Casting for 9mm - how soft can I go?

[hermans]

I mainly use COWW to cast my 9mm boolits for IPSC/USPSA style shooting. The BHN of these boolts with age hardening, measures between 11 and 14, and they work perfectly at the moderate velocities I use, around 1000 f/sec., no leading to speak of and decent accuracy.

The problem is that COWW are getting "harder" to come by, and they are getting very expensive to purchase.
I do have a lot of SOWW as well as a lot of pure lead from other sources.
If I use the Lead Alloy Calculator downloaded from here, the BHN of a 50/50 mix of pure lead and COWW comes to about 10.1.

My question - how "soft" can I go with my alloy to achieve basically the same results as when using boolits cast with COWW?

Will I still get decent fill out in the molds, and what will the accuracy be with these "soft" boolits? The tin content will then be reduced by 50% and will only be 0.25%.......
Also, will the tapered 9mm case not swage down the "soft" 0.3575" sized boolits?

Any advice from the experts will be appreciated!

[ioon44]

Your loading dies will be the main factor on swagging soft .3575" bullets.
Can you find lino to mono type metal to add to your SOWW and pure lead? I alloy my bullets up to 11 bhn to 14 bhn and coat with the Hi-Tek coating and size to .3575".
A larger expander is the best way to stop the swagging and don't over crimp the the loaded round.

[tazman]

I don't have any COWW to use to compare. What I use is range scrap which I water drop for the extra hardness. They come out the same hardness as yours do after a couple of days.
I have been using them for years in several 9mm pistols with great accuracy and no leading.

[oldhenry]

First of all: I'm no expert. I've been casting since '60 & up to joining this forum I always cast COWW only. After joining this forum I tried 50/50 COWW & SOWW + tin. I didn't approach the alloying in a technical manner such as you. I got the "tin cut wire pieces" from Rotometal (a forum sponsor). It comes as 1lb. packets & each packet usually contains 26 of these Sn pieces (you can do the math). To a 10 lb. 50/50 mix I've been adding 3 pieces & am getting good fill-out & no leading. In fact, this alloy seems to make my SR1911 9mm bbl. shine better.

I'm fortunate in that my nearest neighbor (and friend) manages a commercial tire company. I have a good free source of large COWW & SOWW. Alloy wheels are very popular now in the US on "big rigs" which increases the use of SOWW (lucky me).

I'm thinking about decreasing the Sn to 2 pieces per 10 lb.

Henry

[gnostic]

I don't have any COWW to use to compare. What I use is range scrap which I water drop for the extra hardness. They come out the same hardness as yours do after a couple of days.
I have been using them for years in several 9mm pistols with great accuracy and no leading.

What he said. I do the same, nothing fancy with great results. I shoot them out of a 3030 without leading as well...

[JBinMN]

Have a look at the chart on this page & reading the article might help:
http://www.lasc.us/TaylorBulletWeakEnough.htm

You can use tin with SOWW & Lead to reach a close match to COWW only in hardness ( as compared to velocity like in the chart), as well as perhaps consider adding some shot for the antimony & do not forget water dropping as an additional method to increase hardness.

For example, you might take SOWW/lead & tin(10-1) @ approx. 11BHN and water drop to possibly make it to the 11-12BHN of COWW, or add some lead shot for the antimony & not water drop/water drop, to see if that helps find a suitable alloy. Or just combine SOWW with the lead shot & see how that works dropped or not dropped. IMO, you are gonna have to do some testing with what you can get a hold of if you don't want to use your COWW so much. The range scrap idea is a good one as a substitute, but you may not have it available & you might have easier components to alloy instead.

If you keep track of your testing you can figure where to use the alloys in something else later or figure out another combination using such alloys.

It seems to me that right now you will be needing to add a bit of lead shot for the antimony, just like if you were using lead, if the SOWW do not have enough antimony to get you to where you would like to be for hardness.

