Jump to content
Search In
  • More options...
Find results that contain...
Find results in...
Benelli Forums
Unobtanium

Something followed me home today...

Recommended Posts

Why would thermal expansion affect a shot at a deer? Sitting too close to a fire? Gun sitting in the sun? Still makes zero sense.

A deer no, but pigs yes. I just used deer as an example. In a mere 6 rounds, I was hitting 12moa low. You can easily fire 6 rounds at some hogs in some areas. Or just target shooting etc. It shocked me to be honest.

 

Now, I doubt enough heat is transmitted to the mag tube to matter, but I am curious to see, and I do note that the milspec m1014 passed all testing , and it would seem a concern I would think if it exhibited this much shift that fast, but maybe not. I need more data.

Share this post


Link to post
Share on other sites

Lol and that was because of a titanium magazine tube? Not a chance. Sounds more like the nonmechanical portion of the firing cycle to me. Will POI shift with firing and the gun heating up? Absolutely. But you're telling me that's exaggerated beyond a negligible degree by the material of a magazine tube? Not buying it, but whatever helps you sleep at night.

Share this post


Link to post
Share on other sites
Lol and that was because of a titanium magazine tube? Not a chance. Sounds more like the nonmechanical portion of the firing cycle to me. Will POI shift with firing and the gun heating up? Absolutely. But you're telling me that's exaggerated beyond a negligible degree by the material of a magazine tube? Not buying it, but whatever helps you sleep at night.

I am not saying it was the mag tube. I am saying it could have been. Was It? No, I'd need more data. Was it me? No. I was stacking them. I of course thought I was to blame, so I benched the gun and tested as such at 25 yards. At 25 yards, from a sandbag, there is no way this user was to blame. Ymmv.

 

Here is a 50 yard group from a sandbag fired using my benelli supernova as proof of capability. 3 rounds.

 

21752847_935690108961_3880723088400791017_o.jpg?efg=eyJpIjoidCJ9&oh=34e6c7edf5b9d5b2fd25c0e8ba9f142b&oe=5A9F3BCF

Edited by Unobtanium

Share this post


Link to post
Share on other sites

Earlier you were absolutely saying it was because of a titanium magazine tube. Being an aircraft mechanic, there are very good reasons aircraft engineers use titanium in high heat areas due to it's resistance to extreme heat. So six shots will cause enough heat in the magazine tube to cause it expand enough to excuse a 12 MOA shift? I get it, you're no longer claiming that, but that is the most ridiculous thing I've found on the internet this week. Not trying to hijack your thread. Good luck with your accuracy issues, I hope you get that sorted out. I'm done here.

Share this post


Link to post
Share on other sites
Earlier you were absolutely saying it was because of a titanium magazine tube. Being an aircraft mechanic, there are very good reasons aircraft engineers use titanium in high heat areas due to it's resistance to extreme heat. So six shots will cause enough heat in the magazine tube to cause it expand enough to excuse a 12 MOA shift? I get it, you're no longer claiming that, but that is the most ridiculous thing I've found on the internet this week. Not trying to hijack your thread. Good luck with your accuracy issues, I hope you get that sorted out. I'm done here.

 

Well, like in said initially, there were several reasons for my choice. Eliminating that variable is one of them. I would need to do more testing to see if the mag tube contributed. My gut says no, but it IS a variable beyond the configuration the military tested.

 

Ti is very good for high heat areas as you state, but coefficients of expansion must Play Well together. Remember the days of iron blocks and aluminum heads?

 

Again, not saying the tube caused it, just saying it's a variable in play, and at the reduced length of the 5 shot tube , it's not worth messing with, as you state, imo

Share this post


Link to post
Share on other sites

Some very interesting thoughts being proposed. Did similar metals do have different thermal expansion rates.

I really cant get my head around how a Ti tube could dramatically distort the barrel.

Share this post


Link to post
Share on other sites

Seems like a good test. Order a titanium 5 round and leave the install loose so you can swap them. Assess if the tube influences the POA/POI. If no influence, keep the titanium. If it does, sell it for a profit. Win/Win.

Share this post


Link to post
Share on other sites
Some very interesting thoughts being proposed. Did similar metals do have different thermal expansion rates.

I really cant get my head around how a Ti tube could dramatically distort the barrel.

 

I am not saying it did. I do know that after 6 rounds , I had a 12moa shift to 6 o clock. This went away once the weapon cooled...or immediately , if I loosened and retightened the retaining cap, which was tighter than originally, indicating that the barrel had elongated and tension was being applied to the barrel hanger in greater amount.

