Polygonal rifling and the variables involved...

[bullpen7979]

Greetings casters....
My eldest son is now considering a handgun. He is leaning in the direction of the 9mm since that is what I have, and because I am set up to cast/reload in that cal.

I've given him my .02 promoting the CZ 9 line, but he is leaning in another direction at the moment. Fine, but we have that old issue of conventional vs. polygonal rifling. (He's considering the Baby Eagle)

Here is my question: Will the variables of bullet hardness, powder choice and charge level, lube type and proper sizing have an impact on what level of success we might anticipate getting a cast load to work in his weapon of choice (if in fact he ends up choosing a weapon with polygonal rifling).

I have searched the forum regarding cast boolits and barrels of this type, and I read the bottom line to be: 1) some say it's possible.. 2) some choose not to, presumably because (among other personal reasons) the manufacturers don't recommend it.

I'm going to keep recommendations going his way for weapons that have traditional rifling, but I was wondering if the other factors in play can have a significant impact and offset much of the disadvantage of polygonal.

(and, perhaps it's not a disadvantage at all, and I just don't thoroughly understand)

[Wayne Smith]

It is not a disadvantage at all, but many don't bother to slug their barrels and end up with boolits too small. They then blame the leading on the polygonal rifling rather than looking further. If you have searched you have probably found my opinion already. I am shooting lead out of a CZ92 in 9mmMak with no problems at all. Historically we know it works, those who still shoot the Whitworth muzzle loaders don't bother to ask the question because they were made that way and have been working for over 100 years!

[big dale]

I have 7 barrels made by Lone Wolf for my 4 Glocks . When I bought most of them I was still heeding Glocks warning to not use lead in their polygonal barrels. I have now tried boolits in both types of barrels and I can not tell any problems due to the rifilig type. I have always been one of those guys that don't believe much that I am told, but I like to try different stuff and see how it works out for me. I find that I do prefer to use the Lone Wolf barrel in my Glock 20 because it is the longer 6 inch barrel and I shoot that cartridge pretty warm. I like the tighter chamber for that cartridge. I also would have still bought the 9mm barrel for my Model 27 and 35 so that I could shoot that caliber in those guns. If I were doing it over again, I would not have bothered to get a Lone Wolf barrel for my Glock 21 as I see no need for it in the 45 acp caliber.

I have always been curious about the Baby Eagle since it fits my hand so well. I have a friend who has one and 4 grains of red dot with a 125 grain round nosed boolit from a Lee mold does great in his gun when sized to 357.

I still just prefer shooting 45's to shooting 9mm. I guess I just like bigger boolits. I find getting good accuracy from my 45's as easy as falling off a log. Most of the time I have to work harder to get good accuracy from my 9mm's compared to my 45's.

Have fun with this stuff.

Big Dale

[mooman76]

What Wayne Smith said.

[bullpen7979]

Thanks all.

I guess I find it a bit odd that the manufacturers of polygonal rifled barrels (typically?) issue warnings against shooting lead. (They do typically say not to, correct? ) Perhaps because it's easier for them just to say "don't do it" and save their support department two dozen calls a day than to take a moment to explain how it can be done successfully. Strange.

[fecmech]

I have yet to see in writing a warning from a manufacturer not to shoot lead bullets. Glock and others warn against shooting "Reloads" in their firearms but I have not seen anything specific about lead. If someone has a written warning from Glock about shooting lead I'd like to see it. I shot a lot of lead in my Khar K9 which has a polygonal barrel and had excellent results. In fact during a call to the company in regards to different trigger assemblies I had a conversation with the owner of the company. In that discussion I mentioned the excellent accuracy I was getting with my cast ammunition in his product and he said he was not surprised due to the quality of the Lothar barrels. He never once cautioned me about using cast bullets. If I had a Glock it would be shooting lead bullets just like I shot cast bullets in .357 magnums back in the 60's when everyone knew you couldn't do that! The Devil is always in the details.

[MikeS]

I have a Baby Eagle (AKA the Jericho 941) in 45ACP, and I shoot cast in it with no problem, and no leading at all. Fitting the boolit to the bore is the important thing, just like conventional rifling. I think the folks that say NO to cast in polygonal barrels the most are the folks that sell conventionally rifled replacement barrels!

[bullpen7979]

Okay casters...thanks kindly for the input, both general and specific to the Jericho. Guess we'll give it a go.
Just for the sake of further edification, assuming we slug his bbl and size up .001 or .002, and still run into problems, I guess part of the intent of my question was to investigate whether perhaps the situation is likely to be improved by things like:
1. Slower powders
2. Lighter charges
3. Different boolit design

[prs]

Okay casters...thanks kindly for the input, both general and specific to the Jericho. Guess we'll give it a go.
Just for the sake of further edification, assuming we slug his bbl and size up .001 or .002, and still run into problems, I guess part of the intent of my question was to investigate whether perhaps the situation is likely to be improved by things like:
1. Slower powders
2. Lighter charges
3. Different boolit design


1. I opted for faster powders. I wanted to slap that baby's butt and make it obturate right off the "get,go!".

2. My current plinker/practice round is a light load, but I see no reason to limit yourself unreasonably. Work-up your charges as you nromall would to meet your goals.

3. I opted for a TL Lee deisgn that matched the weight of my defense round. I wish it were plain based, but it works wonderfully. Tumble lube is a big advanate if loading in volume.

You missed the more important aspects. Alloy should be tough and not overly hard in my opinion. I am doing well with air cooled 95/3/2 in my Glock 23 OE barrel. Boolit fit (you won't know until he brings the gun home). My Glock has really generous chamber and load my pill at the size they drop (.402 or even plus a tad). Like me, you will want to make sure your dies and brass DO NOT inadvertantly down size your boolits when loaded. I also believe shooting copper condom bullets can make a barrel more prone to leading with "normal" boolits. Clean any copper residue from the tube.

prs

[fecmech]

My experience with the 9mm was that I did not have much luck with the faster powders when trying to duplicate factory jacketed velocities( 1100-1200 fps/120 gr).
Bullseye and 231 worked ok at more sedate target velocities 900-1000 fps but that was it. My best results with cast "at speed" in the nine came with Longshot and Blue Dot. YMMV