PB Cast 405s....

[TonyM]

If you had to choose a powder for a short cartridge/short barrel (16"/1:14 twist)... to shoot PB Cast .458/405s at a relatively slow velocity (1300FPS or less), what powder do you think you would use.

I have the choice between "Lil Gun", H4198, and IMR3031....

What would you choose... and why... Is there a powder out there that in your opinion may work better in a semi-auto/gas operated cycle style rifle?

Thanks for the input... I'd like to come up with a decent cartridge for my innitial cast boolit purchase from Sportsmans... I need to get them all loaded up so I can have the drawer back that they are in...lol

[Wayne Smith]

I think more information is necessary. Low velocity and operating a gas cycle rifle are often not possible. You need a certain amount of pressure over the gas inlet hole to operate the action. Some are adjustable and some are not.

At the very least the specific rifle needs to be known.

[btroj]

Until I saw the action cycling thing I would have said unique or 2400. But like Wayne said, an autoloader is a whole different story. I have no idea what you need there as I have no experience with big bore autoloaders.
Good luck.

[randyrat]

What kind of rifle?
My stand is if one of those powders don't work the other won't work. They are very close to each other for burn rate. I wouldn't load too many of either one. Some testing is in order for you and your gun. You may have to do some action tuning after you find a load that shoots good, if possible.

[jlchucker]

I use a lot of 3031 in my 45-70. Another good one is AA5744, or IMR 4198..

[d garfield]

I use IMR 4759 and love it, shoots pretty clean and does not take much.
I use it in 405s & 320 hp. Works the best of any I have tried.

[TonyM]

Thanks for all the responses guys. The rifle is a 458 SOCOM... and the problem is there is NO data available for shooting cast bullets with this rifle, and VERY LITTLE data for even shotting J's... so I'm doing this on my own it seems (Trial by fire comes to mind... pardon the pun).

I'm going to try the IMR 4759 after I burn up all the H4198. Anyone have a quick insight on what the difference between these powders are?

Also, would someone think I'd be looking for a fas burning powder or slow burning? Because it is in a Semi-auto... the powder needs to burn as clean as possible to ensure cycling in the gas system...

Thanks again for the responses...

[randyrat]

458 SOCOM that's a glorified ar15 with a stopping power bullet OMG I can't believe it's even possible..it's so short and fat and rips out of the muzzle at almost 2000ft/sec. Is it more of a AR10 gun or is it on a AR15 type lower rec? My guess being that short of a round you can use a AR15 lower.

[TonyM]

458 SOCOM that's a glorified ar15 with a stopping power bullet OMG I can't believe it's even possible..it's so short and fat and rips out of the muzzle at almost 2000ft/sec. Is it more of a AR10 gun or is it on a AR15 type lower rec? My guess being that short of a round you can use a AR15 lower.

Yes... uses standard AR/M4 platform. The only thing you change out (And this is optional, BTW) is the buffer spring. It utilizes the same ar-15 magazines (11 single stack into a 30rd mag)...and so far, it's been a dream to shoot (And with the new GC boolits, it's even accurate now...lol)

One thing... it does not like PB boolits. I've loaded some down to about 1100-1200, and I'm going to see if that improves the accuracy at all... Which are the loads that are being referenced in this thread. I just want to get some other opinions on powders for this. The case is only 1.5" long, and the oal is like 2" of the cartridge. But its fat. It neck downs to .458... If you're familiar with H4198, 40gr is the max charge I can do in that case just about...

Although, I will be trying the IMR4759 mentioned above. I also read somewhere that H110 Unique is a good powder for this cartridge.... ???

Here is a good link to the cartridge specs/pictures if you're interested

http://www.thegungarage.com/458%20SOCOM%20project/458socom%20page.htm

[TCLouis]

I would try loads with the last two and see which gave me the velocity and accuracy I was looking for.

The gas cycling thing ought to get real interesting.
Enough, but not too much in that short of a barrel will provide some entertainment.

Getting that much lead going that fast in that length barrel isn't much of a challenge, the gas system . . .

Good Luck

[TonyM]

I would try loads with the last two and see which gave me the velocity and accuracy I was looking for.

