Hakkaa päälle! (Suomi M31 review) Updated- Range Report

[Netpackrat]

Okay, so I got an envelope from TNW in the mail this afternoon. It contained the missing screw (plus a spare), and 3 more original barrel shroud shims. I still want to make just one single shim from the correct thickness material, but I added two more of the originals, which tightened the shroud up smartly. Now, the barrel is floating noticeably fore and aft in the shroud, which I had expected would happen once the shroud was tightened up. I found these guys who make a special barrel shim that is designed to solve this problem, but their website wanted $35 to ship a few small parts to AK via UPS. Yeah, no. I'm going to call them up in the morning and see if they will just put some of them in an envelope and mail them to me. I figure I should get the barrel tight in the shroud before we try to ream the chamber to fix the headspace.

I should probably ship it back and make TNW fix the headspace, but it would inevitably get "lost" or damaged in shipment, come back with other problems, or sit there forever, etc. So, I am just going to have my local guy touch up the chamber slightly with his reamer.

[Netpackrat]

Back with the Suomi project again. Instead of ordering the pre-made shims and hoping for the right thickness, I bought a variety pack of shim stock. Using a dial indicator, I measured .011" of slop in the barrel, so I made a circular barrel shim out of .012" material. I cut it out with a set of sharp tin snips, trimmed on my belt sander, and then used a dremel tool to cut out the center hole. The resultant shim tightened the barrel up nicely in the shroud:



All that remains is to take it out to my friend so he can ream the chamber a little deeper, so I can fire it.

[Netpackrat]

Took the Suomi out to my friend yesterday morning, and he reamed the chamber a little deeper for me. It was about .020" too short. I didn't have time to stop by the range on my way home, but last night I loaded up all but one of my magazines (one that I recently received has a huge dent in it so I didn't use it), plus the 70 round drum.

Got to the range this morning and finally got to test fire it. The good news is that it seems to work fine with the stick mags, and I only had one jam (a failure to feed) out of 5-6 magazines worth of 115 and 124 grain FMJ, and I couldn't get it to repeat the failure even after loading that same magazine up a couple more times. So that was good. Unfortunately, I couldn't get more than a few shots out of the drum at a time between stoppages. I didn't really de-cosmo or lube the drum very well, so I am going to do that and maybe try to put a little more tension into the spring. A couple of the stick magazines seem like they could use a swipe or two of a file across the lug to seat more easily, but other than the badly dented one, they seem good to go.

Anyway, it's a fun little carbine to shoot, although the trigger is atrocious, and it gets a little tiring after a while, as much as it weighs. I expect I will have to do something to improve the trigger at some point. My gunsmith friend helped another customer with one of these, and seems to be pretty familiar with the trigger group, which is unique to the semi-auto Suomi. One thing that was a little annoying is that it throws the brass forward of the firing line. That's annoying for a reloader, but it's probably a nice feature if you actually have to fight a war with one. I had the range to myself for most of the time I was shooting it, so I was able to recover a lot of my brass, which seemed to survive in relatively good order.

The dented mag came from "What a Country" and between that, and them trying to fuck me on shipping on a subsequent order (which I cancelled for that reason), I don't expect I will be ordering from them again. I think I can maybe take the dent out, and the mag might work anyway, but IMO it's not something that should have been shipped.

I ended up ordering more mags and a couple more drums from CTD the other day. I know a lot of people are pissed off at them over the high priced AR mags and other stuff, but they have by far the best prices on Suomi stuff that I have found lately. The pricks won't ship USPS at all though, so I had to have them shipped to a friend down south, who'll be forwarding them up here. It was still cheaper, even having to pay shipping twice.

Next I need to switch my press over to 9mm and start cranking out handloads for it.

[Whirlibird]

A little light reading.

http://guns.connect.fi/gow/suomi1.html

[Netpackrat]

A little light reading.

http://guns.connect.fi/gow/suomi1.html

Thanks for that. I had no idea that the stick magazines were all post war production.

[Erik]

Never shot the Soumi, but I've used the m/45 quite a bit. The m/45 was based on the m31, and it seems the stick mags was actually made for the m/45.
The only way I recall getting a feeding failure was if you either grabbed the magazine, or rested it on something, or if you messed with the springs. A few guys used to put a battery or a piece of wood behind the recoil spring to get a faster rate of fire, which often resulted in feeding failures. Also, the action on the m/45 was pretty open, and if you didn't pay attention it was easy to collect dirt in it, which was also a way to make it stop working.

But if the gun was in good order and no WECSOG work had been done, the most common cause for a failure to feed was that the shooter had either grabbed the magazine or let it touch something. The problem was that in the movies a lot of "soldiers" grab it that way, using it as a vertical grip, and it looks kind of cool on screen. A lot of guys had seen that and tried to do it with the real thing, and it doesn't work. A lot of trainings had the instructors yelling "this isn't a ***** movie!!!"

I have no idea if the Soumi has the same potential problem, but considering it uses the same mags I wouldn't be surprised.

[Netpackrat]

But if the gun was in good order and no WECSOG work had been done, the most common cause for a failure to feed was that the shooter had either grabbed the magazine or let it touch something. The problem was that in the movies a lot of "soldiers" grab it that way, using it as a vertical grip, and it looks kind of cool on screen. A lot of guys had seen that and tried to do it with the real thing, and it doesn't work. A lot of trainings had the instructors yelling "this isn't a ***** movie!!!"

Yeah, I was doing that at least part of the time, which is an AK habit. With the AK it is perfectly normal to grab the front of the magazine when firing.

[Netpackrat]

Nearly forgot to mention that I tested some reloads in this last weekend; worked up to max with 124gr FMJ using Power Pistol. The interesting thing was it seemed to function just fine, even with the starting loads. One thing that I realized that was kind of humorous, is that because it chucks spent brass ahead of the firing line, it's actually way easier and more time efficient to just pick up the spent 9mm brass that is always around behind the line on the concrete pads, than to try recovering my own.

[Netpackrat]

Fired this again some today, with a different handload. Was testing the 124gr plated flat points that I bought from Chris. Had a lot of the same problems with jamming that I experienced before, only much worse. I'm pretty sure it is related to the bullet profile and softness, because they look to be hanging up on the top of the chamber as they go in (or not). It also seemed to be related to how full the magazine was... If I loaded it up to the full 36 round capacity, jam city. If I only loaded to 25 rounds or so, it worked better with only the occasional FTF. I'm going to load the rest of them up and just use them up in that manner, since realistically as heavy as this thing is, it's pretty tiring to run through a full 36 round magazine. Maybe up the charge a little in case drag on the bolt isn't letting it travel all the way back, when the mags are full.

Gripping the magazine or not didn't seem to make any difference in the failures to feed.

Some good news is that I managed to score two full cartons of small pistol primers in the last couple days, after being nearly out, and I have more round nose FMJ projectiles on order.

[Netpackrat]

Not that anybody probably cares about my Suomi adventures at this point, but I loaded up some more of the PFPs but this time I seated them out to a longer OAL. This appears to have made the jamming worse, if anything. I obtained some 115 grain round nose FMJs and will be trying those out next.