M2 60mm Mortar: Complete

The mortar is finished, and what a beauty she is too, though I say so myself.

The adjustable windage is quite smooth, the folding handle giving adequate purchase and leverage.

While the leg spreading system has its advantages, I can’t help but feel there are simpler designs that would have had the same result. Perhaps the reasoning is plainer with a live firing version.

The baseplate has a 3D printed socket for the ball to slot into. On the original this is stamped into the plate design and features a lock, but here the ball is left free so that the barrel can be quickly upended and spent shells ejected.

The spikes on the bipod should keep it raised just high enough to give access to the elevation control in the centre.

A top-down view, showing the windage lever in the stowed position.

Once packed away, this mortar isn’t actually too bad for portability. Considering the complexity and the precision you could achieve out to a respectable range on the original, you can see why modern light mortars are more closely related to this package than the T89 or SMBL 2″ families. While they may have portability and speed on their side, the ability to fine-tune fire for only a little extra weight and bulk certainly has its appeal.

 

If you liked this project or have an idea of your own, drop us a line on enquiries.vintageairsoft@gmail.com to discuss. ‘Like’ our Facebook page or follow the blog to get regular updates on projects and interesting videos and articles.

You can find the build posts for this mortar here.

Don’t forget you can buy some of our complete products via Etsy. If you would like to commission a build like this, please drop us a line on the above email.

 

M2 60mm Mortar: Build 2

The first job of the next leg is to fit the leg limiter. This has two lugs on the centre column and on the left leg. Between this and the attachment at the head of the tripod it helps the user to keep the elevation adjustment vertical, even on sloped or bumpy ground.

When deployed, the limiter sits pretty much horizontal. The collar it is attached to on the leg slides up and down, with a stop at the top of its travel to make it level out. In these two pictures you can also see the elevation adjustment handle. This piece of steel bar was bent and is screwed and pinned in position so that it can’t rotate without operating the elevation screw.

The feet are welded onto sockets that fit over the bottom of the legs.

And are in turn are spot welded onto the legs. These feet will allow the operator to dig the legs into the ground for stability when firing.

The windage screw has a metal sheath, which I’ll be adjusting to be a nice, close fit. It will also have to have a tooth of some kind to work against the screw.

With some rather happy timing, these 3D printed parts then arrived. Printed in ABS for strength, if they prove to not be up to the task I shall try casting them in aluminium. I suspect they’ll do beautifully though, these are very solid shapes.

Roughly put in place, the mortar is really taking shape now. To finish off these parts, I need to fit a large screw to the barrel clamp and screw together the two halves of the windage unit. The windage screw also needs a little modifying to remain locked into the unit, rather than walking out either side.

The two halves of the windage unit screwed together. This is a very rigid unit, as it needs to be to function. The screw thread is very stiff and it will need a little modification to work smoothly.

With a little time on the lathe, I reduced the ends of the screw thread down so that they ran smoothly in their mountings. I also drilled and tapped each end for the stoppers that prevent it from leaving the windage control.

The windage adjustment dial has a folding handle, like the original.
 

In place, it sits well and works quite smoothly. I think the barrel vise will need a little re-enforcing for use but it’s not bad even as is.

A quick demo, it’s a bit awkward videoing and operating it at the same time but it’s easy to use.

 

The last bits are the baseplate and baseplate ball, plus a fair bit of finishing. This thing will take some serious painting!

You can see the previous build post here.

If you are interested in the history of the M2, you can check out the introduction article here.

If you like this project or have an idea of your own, drop us a line on enquiries.vintageairsoft@gmail.com to discuss. ‘Like’ our Facebook page or follow the blog to get regular updates on projects and interesting videos and articles.

Don’t forget you can buy many of our complete products via Etsy.

M2 60mm Mortar: Build 1

The project started with a good deal of research, finding pictures of all the component parts. From this I calculated dimensions and drew up plans.

The M2 is quite a bit more complicated than the SMBL 2″ used by the British. For my flat laser cut parts, I’m looking at around 3x as many pieces: plus a number of cast or printed parts.

The baseplate is the first component to be assembled. This heavy plate is designed to stick into the ground to control and direct the recoil.

Then the feet for the bipod legs and the hinge parts, Although the M2 is complicated, it does fold down quite tidily, which means a lot of moving parts.

With the legs in place, the mortar starts to take shape. The tube through the middle will have the elevation control going through it, at the top of it will be the T-piece where the windage adjustment will sit.

The thread arrived, it is a 20mm trapezoidal threaded rod which should be coarse enough to allow quick adjustments to be made, but fine enough to allow for accurate fire adjustment.

