ISSC Owner's Question

[4tkal]

Another update: did some more work on the firing pin & firing pin return spring last night. I did some more filing on the pin to make everything a little more smooth and to make sure the firing pin moved ALL the way forward once the retaining pin was inserted. I also cut off a few more links of the firing pin return spring, bringing the total number of links removed to 6.

Took it out to the range today with a friend that I haven't seen in a long time. The first few mags ran 100% fine. Then we started having the odd light primer strike again. Then after a while, we started having "strings" of light strikes followed by "strings" of successful firings -- we'd load a new mag and get 6-8 light strikes in a ROW, then it would start working and we'd dump the rest of the mag without problems.

At one point, my friend (who's military) turned to me and said "you know, it feels like this gun needs a forward assist", which got me thinking....

We ended up doing a field strip on the gun and moved a washer (part # 127) in front of the retaining block (part # 57), so that the washer basically pushes the breech housing forward... which is basically what hitting a forward assist would do.

We ran a LOT more ammo through the gun after that and it performed nearly perfectly. In all, we ran about 1200 rounds through it today, about 700 of which were after we moved the washer. I'm going to clean everything out tonight, then run a bunch more ammo through it at some point (either tomorrow or Monday), but based on what I saw this afternoon, I'm VERY confident that I've finally fixed the problems I've been having. I'll report back after I've had a chance to run another 1000 rounds or so through it.

Based on my experience, my original thoughts on this gun stand -- it's a hell of a fun and unique gun if you're willing to do some kitchen-table gunsmithing, but if you're looking for something reliable out of the box, look at the other options out there.

hey alterd3d,
half way through reading your post, I knew exactly what was happening in your gun, and you have now discovered the problem that plauges this rifle.
the whole breach bolt assembly is moving rear ward because the two zinc blocks that sandwich together through the frame, cannot be held securely in place due to the thin section of aluminium frame that the bolt #108 and tapered block are fastened to.
Here is a simple fix that is so far working on my gun. I have over 3500 rounds through it and out of the last 2000 or so, I have not had one single FTF [federal champion ammo].
The clearance holes on your gun have likely elongated, that is why it was necessary for you to shim the action forward, back to where it is suposed to be.
If you have access to a drill press, or a friend who is a machinist, you can do this yourself. If not, take it to a gun smith.
Buy a M4x25 and an M4x16 stainless preferred, bolts. Buy a metric drill bit that is just under 4mm. I cant remember the drill bit #, but it is 3.99 mm in dia.
Line up the drill bit with the clearance hole for bolt#108 and drill another hole right through the top of the frame. DO NOT try to do this with a hand drill as it it needs to be precisely located.
Reassemble everything, shimming the action forward so that the bolt face can mate with the breach face.
Replace the horizontal bolt#108 with the M4x16.
Replace the vertical bolt with the M4x25 and wind it right through the top of the frame. The reason that this new hole is slightly undersized is so that the bolt will push itself through and have zero play.
You will have to cut a notch in the back of the picatinny rail because it sits right over the new hole.
You will now have a much stronger assembly because the new long vertical bolt is going through 2 sections of frame, the top section being thicker than the single section that the two blocks sandwich together on.
After I did this to mine, I ran 525 rnds through it, nothing moved and not a single FTF or FTE.
All this cost me about .50cents for the bolts, around $3.50 for the drill bit and $20. in gunsmithing.
There is more that could be done to make it even stronger, depending on how much $$$ you want to put into it.
This is still THE most fun .22 plinker I have owned, and I have a 10/22 and a 597VTR as well.
I admitt though, that I dont see the ISSC as a last a lifetime gun due to the zinc castings and extruded soft aluminium frame, but I may be wrong..

 

[alter3d]

Glad to hear it is working out for you now.
If possible please post some pics of where the washer is placed now to push the bolt forward.
I dont have this rifle ''yet'' but the info is for a friend.

Thanks

Next time I have everything apart for detail cleaning I'll grab some pictures for you.

4tkal -- thanks for the info! Unfortunately I don't have access to a drill press, and there's exactly ONE gunsmith here in Ottawa, and from I understand he's pretty backed up with work. Gonna run my gun as-is for a while to see what happens.

