500 Magnum accuracy problem.

[MN Nice]

Purchased a PC 10.5" 500 Magnum. I ran out of adjustment on the rear sight, groups great, just 5" low at 25yds.

Put a Vortex Venom on it, out of vertical adjustment, shot 5" low. Was advised to buy a shim for the sight, i did. Still 3" low...

I've tried bullets from 275-440 grain, 3 different manufactures. Same results.

Anyone with any ideas? No, I didn't register it. I've had it for 16 months.

 

[cmj8591]

It's easy to change the front sight. You may need a lower one. Make sure that it's the gun and not you. 500's tend to induce a bit of a flinch, even in experienced shooters. You don't mention your shooting method but also make sure you sight it in using some type of rest, like some sand bags. I wouldn't panic and send it back just yet.

 

[MN Nice]

I started on a sandbag, went to a bipod. Yesterday I was using a Caldwell Precision Turret.

The gun is amazingly accurate, 5 shot groups have been one big hole. The hole is 3" below my point of aim...

I've taken as much of "me" out as I can.

My eyes aren't getting any better, red dots have made shooting without an optic enjoyable again.

Ive been questioning myself, "am I missing something stupidly obvious?"

 

[cmj8591]

I started on a sandbag, went to a bipod. Yesterday I was using a Caldwell Precision Turret.

The gun is amazingly accurate, 5 shot groups have been one big hole. The hole is 3" below my point of aim...

I've taken as much of "me" out as I can.

My eyes aren't getting any better, red dots have made shooting without an optic enjoyable again.

Ive been questioning myself, "am I missing something stupidly obvious?"

It sounds like you are doing everything right. Everyone's eyes are different. It might just be that the way your eye is processing things causes you to shoot low. I will go back to my suggestion that you replace the front sight. If you can't find one low enough to get you to point of aim, then file it down. The only down side is that you will, most likely, not be able to use a glow type sight. As far as your red dot problem, if you have run out of adjustment and still can't get it to where you want it, then you will need to change your mounting system or add more shims. I have a 2x Burris scope on my 8 3/8 500. The gun is extremely accurate and I have been shooting it at 100 yards and getting 2 or 3" groups. Once you get your problem solved and dialed in, you will be hard pressed to find a big bore hand gun more accurate.

 

[Protocall_Design]

One thing you can check for is to see if the barrel is straight to the frame. Sometimes the frame is drilled and threaded slightly off due to not sitting in the fixture correctly. An easy way to check is to hold a straightedge along the top and sides of the topstrap and see if the barrel is parallel to the edge. This can be a little harder if the barrel is tapered, but you can see if it's equal on both sides.

I've seen a few guns with this problem. One was a M29 with the barrel going down and right. I have seen others where the barrel went left or right far enough that you couldn't sight them in. The barrel on this one may be angled down slightly. That would make it shoot low.

 

[505Gibbs]

One thing you can check for is to see if the barrel is straight to the frame. Sometimes the frame is drilled and threaded slightly off due to not sitting in the fixture correctly. An easy way to check is to hold a straightedge along the top and sides of the topstrap and see if the barrel is parallel to the edge. This can be a little harder if the barrel is tapered, but you can see if it's equal on both sides.

I've seen a few guns with this problem. One was a M29 with the barrel going down and right. The barrel on this one may be angled down slightly. That would make it shoot low.

At this point this sounds like the prudent thing to do - IMO!

 

[MN Nice]

One thing you can check for is to see if the barrel is straight to the frame. Sometimes the frame is drilled and threaded slightly off due to not sitting in the fixture correctly. An easy way to check is to hold a straightedge along the top and sides of the topstrap and see if the barrel is parallel to the edge. This can be a little harder if the barrel is tapered, but you can see if it's equal on both sides.

I've seen a few guns with this problem. One was a M29 with the barrel going down and right. I have seen others where the barrel went left or right far enough that you couldn't sight them in. The barrel on this one may be angled down slightly. That would make it shoot low.

Something like that could come out "Performance Center"???

 

[AlHunt]

Something like that could come out "Performance Center"???

Hang around a while, you'll see that zombie horse beaten to death at least once a week.

The optic kind of negates the sight picture issue but I'm wondering what you use. Line the tops of the front and rear sights and set the bullseye on top of that, or do you bring the bullseye down into the sight notch?

Just curious since your POI is low.

 

[__steve__]

With a 10.5" barrel I bet it takes a lot of turns to move the bullet hole up.