Suit Sight farther than 500 yards question

Unable to get an answer here in the lower 48, I hoping members here may have some ideas.
I want to shoot my L1A1 at 800 yards. The cam setting goes to 500 yards where the rifles shoots very well using the Suit Sight. I wondering if I can get the farther distance by adjusting the front mount screw for the sight? Or do I need to make other adjustments to the mount?
I have several Metric rifles and hitting the 800 yard target was easy to do using the optics they were issued with.
I'm hoping one of you have shot the L1A1 with the Suit Sight farther than 500 yards.

Does the SUIT sight have graduations you can use once the elevation drum stops if no you can just Kentucky aim it by placing imaginary lines on the vertical and horizontal stadia just remember the sight picture when you start connecting and draw it up once I was shooting 2 feet high right on a target the cross hairs were looking some dirt and still connecting the black not a great score but damn hard to pick the same patch of dirt for the hold off with a 15 power scope at 900M but it was fun my 15y/o son was impressed I even connected Rifle ~ APRS - 308 168gn A max 42gns 06H off a bi pod with no back bag 37/50:super:

I found under the Stoving paint that the front screw can be backed off quite a bit. There are index marks as well. I need to come up 127" to compensate the bullet drop.
I'm going to try to hit the target at 800 yards this week.

I went to the range today,bright and sunny. 50 degrees F and 15 mph wind at my 7 o'clock.
I had loaded up some M-80 Ball bullets to Britt spec's and gave it a go at the 800 yard target.
The front screw is very sensitive to elevation. I put in what I thought would be about right and the bullet went 1,100 yards down range. After returning to the 500 yard setting I found I only had to go down one notch and put the point of the SUIT Sight onto the center of the man silhouette. Any more or less would go way over or under the target.
The L1A1 has a brand new barrel but I have found that if I can hold 4 MOA that is about the best it can do. I fire 20 shots and got ten hits. Not match winning but good enough to prove that the SUIT Sight can hold is own at 800 yards.
I may return and try my heavier match loads and see how well it shoots.
The Rifle
https://www.milsurps.com/images/impo...perjd4bg-1.jpg
A telephoto view of the target on the right at 800 yards
https://www.milsurps.com/images/impo...njqdmrai-1.jpg
The hits on the target
https://www.milsurps.com/images/impo...sft7t3m8-1.jpg
One of the recovered bullets. Good rifling marks and a good seal around the bullet in the rifle's bore
https://www.milsurps.com/images/impo...koagerfj-1.jpg

To be really honest and it's been aired on the forum several times, while the sight is good, the mount is, at best, crap! We used to say that SUIT - as in your sight - stood for Shooter Usually In Trouble

I'm so glad you mentioned that. I was hoping I didn't buy a broken scope.