• Semi TNW sear
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Semi TNW sear

Posted: Mon Jan 04, 2016 12:25 pm
by maddog51
Can somebody explain how TNW's semi sear works?
I see how the trigger gate hits the sear to release but I don't understand on how it's holding of the firing pin. TNW's set up is all in a horizontal holding and movement of the firing pin. And TNW's small sear spring doesn't look strong enough to hold, but some how it does, against TNW's massive firing pin spring.
I have worked on many sears and all have some surface on another pushing at each other untill one is moved and the other slides off. A good sear has a slight angle opposed to the release sear or release arm. If they were straight & polished you'll have a nice trigger pull but an unsafe firearm.
The surfaces are at different focal points. As in a revolver, the hammer with its sear wants to twist down in a rotating motion with the hammer hitting the firing pin or such. And the trigger sear lever is stopping that until the trigger pull slightly pushes up enough to slide off the hammer's sear then hammer rotates firing the gun.
Most of you here are probably aware of what I just tried to explained but with TNW's sear I haven't a clue.
Can someone explain TNW's set up?

Re: Semi TNW sear

Posted: Sat Jan 09, 2016 11:39 am
by maddog51
WoW Did I join a little to late? A lot of lookies but no cookies. I'm just looking for what parts I can polish to make a nice smooth release.
The lower trigger assembly is nice now out of receiver, smooth pull only resistance is the trigger return spring
which can be lightened.
I used a molly dry film lubricant, it leaves a film. Used on lower receiver, trigger with rollers,trigger arm, which has been polished, & on the lower area of the receiver where the rear trigger roller rides.
Nice pull but sort of gritty feeling in certain areas of the pull. Not a lot and not always in the same area of the pull. I put that to the trigger rollers, either the rollers are not perfectly round, or pin sizes for rollers a little to small. It's really not that bad though I can live with.
Again I ask from all you experts out there , am I missing anything in the sear area that needs to be polished?


Re: Semi TNW sear

Posted: Sat Jan 09, 2016 7:30 pm
by JBaum
It's my guess you have a lot of people interested in helping, but nobody has messed with a TWN sear to give you a valid answer. At least nobody is making stuff up.

Re: Semi TNW sear

Posted: Sun Jan 10, 2016 12:33 am
by messerschmittfan
I polished the bottom of the receiver and the top of the pistol grip area where the rollers roll on all of my TNW MG 34's (three) as well as my a couple of the re-welded receivers that were semi-modified exactly like the TNW 34's. I use a very light coat of grease on the surfaces. I have yet to see a out of round roller from TNW but I have seen the roller (s) too far up or down on the trigger bar. There are two rollers one at the front and on on the rear of the trigger bar (or sear release if you like) and they must exactly in the middle so that the same amount of roller is exposed on the top and bottom of the bar. I send my FA bolts to TNW and have them modified as it is a lot easier than doing myself. However I do fit the SA modified bolts to each gun and have had to polish the bolts to make them work in the guns. The sear for releasing the firing pin is on the bolt not in the grip, the piece that the rollers fit onto (trigger bar) ride back to trip the sear. While I have gotten a smooth release I have not figured out how to reduce the long trigger pull. I can send you some photographs of my guns if you send me an email as I cannot get photographs to post on the forum from my MacBookPro. My email is h.connors@centurylink.net. The TNW semi-MG34 is like all 34's, to get them to run right means everything has to work as designed and they have to be run in. It takes about 100 rounds to get them to loosen up enough to run great. Once that happens they shoot great. I have a couple of video's I can also send. Harry

Pictures from messerschmittfan

Posted: Sun Jan 10, 2016 3:01 pm
by JBaum
Here are the pictures from messerschmittfan. The caption text goes with the picture above it.

These are some of the guns on my work bench. NOTE I am not a dealer I am a collector who has been collecting these for at least 30 years

I have one from each year made from 1937 to 1945, all semi-auto as they had had their receivers cut.

MG34 on modified later Bundeswehr early AA trip-pod. On workbench in rear of photograph is a German Army tool for the MG42 and a small milling machine used to make small parts.

These three are waiting for me to take to a private range to be test fired.

