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  #1  
Old 02-03-2017, 09:00 AM
EricPope EricPope is offline
 
Join Date: Jan 2017
Posts: 6
Default Clarification, Service Rifle Rules

Hello,

What is the intent of the rule is that says the scope must be mounted to the receiver? Does that mean that both mounts, if you are using single rings, have to be mounted to the receiver? Or is one good, in my case the rear ring is on the receiver and the front one is on the forend.

I can see how the intent may have been to exclude long eye relief, forward mounted, scopes but what say the CMP?
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  #2  
Old 02-04-2017, 08:59 PM
park ranger park ranger is offline
 
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Save yourself lots of trouble and don't try to bridge received and handguards. Buy an extended riser.
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  #3  
Old 02-04-2017, 09:20 PM
Gewehr43 Gewehr43 is offline
 
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Location: Denver, CO
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"Save yourself lots of trouble.............. "

What trouble is there in having the mount across both?
I'm curious is all................
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  #4  
Old 02-04-2017, 11:38 PM
EricPope EricPope is offline
 
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yeah, I know. But I'm looking for the right height and the mounts i have are close. And it is working.
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  #5  
Old 02-04-2017, 11:41 PM
EricPope EricPope is offline
 
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Quote:
Originally Posted by Gewehr43 View Post
"Save yourself lots of trouble.............. "

What trouble is there in having the mount across both?
I'm curious is all................
The receiver is the chassis, if you will, so you could have problems bridging the forend especially if something is lose. However, I have been using it and I shoot master scores. I need to make better ammo before I change my scope mount.
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  #6  
Old 03-06-2017, 11:03 PM
AckAck AckAck is offline
 
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Location: Bloomington IL
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The problem that you are going to run into by bridging your receiver and hand guard is going to be flex. It wont be a lot of flex, but it will be enough to move your point of impact when slung up.
Of course its up to you what you do, but go to a major high-power match and look around at all the optic equipped rifles. You wont see many master or High Master shooters with optic mounts bridging the receiver and hand guard.
Its just a potential problem area that can be eliminated by a mount that only contacts the receiver.
But again, its America, you can do whatever you want.
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  #7  
Old 03-07-2017, 05:05 AM
Gewehr43 Gewehr43 is offline
 
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AA:

With your experience then, how much of difference is there being slung vs not?

So when you shot both was the shift consistant? or no?

I shoot SR and the reason you don't see shooters "bridging" is the rules don't allow it. So with SR shooters it's them following the rules, not that one is more or less accurate.

But that is why the OP and I'm asking...............

Here's my test rifle though;



And it shoots groups like this off a bench:



and this:



So it's accurate.
But is it the mount I have across the bridge that is removing the flex?
But as is, you think the flex would still be an issue if I shot with a sling and not off the bench?

What has been your experience?
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  #8  
Old 03-07-2017, 04:08 PM
AckAck AckAck is offline
 
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Location: Bloomington IL
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I guess I'm having a hard time finding in the rules where it specifically states that you cannot have a scope ring that is mounted on the rail. I just looked at the 2017 rules and cannot find that statement (or one like it).
I have not ever shot an AR with the scope mount "bridging" the receiver and hand guard. It was just common knowledge that this would not be the best practice. I would predict that there would be movement of the sights. Actually, there was a pretty long thread on the National Match Forum where guys were experimenting with this exam thing and detected movement. However, with the type of mount that you are using (having looked at the pictures), you may indeed be strengthening the receiver / hand guard connection by using the mount that you are.
Either way, it looks like you are shooting good groups. So, if it works......good deal.
Happy Shooting.
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  #9  
Old 03-07-2017, 07:35 PM
EricPope EricPope is offline
 
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Quote:
Originally Posted by AckAck View Post
The problem that you are going to run into by bridging your receiver and hand guard is going to be flex. It wont be a lot of flex, but it will be enough to move your point of impact when slung up.
Of course its up to you what you do, but go to a major high-power match and look around at all the optic equipped rifles. You wont see many master or High Master shooters with optic mounts bridging the receiver and hand guard.
Its just a potential problem area that can be eliminated by a mount that only contacts the receiver.
But again, its America, you can do whatever you want.
Ok so flex is the problem. I wonder how much the point of impact changes in MOA. I am a Master Shooter and there must have been flex in my A2, between the barrel and receiver. No? I see twisting the scope would do weird things but I have a problem believing its much. From my point of view, this game has so many variables that I always only hope for MOA rifle, ammo, position etc.. But maybe that's why Im a Master and not High Master.

Thanks for the commentary, and FYI I bought the cantilever mount do maybe I will hit HM after all.
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  #10  
Old 03-07-2017, 09:11 PM
AckAck AckAck is offline
 
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Location: Bloomington IL
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Actually, if you were running a free-float tube handguard (like a Rock River, White Oak or Compass Lake) on your A2, there would have not been any flex. The sling mounts to the handguard (float-tube) and the sights are attached to the barrel.
In the old days (before free-float hand guards), the sling was attached to the barrel. Therefore, when the shooter shot with a sling, the sling tension would put stress on the barrel and cause shots to go off call. The free-float tubes provide a solid mount for the sling to be attached to, independent from the barrel.
Good choice on the cantilever mount!
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