Glock pistols seem to have a love-hate relationship with the world - you either love them or hate them. There is tons of discussions out there on the pros and cons of the Glock pistol.

Personally I am not a fan of the Glock, so just because I write this article doesn't mean that I'm a "Glocker". However, I am a student of "Pistol Craft" or "Art of the Combat Pistol" - i.e. the training, eduction, design and use of pistols for personal protection and combat.

In today's world, the Glock is a VERY common pistol to be encountered with police, military and civilian shooters, so if you are a "student of the 'Craft" - you need to spend some time learning and handling them.

The Glock "Mutt" Project was to take a Glock pistol and see what caliber conversions I could make (or get) work RELIABLY and to dispel a lot of the misinformation out there about them. (There's tons of it !)

My goals were simple:

What works? What doesn't work? Is is SAFE? Is it cost effective? Why would I want this or that?



The Glock "Mutt"

Pistol (original): .40SW Glock Model 23 (Glock's compact model)

Calibers: 9mm, .40SW, .357 Sig, .22 LR

Cost:

.40 Glock 23 Gen3 Pistol /w 2x Mags	$490.00
.40SW to 9mm Lone Wolf Caliber Conversion Barrel for Glock 23 and Glock 27.	$100.00
.40SW to .357 Sig Lone Wolf Caliber Conversion Barrel for Glock 23 & Glock 27	$100.00
Ciener .22LR Conversion Kit for Glock 19/23 /w 1 mag	$200.00
Magazines ($25.00 each): 2x 9mm Glock 19 mags 1x .40 Glock 22 mags 1x .357 Glock 31 mags ----- total of 4 mags	$100.00
Total Cost of the Glock "Mutt"	$990.00

Caliber Comparison Data:
*Cost as of today 8/24/2011 at Cheaper Than Dirt.
** Premium JHP's come in 20 round boxes. Price shown was conversion for price per round for 20 round box, then multiplied to cost for 50 rounds.

Caliber	Bullet Wt (grains) / Type of Bullet	Velocity (ft per sec @ muzzle)	Energy (foot lbs @ muzzle)	Cost / box (50 rds) / Brand
.22LR	40 LRN 40 LRM	1240 1255	137 140	$2.65 Federal Clas $1.53 Rem Thunderbolt
9mm	115 FMJ 147 FMJ 147 JHP	1150 990 1000	335 320 326	$8.69 Wolf $12.20 UMC $45.53** Fed Hydra-Shok
.40S&W	165 FMJ 180 FMJ 180 JHP	1150 990 1000	485 392 400	$15.32 UMC $11.96 Wolf $51.65** Fed Hydra-Shok
.357Sig	124 FMJ 125 JHP 140 FMJ	1350 1350 1250	505 506 513	$18.69 Fiocchi $48.60** Speer Gold Dot $19.44 Sellier&Bellot

You Can Go Down, But You Can't Go Up!

Here's couple of rules with converting Glock Pistols:

1) You can convert to same size cartridge or down, but not up - i.e. you can go from .40 to 9mm, but not 9mm to .40.

2) You can only convert between SAME size frames - i.e. you can't convert between standard frame, compact frame, sub-compact frame and the "long frames" (10mm/.45acp pistols)

** Exception 1: Sub-Compact frames CAN use the longer Compact pistol barrels, but they stick out 1" past the muzzle.

3) Magazines are interchangeable only if they are LONGER than the frame, but they will stick out the bottom of the pistol - i.e. standard frame mags can be used in compact frame pistols, but stick out about 1" past the grip.

Breaking Down The Glock:


The Slide:
Pictured: .40SW Slide (LEFT), 9mm Slide (RIGHT)

One of the key elements in building the "Mutt" is the slide. The picture right shows the muzzle of the slide. Even thought it may not look like it, but diameter of the "hole" for the barrel is bigger on the .40 slide (left) than the 9mm slide (right). This is only nature as the .40 cartridge is a larger diameter verses the 9mm, so the barrel has to be also.

So I cannot mix the FACTORY barrels on any of the Glock pistols due to the physical diameter of the barrel.

Second element is the weight of the slide and the recoil spring. The slide's weight and the recoil spring's resistance (in pounds) is what cycles the action and handles the recoil when firing the pistol. Too light and the slide slams back with more force. Too heavy and the slide won't cycle. It's simple physics!

Pictured (right) is the bottom of the slides on the 9mm (LEFT) and .40 (RIGHT). Note the red arrow on the 9mm slide shows where the slide has be milled out to reduce it's weight verse the straight (not milled) slide of the .40 on left. This means the .40 slide is physically heavier and needs more force cycle the action.

However, the 9mm and the .40 Glock pistols, of the same frame size, use the SAME recoil springs. So a 9mm Glock 19 and a .40 Glock 23 use the same 18 pound recoil spring!

Standard from Glock 17 & 22 use a 17 pound spring (longer slide, means more weight. So less resistance needed for the spring.)

