Pedersoli Vernier Sight Issue

[WBH]

The standard vernier sight on my Perdersoli 45-70 RB is the style with the flat spring that you adjust back or forward to get the staff at 90 degrees to the barrel. The issue I have is with the screw that holds the spring in place. It appears to be a 8-36 screw. BUT, with the staff at a right angle to the barrel you can't get a screwdriver straight in the slot so as not to bugger the head. I do loosen it from time to time to allow the sight to go rearward so I can get an OAL for new bullets touching the lands using a Stoney Point or the like.

I would like to put a Torx or a Hex head screw in it's place. I just want to verify that the thread is, in fact, 8-36.

Anyone know the answer?

Why they still use that design is anyone's guess. There are far better bases out there.

[Steelshooter]

WBH
The screws on my pedersoli are metric. When I get home I'll find out size it is since I had to replace mine, it seems that the screws are easy to strip.
Chuck

[montana_charlie]

BUT, with the staff at a right angle to the barrel you can't get a screwdriver straight in the slot so as not to bugger the head.
If the screw has a real wide slot, you are supposed to use a large coin...like a quarter.

I do loosen it from time to time to allow the sight to go rearward...
You really have me wondering, WBH. Every vernier tang sight I have experience with (which includes two Pedersoli models) will lay back without loosening the spring anchor screw.
Just grab the staff and pull.

I imagine you have the USA 430 or USA 436, as they are the ones normally supplied with various rolling block models. I am sure that both of those will lay back without loosening the spring screw. Take a look at this webpage and tell me which sight is the one you do have, in case it's different than the ones I mentioned.
http://www.davide-pedersoli.com/accessoriDettaglio.aspx?CategoriaId=1315&lang=en

As for the screw, itself, it is a metric number. If you need a replacement (or two) they are available at VTI Gunparts (vtigunparts.com). It is the same as the mounting screw for the rear barrel sight, on the 1874 Sharps rifles...except those Sharps screws don't have the wide slot (like on your sight base) where you use a quarter to tighten it.

If you want an identical replacement (with the wide slot), it is Pedersoli part number 700005584. You might get it from VTI, but you may have to go to Flintlocks Etc. (flintlocksetc.com).
CM

[WBH]

MC....the sight is a USA 430...BUT, you cannot move it rearwards. This is the second one I have had in the last 5 years that does this. I have never seen another to compare it to. You will break or bend the staff if using any more effort. A quarter might work, but I really want to change it out to a hex or torx head so I can use an allen key.

I guess I'll just re-tap the hole and put a 8-36 in it with a torx head.

[montana_charlie]

MC....the sight is a USA 430...BUT, you cannot move it rearwards.
Well, sir...you are the guy who is able to see the sight, so I won't argue with you.
But, while your messing with the screw you might decide to take the staff off of it's base.

If you do...and there are three notches on the pivot boss...I'd bet it will lay backward.

Just as general information...
From all accounts, the staffs on Pedersoli sights will not bend. I don't know what they're made of, but apparently they are so hard will break before they'll bend.

That might instill some confidence if one happens to whack his staff against something. If it didn't break...no need to worry about whether or not it's still straight.
CM

[WBH]

I know. I even ground a bigger radius "groove in the rearmost notch on another sight I had.....no luck. I am just going to change the screw out.

That's it. I'm finished screwing with it. No pun intended.

SAhooting some new bullets tomorrow. Will post results.