Air Machinegun Forum
General Air Machinegun Discussion Category => Other Airgun Discussions => Topic started by: camracer on December 16, 2015, 01:25:50 PM
-
I just picked up this new semi-auto repeater 30 round pellet rifle last week.
This is the .177 MCX version. Sig is releasing these first only in .177 cal. The .22 cal version will not be out for a while yet. They are powered with 90 or 88 gram CO2 right now, but HPA versions will be available next year sometime.
For me, that is too long to wait. But what can you do? ....convert it to HPA!
(http://i952.photobucket.com/albums/ae9/camracer1/Sig%20Sauer%20MCX/Sig%20MCX.2_zps15pg4dfn.jpg) (http://s952.photobucket.com/user/camracer1/media/Sig%20Sauer%20MCX/Sig%20MCX.2_zps15pg4dfn.jpg.html)
(http://i952.photobucket.com/albums/ae9/camracer1/Sig%20Sauer%20MCX/Sig%20MCX.1_zpsht1uvpsh.jpg) (http://s952.photobucket.com/user/camracer1/media/Sig%20Sauer%20MCX/Sig%20MCX.1_zpsht1uvpsh.jpg.html)
-
I made this simple adapter on my lathe:
(http://i952.photobucket.com/albums/ae9/camracer1/Sig%20Sauer%20MCX/HPA%20adapter_zpsitvp1oxr.jpg) (http://s952.photobucket.com/user/camracer1/media/Sig%20Sauer%20MCX/HPA%20adapter_zpsitvp1oxr.jpg.html)
I did not even try CO2 with the rifle. As a matter of fact, the first thing I did when I got it was to disassemble it.
The first shots I too with it were just around 1300 psi. I found that the opening of the valve was weak at this pressure. The "bolt" (striker/hammer) is actuated with a spring loaded plunger of sorts. Not sure what to call it, but the spring is weak and tuned for CO2. I am changing out the spring for a stronger one today. That should solve the issue.
I have a bunch of photos of the mechanical inner workings, as well as exploded photos of the valve assembly. The valve is very similar to that of the Drozd, but bigger. It will flow very well for HPA application. I'm sure it was designed with that in mind. I see no need to port it for better flow at the moment.
I will post the rest of the photos later, since Photobucket is loading way too slow at the moment. Check back tomorrow.
---Cam
-
Cool. Can't wait to see the guts, especially the mag. When I got the emails from AGD and Pyramyd I went to buy one but read that 22 caliber wasn't available and that a pcp version would come out. Were you able to use a coupon as well?
TBK
-
Awesome! I have been waiting to see one. Thanks for sharing. I can't wait to see where you take it!
-
Cool. Can't wait to see the guts, especially the mag. When I got the emails from AGD and Pyramyd I went to buy one but read that 22 caliber wasn't available and that a pcp version would come out. Were you able to use a coupon as well?
TBK
Yeah, I wanted the .22 cal, not the .177, but decided to go ahead anyway.
I can see that the innards won't need to be any different for the .22 cal version other than swapping the barrel and the pellet belt inside the magazine.
I was playing around with the "Bolt" spring assembly. Figured how to disassemble it without destroying it! My thought was to just replace the spring inside with a stronger one for more power to open the valve. Then I had a thought that the "bolt" may not cycle/reset properly If I do. The bolt has to reset itself, like the action on a "blowback" action CO2 pistol. I am trying to understand exactly where the air exits the valve to do that, as there is no hole for air to escape to allow that to happen. I am thinking that air must move around the valve stem to do that, somehow.
Another issue I found was with the bolt striking the valve. It only can move the valve about 10 thousandth's before it will not travel further. .......Hmmmn. That pretty weak! I need to lengthen the bolt's striker and grind away a bit of metal to allow for the bolt to travel further.
I wonder why Sig designed it that way. Most likely to keep fps low to comply with laws like Canada has, I assume.
-
Here are more photos of the innards:
-
BTW, I just posted those photos realizing that we DO NOT need Photobucket to do it!!! That is awesome!! You can simply upload a photo straight off your photos files on your computer. Sweet!!
I LOVE this new forum's format.
Oh, BTW, you can load four photos at a time per post.
I have a bunch of photos to upload, so that will save a bit of time!
-
Set #2
-
Set #3
-
Set #4
In the first, second, and third photos you can see a black plastic part that sits behind the "bolt". That is the buffer spring.
It collapses like a telescope when compressed
-
Set #5
In the rest of the photos I had the buffer removed.