Another thing you ay wish to consider is the powder you are using as well, since powder burn rates have an effect on obturation or lack of & can cause issues as well, & BHN/hardness is not just the only thing to consider. Changing to a slightly different powder & a change of burn rate may be something to consider as well...
Just something "to keep in the back of your head.".

This topic here would be a good one to look at, IMO, but it is up to you.
http://castboolits.gunloads.com/showthread.php?139482-BHN-and-Velocity-Pressure

Hope I helped a bit. I think that I could say more about this, but I think I will stop here with what I have added.
;)

G'Luck!
:)

ETA: Just one more link to be aware of if you are not already that may help:
http://www.lasc.us/HeatTreat.htm

[pjames32]

I use COWW and Stick ons calculated to about 11bhn with 1% or so tin added for good fill out. I water drop and end up testing about 14bhn. I shoot these from 9mm and 40 S&W with good accuracy and very minimal leading in most of my pistols. My neighbor is using these in his 9mm for IDPA. I do have some linotype stocked up preparing for when COWW become more scarce.

[JBinMN]

I an going to try to add a chart for folks here to look at & save if they like. I do not know if it will work or not, but it has some handy BHN descriptions to compare alloys. Here it is, I think:
239633

[fredj338]

Start water dropping. I shoot mostly ranges scrap. Today I coat & water drop out of the oven. I get about 12-13bhn. It seems to run fine in my various 9mm about 950fps w/ 147gr, but also with 135gr @ 1050fps.

[gwpercle]

I started stretching my COWW metal with soft lead ( counting SOWW, and range scrap as "lead") 50/50 mix. Air cooled , sized .357 .and lubricated with Lithi-Bee lube .
Using a 124 grain truncated cone boolit gave some problems...seating sized them down and driving fast didn't help leading .
The thing that did the trick is a NOE 358-124-TC-GC mould and NOE expander plug ....seating a gas check on the boolit solved the problems. The hard copper check let me seat the bullet without sizing it smaller and the NOE expander flared the case properly .
The gas check also helped with leading at 1,000 fps velocity. I can also use it in 357 Magnum loads, 1,000 fps is a non leading affair. Also use in 38 special.
Funny thing is this boolit is very accurate when shot out of revolvers and rifles !
It's also accurate in every 9mm I've shot them in , 4 different 9 mm pistols .
I was having a lot of trouble at first...the 9mm wasn't made for cast and soft cast was making me say curse words... but that gas checked 9mm boolits was just the ticket .

If gas checks bother you try coated and sized but 9mm with little or no throats are buggers to get to chamber. Cast 9 mm will test your abilities for sure.
Gary

[toallmy]

I cast with a 50/50 mix of coww / pure for 9mm , 45acp , 38s , & light 357s without problems .

[tazman]

Here is the result of my recent 9mm loading with range scrap which has been water dropped.
Boolit is the Lyman 358212 sized to .357 and lubed with NRA 50-50. Used 3.5 grains of Bullseye for the load.
OAL of 1.130"
This was forty shots at 12 yards.
No leading visible in the barrel.
239666

[hermans]

Thanks everybody for your great advice!
I definitely have more "guts" now to try softer alloy, seems like it can work......tazman's target is the proof of that!

[6bg6ga]

My thoughts...since your speed is 1000fps it doesn't have to be hard it does need to be sized correctly. I've shot straight lead that checked 5 on the hardness scale with zero leading at 1000fps. I maintain that fit is everything. I size my 9mm to .357-358 Hardness of 5 which is straight lead works for me when like I mentioned when it is sized correctly. I go slightly oversize and it works for me. Bullets under .357 leaded in my guns.