So Glock pistols use the slide's weight ONLY to regulate the recoil and cycling of the pistol by using lighter or heavier slides - i.e. cut outs the slide for the 9mm or not for the .40SW.

The Barrel:

Pictured is 9mm Glock 17 barrel (LEFT) and .40 Glock 23 barrel (RIGHT).

Hard to tell here, but the .40 barrel is larger in diameter of the 9mm barrel. This is why the muzzle of the slides above are different sizes.

This means that you CANNOT use a .40 barrel in a 9mm slide (won't fit) nor can you use a FACTORY 9mm barrel in the .40 slide (too much space around the barrel).

Side Note: Notice that the Glock 17 (standard frame pistol) barrel lugs, where the barrel locks into the frame of the pistol, are different from the Glock 23 (compact frame pistol). This is why the barrels and slides of different framed Glocks will not interchange.

The Frame:

The lower frame for Glock pistols is the same for EACH of the frame sizes. That means NOTHING is different between the frame of two standard size pistols. There is a difference in the length and internal lock up for the barrel BETWEEN the frames, which is why you CANNOT interchange between DIFFERENT frame sizes.

But within the SAME frame size you can! So ALL parts for a 9mm Glock 19 Compact WILL work in a .40 Glock 23 Compact and vice verse. So this means that only a FEW of the parts on a 9mm and .40 Glock pistols are different.

The Ejector:

One of the different parts is the ejector. Pictured shows the 9mm ejector (LEFT) is "bent" to the right. The .40 ejector (RIGHT) is straight.

The "bent" 9mm ejector is to reach over and hit the smaller diameter 9mm case in the same frame. Where as the .40 case is better and does not require the ejector to "reach", so it is straight.

However, the trigger assembles (and housings) shown in picture CAN BE INTERCHANGED between frames of the SAME size.

The cutout for the ejector on the slide (bottom/back) is identical for both the 9mm and .40 slides. So you CAN interchange the slides of the same frame.

What does this mean?

The next picture show a 9mm magazine loaded into BOTH the 9mm frame (LEFT) and the .40 frame (RIGHT). Note the location of the 9mm "bent" ejector is more centered to the back of the case verses where the .40 "straight" ejector is more to the side.

Being centered is designed to allow for a "more positive and forceful" ejection - i.e. improved reliability. However, the "straight" ejector does hit the case in a "solid manner". I quoted that as this is MY opinion and MY observation at this point. I was able to cycle the action and the 9mm cases where ejected with the .40 "straight" ejector.

It's close enough for me to take the next steps and buy conversion barrels and give this project a trip to the range.

Building "Mutt":

If you've been around me, you know I spend A LOT of time on doing caliber conversions on different pistols and rifles. It's kind of a "fetish" for me - whatever! But I've done several pistols before using the 1911, Beretta 92, Mauser M2 and some others. Each one had it's own "quirks", but most worked out with me having to partially build another slide to make the conversion OR spending a lot of time "adjusting" things. Let's just say "drop in" isn't a reality most of the time!

Lone Wolf Conversion Barrels:

Until I have stripped down my Glocks and compared them I was very skeptical of the Lone Wolf "drop in" conversion barrels. I had seen them in several parts catalogs and on YOUTUBE videos, but again, the words "drop in" where not EXACTLY correct with other pistols.

First came the 40-9 conversion to convert my .40 Glock 23 into a cheaper to shoot 9mm. The reason you can use THIS 9mm barrel is that the overall diameter of the barrel is the SAME as the .40 FACTORY barrel, so it fits where the smaller Glock factory 9mm barrel does not. Basically, the Lone Wolf "drops into" the .40 slide like a .40 barrel. Nice!

I also bought two Glock 19 9mm mags and I already has some Glock 17 full sized mags. By using regular Glock 9mm mags, the only thing I changed on my Glock 23 was the barrel and the mag - this is truly "drop in".

Shots Fired:

Out to the range, I ran "Mutt" with everything I could find! In the end, it shot everything, ejected everything and the only trouble I had was will some reloads.

The problem the was due to the Lone Wolf's barrel having a tight, "match chamber" verse a "military chamber" of the factory Glock barrels. The reloads that did not work in the Lone Wolf barrel worked fine in my Glock 17.

The .40 ejector - works! The ejection of the brass is not quite as far as with the correct "bent" 9mm ejector, but it works. Long term, we'll see, but so far is good now, even after about 500 9mm rounds through "Mutt".

.357 Sig:

I bought a 40-357 Sig barrel and have had the same results! In fact, I've actually found that I LOVE the .357 Sig round now! In this platform, the .357 Sig is very comfortable, but LOUD! I would love to shoot it more, but the cost is WAY more than shooting .40 and 9mm. So I will shoot it when I can, but either way - "Mutt" shoots it and no problems after about 200 rounds.


The Truth About Glock Magazines:

Pictured is a 9mm Glock mag (LEFT) and .40 mag (RIGHT).

