Click on the image above to learn more about the M1 Carbine
|
T21 Rear Sight |
Post Reply 
|
Page 12> |
| Author | |
carbinekid 
On Point 
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
 Post Options
 Thanks(0)
 Quote Reply
 Topic: T21 Rear SightPosted: Apr 12 2020 at 3:27pm |
|
Has anyone seen one of the modified T21 sights made by Mossberg for standard M1 receivers? I found the thread from 2017 showing the original T21 sight as devised by Inland for its own unique receiver. I think I found one...
       Edited by New2brass - Apr 12 2020 at 6:39pm |
|
 |
|
|
New2brass
Moderator Group 
Dan Pinto, Photo Editor Joined: Nov 29 2015 Location: CT Status: Offline Points: 4415 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 12 2020 at 6:23pm |
|
thanks for reporting.
Which board was that on? We have seen at least one on the special receiver |
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 12 2020 at 6:28pm |
|
the sight is mine. The thread I reference is the one you posted the link to that is on this board.
|
|
|
|
|
New2brass
Moderator Group
Dan Pinto, Photo Editor Joined: Nov 29 2015 Location: CT Status: Offline Points: 4415 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 12 2020 at 6:32pm |
|
Well tell us where you found this great piece of carbine history!
|
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 12 2020 at 7:00pm |
|
no great story unfortunately. I stumbled on it while scouring eBay. The seller had another mixed lot of small screws and other sight bits. In that lot was the missing windage plate and another aperture. Sadly, there must have been something in the pile that was valuable to someone else because what I thought was a totally safe high bid was overtaken in the final seconds. Pretty heart breaking. I asked the seller to pass my info on to the buyer of the lot, crossing my fingers that the person will contact me. I can’t imagine anyone else but me is looking for that bit. If I can’t get it then I’ll just make one. I don’t know if the screw was in the pile or if anything was supposed to go in the whole on the left side or if it supposed to be open.
|
|
|
|
|
New2brass
Moderator Group
Dan Pinto, Photo Editor Joined: Nov 29 2015 Location: CT Status: Offline Points: 4415 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 12 2020 at 7:28pm |
|
Hmm, something looks different
  |
|
|
|
|
GotSnlB28
Hard Corps 
Joined: Jan 01 2016 Location: WI Status: Offline Points: 844 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 12 2020 at 7:59pm |
|
The base isn't tapped for the set screw like the one on X61 in the newsletter is.
Definitely an interesting sight though. |
|
|
|
|
New2brass
Moderator Group
Dan Pinto, Photo Editor Joined: Nov 29 2015 Location: CT Status: Offline Points: 4415 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 12 2020 at 8:28pm |
|
I was pointing out the base difference, but looking at the article again that I linked above
The carbine production expansion program was rapidly accelerating at that time, and a redesign of the receiver would have caused unnecessary delays. The O.F. Mossberg Company was consulted and the T21 rear sight was redesigned to fit the standard carbine receiver. The M1A2 receiver design was then made obsolete on 25 November 1943. A photo of the T21 adjustable rear sight can be found in War Baby! page 96. (The Mossberg-modified T21 rear sight is the common adjustable rear sight that was first assembled onto carbines in March-April 1944.) |
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 17 2020 at 11:05pm |
|
Today I received the sight in the mail and was able to give it a good looking over. Of note, on each side of the sight there some hand added markings. On the right side is a large “7” and on the other side is “.025”. This leads me to believe that perhaps this is sight number seven out of an unknown number. The other marking must indicate an amount of material added or removed, maybe off of the base as the edges of the dovetail show hand fitting. The edge of the dovetail also shows a chisel type stake mark as was common at the time with the stand flip sights.
Looking through the pictures I saved of the parts lot auction I missed out on, I found there was another sight aperture that clearly was a little bit different spec. The sight hole has a larger dish on the front side than the aperture currently installed in the sight. As for the aperture on the sight, perhaps the .025” is in reference to a taller aperture as it looks different and mine also shows to be two pieces with the sight loop brazed on to the base. |
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 17 2020 at 11:32pm |
|
I forgot to add that the on the left side at the end of the windage pinion there is no retaining screw or missing piece. The indented/stepped down appearance is due to how piece is staked in place.
Overall this is a very nicely made sight right on par with the eventual standard type 2 rear sight. Now I need to get to the task of recreating the missing windage plate. Anyone happen to have a spare screw from a the rear of a type 2 rear sight? No idea what the thread pitch is on this sight, but it seems like the first place to start is with what is on the type 2.
|
|
|
|
|
New2brass
Moderator Group
Dan Pinto, Photo Editor Joined: Nov 29 2015 Location: CT Status: Offline Points: 4415 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 21 2020 at 3:17pm |
|
Might I suggest doing nothing that would alter the sight. It detracts from its history.