 

[alter3d]

Had my MK22 out again tonight. Ran 12 mags through it -- had 1 double feed, 1 stovepipe, and 1 mag feed failure (the mag didn't feed the round's nose up properly, and the round jammed forward into the mag casing), but not a single light primer strike. Woot!

 

[tpain109]

Hey guys, new to forum. Stumbled here looking for more info on the MK22 problems. Have read through the whole thread and others including the FNforums one.

alter3d, now that you seem to have your mk22 working in a pretty reliable fashion, would you be interested in doing a detailed DIY fix post with photos?

Im planning on getting an MK22 this weekend (not sure if its a newer or older one) and if I'll have the same issues, but if I do run into them I'd like a go to place where I can see everything that has to be done. So far all the info is spread out in different pages and threads.

Would be greatly appreciated!!
Thanks to everyone who has been posting about this issue.

 

[alter3d]

alter3d, now that you seem to have your mk22 working in a pretty reliable fashion, would you be interested in doing a detailed DIY fix post with photos?

Once I've had a chance to run another few bricks of ammo through it (i.e. I'm 100% sure everything is working properly), sure. I'll probably actually do a video instead since it'll be easier to explain some things that way. Until I get around to that though, I'll be glad to answer any questions you have or try to help with any problems here in the forums if the one you get is one of the problematic ones.

 

[Mantis]

1.) Are you happy with the rifle?

Absolutely thrilled. This is by far the most reliable and fun to shoot .22 that I own. It cycles most ammo flawlessly - even the cheap bulk stuff. Out of at least 2,000 rounds, I've had maybe 12 FTEs and no light strikes. Of those 12 FTEs, they all involved cheap bulk ammo.

2.) If your rifle has issues what were they?

No issues at all. I bought the rifle from Lanz Shooting Supplies, took it right to the range where I cleaned and assembled it and began shooting it. I've had it out to the rnage 4 or 5 times each time putting between 200 and 500 rounds through it.

3.) Would you buy this rifle again, knowing what you do now?

In a heartbeat.

 

[gopher Everett??]

wow it really seems that issc has some QC issues, with some having major mods to get it to work and some running like a champ out of the box.

 

[j-man]

I've posted a database thread if ny owners want to add their details:

http://www.canadiangunnutz.com/forum/showthread.php?t=735542

 

[4tkal]

Hey Mantis,
Glad to hear you got one that runs great! Would you mind contributing to the data base thread? I am interested to know date of manufacture and serial #
Thanks!

 

[jjohnwm]

Sorry if I missed it...how does one determine date of manufacture? I have a trouble-free one to add to your database.

 

[j-man]

Sorry if I missed it...how does one determine date of manufacture? I have a trouble-free one to add to your database.

Just put date of purchase. More as a tracking stat for now, but it may be useful so see the chronological flow down the road.

 

[BuSaPuNk]

Absolutely thrilled. This is by far the most reliable and fun to shoot .22 that I own. It cycles most ammo flawlessly - even the cheap bulk stuff. Out of at least 2,000 rounds, I've had maybe 12 FTEs and no light strikes. Of those 12 FTEs, they all involved cheap bulk ammo.



No issues at all. I bought the rifle from Lanz Shooting Supplies, took it right to the range where I cleaned and assembled it and began shooting it. I've had it out to the rnage 4 or 5 times each time putting between 200 and 500 rounds through it.



In a heartbeat.

That's great to hear. I was thinking of getting one of Lanz as soon as I get my card in hand in a bit. What kind of ammo were you running in it that it worked well?

 

[4tkal]

There was a date printed on the inside of the box that the gun came in. I asume that's the manufacture or packaging date.

 

[Boneman]

ISSC - Out of the Box FUN!

So I finally got out to the range today for the first time with the ISSC Mk.22 and my experiences was very good!

After reading the many mixed reviews of this rifle I wasn't too sure what to expect and was preparing for some disappointment - but instead I was very pleasantly surprised and I was actually very pleased with the performance and accuracy of this rifle! This is my first 22LR rifle so I have no previous 22LR experience to compare this rifle too.

I tried several different brands of ammo:

CCI Blazer
CCI Stinger
CCI Velocitor
Federal Champion

Now, I did do some modes before even firing thi MK22. I changed the 2 bolts in the back of the receiver, for a longer ones, and used the thread locker to keep them in place. I also inserted a flat washer between the back of the receiver and where the screw mounts - pushing the receiver slightly forward. I also inserted HK small push pins in replace of the Chicago style lower receiver screws.

