Indians For Guns

My old SDB 50 that I had earlier retuned had a problem. I found that it would work only with Mastershot Wadcutters and that too with the rear sight in the maximum (fully) depressed position. When I tried a couple of other brands like Marshalshot flat head and GSmith Flat head I found that the rifle was shooting true but consistently high and I could not lower the rear sight any further.

Initially I filed away 1 to 1.5 mm of the top surface of the rear sight and filed a new 'V' notch. This helped but it was not enough. I felt I had no option but to try and raise the height of the the front sight.

When I opened up the front sight this is what I got. The pin was threaded into the barrel and protected by a guard frame held in place by a circular nut at the tip. Initially I thought I could simply stuff a smal ball of paper into the hole in the barrel, but I discovered that the hole went all the way into the barrel.

As regards putting a washer the problem was that the guard frame has a notch that exactly fitted the diameter of the front sight pin, so I would have to use the sight without the guard unless I could find a suitably sized washer. I found an old Meccano set square nut and used a drill to enlarge the hole. It fit well, but broke as soon as I started tightening the sight over it because the hole was too big for the size of the nut.

Finally I had to resort to a crude hack. I cut out three thin washers from an old piece of tin after drilling suitably sized holes. I placed them one on top of the other and screwed the sight in place as seen in the image below. not pretty but it works. The big advantage for me now is that it works fine with Marshal shot flat heads. This is a big deal to me. Marshal shot flat heads are half the price of Mastershot wadcutters.

friend,
you should try mr.brihaji he is a genius.
as for me i feel the weight of the pellet should be the reason to shoot higher than mastershot's.
regards
dr.jk

Dear Benne,
Higher velocity also causes rise in point of impact.I hope your leather washer has settled now.
You have managed to do it very nicely .
I am cocerned about the 'V' and how nicely you have done that.
I have firing experience with SDB 45 and 2000,not of 50 model.
With that experince , I can say ,if tuned ,it can challenge Indian front runners.

Basu

How old is your SDB ?
The front sight looks it's from the Mughal era .. lol.
Why don't you use regular washer , found at any hardware store , instead of the pieces of tin ?

Nice attempt ; good to know it worked for you .

F-N-Five-Seven

I have firing experience with SDB 45 and 2000,not of 50 model.
With that experince , I can say ,if tuned ,it can challenge Indian front runners.

Very true .
I had a chance of shooting the SDB 2000 . Interestingly I got my hands on it in Jharkhand , when I was searching for it in WB .
It's definitely the best air rifles I have handled .

F-N-Five-Seven

Nice job, I like it very much! (sometime when you are bored though you should darken the pieces with paint or a black permanent marker so they blend in better).

Congrats.

Mark

Basu wrote: I am cocerned about the 'V' and how nicely you have done that.

You have hit upon an important point. In fact the rear sight had an issue that I have not mentioned. The rifle was shooting off to the left and even maximum deviation to the right was unable to correct it fully, and this was in addition to shooting high. So when I filed off the old notch I cut a new notch slightly to the right Fortunately the original notch was neither a V nor a rectangle. It was a broad U that just fit the ball at the tip of the foresight. A triangular cross section file did the trick

The accuracy I got after all this is pleasing because it means that the rifle itself is fundamentally good - that is the rifling is good and the muzzle rim at the end of the barrel has been machined to be perfectly flat and orthogonal to the pellet path. All my labour would have been useless if those non correctable (by me) factors were not well made in the first place.

Hi Bennedose,
> Good work there re: the sights on your SDB
> Just a suggestion on sight alignment..........
1. Tie a string to your front sight post...
2. Bring the rear sight to its mid-position - This is half way between the lowest point & the highest point
3. Now stretch the string through the 'V' groove to ensure that the string is absolutely parallel to the barrel of your AR
4. If not adjust the rear sight (up / down) till done
5. In this position you should be able to hit bulls eye at 10mtrs with 14gr pellets
6. Now keep this as your reference point
7. Then shoot at different distances eg. 15mtrs / 20mtrs / 25mtrs / 30mtrs
8. This will give you an idea as to the adjustment needed in the rear sight (elevation & windage) to hit bulls eye
> Of-course the adjustment will vary with pellet weights & their shape (Round-heads / Wad-cutters)
> Once you get the hang of it - Its Bulls Eye all the way
> Lastly the "Crowning" of the barrel end is critical to ensure proper pellet exit. Look up Larry Potterfield on google on Crowning - there is a video clip demonstrating it.
Happy Shooting
Briha

Thanks for the unique tips Brihaji. And yes, "crowning" was the word I was looking for.