Over the years I have rebuilt many 78 hand crank phonograph players, Ford Model T and Model A automobiles and do all the handy work here on the farm but have learned to ask advice before I attempt something I've never done before. I've taken a 1974 vintage Marlin 336 in the 30-30 Winchester out of storage and find after 6 rounds at roughly 85 yards it shoots 3-4 inches to the left. I will shoot some more rounds this weekend to be sure the problem is with me and not the rifle but if I do attempt to move the front sight over need some words of wisdom first.
Not knowing the correct term for this type of front sight let me simple say that when looking through the sight it looks like a vertical letter "i" inside a tunnel. The sight has two mounting screws, one at each end of the tunnel and there is a sloping ramp at the rear of the sight.
When the two screws are loosened somewhat is the whole sight supposed to be shifted left or right or do you just shift the front? Is there some way to mark the barrel, such as the straight edge of a "post it note" butted up to the side of the sight to make sure it has really been moved before tightening down the screws? Any and all advice appreciated.
The front sight should be dove tailed into the ramp,drift the front sight to the right or the rear sight in the direction you need to go. I always try to use the rear sight whenever posable
For adjusting left/right "windage" on sights, and this is just me, mind you, I wouldn't mess with the front sight at all to begin with.
Start by drifting your rear sight first. Since you are shooting 3" or 4" left, you will need to drift the rear sight to the right a fuzz. To mark how much you are drifting it, first put a piece of masking tape on the barrel (on the chamber side of your rear sight), and reference the center of your rear sight by making a pencil mark. Then use a piece of hardwood dowel or similar (not a steel drift punch) and tap against the dovetail of the rear sight (via the dowel) with a small hammer or mallet to drift it a ways. Then make another mark.
Test fire to see where your groups are landing, then go back and adjust some more as necessary. The pencil marks on the masking tape will tell you where it has been for a reference so you can gauge how much more or less you need to drift it.
If doing it this way doesn't work, and you have drifted your rear sight as much as you can without getting the windage adjusted, then we should talk about messing with the front sight.
By the way... Welcome to Marlin Owners.
Thanks for the quick reply's! Since the rear sight does not have any mounting screws I suppose the dovetail fit is just by friction? Do I need to remove the adjustable ramp on the rear sight before I tap on the front where the dovetail is located?
Correct... The dovetail is an interference fit. I didn't remove the elevation ramp when I drifted mine, but also don't see where that would hurt anything by doing so.
As far as the tape goes, you can put it on either side of your sight for your reference marks - - whichever would make it easier for you to mark and gauge how much movement you make each time you drift it.
well let me be the first to say that you need to shoot it at about 25yds at first, just to make sure of what's going on, and yes you need to shoot it some more to get a feel for it. you do not have to remove the elevator for the rear sight to adjust it, it will slide over with the sight. and when you get it shooting strait then you can move out to 85yds.
3-4 inches on a sunny day could be just a little glare on the rear sights notch causing that at 85 yds.
Try another group at the same distance to see if it repeats before drifting the rear sight.
God Bless Our Troops -- Retired Tool & Die Maker -- The center of an Aspirin is the same size as the center of the moon, aim for the center.
Everyone is right... it's best to drift the rear sight left or right first. It's much easier. If indeed you DO end up needing to move the front sight, I recommend you are careful if you're going to tap it with a hammer and punch... make sure the RAMP portion is firmly rested or you have a chance of shearing the ramp off the barrel! Some people remove the ramp and then drift the front sight in its dovetail.
You cannot rotate the front ramp at least not much!
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The rear sight is moved in the direction you want the bullet to go!
Move rear sight to the right to move the bullet(group) to the right!
The front sight (not the ramp if it has one) is moved so that it chases the bullet!
Drift the front sight to the left to move the bullet(group)to the right!
If you drift the front sight in the ramp dovetail make sure to support the ramp when you are doing so!
P.S. If you loosened the front sight ramp screws retighten them well and use LocTite on the screws!