The elevation adjustment screw in place and the T-piece at the top of the column (where the windage screw will go). There is a slit in the back of the column in which a screw sits that locks the inner column into the outer and engages the screw thread.

When the elevation is raised to maximum, you can just see the thread through the slot at the back, but this will effectively be hidden by the barrel.

 

The next components will be the windage adjustment and endcaps. These are going to be 3D printed in ABS for strength and will also have the barrel clamp.

 

If you are interested in the history of the M2, you can check out the introduction article here.

If you like this project or have an idea of your own, drop us a line on enquiries.vintageairsoft@gmail.com to discuss. ‘Like’ our Facebook page or follow the blog to get regular updates on projects and interesting videos and articles.

Don’t forget you can buy our complete products via Etsy.

M2 60mm Mortar: Introduction

The M2 Mortar was a US light service mortar designed for close support by infantry at company level. These filled the gap between hand grenades/rifle grenades and the larger (81mm) M1 used at battalion level.

The 81mm mortar in use with a mortar company of the 92nd Division.

It has its origins, much like nearly every modern mortar, in the WWI-era Stokes design. It was smoothbore, drop-fired and used a bipod/baseplate system.

Doughboys with the WWI Stokes mortar.

Light mortars of the inter-war/WWII period fell into two categories: The first were simple, tubes held firmly by the user when fired and aimed by direct line of sight (such as the British SMBL 2″ and Japanese T89). The latter were complex, with coarse thread screws or other systems to control elevation and windage for very accurate controlled fire.

The M2 fell into the latter category, with an attachment for a sight that could be used for both direct and indirect fire. As a result, it could be used accurately at close to its maximum range (nearly 2,000 yards).

The sight used for the M2.

Post-WWII, the M2 served in Korea and numerous Colonial conflicts with the French, finally in Vietnam. The Chinese also locally produced their own copy. It was eventually replaced in 1978 by the M224 which is still in service today and increased range capacity by about 1/3rd.

 

You can see some footage of the M2 in action here:

The Airsoft version currently being built will fire TAGs and moscarts, with a possibility of using TLSFX shells as well.

 

 

Japanese T89 ‘knee’ mortar

I was recently given this replica T89 mortar replica to convert to fire TAGS. I hope someday to make my own from scratch with a bit more detailing and moving parts.

The first step is to fit a firing pin. This is quite simple, I tapped two disks and threaded them onto a bolt to create a stable unit. This can be pushed down to the bottom of the barrel.

The shells are steel tubes with custom-made caps. This is the prototype, there is a second hole in the production versions to allow quick refiling of the TAGs. The bottom plate is held on by spring pressure.

There are two rows of spacers. The bottom one keeps the shell centred in the barrel, the top, thicker row allows the user to line up the shell before dropping it into the barrel for firing.

The completed shells.

I’ll be taking lessons learned from this design to apply to my other mortars and heavy weapons. I’ll also be offering these quickfill shells as an alternative to the standard 2″ mortar shells I’m providing with the SMBL mortar.

 

If you want a mortar of your own, please do get in touch at: enquiries.vintageairsoft@gmail.com or join us on our Facebook page. Don’t forget you can buy our complete products via Etsy.

British SMBL 2″ Mortar prototype: complete

At last, the mortar prototype is finished. The shells are steel tube and based on (though not replicas of) the SMBL 2″ mortar shells. The six fins and band at the top hold it straight as it is dropped into the barrel.

Inside you can fit a TAG shell or other 40mm grenade. To recharge them, simply remove the tube, reset the firing pin if needed and re-gas. The tube is held in place by the spring tension of the bottom half, these are taped up for dispatch.

Time for some pictures:

Although the early models were supplied with an adjustable sight for targeting at different ranges, these were quickly ditched in favour of the single white line up the back for quick lining up. Adjustments could be made by eye.

This picture shows how the shells come apart to fit a 40mm grenade or TAG shell. The top half just pulls out of the bottom, held in place by spring tension. The shell on the right is taped up ready for dispatch, this isn’t needed for use.

When loaded, these are very safe to carry. MOSCARTs are notorious for going off when dropped. These shells have a firing pin which is recessed well into the tube which reduces the chance of this happening-prarticularly important when using TAG or solid state launchers.

 

If you want a mortar of your own, please do get in touch at: enquiries.vintageairsoft@gmail.com or join us on our Facebook page. Don’t forget you can buy our complete products via Etsy.

Heavy weapons prototype special

Nothing too in-depth today, just a short video showing off some of the prototypes we’ve been working on for over a year…

All of these are now available to order by email, we will be putting up pictures of the finished articles in the next few weeks.

