[docrobby]

Hi:
I am interested in load info for the 300 Gr. Keith SWC in 45 LC using HS6 powder amd large pistol primer.
I can find no info in any of the commercial manuals or upon searching the net.
The intended weapons are a Navy Arms Lever rifle and a Super Red Hawk 454 Casull 9.5".
I would appreciate any help.
Thanks

 

[unclenick]

Welcome to the forum. Rules are to join in and have fun and play nicely with the rest of us kids.

There are a lot of variants on the Keith profile. What is the length of your bullet and what cartridge overall lengths (COL's) do you actually seat it to in those cartridges? Those factors affect pressure, and not just the weight.

HS-6 is a little slow for complete combustion at the 14,000 psi SAAMI pressure limit for .45 Colt, and a little fast for best performance in the Casull. Looking at other HS-6 loads in the Lyman Manual and running guesstimated bullet dimensions in QuickLOAD, I would say you are going to land on around 7 grains of HS-6 at SAAMI maximum .45 Colt pressure.

Are you looking to load warmer for the Casull? If so, is there a reason not to use the Casull case? It'll save you some lead build up ahead of the chamber throat. I don't know the Navy Arms rifle, so I don't know it's pressure limits? One of the lever gun fellows may be able to offer some information in that regard?

 

[docrobby]

Nick:
Thanks for your reply.
I have a large store of HS6 and HS7. I have used HS6 with good results in my AceHindman-built .45 Super.
I would like to develop a load that I can use in .454 and in my wife's .45 LC rifle.
Bullet lenght is .685"
Probabnle overall length-1.58".
Actual lubed bullet weight is ~265 g not 300 (just weighed several)
Thanks.
Rob

 

[unclenick]

One last item. The software has a default case water capacity of 41.6 grains. If you want to measure that, it will increase precision further. But assuming that default number and the lighter and shorter bullet than I guessed at before, 10 grains of HS-16 comes right up to maximum SAAMI pressure (14,000 psi). That means start at 9 grains and work up for a gun that runs in that pressure range normally.

If you are planning to venture into Casull pressures, then you can use rather more, but I am not familiar with your wife's rifle to know what it will tolerate? Until you do know, I would stay with that 10 grain limit. In the Casull itself, you can likely go to half again more powder pretty easily. That should be in the .357/.44 mag pressure range. Going still warmer should be approached cautiously with lead bullets, as they can sometimes upset enough to expand into the forcing cone and cause odd pressure spikes. It depends on how hard they are?

 

[docrobby]

Ehanks Nick

 

[jmortimer]

Where do you get a 300 grain "Keith" style hard cast. The largest one I have seen is sold on this site and weighs 265 grains I believe. Normally I prefer LBT hard cast when you get up to the 300 plus grain level.

 

[Ralph McLaney]

HS-6 data for .45 Colt

Nick:
Thanks for your reply.
I have a large store of HS6 and HS7. I have used HS6 with good results in my AceHindman-built .45 Super.
I would like to develop a load that I can use in .454 and in my wife's .45 LC rifle.
Bullet lenght is .685"
Probabnle overall length-1.58".
Actual lubed bullet weight is ~265 g not 300 (just weighed several)
Thanks.
Rob

You may find the HS-6 data in this article helpfull for the .45 Colt.
http://www.riflemagazine.com/magazine/PDF/HL%20246partial.pdf

If your Wife's rifle is a Winchester 66 or 73 replica, I would not exceed the loads in the 14,000 psi chart.

Ralph

 

[Ken Rummer]

45 colt with HS-6

I just downloaded a great article on the 45 colt which included HS-6 data among others.
Go to www.customsixguns.com
click "writings"
click "Dissolving the Myth"

 

[Carpe Diem]

I'd be careful about data without published chamber pressures. I'd also be careful about load advice from computer models, especially when low pressure loads are a concern.

From Hodgdon's data (afterall they make the stuff):

250 cast - 10.5/HS-6 - 13,300 CUP
260 JHP - 10.7.HS-6 - 14,000 CUP
300 JSP - 10.0/HS-6 - 13,700 CUP

I never used HS-6 in any of my .45LCs but I burned a lot of HS-7. It worked fine for mid-level loads, between SSA and Ruger levels.



.

 

[unclenick]

You have to be careful of all data sources. Never use just one. That's why I used the Lyman manual data as a cross check. Not in HS-6, but for comparative pressure/velocity predictions from other powders.

The discussion of the reliability of the computer models gets played out periodically. Some don't trust them at all, but I've had some pretty spectacular correspondence form some the work with Quick Load. Especially with some chronograph feedback to tweak things a little. The thing I tell people is that data in a manual is fired in a real gun, but it isn't your gun, so YMMV. The computer can be tweaked to match your gun, specifically, but it isn't firing in a real gun, so, again, YMMV.

The plus side of manual loads with pressures listed is the pressure guns have minimum chambers, so you own gun's not likely to see higher pressure. The downside is that most are still the obsolete copper crusher barrels, which have been shown to give so much extreme spread in results for the same load, sometimes even just from changing the technician running the tests, that, as was concluded in Precision Shooting some years ago, it just isn't a terribly useful number. As you see the modern Piezo transducers gradually replace the old copper crushers, that should go away over time.

 

[Carpe Diem]

I am hardly anti-computer. As an engineer I use complex computer models every single day in my work and I trust them....pretty much. But because I am intimately familiar with them I also understand their major shortcoming - they are only as good as the data entered. For this topic that's chamber volume, throat length and condition, actual bore diameter and number/width of lands, powder lot, primer type, bullet design, test temperature.....you get the idea. We are not building fighter aircraft here.

The manuals of today are using piezo equipment more and more....but not always on SAAMI minimum chambers. Too, some of them use pressure equipment to develop maximum loads - then they fire those loads in off-the-shelf firearms to get velocities. Experienced loaders know that simply changing lots of a certain power can change velocities by 50 fps or more. These are a few of the variables that throw major wrenchs in any computer ballistics model. Like the old Powley Computer, modern models are tools to help us develop loads which deliver the performance we want. They are no substitute for actual real-world testing.


When did you write for PS? I wrote for years but stopped a number of years ago when the format and editorial viewpoints changed....
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