For the first 10 magazines, this is the ammo I ran and the results:

1 - Blazer - 22/22
2 - Blazer - 22/22
3 - Velocitor - 20/22 - 2 mag miss feeds (see picture below). This seems to be a magazine/follower feeding issue, not gun related.
4 - Velocitor - 22/22
5 - Blazer/Velocitor mix - 22/22
6 - Federal - 21/22 - 1 Light primer strike (see picture below)
7 - Federal - 22/22
8 - Blazer/Velocitor mix - 21/22 - 1 magazine miss feed again
9 - CCI Stinger - 22/22
10 - CCI Stinger - 22/22

Magazine Missfeeds:

Had a few of these 'stovepipe' feeds. This is exactly how the missfeed presented itself when I removed the magazine from the rifle:

As the day went on and after I ran several hundred rounds through the rifle, I found that the magazines were causing the majority of miss fires - the rounds weren't aligning quite correctly and not feeding. I'm pretty sure this was due to fouling from powder residue.

Light Primer Strikes:

Out of over 500 rounds I only had 2 FTF - yes 2! Here are the light primer strikes:

Here is a picture of the normal primer strikes it was producing:

Other Issues:

- Top rail screws came loose. No big deal, will thread lock them when I clean it later today.

- You really have to give the magazine a good slap to ensure it seats. I actually had it drop out of the mag well once during shooting.

My Conclusion:

I HAD SO MUCH FUN SHOOTING THIS RIFLE!!! This thing is a blast to shoot and was very accurate (25 - 50 meters). Even the iron rifle sights worked very well. I did not try the 'pistol sights'.

So my ISSC Mk22 experience was enjoyable, fun and it actually impressed me, considering I didn't have my hopes set too high.

 

[Boneman]

A few videos:

[youtube]t8Q-5Zc-fbw[/youtube]

[youtube]Fxgen6ZH9Wc[/youtube]

 

[bfiles]

sweet, glad the rifle works great for ya.
That is a cool little range you go to there.

 

[Boneman]

I'm trying to source a 12" "Commando" barrel for this MK22. Anyone got any info if/where these are available? I have a few emails out but no response yet.

Can a 12" barrel be shipped up from the US without any issues?

 

[Boneman]

Found this great discussion topic on the FN Fourms about the MK22 and the many mods and fixes one can do to make this weapon function more reliably.

http://fnforum.net/forums/fn-scar-16s/25613-issc-mk22-supressors-scopes-acessories-etc.html

It's about 20+ pages but lots of info and links. Worth a read for any MK22 owner!

 

[Boneman]

2nd Range Day

Another range day update - 2nd range trip with my MK22.

So after my last range day (see my previous posts), I did a basic clean of the rifle, including removing the CBG, but not taking it apart. I recently bought 1000rds of CCI Blazer from my LGS, as it seemed to run well last time and the price is awesome ($22/brick).

So I put 300 rds through it......DRUM ROLL.....not one FTF!!! The ONLY issue I had all day was 2 FTE/stovepipes on my last two mags (1 each mag). I believe this was due more to me firing as fast as I could . I couldn't believe that I ran through that much ammo without so much as a hickup! When I cleaned it I was light on the oil.

Now I did leave that washer in the rear, but when I cleaned it this afternoon I did remove it. Although I'm not sure if I should since it's been working just fine! This is how it looked prior to my cleaning:

I did a pretty significant clean when I got home today, including taking apart of the carrier bolt for the first time - DIRTY! Taking it apart (5 tox screws) is really the only way to get it clean.

So I'm not sure if my MK 22 is a "2nd Generation" or what's going on, but I'm very happy. At this point I will hold off on further modifications util I need to do them.

 

[Boneman]

A few more mods to my MK22.

Magpul XTM Rail Covers:

Removed the "webbing" from the trigger guard. Used a Dremel tool and some wet/dry 400 sandpaper. Took about 20min.

Also have a set of Magpul MBUS (PTS) flip sights on the way to replace the stock ones - not a fan of how 'loose' the front post adjustment is for holding zero.