Home Forums Hunting & Shooting Gunsmithing Winchester Model 71 -- taller front sight?

Finally got a chance to fire a newly loaded 3-round test group. Not wonderful, approx. 1.3" at 25 yards from a rest. The group is approx. 2.8" high, though, with elevation on the adjustable peep rear sight set as low as it will go... so that's what I'm concerned with first.

I didn't chronograph, but the load was a 200-grain Hornady JFP #3410 (pre-Interlock) at a nominal 2500 FPS, perhaps slightly lower... and there's not much velocity change I can make to get a group low enough to compensate for that kind of height.

Which leads me to believe I need a taller front sight. How do I measure the height of what I've got now -- from where to where? Bore centerline to bead centerline? Bore centerline to top of bead? Elevator (bottom of sight dovetail) to bead? Or...?

Where best to shop for taller versions? Lyman? Marbles? Skinner? etc.

-Chris

Where does it hit at 100 yards?

Drift the sight out and measure it with a caliper. From bottom of the dovetail to the top of the bead will be your height. Brownells has the plug and play formula for sight height, good reference material.

Thanks, Kid. That led me from Brownells to the Marbles site, too, and they have a bunch of "training" info there, also And it looks like I may even have a choice of slightly larger bead if I decide to go that way.

Don't know, Ed, but now it's clear I need to go back to the range to shoot some 100 yard groups before I do anything else.

-Chris

Hmmm... 3-round group (out of 5 shots), 2-5/8" with both vertical and horizontal spreading, 8-3/8" high at 100 yards.

I think I could maybe work with that, given a MPBR of approx 197-yards would be 1.97" high at 100 yards. Looks like Marble offers front sights high enough to give a 6" correction, which is at least closer.

This is with a test load of 58.5-gr W760, the Hornady 200-grain JFP #3410 (probably pre-InterLock, BC = .246) that QL predicts at 2468 FPS. I didn't chronograph (yet) but the QL predict correlates "pretty OK" with load data from Hodgdon (Winchester), Hornady, and at least one Handloader article.

All is not perfect, though, considering those other two shots. One of those was flawed during the loading process (oops), and this was the first shot from a cold barrel... so I wouldn't have been surprised with a flyer... and it was. The other shot, not expected to be a flyer, landed pretty close to it though, spreading the real 4-shot and 5-shot groups to more like 6-1/4". Not great.

Might be technique; I'm not used to holding the forestock down when shooting from the bench, so I may not have been consistent. Also... I can't actually see the target very well. The bead seems to completely cover the 8" bull at 100 yards (using 50-yard pistol target)... so this may be as much about my eyeballs as anything else.

Gotta think on this some more, though...

-Chris

I sometimes rest my arm on the sandbag while hanging onto the forend for heavy recoiling rifles. May or may not help you with repeatability with your 71. Also remember that contemporary writing usually didn’t have 71s being great shooters, good enough for woods ranges and open sights but not really driving tacks. An old friend had several and 3.5” or so groups were fairly normal for most loads. Didn’t stop him from killing deer with them.

Yeah, I'll have to get more consistent. I was resting the back of my hand on the front sandbag and holding the forend there... and I had the buttstock on the rear sandbag and firm against my shoulder. I don't remember much of an issue last time I sighted in the .338WM, but maybe I was just more consistent at the time. Or maybe the M71 reacts slightly differently. Or all of the above. Or something else.

I know not to expect match accuracy, and minute of whitetail or feral hog or whatever will be fine.

My current front sight is about .280" high, so it looks like (from their into) a Marble's .34MR will give me a little over 8" correction easily enough.

In the meantime, I'm debating (with myself) pros/cons for going with a smaller 1/16" bead which would subtend 9.375" at 100 yards (mine is .080, 12" @ 100) or a larger 3/32" bead (14.0625")... and/or going from brass to ivory. At least once I did the math I could 'splain why my current bead completely blotted out the 8" bull I was using. I suspect I could do a little better by making a custom target better suited to "bead blot."

As I type this I think I'm leaning toward the slightly smaller bead (1/16) and staying with brass. (Assumes I'll still be able to see the actual bead, at that size.) I think I'd be leaning toward a larger bead if I was expecting a brown bear to come waltzing by, but they seldom do that around here.

-Chris

I have a brass or gold sourdough style front sight on all my peep sighted rifles. I find it much more precise than a bead. Bad news is that Redfield stopped making them about 40 years ago. Might still turn one up on eBay or somewhere.

I think I'll be limited -- at least in the short term -- to whatever I can get. I backordered the Marble 34MR with 1/16" brass bead... and it might be expected in stock soon... but I reckon that'll be a bit iffy. I can continue to consider options forever, though.

-Chris