what the HELL happened with my .22LR conversion kit???

TonyDedo

TonyDedo

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I recently bought a Marvel .22LR Conversion Kit for my Colt 70 Series Combat Commander.

I first took it to the range about 2 weeks ago, where I shot about 100 rounds of the Wally World 550 round Federal bulk packs of .22LR (high velocity). The only problem I had was occasionally (maybe once every 20 rounds) the slide would not lock the hammer back, and I was have to cock it manually. I figured this may be due to the custom hammer and other parts on the gun (drop in trigger job kit from Cylinder & Slide).

My buddy shot about 20 rounds of standard CCI .22LR with it 1 week ago, with no problems at all.

This past weekend I took it to the range again and loaded CCI Stingers (hyper velocity). About half way through the first magazine, I heard an unusual POP and I got a face full of gas and crap (not sure exactly what it was) blown out the back of the slide. Once I assured myself that I was bleeding from the face, I checked the cylinder. The next round was chambered, but the ejector wasn’t catching on it. So I unloaded the gun, disassembled the conversion kit, cleaned out all the crap that was all over the chamber and barrel, checked for damage, and finding none, reassembled. I got half way through the second magazine, when the same thing happened. This time the next round (not the empty brass, but the round that should have been chambered) was stove piped on the LEFT side of the chamber (the conversion kit ejects to the right, like a normal 1911, but when the slide is pulled back, the chamber is exposed on both sides). Again, I disassembled, wiped out all the crap, and reassembled.

This time I reloaded with the same Wally World Federal I had used before. I shot about 150 rounds, and the only problem I had was the hammer not locking back (happened once almost every magazine). Then it happened to me again.

At this point in time I was tired, frustrated, and my face felt like fire ants were crawling all over it, so I packed up my gear and went home.

I plan on calling Marvel this week, but I wanted to run the problem by you guys first and see if anyone has any insight. Does anyone know what was happening???
 
I'm not sure what's going on here but I know from experience that .22 conversion kits aren't very reliable. They are a great idea in theory but in the real world just typically aren't very reliable.
 
My somewhat limited experience with .22lr conversion kits is that they do not always generate enough "oomph" to lock the slide or hammer back. But on the plus side they can give you plenty of malfunction clearing experience.
 
This past weekend I took it to the range again and loaded CCI Stingers (hyper velocity). About half way through the first magazine, I heard an unusual POP and I got a face full of gas and crap (not sure exactly what it was) blown out the back of the slide. Once I assured myself that I was bleeding from the face, I checked the cylinder. The next round was chambered, but the ejector wasn’t catching on it.
Click to expand...

What makes you think it's the kit and not the ammo? Especially as it didn't happen with the OTHER ammo you'd been using?

"Hyper velocity" is not the correct ammo for a target conversion and what you described sounds like a case failure or premature slide retraction.
 
Scrivener said:
What makes you think it's the kit and not the ammo? Especially as it didn't happen with the OTHER ammo you'd been using?
Click to expand...

I'm not saying it was either. I'm saying I have no idea what happened, and looking for input.

And to clarify, the failure occured using both the Stingers and the Federal ammo, just far less often with the Federal ammo.

If your explanation is that conversion kits aren't mean for high velocity ammo, that makes sense to me. I wasn't aware of this, and there were no warning labels or instructions with the kit to lead me to believe I couldn't or shouldn't shoot certain types of ammo.

I'm just looking for some feedback before I call Marvel and tell them their conversion kit sharted in my face. And if they tell me "Only use standard velocity ammo" than there is my answer.
 
Did you clean the lead from the barrel before using the stingers????

Did you check for a pierced casing rather than just an indent?

Is it at all possible there was a barrel obstruction that was cleared by the round that gassed you??

Just some ideas.
 
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livinlawatertown said:
And to clarify, the failure occured [sic] using both the Stingers and the Federal ammo, just far less often with the Federal ammo.
Click to expand...

