Benjamin rear sight adjustment

Benjamin rear sight adjustment

Joined: July 24th, 2005, 2:05 pm

May 21st, 2012, 9:26 pm #1

Wasn't really looking but found a mint condition Benjamin 397PA with nice walnut stock at a great price. Shoots great, but noticed the rear sight elevation screw was missing. On my 392PA, which also shot a little high, I had to remove the screw and tape the sight leaf to the compression tube with a couple turns of black electrical tape to get it to shoot to point of aim at 33 feet. Now with this new rifle, a virtual twin of the 392, the sight spring is actually sitting flat on the sight body; in other words, it cannot go any lower. Still shoots 3/4 inch too high at 33 feet. Both guns are in pristine condition, with barrels tightly soldered to the body. How can I make the 397 shoot to point of aim, with no vertical adjustment left?
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Joined: April 1st, 2009, 3:18 am

May 21st, 2012, 9:40 pm #2

Come up with a way to add some material to the front sight. That will lower the impact point.

"The majority of things in our lives are created by folks no smarter than the rest. Afterall, the world is comprised, and operated by C average people intellctually, academically, and morally. These people are often the great pioneers that set the precedent for what excellence should be."
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Joined: November 28th, 2002, 6:26 pm

May 21st, 2012, 9:44 pm #3

Wasn't really looking but found a mint condition Benjamin 397PA with nice walnut stock at a great price. Shoots great, but noticed the rear sight elevation screw was missing. On my 392PA, which also shot a little high, I had to remove the screw and tape the sight leaf to the compression tube with a couple turns of black electrical tape to get it to shoot to point of aim at 33 feet. Now with this new rifle, a virtual twin of the 392, the sight spring is actually sitting flat on the sight body; in other words, it cannot go any lower. Still shoots 3/4 inch too high at 33 feet. Both guns are in pristine condition, with barrels tightly soldered to the body. How can I make the 397 shoot to point of aim, with no vertical adjustment left?
...to drop the point of impact by 3/4" at 33 feet.

Steve
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Joined: May 31st, 2005, 5:24 am

May 22nd, 2012, 5:51 am #4

Wasn't really looking but found a mint condition Benjamin 397PA with nice walnut stock at a great price. Shoots great, but noticed the rear sight elevation screw was missing. On my 392PA, which also shot a little high, I had to remove the screw and tape the sight leaf to the compression tube with a couple turns of black electrical tape to get it to shoot to point of aim at 33 feet. Now with this new rifle, a virtual twin of the 392, the sight spring is actually sitting flat on the sight body; in other words, it cannot go any lower. Still shoots 3/4 inch too high at 33 feet. Both guns are in pristine condition, with barrels tightly soldered to the body. How can I make the 397 shoot to point of aim, with no vertical adjustment left?
instead of adding material to the front site which is easily broken off or can look terrible, i remove some of the rear site. this is a whole lot easier and if done right unnoticeable. i remove the rear site blade and put it in a vise. i carefully file the same amount of material off both sides until i'm almost to the bootm of the small groove you sight thru. then i take a dremel tool with a cutter wheel and make the groove back deeper to it's original size. i dress everything up using a little cold blue and reassemble. works everytime. for some reason this is a problem with later crosman benji/sheridan guns. shooting high even with the rear site as low as they'll go, but the way i do it has seemed to correct the problem everytime. i have also ran into the same problem with the williams peep site shooting high even adjusted as low as it will go. again i remove material from the bottom of the site until it will go low enough to correct this. then just use a little flat black paint to cover every thing. doesn't show that much underneath anyway.
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Joined: April 1st, 2009, 3:18 am

May 22nd, 2012, 6:01 am #5

The slightest flex upward will cause the gun to shoot high. Benji guns are known for this. In fact, I do believe Steve has doone oodles of testing on this. I have myself, for an SSP Benji, though an extreme example, flex was present.

"The majority of things in our lives are created by folks no smarter than the rest. Afterall, the world is comprised, and operated by C average people intellctually, academically, and morally. These people are often the great pioneers that set the precedent for what excellence should be."
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Joined: May 31st, 2005, 5:24 am

May 22nd, 2012, 8:09 am #6

with poor design by crosman instead of flexing. i have about a dozen old dans and old benjis that i shoot regularly and never seen this problem in any of them. seems to be a problem with the later guns now owned and made by crosman. you can contact crosman but it doesn't seem to matter to them. like the overspray you have to clean out of the muzzle of every single one you get nowadays. the 397, 392, and the .20 or 5mm sheridan. the rear site has been a poorly designed problem even back in early sheridan days when they went from the soldered on site to the one i'm talking about now. they cause barrel seperation and crosman will not change the way they mount. it's not if, but when they'll seperate with that clamped on site. by the way the flexing must be the exact same every time. i have a second variant dan, (unmodded) with a redfield 4X pistol scope scout mounted with an original 2 piece intermount (not overtightened) that i shoot always with the same number of pumps. this gun chronies 735fps with a jsb 13.8 pellet on 8 pumps and shoots a ragged hole off the bench at 25 yards. the gun is zeroed for 25 yards but i take squirrels with it out to 50 yards. haven't tried it at different number of pumps to see if the POI would change. the gun will chrony about 770 on 9 pumps but then it will have a slight amount of residual air left so i just use 8. it has the soldered on rear site which i think sheridan changed to that barrel seporater clamp on site around 1956. imagine that, a known problem for over 50 years that just won't seem to be ever corrected.
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Joined: February 9th, 2006, 10:35 pm

May 22nd, 2012, 12:43 pm #7

My '65 has small set screws to hold the rear sight in place. I think the clamp on design came about in the '70s.

With my '08 model 392 I had to work through just about every ailment known to late model B-S rifles (paint in muzzle, tigger, find the right pellet, aluminum valve yukkies, etc...), everything except rear sight issues. Never had a problem getting the sight adjusted to shoot correctly at even 10 yards. And the sad thing about that is, I mostly shot it with a scope! LOL

I'd rather work on the rear sight than possibly mess up the front sight though. That front sight is small and fragile on the newer rifles, it wouldn't take much to really screw it up.

I plink, therefore I am.
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