Gunboards Forums banner

Centerfire System's Finnish Suomi M31???

150K views 389 replies 87 participants last post by  zee10103 
#1 ·
These are due to hit the market this week (http://www.centerfiresystems.com/). Anyone getting one? Has anyone had an opportunity to preview the semi-automatic version of this classic WWII smg? If so, how did it function? What about accuracy?

Inquiring minds want to know as I am seriously considering buying one.

Tim
 
#126 ·
My Suomi is on the way from Centerfire as I type this.Hopefully by Friday. I am about as far away as you can get from Versailles KY in the original 48 states. Looking forward to firing and updating you guys on how well this one will function.
 
#128 ·
I don't know about the rest of the guys but the difference between my first Suomi and the replacement, 360 serial #'s apart, is like day and night. The new one's bolt moves much more smoothly in the receiver and closes with considerably more force to the chamber, and the trigger is smoother. I have yet to shoot it but I suspect it will be a winner.
 
#133 ·
Took the Suomi to the range today to give it a good workout. Filled up a 70 round drum and commenced to fire. Unfortunatly, it still had some issues. It would fail to fire every few rounds.

At first I thought that I wasn't pulling the trigger hard enough. But after a couple of times of putting the gun on safe and pulling the bolt back a little to see if a round was chambered, which it was, I'd put the gun on fire and it would. After a few more times, I put the gun on safe then back on fire and it would. Then it wouldn't. Sounds confusing right?

Since the trigger pull felt different when it malfunctioned, I decided by the last 10 to get into my target shooting mode and hold the trigger back and slowly move my finger forward until the trigger reset. Low and behold, it worked every time after that. I'm going to try again tomorrow and then call up TNW to talk again about what is going on with it.

Needless to say, frustration rears it ugly head again.
 
#135 ·
Hats off to TNW for standing behind their product and taking care of everyone that has had problems. I'm sure it's frustrating for the owners to send it back but it sounds like the end result is positive. I would like one of these but have been waiting to see how things have been going for all with troubles.
 
#138 ·
70 rounds fired yesterday.

After around 40 rounds an extraction/feed jam took place. The mouth of a fired case was damaged from being pushed into the side of the chamber. It also bent the extractor to the point it would not work. The jam took place with a stick magazine.

After unloading and clearing the weapon, I took out the bolt, removed the extractor and bent it back into shape. It functioned properly after that. I was using a mixed lot of older and new ammo. Was it the ammo? I'm not sure, so I'll do some more shooting and see if it happens again before calling Hank.
 
#139 ·
My gun is in the early 500's serial number range. Fired 100 rounds of Winchester white box and only had one jam and that was using the stick mag. Drum ran perfectly. Will fire some more soon and report back. Never had any trigger problems or light strikes. Overall I'm very happy with mine. What's the highest serial number gun anyone's had trouble with?
 
#140 ·
Just picked mine up tonight. Mid 500's serial number. Gonna take it out for a test run tomorrow, run 100 rounds through it, a drum and a mag....

See pics in other thread...
 
#142 ·
I called today to inquire about mine as it has been a couple of weeks since I sent it back. I was told that they are waiting on parts to complete the new updates. I stated that there is a lot of conversation on Gunboards about the issues and that I had seen at least one case where the rifle was replaced with a new one. I was told that due to the parts needed they would not be able to even produce a new updated Suomi until their supplier is able to supply the needed parts. I asked why they do not test fire all of these at the factory and was told they fired all of them. I said that they could not have fired mine more than once as it has never shot two rounds semi-auto; no rebuttal. It might be awhile.
 
#144 · (Edited)
I did a few mods to mine already. I ran about 300 rounds through it this weekend without a hitch. Only trouble has been how stiff the trigger pull is. To be honest I will be building a trigger pack with a modified bolt and a Remington 870 FCG for it and replacing the striker fired setup. The striker setup is remarkable though in its own right. Its a heavy trigger pull but the design is quite nice.

 
#145 ·
persevere!

I was told they test fire every fifth one,,,, mine is in the mid 600s, but works great. When I received the M31 its bore was black. Assuming it had been test fired, I was bummed out, then ran a patch up the bore,,, just cosmoline. There is that one sear bar you have to be aware of,,, I'm not taking the trigger group out very often.