Let's review your original post:

This past weekend I took it to the range again and loaded CCI Stingers (hyper velocity). About half way through the first magazine, I heard an unusual POP and I got a face full of gas and crap (not sure exactly what it was) blown out the back of the slide. Once I assured myself that I was bleeding from the face, I checked the cylinder. The next round was chambered, but the ejector wasn’t catching on it. So I unloaded the gun, disassembled the conversion kit, cleaned out all the crap that was all over the chamber and barrel, checked for damage, and finding none, reassembled. I got half way through the second magazine, when the same thing happened. This time the next round (not the empty brass, but the round that should have been chambered) was stove piped on the LEFT side of the chamber (the conversion kit ejects to the right, like a normal 1911, but when the slide is pulled back, the chamber is exposed on both sides). Again, I disassembled, wiped out all the crap, and reassembled.

This time I reloaded with the same Wally World Federal I had used before. I shot about 150 rounds, and the only problem I had was the hammer not locking back (happened once almost every magazine). Then it happened to me again.
Click to expand...

So the last "it" was the "POP;" not the hammer failing to lock back, then. It seemed from the post that the "POP" was purely a Stinger issue.

Note: There is no "cylinder" in a 1911. [wink]

I'm just looking for some feedback before I call Marvel and tell them their conversion kit sharted [?] in my face. And if they tell me "Only use standard velocity ammo" than [sic] there is my answer.[/QUOTE]

I would definitely contact Marvel, which is considered an excellent unit. I would also check the recoil spring, guide rod, etc., to ensure that it is functioning properly. It may not be seating the slide properly.

Also, clean the firing pin channel. If the pin is jamming, it could cause a slam-fire.
 
Diagnosing something like this sight unseen is an exercise in speculation, but let me offer the following:

.22 autos are "blowback" designs. This means that the timing of breech opening is based on a careful balance of cartridge recoil and slide mass.

With .22 conversion kits in Gov't Model pistols, this careful balance is complicated by the use of a floating chamber, the function of which is multiply the recoil potential of the diminutive .22 round.

In all auto pistols, there must be a delay between round discharge and the commencement of slide retraction from the rear chamber plane; during this time, chamber pressure has to decay from whatever it was at peak to not more than about 10 psig. In "locked breech" pistols, this delay is accomplished by the period of time during which the slide-with-locked-barrel can move back without unlocking. In blowback pistols, the delay is a function of the intertial moment of the slide mass.

The scenarios you have described sound like (I say again, one cannot diagnose with any authority from a distance) premature breech opening. This could well be an ammo issue.

What I would be inclined to do is as follows:

1) completely disassemble the kit;

2) carefully inspect for non-spec conditions;

3) carefully clean all parts;

4) re-inspect for non-spec conditions;

5) assuming "SAT" on steps 2 and 4, reassemble and feed the pistol a bunch (couple of hundred rounds) of plain old "green Remington" through the kit.

If all works OK, I'd conclude it was the hot ammo.
 
Check the manual for the kit and see what type of ammo they recommend. Standard velocity or high velocity? I shoot CCI standard velocity and I have had one misfire in 15k rounds. I remember because I had to call an alibi. Try calling them and asking if there is a specific brand of ammunition they recommend. CCI SV can produce dime sized groups @ 25 yards out of a S&W 617. Four Seasons has them bulk packed for short money.

http://www.midwayusa.com/eproductpage.exe/productview?saleitemid=271391&t=11082005

I would wager that it is designed for standard velocity ammunition if it is being targeted towards Bullseye shooters who want to use the same frame for Centerfire/Rimfire.

You can buy a new mainspring housing assembly and put a 19 pound mainspring in and then swap it out when you need to carry the gun. That should help it cock the hammer more consistently although it might hurt ignition.
 
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RKG said:
....22 autos are "blowback" designs. This means that the timing of breech opening is based on a careful balance of cartridge recoil and slide mass....
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Not to hijack or sidetrack the thread, but,

Are there any non-blowback .22's? Are there any blowback actions for anything bigger than maybe .380 ACP or Makarov, or are those the biggest? Just curious.
 
