Oregon Trail Laser-Cast bullets, Brinell Hardness and leading in barrel?

[243winxb]

If you want high pressure/high velocity loads, use a slower powder

What mal h and old fuff said. Bullets do not need to obturate at all to work well. With fast burning powder and cast bullets the gas cutting can be a problem when the bullet jumps from the cylinder to the barrel. The gap between the cylinder and barrel should run between .004" to .009" The old Rugers in 357 Maximum is a great example of gas cutting.

 

[Mal H]

What he met to say was .00015" to .002"

Old Fuff, you have got to get that sticky '0' key fixed on your keyboard. I think there's still too many zeros in that sentence.

 

[Old Fuff]

Darn!!!!

But I fixed it...

I think I need a new keyboard, another cup of coffee, and to go back to feet and yards...

 

[Walkalong]

Good measurements 1858. As already posted, you are in great shape. All you need are some bullets of appropriate size and hardness. You are good to go on the Redhawk itself.

I once asked a dealer if he minded if I came back and measured a Ruger single actions throats(.45 Colt) before I bought it. He said sure, although with a puzzled look. When I came back and actually measured them, he told me I was the only one he had ever seen do that. They measured good, and I bought it. It would push heat treated cast bullets as fast as "Ruger Only" Speer data would push them, with no leading. It would also shoot low pressure loads with no leading, with much softer bullets of course.

 

[MCMXI]

Make up some moderate "cowboy" loads and I think you'll have excellent accuracy with little or no leading.

Old Fuff, I bought the Rodeos for that. My plan all along with this Ruger has been to work up to John Linebaugh type loads between 25,000 and 30,000 CUP with velocities in the 1400 fps range using cast bullets. I thought I was onto a winner since the OT bullets have a BHN of 24 which according to the MBC formula makes them ideal for the pressure range that I'm looking at. However, it's a complicated world out there and I think Mal H is really onto something with his first post in this thread particularly with regards to the speed of W231. I'm going to try the OT bullets with H110 and see how that goes. I'm going to order some 250 and 300 grain lead bullets too.

Walkalong, thanks ... it"s good to know that the equipment is fine, not sure about the operatator yet ....

 

[mkl]

FWIW, I use the OT bullets in my 45-70.

I can push the 405 grain to about 1300 fps with zero leading. Given the surface area contact of the 405 grain, I think no leading is pretty good.

I would bet I could push it faster and still get no lead, but my old shoulder probably couldn't stand the recoil.

 

[Uncle Chan]

I shoot OT 405s in my 45-70 over a cartridge full of 777. They lead-up BAD.

 

[mkl]

I shoot OT 405s in my 45-70 over a cartridge full of 777. They lead-up BAD.

Try IMR 3031 for full power loads.

For a light load with the 405's, try 13.5 grains of WSF and a Federal 215 primer. That load gives 1133 fps per my Pact I chrono out of my Marlin 1895 with a 24-inch barrel. No leading.

 

[Old Fuff]

Old Fuff, I bought the Rodeos for that.

I know, but the issue here is leading. We know that an upper-range load using fast-burning powder does lead the barrel. Now the question is, what happens if you go to a lighter load using the same or a similar powder? If you still have excessive leading and we know (or apparently know) that the cylinder throat/barrel diameters are correct we'll need to change directions and look at other potential causes. But when you have a situation like this it's best to eliminate one possible reason at a time...

Besides, you need an excuse to try out the Rodeos...

 

[MCMXI]

Old Fuff, last night I loaded the following:

For the Rodeos
200 grain OT RNFP
6.0gr and 6.5 grains of Trail Boss (20 of each)

For the Marlin '94
200 grain OT RNFP
7.5gr, 8.0gr, 8.5gr*, 9.0gr* W231 (5 of each)

For the Ruger Redhwawk
200 grain OT RNFP
7.5gr, 8.0gr, 8.5gr*, 9.0gr* W231 (5 of each)

My intention for the '94 and RH is to start at the bottom and work my way up checking for leading after each 5-shot group.

I'm not expecting any leading in the Rodeos but who knows. I can't say for sure whether both the 10.5gr AND 11.0gr of W231 caused the leading but it'll be irrelevant if leading occurs at 8.5gr or 9.0gr



* CAUTION: These loads are NOT intended for original SAA revolvers or their clones.

 

[Old Fuff]

Win. W231 is a fast burning powder, intended for light to medium loads in handguns. In the carbine for example the whole charge will burn in 5 to 8 inches, and thereafter the bullet will slow down. Generally speaking, high velocity loads combined with lead bullets don't work well from an accuracy perspective because of Marlin's shallow micro-grove rifling. I suspect that your Trailboss load may do better, both from leading and accuracy.