 

Would the steel mag tube grow at the same rate as the barrel? Doubtful. It doesn't get as hot as fast. Still a curious test.

Share this post


Link to post
Share on other sites
You happen to try a different barrel?

 

You still have the rig?

 

I did not. I will see what this SBS does. I am curious if anyone else would care to replicate my test with THEIR M1014/M4.

 

It's easy enough, get 6 targets, place at 25 yards. You should be able to place a slug within 1/2" of POA at this distance on demand from the prong over a bag. Shoot all 6 bulls rapidly, see where shot #6 ends up... They make a "6 bull" target and sell it at most stores. If not, I am sure it could be improved, fire 1 round on target, 5 into the dirt, 1 round on target, see where the two are in relation, etc.

Share this post


Link to post
Share on other sites
I am not saying it did. I do know that after 6 rounds , I had a 12moa shift to 6 o clock. This went away once the weapon cooled...or immediately , if I loosened and retightened the retaining cap, which was tighter than originally, indicating that the barrel had elongated and tension was being applied to the barrel hanger in greater amount.

 

Would the steel mag tube grow at the same rate as the barrel? Doubtful. It doesn't get as hot as fast. Still a curious test.

 

Im not doubting your thoughts on this. I am simply interested in this. Had never thought a mag tube would be a variable.

Your thoughts on this are VERY eye opening.

 

The barrel is expanding due to the heat. The titanium is less effected by heat, if the tube is a variable, this is it.

Edited by M2_shootr

Share this post


Link to post
Share on other sites

There was another data point to consider in this. Iron sights vs. receiver mounted optics. If I recall, the shift was less pronounced with iron sights since the front sight shifted with the barrel.

Share this post


Link to post
Share on other sites
Earlier you were absolutely saying it was because of a titanium magazine tube. Being an aircraft mechanic, there are very good reasons aircraft engineers use titanium in high heat areas due to it's resistance to extreme heat. So six shots will cause enough heat in the magazine tube to cause it expand enough to excuse a 12 MOA shift? I get it, you're no longer claiming that, but that is the most ridiculous thing I've found on the internet this week. Not trying to hijack your thread. Good luck with your accuracy issues, I hope you get that sorted out. I'm done here.

 

Hallelujah - Trying to excuse an MOA shift on the magazine tube WTF? The M4 is a tactical shotgun it is not a race car as has been alluded to numerous times here! Go tune your cars and shoot your guns.

Share this post


Link to post
Share on other sites
Hallelujah - Trying to excuse an MOA shift on the magazine tube WTF? The M4 is a tactical shotgun it is not a race car as has been alluded to numerous times here! Go tune your cars and shoot your guns.

 

Agreed. 100%.

Share this post


Link to post
Share on other sites
There was another data point to consider in this. Iron sights vs. receiver mounted optics. If I recall, the shift was less pronounced with iron sights since the front sight shifted with the barrel.

 

 

You're on to something there...

Share this post


Link to post
Share on other sites
My money is on the ammo causing the huge POI shift.

But only when hot , and immediately corrected by loosening and retightening the mag cap?

Share this post


Link to post
Share on other sites
There was another data point to consider in this. Iron sights vs. receiver mounted optics. If I recall, the shift was less pronounced with iron sights since the front sight shifted with the barrel.

 

Correct. With irons in got zero difference in poi shift. With the receiver mounted optic, I got the shift. This furthers my opinion that barrel expansion is the cause, as if the barrel moved, the FS moved with it , compensating aim for the movement.

Share this post


Link to post
Share on other sites
Hallelujah - Trying to excuse an MOA shift on the magazine tube WTF? The M4 is a tactical shotgun it is not a race car as has been alluded to numerous times here! Go tune your cars and shoot your guns.

A 12 moa shift kinda matters...

1moa? Whatever, but 3 to 4 inches at 25m?

Share this post


Link to post
Share on other sites
Correct. With irons in got zero difference in poi shift. With the receiver mounted optic, I got the shift. This furthers my opinion that barrel expansion is the cause, as if the barrel moved, the FS moved with it , compensating aim for the movement.

 

Probably that EOtech heating up...

Share this post


Link to post
Share on other sites
You're on to something there...

 

By the very fact that something is hanging off of the M4 barrel (Magazine Tube, Forward Stock) and it is not free floating throws all these theories out the window! Every time you bench rest or hold the M4 while shooting you are potentially changing the MOA. The M4 is one BadAss shotgun, accurate as He11 but it is not a precision rifle PERIOD!

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...