Just slugged a few GLOCK bores. Do these numbers sound right?

[Oreo]

(Noob alert.)

I just jerry rigged up a way to cast myself a few ~40cal slugs of pure lead and hammered them through three different barrels. One O.E. G23 barrel, one O.E. G20 barrel, and one Lone Wolf G20 40s&w conversion barrel. Looks to me like the Glock barrels are running a little tight at .399" groove / .389" land diameter. The Lone Wolf barrel is about a thousandth larger for both dimensions. So that means I should be looking to size my boolits at what, say, .401" on the mark? Or should I go a little larger?

Furthermore, If I order a custom mold, how deep should I make the lube grove based on these figures? .389" diameter?

[Oreo]

50 views and nobody has any insight? Opinions?

[sig2009]

Here's one. I just got an email from Wilson Combat. I never knew they were now making match grade wilson barrels for Glocks. My advice ditch the Lone Wolf and go for the Wilson Combat!
http://shopwilsoncombat.com/Glock-Accessories/products/169/

[nicholst55]

I'd think that .401" should work. If it doesn't, you may need to try .402".

[Bwana]

I use .401" in my G20, G23 O.E. bbls and also in my LW G20 10mm and 40S&W bbls and in my Federal G23 bbl. Water dropped WW and medium hard lube works for me.

[Ausglock]

.401 works in my G35 40S&W factory barrel.

[Elkins45]

I would try .401-.402. My experience has been that .001 too big doesn't make much of a difference, but .001 too small does. If you get them too small to seal well you will have all sorts of leading issues. Given that the Glock polygonal rifling is infamous for leading issues anyway I don't think I would want to tempt fate.

[prs]

My GLock 23 barrel sized a soft lead ball to .400" on my micrometer. It was an odd experience due to the ***** type of "rifling" they use. My only sizer for 40 is the Lee .401 and it works great. My unsized boolits from both the Lee 175g TL SW and the similar Lee lube grooved TC are dropping just under .403 with my alloy and they shoot fine too even though the cases squash them a tiny bit. My glock barrel has no trouble chambering the fatter rounds, my Wolf barrel occasionally fails to fully chamber them -- so I size them all all now. Funny thing is, my "dangerous with lead" Glock barrel does not lead at all and my "safe with lead" Wolf does lead a little. I think the Wolf barrel has a too abrup onset of the rifeling; needs some "lead so it won't lead" is the long and short of it. vowels that is.

prs

[GREENCOUNTYPETE]

consider yourself lucky to get those numbers tight is easier to deal with than big

my s&w 40 barrel was every bit of .401 in the grooves , try getting that bullet to seat in a case and not swage down to be undersized
i stuff them in at .403 and they swage down to .402 but work fine

start sizing .401 and you should be just fine with a .399 groove

if it chambers , unless your putting the coals to it (added danger of excess pressure), it should size down to what ever it needs to be just fine

think of it this way if your using a Lee sizer they only make .401 , you open it up if that is to small

[turbo1889]

I've got a couple 400-Cor. chambered Lone-Wolf barrel for my Glocks. They measure 0.400" right on the mark. I shoot 0.402" in them with only very slight leading of the bore that doesn't seem to build up; I am using a hard alloy with almost no tin in it though and the 400-Cor. cartridge is far more prone to lead then the 40-S&W and even the 10mm since it is a high energy bottle neck cartridge (as in 45-ACP necked down to take 40-cal boolit and loaded to fairly high pressure levels).