I'm sure there are better powders on the market now, but for medium and high velocity loads in .45 Colt old timers' prefered powders such as Unique and #2400. Try working up a load using 20 to 22 grains of #2400 powder behind that 200 grain bullet in the Redhawk and Marlin (not the Rodeos - they wouldn't blow up but the load might be considered abusive) and see what results you get.

 

[MCMXI]

Generally speaking, high velocity loads combined with lead bullets don't work well from an accuracy perspective because of Marlin's shallow micro-grove rifling.

My Marlin has Ballard rifling ... ... but I completely understand and appreciate your point. I did buy 8lb of H110 for the Ruger and that will be the powder I'm eventually going to use, but when I noticed that "typical" 231 loads use a lot less powder with "similar" velocities I realized that the 5lb of 231 that I have would go a lot further than the H110. In these uncertain economic times I'm trying to get more "bang for my buck" so to speak. Referring to the VV reloading guide and powder burn rate chart, 231 and Trail Boss are virtually identical in terms of burn rate so I'd expect similar performance in the Marlin. I did shoot some 200 grain OT bullets with 6.0gr of TB in the Marlin and they were accurate despite a dodgy barrel and crappy sights. I now have a new barrel and XS sights so I'm looking forward to the results. Referring to the VV burn rate chart, H110 is A LOT slower than 231 and TB.

Thanks for all the help Old Fuff ... you've educated me this week and I appreciate it.

 

[Old Fuff]

H-110 loads are larger, but it burns slower, and gives you a longer pressure curve. It sort of accelerates the bullet rather then kick it in the butt. In longer barels (4" and more) it will safely give you higher velocities.

On the other side of the picture, use the W231 to make cowboy loads, that will work fine in both the Ruger and Marlin (next to no recoil) and of course the Rodeos.

The advantage of Trailboss is that it bulks up better in large capacity cases that were designed around black powder. Thus ignition is (in theory) more uniform.

 

[jimmykan]

I'm not sure if this thread is still alive, but I have had similar concerns regarding the hardness of Oregon Trail bullets.

I read an article on the Real Guns about the Lee Hardness Tester, in which the experimentally obtained BHNs of three commercially cast bullets were:

Oregon Trail Lasercast BHN 16.6
Cast Performance BHN 20.9
Meister BHN 16.6

Here's a link to the article:
http://www.realguns.com/archives/118.htm

I would believe 16.6 BHN more than 24 BHN.

If I were to believe that OT's bullets were 24 BHN, I'd probably also have to believe their other claim, that the bullets are made of a silver alloy, and I doubt that (Maybe it's a lead alloy with traces of silver).

 

[Shoney]

When people use the wrong terminology, I have a tendabcy to think considerably less of their information as a whole.

Let us get the terms straight first.

OBTURATION –(Sniper Country) The sealing of propellant gases within the chamber of the firearm.

OBTURATION (SAAMI) The momentary expansion of a cartridge case against chamber walls which minimizes the rearward flow of gases between the case and the chamber wall when the cartridge is fired.

Merriam-Webster definitions
OBTURATE - obstruction; closure

OBDURATE –
1a. stubbornly persistent in wrong doing
1b. hardened in feeling
2. - resistant to persuasion or softening influence
obduration is not listed as a valid word

 

[MCMXI]

jimmykan, my initial problems with Oregon Trail's Laser-Cast bullet was due to my choice of the wrong powder for the velocities that I was trying to achieve. I've been shooting the 250gr RNFP for months now using H110 and I'm very pleased with the results particularly since I started using CCI Magnum large pistol primers. The velocity increased by about 100 fps over the WLP primers I was using. I don't get any leading in my Ruger Redhawk or Marlin (both in .45 Colt) with 22.5gr** of H110 and the cases seem to be fine even after multiple loadings. I've chronographed the 22.5gr load at an average velocity of 1570 fps out of my 20" Marlin with no leading so I'm pleased with OT's bullet. I haven't chronographed that particular load (with Magnum primers) out of the Redhawk yet but that's my next task. They don't cause any leading with 6.0 grains of Trail Boss in my Rodeos either.

I don't know what the actual BHN of the Laser-Cast bullet is and at this point I don't really care since I like them and plan to buy more ... I only have about 5000 at present.