All and all its a magnificent effort by the folks at TNW. Sort of an obscure weapon to the general public,,, but if you are interested in weapons or WW2 history, and/or like myself collect Finnish weapons, it is the crown of my collection, along with my Lahti pistol. Working on a SBR permit,,, and think of blueing it, to be more original.

You all whose ones do not work just yet, persevere! They are worth it.
 
#146 ·
Check your fired brass - what do the primers look like?

NOTE: As you fire your M31 rifles, pick up some of your spent brass and check the primer pockets. Do you see anything odd? Any primers backing out of their primer pockets? Here is why I ask:

I met my friend Steve at the range to shoot the M31. Steve is a gunsmith, and is certified as an expert witness regarding firearms by many state and federal courts around the country.

At first Steve was impressed with the M31. The trigger pull was good and so was the accuracy. But as we continued to shoot the M31 things went down hill......

After about 50 rounds there were an increasing number of light strike failures to fire. The light strikes were odd given that the rifle has a new heavy striker spring.

Along with the light strikes the rifle fired a couple of two shot bursts and jammed. The last straw was a burst of about 7 shots. (Commenting about the unexpected burst of fire from the M31, Steve's lovely girlfriend said it sounded like it ate too much bean soup. Nothing like a little bad humor to make a bad day better.)

After investigating the above failures of the M31, we think it may be related to excessive head space. Examining the fired shells we could see that primers were protruding from primer pockets. In some cases primers had been blown clear out of their pockets. And a large number of primers had ruptured holes at the firing pin impact point. Through these ruptured holes hot gases under pressure were able to blow into the firing pin hole and enter the bolt. Carbon or maybe bits of metal from primers appear to have made the firing pin sticky enough to go full auto. The high pressure of the gas was evident after I removed the bolt from the rifle. The firing pin retaining pin was bent from the firing pin being forced back against it at high pressure. It is so badly bent that I could not take it out at the range. By the way, this is the new bolt TNW sent me to replace the original bolt which had a cracked bolt face.

What of the light strikes which failed to fire so many rounds? This appears to have been caused by the excessive head space which requires the firing pin travel a longer distance. Another reason is the dirty firing pin hole. A dirty firing pin can't travel fast enough to ignite a round. Another theory of mine is that the point of the pin may be too sharp.

My friend Steve liked the M31 in general and said he might consider purchasing one IF the bugs are ever worked out. But as it is now, Steve considers my M31 an unreliable over priced wall hanger.

On Tuesday I'll try to find the time to make another call to Hank at TNW. I'll keep you posted.


Best regards,
Greg
 
#147 ·
What ammo were you using?

Also, does not sound like "excesive headspace". Sounds like firing pin hole getting dirty, first causing light strikes then the pin getting stuck, causing the primer issues and the multiple rounds going off. I would detail strip the bolt and clean the pin and pin channel. That's what I did even before mine went to the range for the first time.
 
#149 ·
The action has been detail striped and cleaned after each firing session. That's how I discovered that the first bolt was cracked. I have been checking everything on the M31 ever since.

I used CCI Blazer, Winchester, and a few rounds of other brands. All of them had popped out primers. The primers pop out with the gun clean or not.

Primers poping out is not a result of a dirty firing pin hole. The firing pin hole became dirty because of punctured and popped out primers. The poor strikes and stuck pin follow in logical order.
 
#154 ·
Did not look at primers. Other problems took precidence.

QUOTE=45Auto;1014859]Yesterday I spoke with a woman at TNW, she appeared to be knowledgeable. She took down my information for Hank. But so far Hank has not called me back.

Guitarzan, did you notice if you had primers backing out of your fired brass?[/QUOTE]
 
#155 ·
It would be nice to know the details of what the problems are with these guns. If it is a design flaw, they should all be recalled and repaired. If it's a defective parts problem, all guns with those parts in them should have them replaced. It's obvious that extensive or even adequate testing of this design was not performed.

I appreciate the cordial handling from their customer service but am having a hard time understanding how the overall problem resolution is being effected other than ad hoc.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top