I can't see why any engineer would look at a .22 and think "I better find a way to lock the breech closed" It takes very little weight.

All right, looking at the parts diagrams it does indeed look like Hi-points are blowback. I don't know how they do it for .45 in only 32 ounces even with a polymer frame.
 
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I know when they came out with the Ruger 10/22 in .22 Mag, it took a bit of engineering to get the weight and spring rates just right for the timing on the action mechanism. I don't think they make those any longer. I wonder if there were problems.

Could be similar issues with .22 conversions.
 
I would double check and see if there are any ammo recommendations. I have an Advantage Arms .22 conversion for my Glock. It recommends 2 specific brand and types of ammo. (both High Velocity IIRC). Those are the only 2 I have tried in it, and it has been flawless.
 
Round Gun Shooter said:
Did you clean the lead from the barrel before using the stingers????

Did you check for a pierced casing rather than just an indent?

Is it at all possible there was a barrel obstruction that was cleared by the round that gassed you??

Just some ideas.
Click to expand...

Yes, I cleaned the barrel after each weekend of shooting.

No, I couldn't find the casing (or I didn't find an unusual looking casing in the vicinity)

Sure it's possible there was a barrel obstruction, but I wouldn't expect repeated barrel obstruction in such a short period of time.

Good thoughts, though...
 
Coyote33 said:
Are there any non-blowback .22's?
Click to expand...

One hates to be absolute about a negative, but none comes to mind.

Coyote33 said:
Are there any blowback actions for anything bigger than maybe .380 ACP or Makarov, or are those the biggest? Just curious.
Click to expand...

In a pistol, I think .380 is the largest I'm aware of; after a while, the mass required of the slide makes the arm a bit heavy.

The .45 ACP Thompson is a blow back, and has as you might suspect a pretty massive bolt. The M3A1 was a blowback, as well as (I believe) the Reising. Toward the end of WWI, Springfield Armory produced a sort-of conversion kit (the Pederson Device) to allow '03 Springfields to shoot a special pistol cartridge, and it was also blowback. And there's probably a whole list of other, larger-than-.380 shoulder-fired blowbacks I haven't thought of.

Edit: And how could I forget: the 9 mm Uzi. The reason why blowback SMGs have such short barrels for their OALs is the need to provide room for the massive bolt aft of the breech. The Uzi was a clever design that employed a bolt that was "hollowed out" so that part of its mass resides forward of the breech face when the action is closed. This allowed a much shorter weapon for its barrel length; it also helped with balance, provided a favorable reduction in the climb-to-the-sky tendency of such weapons, and enabled the magazine to be located within the pistol grip (rather than forward of the trigger guard).
 
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The Marvel Unit #2 is designed for High Velocity Ammo.
The Marvel Unit #1 is designed for Standard Velocity Ammo. I have a Unit #1 and shoot CCI standard velocity with zero problems.

Bob
 
RKG said:
One hates to be absolute about a negative, but none comes to mind.



In a pistol, I think .380 is the largest I'm aware of; after a while, the mass required of the slide makes the arm a bit heavy.

The .45 ACP Thompson is a blow back, and has as you might suspect a pretty massive bolt. The M3A1 was a blowback, as well as (I believe) the Reising. Toward the end of WWI, Springfield Armory produced a sort-of conversion kit (the Pederson Device) to allow '03 Springfields to shoot a special pistol cartridge, and it was also blowback. And there's probably a whole list of other, larger-than-.380 shoulder-fired blowbacks I haven't thought of.

Edit: And how could I forget: the 9 mm Uzi. The reason why blowback SMGs have such short barrels for their OALs is the need to provide room for the massive bolt aft of the breech. The Uzi was a clever design that employed a bolt that was "hollowed out" so that part of its mass resides forward of the breech face when the action is closed. This allowed a much shorter weapon for its barrel length; it also helped with balance, provided a favorable reduction in the climb-to-the-sky tendency of such weapons, and enabled the magazine to be located within the pistol grip (rather than forward of the trigger guard).
Click to expand...

