20mm Lahti L39 Antitank Rifle: Shooting & History

Fun? Hi guys, thanks for tuning in to another video on ForgottenWeapons.com. I'm Ian, I am of course here today at the James Julia Auction Company taking a look at some of the guns and cannons that they are going to be selling in their October of 26 Firearms Auction. Now we've got this one outside right now because it is an absolute behemoth of a gun, and because we're actually going to do some shooting with it. And I figured if we're going to drag it out to the range, I don't want to have to drag it into the photo studio. Now this is a Lati L39 20mm anti-tank cannon. This is a type of firearm that was popular in pretty much ... almost all of the major European militaries in the 1930s. But it's a type of gun that became obsolete almost immediately upon the beginning of World War Two. So the idea was in the early 30s, and even into the mid-30s, a lot of the mainline tanks were actually quite lightly armoured. Light enough that you could build a really big rifle, like this, and have a one or a two man crew that could actually carry the thing around and destroy enemy tanks. And it's really cheap, you know, this is an expensive gun to make, but compared to a tank it's super cheap. This was a really cost-effective way to fight an enemy that had a lot of armoured vehicles. So that was the idea. The British had the Boys anti-tank rifle, the Germans had the Panzerbüchse 39, the Americans never really had one, the Poles had one, a lot of different people had these things. And the Finns are a little bit unusual in that they actually opted for 20mm instead of what was normally about a 50, well in the German case a very high velocity 8mm round, but normally these were .50 calibre cartridges used. As a matter of fact, when these guns were being designed and developed there was a lot of argument within the Finnish military and bureaucracy about what cartridge to use. And the designer, a guy named Aimo Latti, who was like the John Browning of Finland, he designed pretty much all of the major Finnish firearms, he was really arguing for a 13.2mm cartridge. And they did a lot of testing with that as well as 20mm, and the argument for 20mm was a lot of people who wanted to use the same ammunition, and possibly the same guns, for both anti-tank and anti-aircraft purposes. Which makes sense logistically, but there were questions about, well, you know, if you have a smaller projectile you can give it a nice hard armour-piercing core and get it going faster, whereas a larger projectile you could have an explosive payload. Ultimately Latti lost out and they decided to adopt the 20mm version of the gun, which he dutifully built and did a gorgeous job of it. These are fantastic guns. The gun was formally adopted in September of 1939, and then the Russians promptly invaded in November of 1939. And that was the Winter War, and these guns were not available. In total there ... were two prototypes in an early, a slightly smaller version of the cartridge, I believe it was 20x102mm or 113mm. It was an early prototype cartridge, prototype rifles. Those two guns were actually used in the Winter War pretty effectively, but that's it. Now, as the Winter War was concluding, these things really went into production because this was a very high priority project for the Finns. They didn't really have a lot of tanks, and the Russians, by golly, had a lot of tanks. Unfortunately, by the time the Continuation War picked up, the Russian tanks were things like T-34s and KVs that were too heavily armoured to really care about something like this. So these were used extensively in the Continuation War. They had, you'll see most sources say like 1,750 or 1,800, a little less than 2,000 of these guns. But I'm aware of a picture of one that has a serial number that's like 2,600, so maybe there were a few more. It's hard to say. But during the Continuation War they were primarily used as kind of ... a combination between a long-range sniping rifle and a long-range anti-material rifle. While these couldn't take out a tank's armour, they could do things like shoot through the ports on a bunker, or you could shoot up an enemy machine gun nest with these at pretty long range. They have fixed barrels, they're gas-operated, semi-automatic guns, and they were found to be really quite accurate. Now I know people are going to ask if they put scopes on them. No, they never put scopes on them. They have iron sights. But the Finns were really good shots with iron sights and didn't necessarily need scopes to do good work with something like this. So the cartridge that this uses is the 20mm by 138B. It's a belted case. Typically called the 20mm Solothurn Long, and it was a common cartridge at the time actually. It's the same cartridge that was used in the Solothurn S18 1000 anti-tank rifles, and in much greater numbers it was used in the German Flak 30 and Flak 38, which were the single-barrel and quad-barrel anti-aircraft guns. So as the Finnish bureaucracy had wanted, this actually was a cartridge that was used for both anti-tank and anti-aircraft purposes. In fact by 1944 they would develop a full-auto version of this gun, fired from a mount, for anti-aircraft use. Different types of projectiles were available for these. We're going to be shooting dummy training rounds today, they're just inert solid bullets. But they also had armour-piercing, armour-piercing tracer, they had phosphorus incendiary rounds, they had high explosive rounds, all sorts of fun stuff. In fact one account I read said that during the Continuation War one of the things that Finnish soldiers would do from time to time is take some of those incendiary phosphorus rounds and crank the guns up to a really high angle of elevation and lob some phosphorus projectiles over as far behind the Russian lines as they could to try and start forest fires. Just, you know, to be obnoxious. So there are a couple unusual elements to the operation of this gun. It has a 10 round magazine, which we'll load up in a minute. It has a crank style of bolt handle because the recoil impulse from this is so significant that if you were just to try and pull the recoil spring back, really no normal human could. So instead there's a ratcheting crank handle that you turn to open the bolt, and while it's semi-automatic