Well, darn, guess I won't be able to shoot cast in the Glock barrel...

[BK7saum]

I have been getting ready to load up some Boolits for my Glock 40 10mm. After checking a few things out, the math doesn't add up for cast.

The chamber pin gauges 0.425-0.426. The brass I have measures 0.011-0.012 at the mouth depending on brand. That leaves 0.401 for a conservative boolit measurement. Well, I got to thinking that I ought to slug the bore and the bore slugged at 0.4014-0.4015. It just doesn't look like it's going to work.

Does anyone have a bore measurement for a Glock 10mm or 40 S&W? I was just wondering if most 10 and 40 barrels ran bores that large.

What do lone wolf and the other aftermarket bores run?

Any suggestions on an aftermarket barrel? Need a 6" as the model 40 is the long slide.

Thanks, Brad

[jmort]

Many shoot cast in every caliber/model Glock sells. Just keep an eye out for leading. There are many threads on this issue. You need to make your own informed decision, but if it were me, I would use the gun as is.

[BK7saum]

I plan to give it a go, but my 1k of Starline measures 0.012" at the case mouth. My boolits will have to be smaller than bore diameter to seat in the case and not be larger than the chamber. Not a good scenario.

[Walt]

I don't have a G40 but I've got a G20 and five 40 caliber Glocks that all shoot .401 sized bullets quite well.

[35remington]

Run what you got before buying anything. Often measurements that require cipherin' have enough slack that what you think won't work, will.

[FergusonTO35]

My 9mm Glocks with factory barrels prefer .356 boolits, not .357. Go figure!

[Catshooter]

I have a Winchester 38-55 with a bore of .3795. The largest I could get my Lyman 375449 to cast was .3793 or so.

Five hundred rounds at 1,800 fps and no leading the full length of the 26 inch barrel. So you never know until you try.

I will say though that all of my Glocks require their boolits be water dropped regardless of fit.

Good luck.


Cat

[BK7saum]

The boolits i have cast are water dropped range lead that are 20-22 bhn. As soon as I get an appropriate expander, I plan to load some up.

[Packy]

My glock 40 slugged out out a little over .400. Shooting boolits sized at .402, wont shoot a group less than 3 inches, with a rest and a red dot. Got to looking at the brass it measures .432 at the base after being shot. Dropped a loaded round in the chamber and it wobbles around, shake the barrel and you can hear the round bouncing around in the barrel. I took a sized 41 mag brass and stuck it in the chamber and it goes in little over a 1/4 inch. The 41 mag brass wont even begin to go in my other 10 mm chambers.

[35remington]

Packy, your group size has more to do with how tightly the barrel and frame is fit than your chamber dimensions. Barrel/slide/frame slack always accounts for the accuracy you see from autoloading pistols for the most part. The gappy frame/slide fit on Glocks is hard to overcome even if the barrel is tight as there's not a lot of bearing surface to tighten up....only tiny frame rails of not much length. If those groups are at 25 yards that's probably a little better than average for a Glock and a stock barrel.

[FergusonTO35]

I would be overjoyed if I could shoot 3 inches at 25 yards with any sort of handgun. A Storm Lake barrel will probably help you alot, Packy. They have pretty snug chambers .

[BK7saum]

Update....

I received my expander from 0.401x0.405 expander from Buckshot and started reloading for my glock 40. NOE 200 WFN bullets sized to 0.402" and lubed wirh Bens Red, FC brass, with 7.5 grains of 800X. Nice groups, but not revolver nice. Overall pleased with how it shoots. 7.0 grains didn't shoot well, but 7.5 was way better. Changed out the sights to adjustable night sights for now to compensate for it shooting high.

Can ring a 2/3 IPSC steel from a ways out and am getting decent 25 yards groups freestanding.

Brass at the case mouth is about 0.001" clearance. Not as tight as measurements would have indicated. I have the same concerns as Packy with the chamber being bucket mouthed.