-
Set #6
-
Set #7
Here's the valve assembly taken apart. I am holding the the valve showing the valve's inlet hole:
-
Set #8
The part in the middle of the last photo is what I will call the "breech plug" for lack of a better description. It moves forward and seals itself against the back of the magazine in contact with the pellet feed belt.
-
Set #9
First photo is the back of the magazine
-
Set #10
This is the buffer disassembled:
-
Set #11
Magazine and it's pellet belt
-
Set #12
-
How are you liking it now? I am still holding out for the .22 and want to see what the PCP version looks like. But, it is almost too hard to pass up! Oh, and awesome documentation of the insides!!
TBK
-
I like it a lot. Very cool!
I tuned it for power using HPA. I have put just 1300psi into it. I stretched out the "buffer" spring a tad and also replaced and lengthened the valve striker inside the "bolt" so the valve would open longer. I found that the system was perfectly tuned for CO2 and needed to be worked on for HPA. I got it all working fine....for six shots... when something let go causing a major leak.
I opened it up and found that the valve stem broke right off the valve!!
Upon careful inspection of the valve, I determined that the valve is just weak in it's design. I honestly feel if I held the valve in one hand and pushed on the valve stem with my thumb I could have broken it just like that! I ended up turning a new valve out of stainless steel that is much stronger. Now it works great!
Here's the broken valve:
-
BTW, It will be easy to convert the .177 cal version to .22 cal. if you want to. Just swap out the barrel and drill out the pellet belt to fit .22 pellets.
For my .177 cal version, I have fired both pellets and those new H&N Excite Smart Shot copper plated lead ball. Both work great.
I do want the 22 cal version still, but I am going to leave this one alone and wait until the HPA .22 cal version comes out.
Maybe we will have some news about that from the Vegas Shot Show in a day or two.
-
That is very cool, but it's screaming for a full auto mod of some kind, and that might not be that easy to do..... any ideas yet?
-
I really hate to say it, but it can't be done with the design of it's guts.
-
Is there no way to do away with the belt feed, and mod it with a rotary mag like is tried, and true in airsoft?
-
Somehow I missed all of the pics except for the gun. Cam. Exactly how do you upload photos from your computer without Photobucket?
-
When you reply to a post, under the box you type your new message in, you will see "Attachments and other options". Click on that. Then look for "Browse" and click on that. If you have loaded the photos from your phone or camera onto your computer (into your photos file) then a window will open. Choose your photo, and "open" it to select it to the "browse" bar. You will only see the photos after you post.
-
Cool! Thanks.
-
Well I've fired one 90 gram CO2 bottle thru my MCX without issue. I recently purchased the MPX from Pyramyd Air and after the second shot started leaking CO2 somewhere in the receiver.So still with in my 30 days I sent it back and they sent me another one. Well today I just got done sighting it in with my new red dot on it and guess what....same thing started leaking.And I waited hoping that by now they would have corrected the issue's with these guns.No wonder the 22 version is a year behind release.
-
I wonder if those leaks are from the same problem mine had. Read one of my previous posts from Jan 23rd. My valve's valve stem actually broke off (see the photos I posted). And I did not put any CO2 through my rifle at all. I went directly to HPA.
It makes me wonder that when the valve gets freezing cold during your CO2 use that it might make the valve stem fracturing problem even more pronounced.
I suspect there will be a bunch of complaints about this problem from others until that valve is redesigned.
-
That doesn't sound very good. I will have to look back at your pics.
-
I wonder how a company like Sig could bungle something like this. Hopefully they will make it good. It would probably be a good idea to contact them to help them to resolve the issue.
-
And if you look thru some of the reviews and theres not a lot you'll see I'm not the only one to have had this happen to.Really a big disappointment on this line of guns.Geez did anyone do any kind of lengthy real world testing before release. Makes you wonder just how bad the 22 version was that a year latter still isn't available.
-
Now I am glad I waited. I would like the .22 cal PCP. It would be fun to play with the mags, though, as well.
-
IS IT FULL AUTO ?????
-
Well with the issues I had with the MPX right off and lucky enough to send back and get a refund now after 2 months my MCX bit the dust. Started jamming all the time then blew out like my MPX and leaking CO2 out the receiver.Really what can one say?Now it will no doubt cost to ship back to Sig and really is it worth it. I'd just as soon smash it to pieces than spend 50.00 dollars in shipping and end up with another POS.
Ordered a 4500 psi compressor and getting into PCP. Done with these cheap POS.
-
Sorry to hear that. It reminds me of what my grandfather used to tell me. He would say, "Boy... When life gives you lemons make Tannerite... Shove it up those lemons' a$$es, and hit'em with a .30 cal... Then put that $h%t on YouTube!" God rest his soul. He died in 1987.