Mosin Nagant Trigger Improvement
 

For those who have, or are thinking of getting a Mosin Nagant rifle, the trigger pulls leave something to be desired. Yes, they work, but tend to be "crunchy."

Here are some things I've found to help the trigger pull:

In the wonderful Finnish MN39 rifle, they improved the trigger pull by inserting 2 hardened steel pins in the top of the trigger. Rather than the normal trigger's inner top surface (usually rough) scraping along the top flat surface of the sear/bolt stop, you've got 2 small contact points of hardened steel sliding along the sear. If you can find a modified MN39 trigger, that will put you ahead of the game.

Using your Dremel tool (you've got one, right???), a felt polishing wheel, and some emery buffing compound, there are a few areas you can polish to greatly improve the trigger pull. You are NOT grinding away at the metal to change its shape - you're just smoothing the existing surface. In the pictures below, I've tried to show the areas to be polished by putting them in
red boxes.

On the cocking piece, polish the little tab that engages the sear/bolt stop. Maintain as much of a flat surface on this as possible. I usually use a fine polishing stone with some CLP as a lube, then finish it up with the Dremel tool.

On the sear/bolt stop, polish the surface that engages the cocking piece, and also the flat surface that scrapes against the inner surface of the trigger as it's pulled.

Once everything is polished, reassemble using some decent moly/graphite containing grease (I use Chip McCormick's Trigger Slick) at the contact/scrape surfaces.

When you reinstall the sear/bolt stop, make sure it has clearance on either side to move freely up & down in the receiver as the trigger is pulled. If you're not careful when torquing down the screw that holds the sear/bolt stop in the receiver, you'll rotate the sear a little bit so it will slightly bind against the receiver. Not good.

On the pic of the polishing point on the sear/bolt stop engagement surface, note that on the Finn part, there's a slight angle to the top 1/16" or so of the mating surface. On the Russian parts, this surface is just flat. The relief angle is almost like the angle polished on the "nose" of a Colt 1911 sear to improve trigger pulls.

As a last resort, AFTER buying a replacement spring, you can try cutting 2-3 coils off the firing pin spring (striker spring) with a Dremel cutting disc. This will reduce the trigger pull & bolt lift effort, but you also run the risk (slight) of having some failures to fire due to light primer strikes. Spare springs, sear/bolt stops, and triggers are available cheap from www.tngunparts.com (Layne is a good guy to deal with). Unfortunately, he no longer has the modified Finn MN39 triggers listed on his website.