Feeding has been reliable with only one failure to feed with a boolit hung up on the barrel hood. Not sure what happened, but the only issue so far.

Just have to wrangle a holster for the beast right now.

Brad

[BK7saum]

Packy, have you considered just partially resizing the cases? Leaving the brass near the case head at fireformed dimensions would decrease the rattling around of the cartridge a bit. My RCBS carbide sizer sizes the cases to 0.420.

There were a couple of 10 mm cases I threw out due to thick case walls. After running the expander into the case, there was a very large bulge from the expander. I just tossed those into the scrap brass bucket. They were expanded too much to chamber.

Brad

[FergusonTO35]

Hey BK7, how high was your pistol shooting with factory sights and what did you get to replace them? My Glock 19 has always been very accurate but shoots very high, like 4" at 7 yards. I ordered a Hi Viz .215 front sight for it, hopefully that will correct it.

[BK7saum]

I was about 10" high at 25 yards with slow 180 loads. I figure that with fast 155 grain loads it would have printed close to point of aim. I got the meprolight adjustable night sights. I don't like the fact that they hang over the back of the slide but I'll live with it for now.

The MOS plate required that the rear sight dovetail be moved back more than other models.

[EDK]

I bought a 34 MOS and then noted the rear sight positioning when I wanted to have DAWSONS installed. I'll bite the bullet and get some kind of optical sight, but the MOS is not going to get much time in my holster.

Check out the BLADE TECH holsters. Discounted on eBay. I use the one for my 26 for 17, 34, and 41 also.

[Lloyd Smale]

all my glocks shoot cast just fine. No theyre not going to win any bullseye match using cast but they wont with jacketed either. I learned long ago to shoot a gun. See if it does what I want before I touch a measuring tool to it. If it doesn't shoot then measure things up, see what the problem is and try to fix it. bottom line is the only glock I shoot that I need to do better then 3 inch at 25 yards is my 20 as it might be used for deer hunting but truth be told it hasn't yet and probably wont be.

[BK7saum]

My glock 40 has been shooting decent 6" or so groups and under groups at 25 yards with 800x and 200 grain Noe boolits. This was standing unsupported. I could cut that considerably, I think, from a rest. Just don't see much point of shooting a non target handgun from a rest except for some load development.

Brad

[BK7saum]

Well, I'm getting leading with the 200 grain water dropped range lead in 10mm brass, but the same load in 40 S&W brass shoots clean. In fact, sometimes I shoot a mag of the 40 brass loads to clean out slight leading from the 10mm brass loads. About ready to just buy the dad gum aftermarket barrel and be done with it. I still think that the chamber and case are causing the boolit to swage down a bit on firing whereas the 40 case allows a bit better release from the slightly larger case mouth. I'm using Bens Red lube and have always had good luck with it in my 357s, 41s, 44s and 45s. Load is 7.5 grains of Longshot and the boolits are BHN of 21 or so. I've tried air cooled and air cooled with plain base gas checks. Same thing. Leading in 10mm brass.

Groove is 0.4017" or so and chamber at the throat is 0.425" or slightly less. Most of my brass is measuring about 0.011" or bigger. Boolits are sized to 0.4022" plus or minus a ten thousandth or two. Any larger and they won't plunk without a super heavy crimp.

[BK7saum]

Sure wish the groove on this barrel was 0.400 like it should be. If it was, I think this sucker would shoot just about any boolit 0.401-0.402" in diameter.

[Catshooter]

BK,

I sympathize with your plight. Oversized bores can be a real struggle. I have a friend with a 444 Marlin, bore is .4329 and finding a mould to fit is dang tough. I've suggested Accurate Molds, but he's short of funds.

How is your throat? Does it have one? Seems like they're getting shorter and shorter (esp in autos) these days. The no leading in the shorter brass made me wonder if the boolit is liking the run it's getting before it hits the throat that it can't get from the 10 brass.

Good luck.


Cat