloy?
A: This is made up of 90% lead, 5% tin, and 5% antimony.

Missouri Bullet Company list it as CUP's PSI & CUP are very different i think. Bullet's BHN x 1422 = Pounds per square inch. http://en.wikipedia.org/wiki/Obturate Cast bullet go thru a swaging process, same as a jacketed bullet when they enter the barrel. Obturation is not needed or wanted. This is why we size our cast bullets .001" to .002" larger than groove diameter. Bullet alloys containing 3% antimony 0 Tin with the correct lube can be shot up to 900fps. Between 900 and 1400fps a different alloy is need containing Tin, like Lyman #2. From Lyman-

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

Above 1400fps, a gas checked based bullet is need. IMO

 

[MissouriBullet]

Lyman #2

To rectify a bit of confusion, our use of the term "Lyman #2" relates to the modern usage. In my circle, Lyman #2 is 2/6/92 alloy and duplicates the classical pB/sN admixture. This is one of those "terms of art" things that is a little bit confusing.

Anyhow, FWIW.

Brad

 

[freakshow10mm]

Lyman #2 as I know it is the 2/6 alloy. Too many people think if you match the BHN that's what the alloy is when in fact it's just an alloy that matches the BHN. A true Lyman #2 alloy is the 2/6 alloy. If it isn't 2/6 it isn't Lyman #2.

 

[rcmodel]

Lyman #2 has long been known to be:

90% lead
5% Tin
5% Antimony

It has a BNH of 15.

You can mix 10 pounds of #2 with:
5 1/2 pounds wheelweights
1 pound 50/50 bar solder
3 1/2 pounds pure lead

Or:
4 pounds Linotype
1 pound 50/50 bar solder
5 pounds pure lead

rc

 

[243winxb]

RotoMetal listed Alloys

http://www.rotometals.com/Bullet-Casting-Alloys-s/5.htmRC knows is alloys . the 2-6-92% is a good blend. Its just not Lyman #2. This came with my latest Lyman mould instructions. Click it for larger view.

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[MissouriBullet]

It's a religious argument

Here's what Midway says to describe their Ney 2/6/92:

Alloy consists of 2% tin, 6% antimony and 92% lead. This is an excellent all around alloy for most handgun bullets and many higher velocity rifle cartridges. This is a modern version of the old Lyman #2 alloy. The Brinell Hardness of Hardball alloy is about 16. Sold by the ingot, not by weight. Approximate weight is 7.4 lbs. per ingot.

http://www.midwayusa.com/viewProduct/?productNumber=570058

Brad