If these products are of interest to you, please do get in touch at: enquiries.vintageairsoft@gmail.com or join us on our Facebook page. Don’t forget you can buy many of our complete products via Etsy.

 

British SMBL 2″ Mortar prototype

I’m afraid I have been somewhat remiss on photographing this build, but it’s quite a simple one in terms of components… The baseplate is an early war design which suits itself to precision rather than speed. The spiked arrangement on the bottom digs into soft ground to provide stability. The curved plate is your elevation control.

The bottom of the barrel/chamber, shown just after welding. The main body of the barrel is easily removable to remove the shell if you need to.

And the finished prototype! There will be a few modifications for production that allow the barrel to sit flatter for transport and the shell will have cutouts in the fins for lightness.

Something worth pointing out is that this is designed mainly for use with TAG shells to take out targets at long range or lay smoke screens, though you can put in any 40mm shells you like. During testing we did experiment with scatter shells and they were  effective at clearing a wide area ahead of the mortar.

Also, dropping the shell is unlikely to set it off. The firing mechanism is sat well inside the shell and will only be fired if activated by something goes that far into it. This makes it safer than just carrying moscarts which can go off when dropped on their base.

 

If this product is of interest to you, please do get in touch at: enquiries.vintageairsoft@gmail.com or join us on our Facebook page. Don’t forget you can buy our complete products via Etsy.

LAW M72 V0.2 and v0.3

For those of you who have been following the blog for some time, you may remember the first rendition of the LAW M72 light anti-tank weapon built out of plastic tubing and fibreglass. Since then Vintage Airsoft has been working slowly in the background on several anti-tank weapons including an improved version of the LAW.

When we say a while, we mean it. This is a photo of the new trigger mechanism housing being bent into shape in the old workshop.

The housing in shape.

When products are in development, they undergo a LOT of tweaking and changes in design, this photograph is a case in point. A dramatic change to the design of the shell meant that the original spacer would no longer fit, making it time for a gaffer-tape based solution.

One of the modified trigger units straight after being brazed.

This is the sear bar straight after being brazed. The protrusion nearest the camera is the sear, which is pushed down inside the tube above and allows the bar to slide forward under spring tension.

The sear unit in position under the trigger mechanism housing. At the back is the wire that actuates the firing pin.

Here you can see the firing pin (screw) and the actuator rod that the wire pulls to depress the pin. It certainly isn’t pretty but it did work. However this mechanism would be unsuitable for field use as it is unsafe to drop. However the principal can be applied to a more elegant system…

The new trigger mechanism. The transfer bar is pulled forward by a tension spring and is controlled by a sear activated by the trigger.

In place on the launcher, the tabs attached to the trigger unit can be welded down. The trigger unit can still be removed by undoing the screws and lifting straight out for servicing. There is also a tab that lines up with the hole in the cocking handle through which an R-clip or pin will be inserted as a safety catch.

 

And finally, painted up for testing! This will be painted green for production, but as it is a prototype the finish just needs to protect it from the elements.

If this product is of interest to you, please do get in touch at: enquiries.vintageairsoft@gmail.com or join us on our Facebook page. Don’t forget you can buy our complete products via Etsy.

 

Oh, for those of you who want to see/hear the dry-firing….

Light Mortars: SMBL 2″ mortar

History

Mortars are artillery that fires at a steep trajectory, used originally in sieges to target buildings inside walled towns that would be unreachable by conventional artillery.

They have been used by armies ever since, though the modern mortar is a very different beast to its medieval counterpart. This pattern of man-portable mortar was developed in the Great War: when remaining in cover while targeting an enemy in cover was necessary to survive. This close-use artillery needed to be small enough to live in conventional trenches but provide greater firepower and range than rifle grenades.

The Stokes mortar was introduced by the British in 1915 and the design was widely modified and used by other countries. It is the grandfather of all modern mortars.

The Ordnance SMBL 2″

The 2″ mortar as used by the British Army in WW2 was developed from a Spanish 50mm mortar, though with modifications to make it suitable for British service. By the end of the war there had been eight marks with countless ‘*’ designations (used by the British at the time to denote small changes that did not add up to a full Mk).

Originally the mortar was supplied with a collimating sight with spirit-levels and adjustment to allow for carefully aimed fire, however this was dropped on many of the marks, being replaced by a simple white line up the length of the barrel which was pointed at the enemy and fire adjusted until the bombs landed on target.

 

Vintage Airsoft have built a prototype mortar and will be demonstrating it very soon.

If this product would be of interest to you, please do get in touch at: enquiries.vintageairsoft@gmail.com or join us on our Facebook page. Don’t forget you can buy our complete products via Etsy.