Help!- confused by my target from the range today.

[txfireguy2003]

Pretty impressive huh?

Sent from my SAMSUNG-SM-G891A using Tapatalk

[Bill]

No- I never realized the relationship with how tight a screw was and how much force it holds 2 things together. Or the same torque on a smaller screw results in more force. Or a clean screw exerts more force than a dirty one.


μολν λαβ

[JW]

Help!- confused by my target from the range today.

No- I never realized the relationship with how tight a screw was and how much force it holds 2 things together. Or the same torque on a smaller screw results in more force. Or a clean screw exerts more force than a dirty one.


μολν λαβ

Me either! Same for an 8-40 screw?


Sent from my iPhone using Tapatalk

[Bill]

8-40 is 0.160 diameter. You'd need to increase the torque to ~30 inch points for the same force.

I do not know how the scope/ rings guys calculate the correct torque spec for their products.


μολν λαβ

[JW]

8-40 is 0.160 diameter. You'd need to increase the torque to ~30 inch points for the same force.

I do not know how the scope/ rings guys calculate the correct torque spec for their products.


μολν λαβ

Me either. I went 30 anyway. Ima rebel like that.


Sent from my iPhone using Tapatalk

[bboswell]

8-40 is 0.160 diameter. You'd need to increase the torque to ~30 inch points for the same force.

I do not know how the scope/ rings guys calculate the correct torque spec for their products.


μολν λαβ

I'm not sure about the scope guys but torque is usually calculated in relation to the yield strength of the screw.

[WItoTX]

Any update on your groupings?

[Horitexan]

Here's some mechanical engineering 'trivia'. The so-called axial force is what you would measure if you put a super-thin stress gauge between the scope ring and the receiver.

The relationship between axial force (A), screw torque (T) and the screw diameter (D) is:

A= T/DxC

Where C is a constant related to how clean and friction on the screw threads. For steel-steel it's assumed as 0.2.

So, for a 6-48 screw with a diameter of 0.135",

A= 25 in-lb/ (0.135 in x 0.2)
A= 925 pounds,

x4 screws = 3,703 pounds of force is holding the scope rings to the receiver!


μολν λαβ

I'm confused by this post. Lol! I can offer no insight.


Sent from my iPhone using Tapatalk

[Bill]

4 teenie, tiny screws in the scope bases torqued to 25 inch- pounds are generating 3,700 pounds of force holding the bases to the receiver.


μολν λαβ

[Bill]

Help!- confused by my target from the range today.

A co-worker got a big box in work with a lead sled for the AR10 he's building (imagine that, Nancy Pelosi!) and it's mine to borrow for my next trip to the range.

I wonder if the screws torque being too low caused the drift when the barrel got warm?


μολν λαβ

[txfireguy2003]

A co-worker got a big box in work with a lead sled for the AR10 he's building (imagine that, Nancy Pelosi!) and it's mine to borrow for my next trip to the range.

I wonder if the screws torque being too low caused the drift when the barrel got warm?


μολν λαβ

Usually, heat drift is from contact between barrel and stock forend. As the barrel steel heats up, it expands and changes the amount of pressure where it contacts the stock, changing harmonics. Now, if you continue to have accurate groups but not precise ones (still clustered around the point of aim, just not a tight cluster) that could be blamed on barrel heating, although I'm not sure what mechanism causes this effect. But as I recall, you have a consistent progression from accurate shots to off center shots.

Now, loose bolts can cause shifting, but one would not expect a repeating progression like you have.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[backwoods]

Interestingly Im going through the same thing right now with my 7mm Mag that also has a VX1 scope so this thread is of interest to me.
My rifle is a Weatherby Vanguard Deluxe. My groupings just aren't patterning consistently. They are about 4" groups. I've tried two different ammo brands. Im going to clean the barrel and try a third brand. This Weatherby is no free floated so diagnosing the problem may be a little more tricky. The barrel gets very hot very quickly so testing on the range is a pretty long process waiting on the barrel to cool

[JW]

Interestingly Im going through the same thing right now with my 7mm Mag that also has a VX1 scope so this thread is of interest to me.

My rifle is a Weatherby Vanguard Deluxe. My groupings just aren't patterning consistently. They are about 4" groups. I've tried two different ammo brands. Im going to clean the barrel and try a third brand. This Weatherby is no free floated so diagnosing the problem may be a little more tricky. The barrel gets very hot very quickly so testing on the range is a pretty long process waiting on the barrel to cool

Don't print it with a clean barrel.


Sent from my iPhone using Tapatalk

[Mike D]

A co-worker got a big box in work with a lead sled for the AR10 he's building (imagine that, Nancy Pelosi!) and it's mine to borrow for my next trip to the range.

I wonder if the screws torque being too low caused the drift when the barrel got warm?


μολν λαβ

I personally hate shooting off a lead sled. I shoot way better off of bipod and a bag.

[bboswell]

I personally hate shooting off a lead sled. I shoot way better off of bipod and a bag.

I will not shoot off a lead sled. Cheek weld seems impossible.