CAUTION: This load is for Ruger Redhawk/Blackhawk and T/C ONLY!! This load is not safe in Colt SAA revolvers or their clones.

 

[Beagle-zebub]

What are people using these 21-24 BHN revolver bullets for? Do they ever obturate?

Isn't linotype only 22 BHN, and still too hard to cast with straight?

 

[Peter M. Eick]

Try about a lot of longshot with a 10mm round and some 180 lasercasts. They obturate!

 

[MCMXI]

What are people using these 21-24 BHN revolver bullets for? Do they ever obturate? Isn't linotype only 22 BHN, and still too hard to cast with straight?

Beagle-zebub, I don't know what others are using the hard cast bullets for but I'm hoping that a 250gr Laser-Cast hurling along at 1500 fps will stop a wild pig anywhere from 10 yards to 100 yards.

I have no idea as to whether or not the Laser-Cast bullets obturate. I shoot them with 6.0gr of Trail Boss and 23.0gr of H110 so it's unlikely that they react the same way with both loads ... however, neither load causes leading. Basically, I'm not sure if obturation is necessary to avoid leading. It may be a lot more complicated (or simpler) than that. Perhaps some lead alloys need to obturate and some don't.

If I were to believe that OT's bullets were 24 BHN, I'd probably also have to believe their other claim, that the bullets are made of a silver alloy, and I doubt that (Maybe it's a lead alloy with traces of silver).

jimmykan, I'll report back with the weight % and atomic % of Ag in OT's bullets this week ... maybe as soon as tomorrow. In fact, I'll let you know the weight % and atomic % of all the major elements in their bullets. I'll only look at three bullets from the same lot but it should be interesting nonetheless. I can PM you with that information if it's not appropriate to report proprietary information on a public forum.

 

[243winxb]

Cast Bullets & Obturation

jimmycan, your link to Lee's hardness tester would show that Lee does NOT want people loading to higher pressures that would cause a cast lead alloy bullet to OBTURATE http://en.wikipedia.org/wiki/Obturate The formula used to calculate the pressure required for solid base bullets is: BHN X 1422 = Pounds per Square Inch (psi). This is almost exactly what the Lee chart has. I could be wrong, but thats how i understand it.

 

[Snag]

Sorry to bump an old thread, I haz questions.

What are people using these 21-24 BHN revolver bullets for? Do they ever obturate?

Laser-Cast has this pdf on Obturation available here where they give a formula for how much pressure is required to cause obturation given a bullets hardness.

Formula is 480 x BHN. They say their bullets are 24 BHN, so according to that formula at 11,520 psi obturation starts and they say in the pdf at 13,000 psi the base is fully obturated. What do you guys think of this theory?

I've shot up a box of their 45 Colt 250 gr RNFP with 8.0-8.5 gr of Unique. 8.5 is what I've settled on, all loads in that range leave quite a bit of lead in the first inch of the barrel. 4 5/8 Flattop Blackhawk. I'm considering either pushing them harder or switching manufacturers to see if things change. Laser-Cast are available locally, that's their plus.

 

[texagun]

I've shot up a box of their 45 Colt 250 gr RNFP with 8.0-8.5 gr of Unique. 8.5 is what I've settled on, all loads in that range leave quite a bit of lead in the first inch of the barrel. 4 5/8 Flattop Blackhawk.

Snag: I've had the same experience with the same bullet and load in 2 different 4 5/8" Blackhawks. I've just switched to another bullet supplier.

 

[Canuck-IL]

Laser-Cast has this pdf on Obturation available here where they give a for ...

That link wasn't properly pasted ... try
http://laser-cast.com/files/LM_Bullet_Obturation.pdf

/B

 

[41 Mag]

I guess I am just one lucky ol fart, least thats what the wife keep telling me.

I have run several boxes of the .358-158gr RFN, the .452-200gr RFN, and the .452-255gr RFN, through several revolvers and autos and not had much if any leading. I have run the 158's at full magnum loads as well as the 255grs in my 45 ACP at around 650fps, as well as my Ruger 45 Colt up to around 1200fps Ruger only loads.

Fit is definitely king and once they fit they rarely lead. One thing that will definitely cause it is having copper in the bore. If it isn't squeaky clean the lead will pile up shot after shot. If it is clean however I rarely clean until the accuracy starts to fall off. That might be 20 rounds or 200 depending on what the powder and lube leave behind.

 

[Walkalong]

Laser-Cast has this pdf on Obturation available here

That PDF says a 22 BHN bullet obturates at 10,600 PSI. I find that hard to believe, and it goes against my experience.