[fredj338]

My thoughts...since your speed is 1000fps it doesn't have to be hard it does need to be sized correctly. I've shot straight lead that checked 5 on the hardness scale with zero leading at 1000fps. I maintain that fit is everything. I size my 9mm to .357-358 Hardness of 5 which is straight lead works for me when like I mentioned when it is sized correctly. I go slightly oversize and it works for me. Bullets under .357 leaded in my guns.
To a certain pressure point this is true. Vel isn't what I causing leading generally, it is higher pressures & what that does to a softer bullet.

[hermans]

My thoughts...since your speed is 1000fps it doesn't have to be hard it does need to be sized correctly. I've shot straight lead that checked 5 on the hardness scale with zero leading at 1000fps. I maintain that fit is everything. I size my 9mm to .357-358 Hardness of 5 which is straight lead works for me when like I mentioned when it is sized correctly. I go slightly oversize and it works for me. Bullets under .357 leaded in my guns.

I agree that in most cases fit is king. My barrels are between 0.355 and 0.356, so I size 0.3575, and with my COWW I have very little, if any leading at around 1000 f/sec.
I am going to make up a batch of 50/50 mix with SOWW and COWW, and will report back on how that works.
I did discover some ingots of Linotype which I bought many years ago from a friend who stopped casting, so I think I could add a little of that to the alloy just to get a little more Tin for a better fill out, but I will try first without that to see if I get reasonable fill out.

[6bg6ga]

To a certain pressure point this is true. Vel isn't what I causing leading generally, it is higher pressures & what that does to a softer bullet.

Your stating the obvious here. More velocity = more pressure. When the velocity hits over 1000fps the pressure is higher and leading is likely to occur. Most generally a properly or oversized bullet will not lead up to 1000fps. I've done the chron tests to back this up. Exceed 1000 fps the pressure is higher behind the bullet and the bullet either needs to be slightly harder or a gas check needs to be used. One needs to remember there is a point where very hard bullets can also cause problems.

[franciscom]

Your stating the obvious here. More velocity = more pressure. When the velocity hits over 1000fps the pressure is higher and leading is likely to occur. Most generally a properly or oversized bullet will not lead up to 1000fps. I've done the chron tests to back this up. Exceed 1000 fps the pressure is higher behind the bullet and the bullet either needs to be slightly harder or a gas check needs to be used. One needs to remember there is a point where very hard bullets can also cause problems.

Keep in mind that a slower powder can give you more velocity at lower pressures. Leading is a consecuence of lead alloy reaching its maximum stress. Higher pressure, not velocity, is what leads to higher stress.


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[gareth96]

Keep in mind that a slower powder can give you more velocity at lower pressures. Leading is a consecuence of lead alloy reaching its maximum stress. Higher pressure, not velocity, is what leads to higher stress.


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So try Blue Dot?

[6bg6ga]

Keep in mind that a slower powder can give you more velocity at lower pressures. Leading is a consecuence of lead alloy reaching its maximum stress. Higher pressure, not velocity, is what leads to higher stress.


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Everything I have ever read says velocity and or pressure or both = leading. My crono results seem to back this up.

[gwpercle]

Gas checks can help...do not fear the checked boolit

[pakmc]

I shot pure lead that was powder coated between 900 and 1,000 FPS. I had no leading problems(I shoot CZ 75B's and/or 75D's or a CZ champion in 9mm. I never had a leading problem. I shot 8 inch steel plates at 10 yards. these rounds where accurate enough to get 6 plates out of 6 shots. (i never put them on paper)

[Silvercreek Farmer]

I shot pure lead that was powder coated between 900 and 1,000 FPS. I had no leading problems(I shoot CZ 75B's and/or 75D's or a CZ champion in 9mm. I never had a leading problem. I shot 8 inch steel plates at 10 yards. these rounds where accurate enough to get 6 plates out of 6 shots. (i never put them on paper)

Yep, powder coat will let you get by with softer lead. Just be sure not to over crimp into the softer boolit.

[outdoorfan]

50/50 at ~8.5-9 bhn. Good for ~1100 fps in Glock 19.

130 grain Miha mold with Unique powder