Any luck with the seller contacting the buyer of the loose parts?
|
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(0)
Quote Reply
Posted: Apr 28 2020 at 1:24pm |
|
Still no luck getting the missing piece to the sight. I did get an appropriate screw from a local old time gun shop. I have a buddy working on fabbing the plate up. Not original, but it will complete the look. Nothing on the sight will be permanently modified of course.
I’ve got a Winchester carbine on the way that was victim of some light sporterization. The rear sight is fubar, so I’m going to give this one a go and see how it actually works out...at least for one range trip.
|
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(0)
Quote Reply
Posted: May 04 2020 at 10:14pm |
|
I spent some time fabbing up the missing rear sight windage plate and modifying the retaining screw.
As it turns out, a flip sight leaf spring is the perfect material and thickness. I had several that are likely repros given what I paid for them, I still see them listed on eBay all the time. So, I sacrificed a couple for the cause and I’m very pleased with the end result.   Edited by New2brass - Nov 23 2022 at 11:22am |
|
|
|
|
W5USMC
Moderator Group
Joined: Apr 29 2017 Location: Missouri Status: Offline Points: 2815 |
Post Options
Thanks(0)
Quote Reply
Posted: May 04 2020 at 10:44pm |
|
That looks pretty good, nice job.
|
|
|
Wayne
USMC Retired NRA Life Member |
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(0)
Quote Reply
Posted: May 17 2020 at 3:06pm |
|
Anyone have a copy of CCNL #168? Looking through the index I see that there is some discussion of a prototype adjustable rear sight.
|
|
|
|
|
New2brass
Moderator Group
Dan Pinto, Photo Editor Joined: Nov 29 2015 Location: CT Status: Offline Points: 4415 |
Post Options
Thanks(0)
Quote Reply
Posted: May 17 2020 at 4:28pm |
|
CCNL 168 Discussed the original prototype adjustable rear sight. If you read an early FM-7 1942 it states "models of the carbine initially will will be equipped with an L-type rear sight, consisting of two arms at right angles, each pierced with an aperture .... Later models of the carbine will be equipped
with an adjustable sight generally similar to that shown in other figures in this manual." page 11 shows the rear sight and it appears to have two knobs. One for elevation and one for windage. There is another thread somewhere. Maybe someone remembers it and can link it.
|
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(0)
Quote Reply
Posted: May 17 2020 at 5:00pm |
|
The double knob sight sounds like the oddball prototype that Ruth discusses in War Baby.
|
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(1)
Quote Reply
Posted: Jun 01 2020 at 12:44pm |
|
So I got in touch with the folks that handle some of the historical records of Mossberg to see if they could shed any light on their participation in sight development for the carbine. Unfortunately they couldn’t provide much. What they did provide was enlightening though. Below is what they told me. Also I managed to find the patent file showing the sight. Very different from mine and the other version of the T21 from the M1A2.
“Most of what we have is anecdotal, with a small blurb related to the patent 2,407,437 which was received by Harold Mossberg The number S105 was assigned to a receiver sight listed as "designed for the War Department, June 1943 for use with the M-1 .30 caliber carbine", yet no record of an approved contract or production numbers can be found. Mossberg would have made pre-production prototypes and samples of course - yours could be one of those.“
Edited by New2brass - Nov 23 2022 at 11:23am |
|
|
|
|
Marty Black
Moderator Group
Editor in Chief Emeritus Joined: Dec 30 2015 Location: Pismo Beach, CA Status: Offline Points: 100273 |
Post Options
Thanks(0)
Quote Reply
Posted: Jun 01 2020 at 2:01pm |
|
Nice job, Carbine Kid !
MB |
|
|
Marty Black
|
|
|
|
|
carbinekid
On Point
Joined: Jan 24 2016 Location: SE Michigan Status: Offline Points: 422 |
Post Options
Thanks(1)
Quote Reply
Posted: Jun 01 2020 at 3:51pm |
|
I just got another update from the Mossberg folks. This was in response to me saying that my sight and the drawing show significant differences...
“One of the things that Alan Mossberg told us when we interviewed him for the book back in 1993 was that patent drawings versus production samples are designed to be approved "substantially as rendered" rather than "exactly as rendered." Having never seen one in hand, I don't know if they would have been stamped S105, as the peep sights were stamped S100, No 4, S130 etc.”
|
|
|
|
|
Post Reply
|
Page 12> |
| Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You can vote in polls in this forum |
Topic Options