The gas cycling thing ought to get real interesting.
Enough, but not too much in that short of a barrel will provide some entertainment.

Getting that much lead going that fast in that length barrel isn't much of a challenge, the gas system . . .

Good Luck

With the three powders I have been using (I've since stopped using the 3031..), I haven't had any cycling issues on a fairly short range of loads so far... going +/- 2-3-4 grains on the reliable "J" data I have...

I wonder if the powder actually got too slow, it wouldn't charge the bolt properly... Does that sound like it makes sense? Or do I have it backwards.... [smilie=f:

[Wayne Smith]

It's gas pressure you need to be concerned with, not precisely the same as burning speed. True, a slower power is likely to have a lower port pressure, but that is in part determined by the location of the port on the barrel. Slower powders hit peak pressure a little further along the barrel than fast powders, some of which may reach peak pressure in the cartridge. Bullseye for example. I have no idea how much pressure it takes to operate the action, or do I know where along the barrel the gas port is.

[TonyM]

Just some info on the rounds I got to chrono today... with details

OK... FINALLY I got some load data... and I'm right about where I thought I was going to be.

First of all...THESE PB bullets over 1200FPS are garbage. The ones I were shooting were fairly hard.. and even at 1300FPS not only did they go EVERYWHERE (Not one on paper at 100yrds), but they leaded the $hit out of my barrel.

Alright... on to the numbers game.

Each are averages from a single string of 20 rnds (Two ten round strings actually). All rounds were shot using CCI 350 Large Pistol primers, and an OAL of 2.015" to 2.02"



Group 1
.410gr Cast GC (Lyman #2 BH approx 15) .458 Diameter
36gr H4198
FPS: 1528
ES: 74
SD: 20
MOA: 4"ish

Group 2
.410gr Cast GC (Lyman #2 BH approx 15) .459 Diameter
36gr H4198
FPS: 1565
ES: 94
SD: 26
MOA: 3"-4"ish

Group 3
.410gr Cast GC (Lyman #2 BH approx 15) .458 Diameter
27gr Lil Gun
FPS: 1570
ES:45
SD: 12
MOA: 1.5"-2"ish

Group 4
.400gr Barnes JFN "Bone Busters" .458 Diameter (Slightly compressed)
38gr H4198
FPS: 1621
ES: 75
SD: 21
MOA: 1"-2"ish (Was about an inch higher on paper than the cast rounds)

At this point... I think the H4198 can be ruled out as my "Perfect" powder. At this point it is Lil Gun, but I am going to pick up some Unique tomoarrow, and see how that does.

Another thing, not a big difference between 458 and 459 (Well accept 459 varried more in speed). I am going to try .460s and see if there is a noticeable difference.

The 4th group was the most accurate of the run, and the 3rd being the most consistant... and almost just as accurate.

There was no noticeable leading, until I shot the PB boolits.... and it was bad. I almost didn't finish firing them, but I needed the brass back...lol

So far it seems Lil Gun with the GC cast rounds in the 400gr weight are the best so far...

I will keep this thread updated with data as I go. I plan on turning up the lil gun charge a bit next round... and trying the Unique... I am still playing in the 400gr boolit weight though (Because that it was I intend on hunting with). I will go to a slightly lighter round 380's I think? with a slightly less hard BH (Around 12-13 or so).

[HORNET]

Leading and bad groups at 1200 fps? What diameter does that barrel slug at? Sounds like undersized boolits to me. Plain based boolits will usually hold up until about 1500 fps with little trouble if they're fat enough, sometimes much faster.

[Doc Highwall]

The bullet diameters you posted of .458" and .459" look small. I would try a bullet that is .002" larger the your barrel slugs.

[45r]

A GC bollit would work better and not put as much lead in your gas tube.You might want to clean the tube often shooting cast in a AR rifle.I've never shot cast in a AR but seems it would need a little Xtra work.Some are going to direct impingement AR's to keep from getting residue in their receivers and lead going there would be hard to clean out.

[TonyM]

Yeah... I won't be shooting anything but GC boolits through it over 1000FPS. I've loaded some more of the PB guys with some IMR3031, and it should be right around 800-900FPS. If it still does that to my barrel, Im' throwing the rest away out of spite... [smilie=b: