A classic of WW-II and the Winter War. I wonder if optics can be readily mounted ??
The part that really caught my eye was the unmodified feed lip. I could understand how it could be kept if it was a new made bolt, but it sure looks like the bolt is an original which would be contrary to the approval letters out there for the suomi.
Of course its not my problem but I tend to think that TNW submitted their own sample to the ATF for approval and was approved based on that design. Not the most consistent Gov't agency on the planet. I'm sure one examiner approves all kinds of stuff that another kicks back. We only see the kicked back letters.
How's yours run? Lots of people having to send theirs back for service. TNW is stepping up and getting them fixed for them. Seem to be hit or miss at this point. Some run great while others don't??
Ive got a later one in the 400 range and Ive put 400 rounds through it without a hiccup so they might have the problems taken care of. The whole thing is pretty simple and if there is a problem I don't think that there will be a huge issue fixing it without involving the original builder. having said that I am going to be going to a hammer fired setup. The trigger pull is far in excess of what I am comfortable with.
It's a striker fired design with the lower feed lip intact? I can't believe they got that approved.
this might help with the feed lip -v- feed lip's and the open boldt from the ATF. letter #2 will give the green light to leave the feed lip not lip"s. this goes back to the sten boldt with feed lips IMHO. muttman
The lower feed lip on the bolt face of fixed firing pin open bolt subguns is there to keep the round in front of the firing pin during the feed cycle. Removing it is normally required on a semi, if it was intact all you would need to do is jam the firing pin in a forward position and the gun would empty itself when the bolt is dropped on a full mag. If it is removed and you jam the pin forward, the back of the case slides up the smooth boltface and jams against the underside of the pin, preventing feeding.
Being striker fired, all one has to do is disable the disconnector or remove the sear and now you essentially have an open bolt subgun. The "Closed bolt" version of the full auto UZI uses a similar setup, the semi auto striker system is used with a modified FA bolt. The bolt slams forward, feeding the first round and leaving the striker cocked. Pulling the trigger drops the striker, but on subsequent FA shots the striker simply travels forward with the bolt acting like the fixed firing pin of the open bolt version. When the trigger is released the striker is again held rearward and the bolt feeds the next round.
Its enough to make your hair hurt isn't it? There is a letter on weaponeer that "suggests" that the feed lip be removed on a suomi bolt. Here is another one that states its ok. I have a kahr thompson that has a ring that extends on the bolt face. The firing pin extends about 3/8"-1/2" past the bolt face so if it were to follow the bolt home it would jam. Greg Clark spoke up on another board about this tnw conversion and basically what I got out of it was that its not a feed lip as much as it is a ring since its not broken by the mag cuts like on a sten or pps43, and the conversion is looked at as a whole. It will make for a much more reliable bolt with less tweeking to get it to work. Kuddos to TNW.
Last edited by moleman; 09-09-2009 at 10:12 PM. Reason: spelling