You have the newer model Marbles tang sight that is for the newer post-1988 39a's. Call Marlin, get them to send you a stock bolt for mounting the pre-1988 model, problem solved.

SqHunter;

Why not use the Marbles sight for the 336 series rifles? It's designed to sit back farther than usual on the tang due to the long bolt travel on these rifles. Additionally, in spite of being intended for two closely-spaced mounting screws, just using the main tang screw alone works fine. If my memory serves, the stock screw is long enough on the 39A.

My 39A is set up this way. Unfortunately, I don't know how to post photos here. The only problem I had was the elevation didn't go quite low enough for chickens. A taller front sight might have been a good fix, but I decided to make a shorter replacement stem instead.

- Brian Wakefield

Cimarron Red is absolutely right about not having to d & t through the serial number. However, you need to know that the base itself will cover all but the first 3 numbers of the serial number.

eagleeye42 wrote: ↑Mon Nov 26, 2018 3:55 pm Cimarron Red is absolutely right about not having to d & t through the serial number. However, you need to know that the base itself will cover all but the first 3 numbers of the serial number.

The MVA base? Thanks, that is good to know.

I am going to call Marbles again tomorrow to see if their technician is around, maybe he will know for sure if the improved will fit my rifle.

Thanks for the ideas everyone!