Glock cast boolit help

[Bushrat]

My friend has a glock 9mm and recently he tried cast bullits from a Lyman mould #2670402 a 120 grain SWC. With several different loads the best he could do was 10 inch groups at 10 yards. With factory hardball the same pistol shoots 1.5 inch groups.
Anyone with Glock cast bullit experience we need help.

[762cavalier]

If he is using a stock Glock Barrel that could be the problem. To shoot cast he should use an aftermarket barrel like a Lone Wolf or Storm lake barrel.

[deltaenterprizes]

Try 147 gr bullets, more bearing surface area on the driving bands grip the rifling better.

[DLCTEX]

He needs to slug the bore and size the boolit to at least .001 over. Manufacturers of barrels and moulds may not have machined to what spec. is. Then load to cast bullet specs, not jacketed, using some different powders, not just different amounts of the same powder.

[casterofboolits]

Bullet size matters in the standard Glock barrel. I worked with a Dayton, Ohio police armoror to develop a cast boolit load for the first glock in Dayton. He was determined to shoot cast boolits in the Glock.

We setteled on an H&G 125-TCFPPB sized .357 on top of 6.5 grns of Bluedot. This load has been put thru quite a few Glock 17's. One of my friends has put over 20,000 of this load thru his standard Glock 17. Minimal leading and it is accurate.

[mtgrs737]

I have heard that polygonal rifling likes big boolits for a better seal and no leading. You might even try .358" if the loaded round chambers easily.

[Milltown353]

I hand loaded some .45ACP cast boolits yesterday as well as some 9mm. Both were loaded light with unique. The .45ACP had .5cc of unique which was loaded to light to effectively cycle the action. I used LEE's 230 grain tumble lube boolit with LLA. The 9mm was loaded with .49cc of unique that cycled the action. It was a 124 grain lead boolit that was tumbled lubed but was not a TL boolit. Both were round nosed boolits.

They both were pretty accurate at 10 yards.

I shot the .45ACP through a stock barreled Glock 21 with no apparent leading. The 9mm was shot through a compact XD.

[MtGun44]

FIT ! Most 9mms need at least .357 to work well, and many prefer .358 diam. The big
issue is will the chamber accept the fatter rounds. I am NOT a Glock loader so I have
no direct experience, but I think I have heard that Glocks tend to have large chamber
dimensions, if so - .358 maybe a great diameter.

Slug the bore and load .001 to .002 larger. Lee 356 124 TC at .357 or .358 (regardless of
the name!) are extremely good in many 9mms for me and for several others on the
board.

Bill