You can shoot 9mm in .40SW mags.

You can interchange .40 and .357 Sig mags.

You cannot shoot .40's or .357 Sig in 9mm mags.

You cannot RELIABLY shoot 9mm in .357 Sig mags.

9mm in .40 mags:

Yes, no problems. The .40 mag's feed lips are a little wider (see picture), but there is still plenty of retention to hold the smaller 9mm case in place and RELIABLY work. My only concern here would be long term storage of these mags LOADED as they may be damaged if left loaded. For short term shooting, no problems. So if you only want to buy the Lone Wolf barrel for your Glock .40 pistol so you can shoot more with cheaper ammo, you can and not worry about buying any extra mags.

.40's and .357 Sig mags:

These are totally interchangeable! There is a slight difference between the feed lips of the .40 and the feed lips on the .357 Sig mags, but I cannot find anything PRACTICALLY different in their performance. You can freely swap these around!

No .40's or .357 Sig in 9mm Mags:

The .40's and .357 Sig's will NOT fit and function in the 9mm mags. So 9mm mags are 9mm ONLY!

No 9mm in .357 Sig mags:

This one is still not 100% reliable as I would like. The combination of the difference with the .357 Sig feed lips (verses .40 mags) and the slope of the .357 Sig follower seem to allow the 9mm to move around more than when you use the .40 mags. So even though they will "kinda" work, I would worry about it unless you have a .357 Sig Glock - i.e. see RELIABILITY notes below.

Ciener .22 LR Conversion Kit:

Okay, I'm going to fess up here a bit....I actually don't have the Ciener kit for "Mutt" yet :P

I have it for my 9mm Glock 17, so I've got the experience using one on a Glock and have absolutely NO inhabitions that it wouldn't work the same way with another kit on the Glock 23.

In fact, one of the reasons I have a Glock pistol was for the Ciener kit. These kits use an aluminum slide! This makes for an EXTREMELY light pistol on the Glock. My unofficial guess is about 16 ounces loaded with 15 round magazine.

This kit gives you cheap practice time on your pistol using the same trigger group as you would with other calibers.

The Big "Con" - Magazine Jams:

The one thing that I have found while building "Mutt" is an issue that I think is worth mentioning. With NEW Glock magazines that are loaded to the max number of rounds seem to want to jam when feeding the first round. (Maybe it's just me!) This seems to be consistant regardless of caliber or magazine used. If I load one round less, this problem goes away.

It seems to come for the tension on the first round against the feed lips of the magazine. To correct it is simple - a bump on the back of the slide and the round comes free of the magazine and loads into the chamber. It's done this on new factory .40 and 9mm magazines.

My solution has been to cut ONE revolution of spring from the bottom of the magazine spring. Since I've done this, I have not experienced ANY feed jams loading the first round.

Anyway, that's the only thing I've run into with the Gen 3 Glock, so I thought I would mention it.


100% Reliability - Converting the Glock for Personal Defense:

Even though I have had good luck with "Mutt" and have experienced excellent reliability with everything above, I would still consider some changes if I NEEDED to use "Mutt" for personal defense.

1) Use the factory ejector for the caliber I'm using for defense. Yes, the "straight" ejector works, but for peace of mind.....

2) Use the factory magazine for the caliber I'm using for defense. Main reason here is the same as I mentions above in keeping .40 mags loaded with 9mm's. Best to stay "factory" if it's for personal defense.

The reason - It's too cheap!

To make my .40 Glock 23 COMPLETELY into a 9mm Glock 19, I need the following:

9mm "bent" ejector housing is #22 - "Trigger Mechanism Housing" = $9.00
9mm Glock 19 magazine = $25.00

So for $34.00 I can COMPLETELY convert "Mutt" into a FACTORY 9mm Glock.

But let's got one more step and make it easier to SWITCH back and forth by getting the rest of the trigger assembly making it a single unit to swap out. (Remember those pics of the ejector above? yeah that's the complete trigger assembly.)

To do this, I add the following:

Trigger bar #25 = $18.00
Trigger Spring #24 = $2.00
Connector #23 = $6.00

That's only another $26.00 to make converting from 100% .40 to 100% 9mm in about 15 minutes!

The Beauty behind the "Mutt":

There's several things unique to the Glock "Mutt".

1) "Mutt" can be purchased in pieces so you don't have to shell out the $990 all at once. With a only a $100.00 Lone Wolf 9mm barrel you CAN shoot your "Mutt" using your existing .40SW mags for practice.

2) Glock parts are cheap! IF you tear something up, parts are cheap! If you want to add something (like the 9mm trigger assembly) it's $60.00 (with a new mag) - that's cheap! There is NO other pistol out there with parts that are so available and cheap - that includes the magazines!

3) If I drop, kick, scratch "Mutt", I really don't worry about it. For $490, it's a inexpensive pistol that I can "kick it" around and not care too much about. You won't see me doing that to my .45 Colt 1911 or my 9mm Kimber Aegis II Pro!