One screw D&T'd will work just fine the other would end up going into the recess milled into the receiver for the ejector. It won't be able to grab even one thread. This sight is made to be mounted on the receiver. I'm trying to mount it as far back as can be done but that milled slot runs the entire length of the receiver. How did it get mounted back in the day?

My first suggestion is to get another sight that uses factory holes, IMO the Redfield 102's are very low end and with them requiring extra holes are not a good option. A couple for 99's just sold on eBay, here's the cheapest one, others have brought up to $45 - Redfied 102 - for an extra $50 to $75 you can get a sight with much better adjustments that will fit existing holes, and you will be able to get most or all of your money back out of it if need be, you will never get anything back from adding extra holes.

These sights are made to only mount in one location, here is a composite showing where one goes (probably not to correct scale) -



Here's some other options that do not require extra holes (and have much better adjustments) -

sight-box-Savage-model-99-/331952086629

-SIGHT-FOR-THE-SAVAGE-99-RIFLE-/311687379098

Redfield-80LH-Micrometer-Receiver-Sight-for-99-Savage

Redfield-70-Receiver-Peep-Sight-for-Savage-Model-99

Williams-Foolproof-Receiver-Sight-FP99-Savage-99

If you have an older gun drilled & tapped for a tang sight, traditional style Marble's & Lyman tang sights have been going for $75 to $100.

Thank you Gene. I appreciate your help.

Don't do it!

Redfield 102s are crappy sights and since they require 2 holes to be d&t into the left side of the receiver, they are value killers. If you want to shoot a peep sight, buy a style from Lyman/Redfield/Williams that was designed to fit factory d&t holes. Better, finer, windage and elevation adjustments, and no extra non-factory holes to d&t.

There's a proper Redfield receiver sight for sale on this sight now. As 260 says, it's a deal breaker and a value breaker. Don't do it. I have a NOS 102 in the box with the drill template for my Remington 141 that I bought in ignorance. I will never use it. Plus, on the 102 the adjustments are opposing screws, not micrometer clicks.

I agree with the notion about not drilling and tapping the receiver needlessly. I will disagree with the notion that the 102 is a bad sight. For a target shooter, the lack of repeatable screw/click adjustments is a non-starter, but for a hunter it's not that bad. I have used sights with primitive adjustments like which is on these, and once zero-ing is achieved one simply cinches down the screws and forgets about them. If said user fools around with multiple loads then they become a problem again, but if it's a once a year rifleman/hunter who shoots one load they are a very usable sight.

I had two Krags along the way that had Redfield 102 No-Drill sights on them and they functioned just fine.

Yeah, the 102 is fine within its intended context of hunting. Lyman made a similar sight for the Super Sporters and others and they seem to be fine for their intended purposes too. I wouldn't drill an unmolested rifle for one, but I don't think that I'd turn my nose up at a 99 that had been previously drilled for a 102, especially if the price was right. Functionally, it's not a bad idea.