Detonics marketed a small blow back operated 9mm briefly.
 
I have had both these problems with 22LR conversions. The explosions and crud are the result of the pistol firing out of battery. Enough unsupported case is exposed so that it fails upon ignition. Dirt in the chamber can cause the round to fail completely chamber. The solution is to clean the chamber completely after the first incident and keep an eye on it. The first KB could have been just bad luck and failure to completely clean the chamber set the stage for further KBs. Firing out of battery (even if the case doesn't fail) generates less pressure and energy which could cause the slide to fail to cock the hammer.

Another possibility is that you have a rough chamber. I had a DPMS 22LR conversion that would fire out of battery (and blow some cases) even if I cleaned it regularly. I polished the chamber which was an instant solution to the problem. I would return the kit to Marvel rather than attempt this cure myself.

A possible cause of the hammer's failure to cock is plain old friction. I use 5wt synthetic motor oil in my 22 conversions, you might try that as it is certainly cheap enough. Ciener recommends 5wt synthetic motor oil in his conversions.

Another posible cause of the hammer's failure to cock is the ammo. Both my conversions (Marvel Long Slide and DPMS) seem to prefer CCI Blazers. I would start with the hot stuff to get the gun to function.
 
The Marvel unit that is the full slide requires that you shoot Hi Velocity ammo, and you install the supplied mainspring. CCI Mini Mags are recommended and work 100% in mine.
The Target version, the one that has a small moving slide and the barrel assembly with the rail is non moveable, requires standard velocity ammo.
You had a slam fire. Also, Marvel states not to use Federal ammo.
One other thing to check, make sure the top of the magazine is not dragging on the bottom of the slide, this will contribute to short stroking.
 
I forgot. My Long Slide conversion's slide (the two piece model) made contact with the top of the mags which all had to be trimmed. Also the feed lips were rough and had to be smoothed before feeding was 100%. I wasn't aware that Marvel recommended standard velocity ammo for this type of conversion. Neither was the gun as it won't feed standard ammo reliably, only Blazers.
 
Thanks a lot for the feedback, guys.

I disassembled and cleaned the unit after both KBs (if that's what I should call them) and could identify no damage or indications as to what went wrong. I'm hoping that there's nothing wrong with the unit itself.

As for the ammunition, this is a Unit 1, so these failures would make sense to me if the unit was only designed for standard velocity. Thus, many failures using hyper velocity, fewer using high velocity, and none using standard. As I mentioned before, the unit came with no warnings or instructions indicating a certain type of ammo should be used.

I've left several messages and sent emails to Marvel, but haven't gotten a response yet. See my earlier thread on ordering the unit for my thoughts on Marvels (lack of) customer service.

However, if I can confirm the ammo requirement with them, hopefully that will resolve this issue. In hindsight I probably should have bought the Unit 2 model...

In regards to the hammer issue, does anyone know an easy solution to helping lock that hammer back more reliabily (besides more oil - I tried that one)? I know my way around the 1911, but (as the saying goes) I'm not a gunsmith, nor do I play one on TV.

Thanks again!
 
Like I mentioned you can try putting in a lighter mainspring. The standard mainspring is 23 pounds and you can still get reliable ignition with a 19 pound mainspring with centerfire ammo. I do not know how it will perform with rimfire ammo. Brownells carries Wolff springs. This will allow the gun to cycle a little more positively as the hammer will not resist cocking quite as much.



I would not consider the following modification until you have put at least 5k rounds through it and thoroughly broken it in.

You can check the bevel where the slide meets the hammer. On a normal 1911 this would be a removable part called the firing pin stop. The degree of bevel affects how much mechanical advantage the slide has over the hammer. If this surface is square the slide will have the most resistance from the hammer. I would not modify it if it is not a removable part. If it is a removable part I might consider buying a new firing pin stop that is already beveled and using that.

Whatever you do don't modify stock parts. Buy replacements and mod those.
 
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