9mm gages-help

[RamRoddoc]

Hey guys I'm in a pinch.

I had some 9mm 147 grain lead cast that I loaded up and had issues with my two Storm Lake 9mm barrels that I corrected most issues with a special Lee Factory Crimp (bulge buster) die. The Glock 17 barrel was manufactured in 2008 or there abouts. It is stainless and very well machined. It fit right in my G17 Gen II without fitting.


I recently purchased a new Storm Lake Glock 34 barrel and had it isonite coated. The barrel hood needed to be fitted slightly.

I thought I had the issue licked but I tried loading some lead cast 124 grain bullets and issues arose again. The Glock 17 stainless barrel chambers them fine but the new Glock 34 isonite barrel is tight enough to stop the round from chambering.


Here are pics with the fresh reloads, then the rounds reversed. The Glock 34 barrel is on the left and the Glock 17 barrel on the right.

I though perhaps I seated the bullet too deep and due to the taper of the case was causing it to hang up toward the front of the case. I backed my bullet seater out and adjusted it to slowly checking both barrels but the seating depth is more of an issue if it's too far out and engages the lands of the rifling.

So what's going on with this new Glock 34 isonite coated barrel? My first thought was the chamber is excessively tight (not in SAAMI specifications) or it’s just cut to minimal specifications and perhaps the isonite added a few thousands to the barrel. Does this occur? The new markings on the barrel and perhaps new machinery allow a tighter cut to even a tighter end of specification.

I'm looking for a set of 9mm chamber gages go/no go to check this Glock 34 9mm chamber. So if anyone has a set let me know so I can check it. Thank you.

 

[speednut]

I have subscribed to this thread I am curious about the coating.

 

[EMC45]

I believe the coating has shrunk the tolerances even more than the tight chamber was to begin with.

 

[Clarke123]

Sounds like the coating(?)
I use Lyman's Gauge, but if I had it do over I would have probably
gotten a full set form:

http://www.egwguns.com/index.php?p=catalog&mode=search&search_in=name&search_str=chamber+checker

Hey, you may even want to call them for some advice on this problem (?)

 

[acmech]

I just did some reading on Storm lake barrels and the ferritic nitrocarburizing process. You already know storm lake barrels are made to tight specs, way tighter to glocks in chamber dimensions. The ferritic nitrocarburizing from what I read may add .001 to .002 to your part. If it was .002, that inside chamber dimension has now been reduced by .004 total, which is a lot! Did the rounds seat fine before the Isonite process was applied?

 

[RamRoddoc]

I just did some reading on Storm lake barrels and the ferritic nitrocarburizing process. You already know storm lake barrels are made to tight specs, way tighter to glocks in chamber dimensions. The ferritic nitrocarburizing from what I read may add .001 to .002 to your part. If it was .002, that inside chamber dimension has now been reduced by .004 total, which is a lot! Did the rounds seat fine before the Isonite process was applied?

This is what I was thinking. I looked earlier but ran out of time hunting for information. Do you have a link to the process so I can again contact Storm Lake. They first informed me to send it in and they could ream it out for $60. I just dropped over $200 on a new barrel and to put even more money into it seemed wrong too me.

The older raw Stainless Storm Lake barrel accepts what the coated one rejects. If I have some good material to back me up, I'd ask them to consider this for future buyers as not many will be happy to have to fix their barrel before they can run their reloads in it, a primary reason to purchase such a barrel for a Glock pistol. At the very least make the public aware of it and just stick to raw stainless.

The barrel was never fired prior to the isonite coating/finish. I did have to just barely fit the hood to slide interface with a bit of file stroke.

Thanks everyone for your assistance.

I'll update as new information comes to me.

 

[dial1911]

Have you checked it with a factory loaded 9mm round? Just a thought, but I'd be curious if they slide right in, or have to be pushed in, or just don't go in.

If I had a set of go/no-go gages, I'd mail them to you just out of curiosity... unfortunately I don't have such a critter.

 

[RamRoddoc]

Have you checked it with a factory loaded 9mm round? Just a thought, but I'd be curious if they slide right in, or have to be pushed in, or just don't go in.

If I had a set of go/no-go gages, I'd mail them to you just out of curiosity... unfortunately I don't have such a critter.

Well I went through what little factory ammo I had and to answer your question, yes and no. Most of the factory ammo (5 separate makes/types) did slide in but there was no play what so ever went chambered. I stated most but not all factory ammo. I had some older 124 grain Federal Hydro-Shocks (the sub-sonic vintage) that it was about 50/50 for the 20 or more rounds I had left. I had what I think is Atlanta Arms (115 grain?) factory remanufactured ammo and it failed to fully chamber.

Here is a pic of the worst (federal 124 grain Hydro-Shocks) and the lesser of the rounds not fully chambering. The lesser of the two evils could be forced with thumb pressure to seat but took a cartridge rim to rim and be forcefully pulled out.

The evil

The bad

I did more searching and located http://coalcreekarmory.com/custom_finishing.html#Melonite They state: "with surface dimensional growth of only .0002" to .0004"(negligible), so post-treatment fitting is not a concern".

Perhaps but a bore that is already exceptionally close to the low side of acceptable tolerances and being a circle the sum of maximum could be 0.0008". Is it an issue?

I at least thinks it begs an answer and the Storm Lake raw stainless readily accepting what the Storm Lake Isonite processed barrel rejects lends some credence to this theory. I also had to hand fit the Isonite coated barrel but did not on the raw stainless barrel. To add to the variables in the manufacturing process fresh new tooling will get you closer to spec than worn tooling. Tooling has a life span and if your item was made toward the end of the tooling life span then your tolerances will in general be greater. This may be more the issue but it has got me thunking pretty hard.

I will state it bears little to the quality of the barrel as I have been impressed with the machining for the dollar and value Storm Lake barrels represents.

If anything if one were to purchase an Isonite treated match grade barrel for competition may need to be aware that there may be an issue with chamber dimensions.

To be honest I really don't think the chamber needs a good reaming but rather a good polish and I suspect all my chambering woes will reduce or simply go away.

Does anyone have good suggestions on polishing a 9mm chamber?

 

[RamRoddoc]

Hah! I had time finally to play with my 6.02" Storm barrel Glock 20 and guess what........chicken butt!

Yes sir same issue but with virgin never fired Starline brass and a 135 grain bullet ran through a Dillon press. It also did the same with 180 grain bullet but was noticeably less an issue. Odd it seems the lighter the bullet more issue with the round's butt hanging out of the chamber like a home chicken's pants with these two isonite coated barrels.

I ran the rounds through my Lee "bulge buster" but the round slipped through without any reduction to the case. In specification? A factory round (only one tested) dropped in but there was absolutely no play. The chamber seemed a bit rough too and "grabbed" on the virgin brass like a football player on a prom night date. Abrasions were noted the first two thirds of the case.

Dang these barrels are tight!


One of the worst fitting rounds (virgin brass-Nosler 135 grain HP jacket)

The rounds

Scuffs of the brass from the chamber.

I'm not sure if it's the isonite or Storm Lake just has extremely tight tolerances for Glock barrels (?). The isonite does increase dimensions but I'm told it's like 0.0002" that shouldn't be an issue? If what I'm told is accurate as truth does have a date and time group. Perhaps it's just better/newer tooling?

Any hoe, it looks like both new barrels will need a bit of polish to work with reloaded ammo. I ordered a couple of chamber hones from Amazon for less (<$15) than 1/2 what Midway wanted.