the gun actually locks open after every shot is fired. Probably to help cool and ... I don't know, it's an unusual system you don't really see elsewhere. There's a grip safety, and what happens is when you depress the grip safety it releases the bolt. So when you're ready to shoot, get in position, grab the grip safety, the bolt drops, and then when you're ready you pull the trigger and fire. One thing we're going to have to be very careful of, and this is important for everyone out there who owns Lotties, because there's actually a substantial number of these out there, and there is ammo, and they do get fired. Do not put your hand in front of that trigger guard. That's a big hefty trigger guard, and it is there because these cases will eject pretty much straight backwards. And if you put your hand in front of that trigger guard, you are literally going to lose fingers that are crushed by the ejecting case. This is something that has happened to at least a couple of people who didn't know better, and you really want to avoid that. That will definitely ruin your shooting day. So, keeping that in mind, I think it's about time we did a little bit of shooting with this. Oh, I should point out it has a dual type mount. They've got skis there for when you're on soft ground or snow, you know, not that there's ever really soft snow in Finland in the winter. And then if you're not on soft ground, there are bipods with some nice pointy feet on them. So we're going to be shooting it from the bipod today, because we've got some nice hard ground to stick that into, and that'll prevent this from actually sliding backwards under recoil. Because that is, it would fire the different types of projectiles, obviously, ranged from like 1800 grain up to 2500 grain. That's on the order of, what, 120 to, I want to say 140 gram projectiles, with muzzle velocities of 2,600 to 3,000 feet per second, so 800 to 900 meters per second. This generates 35,000 foot-pounds of muzzle energy, which is approximately three times that of a .50 BMG. So, that's why it weighs 109 pounds. When this was carried, it was actually typically carried by a two-man team, and you'll see pictures of guys carting these around. Obviously, they'd throw them on a truck any opportunity they had, but if not, you get one guy carrying the barrel, and you get one guy carrying the stock end. Alright, enough of that, let's do some shooting. So, the first thing to do when you're getting ready to shoot a lottie, is don't forget to take the muzzle cover off. This little spring tab here just hangs by its chain. If you forget to do that, you're going to get this really cool one-time thing where you blow this muzzle cover downrange, but then you're going to have to find another one. So, take that off. Next up, we have some basic operation of the gun. We're going to start by opening the dust cover. That's just held in place by the magazine catch, keeps junk from getting into the gun. Right now, the bolt is open. So, I'm going to run you through the operating process here. While this is semi-auto, it does lock open after every shot, and to release the bolt, you depress the grip safety. Once that has been depressed, you hold it down, and when you pull the trigger, it fires. Now, if you want to manually open the bolt, you have this crank handle. This is like the world's most ballistic crossbow ever. Push that in to unlock it, and then two full revolutions or so, lock the bolt open, release the crank handle, and now you're good to go. We have iron sights here. They go from 200 yards up to 1400 yards, the front sight's way out on the barrel there. And that's pretty much it. You will notice there is a little rubber buffer wheel here. That's because that's where this brass is getting ejected. So, again, don't put your hand here. Don't do it. Put your hand up on the back somewhere. Last bit of prep work. Once you're in position, this is the manual safety. This is the fire position. That's the safe position. It just disengages the trigger. So, here's our 10 round magazine. The Lodi very thoughtfully comes with a loading tool. This one's in the spare parts kit that comes with this gun. What this does is simply allow you to manually depress the follower, and then we can slide the cartridge in, like that. Slide it all the way back, repeat that nine more times, and you have a fully loaded magazine. There is a little viewing strip here, so you can see how many rounds you've got. I'm gonna leave that at one for our first shot. Alrighty, here we go. Open the bolt. No hand in front of the trigger guard. Here we go. Hee-hee! Let's do some more. All right, we're ready to go with a second shot here. I'm shooting kind of downhill, so I actually have to lift the back end of the gun up higher than you normally would. Close the bolt, and we're ready to go. These are really fun. And I think we set off the car alarms again. We gave them just enough time to shut up, and now they're back. Ah, yeah. One thing I noticed reviewing the high speed on this is that the brass is actually bouncing off of this rubber buffer, which is clearly what it was put there for. I believe not all of the guns actually have those, so be aware. And even with that buffer, I'm not putting my hand anywhere near the front of this thing. I do not want to get hit by that ejected case. Well, thanks for watching guys. I hope you enjoyed the video. This thing was a lot of fun to shoot, and it is of course coming up for sale here. You used to be able to buy these in the 60s out of magazines, and so a lot of them actually got purchased, and they're on the market now, and they're guns like this. This one in particular comes with the original humongous wooden crate. It's got all, I believe, four cases of magazines, two mags each. So you got eight magazines for the thing. It comes with a bunch of ammunition already loaded and ready to go. And, well, as you can see, it's a tremendously fun thing to shoot. So if you're interested in it, take a look at the description text below this video. You'll find a link there to the James Julia catalogue page on the gun. You can check out their pictures in their description, and then go back, watch the shooting footage again, and call them up to place a bid, or come up here to Maine and participate in the auction live. Thanks for watching.