need help for IWI 9MM pistol

[crackerjack57]

Hello All

I have an IWI Jericho 941 in 9mm. I am looking at casting for it. bought a nice lee 6 banger mold and it does a great job of casting nice 125 grain bullets. i thought it best to probably size the bullets before loading so I slugged the barrel. I did it twice on a clean barrel just to make sure that the results were right and here is what I got.

.352" and the rifling isn't as defined as I am use to.

The barrel is squeaky clean as well. I was looking on the net and they were saying that the IWI 9mm have something like a polygonal rifling system or something like that. my cast boolits are coming out of the mold at .356". should I resize and if so, down to what OD? .353"??

anyone else out there casting for a jericho 9mm?? any pointers on my question?

I bought unique powder that I am planning to load at between 4.5 - 5.2 gr. I have a chrony and will check my fps on .2 gr increments. what should be my max fps using the unique? oh, I should probably mention that I was planning to cast with the stick on wheel weights lead. it comes out to a Bernelle of 12 and this is air cooled not water quenched.

Please guys......... questions, comments, snide remarks or any other thing useful.

Crackerjack57 in the great white north. north of the 49th parallel

[9.3X62AL]

No experience with the Jericho pistol, but I did some "tale of the tape" on a Glock 45 ACP barrel with octagonal-form polygonal rifling. "Peaks" on the slugs mid'ed @.453", "valleys" mic'ed @ .449". Throat was .453" I tried both .452" and .454" castings, and both sizes did very well, with no significant performance differences. No leading occurred with some 450 rounds fired in both diameters.

I treat 9mm and 40 S&W pistols as if they are rifles--they share with rifles the characteristics of relatively high operating pressure and relatively fast rifling twist rates. I predicate boolit diameter on throat diameter--slug the barrel's throat area, and match that diameter or exceed it by .001", and you should be all right. BHN of 12 should be all right, I like 14-15 (92/6/2 alloy) and softer lubes like Javelina Alox.

[bobthenailer]

Barrel dia for the 9mm are all over the place , more so on older guns made overseas but in some cases the bore is larger than .355 dia in my 3- 9 mms & 2 38 supers i use cast bullets sized @.357 dia for best accuracy even if bores measure .355 dia . with the 9mm you could possibly size from .356 to .360 dia for best accuracy .

[HDS]

The barrel is squeaky clean as well. I was looking on the net and they were saying that the IWI 9mm have something like a polygonal rifling system or something like that. my cast boolits are coming out of the mold at .356". should I resize and if so, down to what OD? .353"??

I used to have one bit it was an IMI and not an IWI model, mine did not have polygonal rifling. It was a 2006 model and it was around then they switched to normal rifling again as I understood. But if your rifling looks weird then maybe it's polygonal. Sounds strange it should be that small though.

[NickSS]

I have a Baby Eagle which is the same gun as the Jerico only made later. Mine has polygonal rifling and I have never slugged it. I shoot the lee 120 gr TC bullet sized to .356 and it shoot just fine without any noticed problems from my pistol. I use the same bullet in alt least half a dozen 9mm including one glock and it works great in all of them. My bullets are cast from WW and air cooled.