Here are a few patent drawings on some of them

The No. 1A Ramp Front Sight

The No. 1 ramp sight, the drawing is of an earlier design, so not really sure why they even sent this one in.

 

Way too cool.

 

I have images of two front sights and two rear sights to supplement Bone's sequences listed above. He mentions the existence of all of four them. As Bone mentions above, corrections and additions are welcome.

FRONT SIGHTS
The front sights predating the No. 1 front sight were acknowledged but not described or shown in Cheryl Havlin's 2001 article that Bone mentions (NMCA 13:1:1-4). As early as 1927 Mossberg was using ivory bead front sights on Model B and its trade brand versions. And the sight continued until 1932. In addition to the ivory bead that Bone shows above several members have posted closeups of the ivory bead front sights, with their distinctive shoulder and rounded edges. Here is another view of what they look like up close. Most have lost their ivory bead.

Mossberg ivory bead front sight (roughly 1927-1932)

For more ivory bead images, see https://www.rimfirecentral.com/thre...y-mossbergs-with-ivory-bead-front-sight.1316135/?post_id=13647457#post-13647457

Next, Bone mentions "an early brass beaded sight similar to the ivory beaded sight." These come on the heels of the ivory bead in 1933 and are probably best thought of as a short-lived and cheap alternative to the ivory bead, since the Model 10 was the bottom end single shot introduced in 1933. That year's new top range rifles (Model 30 and Model 40) were provided with No. 1 front sights.

I have two of these, both on Model 10 rifles, and both without their brass insert. For lack of any previous name I'll call them the "Model 10" front sight. They consist of a very similar base to Mossberg ivory bead, but with a taller and simpler rectangular blade, and with the front corner cut by a 45 degree slot for the brass "bead."

Mossberg "Model 10" front sight

That is the end of the simple Mossberg dovetailed front sights without hoods, but it is not the end of that diagonal notched blade receiving the brass inset. At least some of my No. 1 sights also have that same diagonal cut on the front top corner of the blade - its just that on the No. 1, the longer blade is sitting on a ramp that is screwed down to a dovetail.

Next come the front sights - the No. 1 ramped sight and the No. 1A front sight with selective posts, as seen above.

It is also worth mentioning that the late 1930s front sights again include a simple dovetailed blade that is slotted for a bead and held short (.625 inch) hood. First seen on late 1930s target rifles, the S122 continues on the WW2 training rifles.

S122 target sight. Found on many Model 26 and Model 44 variants.




REAR SIGHTS
Bone describes the Model L and Model R rear sights above. These two have a visually very similar sight portion but different sizes and very different elevators. The earliest, coming after or at the same time as the Model K is the Model L.

The Model L type rear sight has the normal triangle in front of the dovetail, then has a narrowed waist and center-slotted back to the simple upright v-sight. The sight is typically 2.3 inch-long and it has a simple elevator that is .937 inch-long.

Model L type rear sight from a circa 1929-1930 late Model B (one piece bolt) rifle.

The Model R type rear sight has the same appearance as the Model L type. But it is notably longer, typically 2.575 inch-long and it has a distinctive, stepped-base, 1.75 inch-long elevator with the step lifting through the blade.

Model R type rear sight on a circa 1931-1932 late Model B (one piece bolt) rifle.

Model R type rear sight on a circa 1933 Model 10 rifle.

As described by Bone up above, the Model R type front sight is followed by the No. 2 Sporting Rear sight. The No. 2 rear sight was introduced in the 1935 Mossberg catalog, at the same time as the company began to reverse its 1933 and 1934 decision to leave rear barrel sights off of rifles with the standard equipment rear receiver #3 peep sights.

The No. 2 rear sight was followed by the 2A version of the dial adjusted rear sight with the Mossberg stamped dial (1938-1940 - correction 1938-1939)

Then the S102 version of that same sight with the "compass" stamped dial brings us up to 1940.

 

Great info and thanks for adding. I was trying to stay with the Pre 2a/S102 sights, as we had another post. But that still helps with the dating of the sights.

Now that you have posted a picture of the front beaded sight. I now recall seeing pictures of it, I am watching one now at auction minus the insert. But that's easily fixed.

I also wasn't aware of the L and R sights being different lengths. But that makes since now, I have another one coming in off of an Essex rifle which I think was a Model 10, I also think it is the longer version. Now to see if I can find one of the longer elevators for it. I may need to get a drawing and/or some measurements from you to make one. Doesn't look to hard, should be able to scale it out off of your pictures.

 

I may need to get a drawing and/or some measurements from you to make one. Doesn't look to hard, should be able to scale it out off of your pictures.

Yes, the stepped elevator is harder to come by. I'm looking for a couple also. I'll pull one off and loan it to you express mail for an exact pattern.

Here's another photo to give a clearer idea to folks what we're talking about.

 

That would be greatly appreciated. I think, well I know I have something that I can repay the offer with.

I may check to see what the cost would be to have them drawn up and laser cut. But more than likely we/I could not justify the cost to have them made. Getting them drawn up is the expensive part, cutting not so bad on price. Probably a couple of bucks to cut per each.

But I have shop local that I use for other items, so we shall see if they can help.

The good is that the elevator would work on either sight.

 

Gentlemen,

Thank you for the info and taking the time to record the details. Great job. 👍