Troubleshoot custom 300 weatherby reloading issues 180 hammers

[Blue Ridge Rifleman]

Look up some videos of the flex of the barrel when shot. That movement also goes through the action some. With it being able to move backwards freely it lesson some of the force.

It lessens the force on what? Newton's First Law tells us that objects at rest will remain at rest unless acted upon by an external force. In this case, the object at rest is the scope and the external force is the recoil motion of the receiver. If the receiver can move freely, it accelerates at a much higher rate and to a greater total amount than if it is restrained by a brake, by a shoulder, or by a lead sled. It seems like the force on the mounts and on the scope internals would be higher if free recoil allows for higher acceleration, and lower if the acceleration is slower. Am I thinking about this correctly?

I did find this YouTube showing flex in mounts and scope, granted it's a 50 BMG, but this looks like a very heavy rifle with slow acceleration. Imagine if the rifle were light and the acceleration were much higher.

 

[MZmoose]

I'm not an engineer but that makes sense. The faster and harder the gun moves backward in recoil the more force is transfered to your scope. That's why a heavy target rifle with low recoil doesn't doesn't bust reticles loose but an african stopping rifle will.

 

[HARPERC]

Look up some videos of the flex of the barrel when shot. That movement also goes through the action some. With it being able to move backwards freely it lesson some of the force.

As well as the stock. Especially with a muzzle brake.

 

[snox801]

It lessens the force on what? Newton's First Law tells us that objects at rest will remain at rest unless acted upon by an external force. In this case, the object at rest is the scope and the external force is the recoil motion of the receiver. If the receiver can move freely, it accelerates at a much higher rate and to a greater total amount than if it is restrained by a brake, by a shoulder, or by a lead sled. It seems like the force on the mounts and on the scope internals would be higher if free recoil allows for higher acceleration, and lower if the acceleration is slower. Am I thinking about this correctly?

I did find this YouTube showing flex in mounts and scope, granted it's a 50 BMG, but this looks like a very heavy rifle with slow acceleration. Imagine if the rifle were light and the acceleration were much higher.

So if we know the barrel and stock flex as the bullet leaves. If in a sled it can't move back so more of that energy is in barrel and action and stock. Flexing possibly the scope while at it. If it's on my shoulder and not the sled it is able to move backwards and my shoulder and body absorb some of the energy instead only the barrel and action.

 

[snox801]

It lessens the force on what? Newton's First Law tells us that objects at rest will remain at rest unless acted upon by an external force. In this case, the object at rest is the scope and the external force is the recoil motion of the receiver. If the receiver can move freely, it accelerates at a much higher rate and to a greater total amount than if it is restrained by a brake, by a shoulder, or by a lead sled. It seems like the force on the mounts and on the scope internals would be higher if free recoil allows for higher acceleration, and lower if the acceleration is slower. Am I thinking about this correctly?

I did find this YouTube showing flex in mounts and scope, granted it's a 50 BMG, but this looks like a very heavy rifle with slow acceleration. Imagine if the rifle were light and the acceleration were much higher.

Maybe a better way to think about it is a 1/4" wooden rod. If you put it on the cement floor and push it can only flex if you push it against something that can give a bit then less flex happens in the rod. If all else is equal as it has that slight movement. Again I'm no expert but I've seen scope get eaten a good deal and that is what I think is happening.

 

[Blue Ridge Rifleman]

Maybe a better way to think about it is a 1/4" wooden rod. If you put it on the cement floor and push it can only flex if you push it against something that can give a bit then less flex happens in the rod. If all else is equal as it has that slight movement. Again I'm no expert but I've seen scope get eaten a good deal and that is what I think is happening.

So the opinion is that it's flexing, rather than impulse (shock) forces that damage the scopes? I could see a lead sled increase the flex on an action and on a scope. Has anyone had better or worse experience with one action over another? As for me, I use lead sled for load development on all rifles (way more than I would ever admit to) including 300 Wby, 338 Win, 375 H&H, 458 Win, and have never lost even a middle of the road scope. I guess I'm just lucky.

 

[snox801]

I believe they are flexing but I have no real proof. I think it's very hard to say but I have had many more fail in a sled than should and the recoil impulse would be less so I assumed it's flex. But like you I used to shoot every trip out of a sled. Mainly smaller caliber to try for great groups. Heck even a bsa survived on my .22-250.
It could also be luck of the draw every scope can fail even the best. I've had vortex, Nikon and even a Leica fail on me very early. Then got the replacement scope and never had an issue even after extreme abuse.
I have the only range past 300 in my area so I get a lot of shooters and always makes me laugh when they say something like it's a "name a scope and cost so much so I know it's not that"

 

[MZmoose]

So if we know the barrel and stock flex as the bullet leaves. If in a sled it can't move back so more of that energy is in barrel and action and stock. Flexing possibly the scope while at it. If it's on my shoulder and not the sled it is able to move backwards and my shoulder and body absorb some of the energy instead only the barrel and act

So the opinion is that it's flexing, rather than impulse (shock) forces that damage the scopes? I could see a lead sled increase the flex on an action and on a scope. Has anyone had better or worse experience with one action over another? As for me, I use lead sled for load development on all rifles (way more than I would ever admit to) including 300 Wby, 338 Win, 375 H&H, 458 Win, and have never lost even a middle of the road scope. I guess I'm just lucky.

I have had zero scope failures on any guns used in my lead sled, and some were garbage scopes. IMO The only thing a lead sled may put more stress on is the stock because it's adding weight to the shooters shoulder. Or you could look at it as adding weight to the rear of the stock.

 

[willfrye027]

Well here's some follow up information for everyone.


did some more shooting and groups were bouncing around on the target by 6-10 inches or more.


I went through all the rings (nightforce), bases, and action screws and they were all tight.

checked the rate of twist manually and it's appropriate for the bullets being shot.

put a SWFA 6x mil quad on there and shot some good groups more in line with what I'd expect hammer hunters to shoot like.

So I think it's the scope. Called nightforce and they said send it back, but "we do this quite a bit and it's never the scope". So we'll see what they say but unless others have ideas...seems pretty clearly a scope failure possibly caused by the lead sled.

 

[North Idaho Hunter]

Put the nightforce on a proven rifle and see if you get similar results.