Cleaning day, I traded the bottom BAR for a nice FN D-1 BAR kit that I am making into a semi-auto. The M53 was my first semi-auto 42 and is a mix between M53 and WWII German parts. I am replacing the German parts with Yugo now as I have three almost complete German WWII MG42 Parts kits waiting to be made into semi-autos.

Re: Semi TNW sear

Posted: Sun Jan 10, 2016 3:21 pm
by maddog51
Thanks Harry (messerschmittfan)

I think I covered all the areas to polish (I hope).
You did mention that: (I have seen the roller (s) too far up or down on the trigger bar. and they must exactly in the middle so that the same amount of roller is exposed on the top and bottom of the bar.)
Right away I looked to see how my rollers were and the back one on the rear of the trigger bar was a little higher.
I got this drawing off of Weaponeer's forums (See attachments)
And mine do mic out to the roller pin holes as in drawing. But also I did notice a little wobble of the rollers on the pins. I think I can live with this trigger pull. Knowingly it can be lightened by the firing pin spring in which it trips the sear at the very end of the pull Also if I need to lighten the long trigger pull before sear release , Changing the trigger spring to a lighter one should do that.
You also said that you wanted to reduce the long trigger pull, the only way I can see would be to drop a little weld in the trigger housing where the ears of the trigger slide reducing anymore forward motion. Or temporarily use one piece of metal to fit in front of the trigger in the area where the trigger ears slide. Just a quick thought.
With that fix you'll lose the closing of your dust cover.
Again let me say THANKS to all,

More gun porn from messerschmittfan

Posted: Sun Jan 10, 2016 3:29 pm
by JBaum
Here are more pictures from messerschmittfan. The caption text goes with the picture above it.

Brother and sister act. I dislike the appearance of the AR15 trigger so I hide it under a modified M53 trigger.

All matching number Portuguese 34 on a modified post war Bundeswehr mount. Works great and with the remote trigger will eat up your pay check really fast!

Just finished a 1919a6 to compare with the German Guns.

Only had one MG42 finished when I took this photograph of the dual mount.

This is the best firing semi-auto remake of a MG that I have. The tripod was used by the German Army in WWII and I picked it up in Germany years ago from the son of a WWII German Army Vet who had passed. The Madsen eats 7 x57 Mauser, 30-06 and 7.92 x 57 with a simple change of the barrel/lock unit.

This M1910 Maxim is fun to shoot but too heavy to move around all of the time. It was made by Dennis of Midwestern Metals for me years ago.

And a move of messerschmittfan's MG34 semi

Posted: Sun Jan 10, 2016 5:45 pm
by JBaum
And a movie of messerschmittfan's MG34 semi (about 30 megs):


Re: Semi TNW sear

Posted: Sun Jan 10, 2016 7:04 pm
by messerschmittfan
Maddogs2 That drawling is pretty much the same that TNW uses for their modification. I have shortened the trigger pull somewhat by moving the rear roller to the rear as it is the part that trips the sear in the bolt. I am still playing with one that actually has a longer extension to the trigger bar with three rollers. So far it is very smooth but it does not always trip the sear on the bolt that matches the gun. It will work with another bolt in the gun. So I am checking the bolt to see what I can do to improve. I always lighten the firing spring a little but not much because I have found that after a few hundred rounds it lightens itself. Using the Romanian 7.92x57 ammo requires a strong hit to shoot them. Thanks to John B for posting my photographs. Harry

Re: Semi TNW sear

Posted: Sun Jan 10, 2016 7:11 pm
by anjongni
Maddog, some builders here have had good luck using the original German firing pin spring in the TNW bolt.
The giant heavy spring was supposedly necessary to set off "hard-primered military ammo".
I don't see where the TNW firing pin spring would need to be so stiff...or any stiffer than the original F/A. The striker-firing TNW-34 sear is well-shrouded and doesn't look to be able to cause "out-of-battery" explosions or "run-aways" like a broken pin in a hammer-fired semi-42 system can...Phil

Re: Semi TNW sear

Posted: Sun Mar 05, 2017 4:07 pm
by Sparky88
Thanks for posting the pic. My setup is canted a few degrees and isn't squarely engaging the sear ring.

Re: Semi TNW sear

Posted: Sun Dec 31, 2017 10:17 am
by 42rocker
Some really great pics in this thread.
Thanks for sharing.

Later 42rocker