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2/25/2010 12:34:03 AM EDT
Planning on picking up a used acog soon and today I had a thought...  If I had both an acog and a different scope (3-9x or something) both in quality QD mounts, could I reliably switch between them at the range and expect them to hold zero?  I'd like to run the acog mostly but toss on the scope when i want to shoot small objects far away...
2/25/2010 4:37:50 AM EDT
[#1]
If you use LaRue mounts, then yes.
2/25/2010 4:53:35 AM EDT
[#2]
Quoted:
Planning on picking up a used acog soon and today I had a thought...  If I had both an acog and a different scope (3-9x or something) both in quality QD mounts, could I reliably switch between them at the range and expect them to hold zero?  I'd like to run the acog mostly but toss on the scope when i want to shoot small objects far away...


Yes this is a good thing.  My brother has the same concept going on his rifle.  He uses an Aimpoint CompM4s as his standard optic.  He also has a scope that he uses on the same gun.  He has them both mounted in quality mounts that maintain zero.  (we use Larue)  He is able to switch back and forth with no loss of zero.
2/25/2010 5:13:13 AM EDT
[#3]
Several of my platforms have multiple optics, and I swap them on a regular basis.  When uisng a quality QD mount, the POI shift will typically be less than most ammo is capable of.
2/25/2010 5:46:38 AM EDT
[#4]
Quoted:
Several of my platforms have multiple optics, and I swap them on a regular basis.  When uisng a quality QD mount, the POI shift will typically be less than most ammo is capable of.


That's been my experience as well.
However, you do have to be careful what rail spot you occupy on some uppers/rail combinations. Others, it doesn't seem to matter so much.

For instance, when using the "hump" on my KAC RAS II, certainly a more extreem example due to the shotness of the elevated rail, one slot forward or backward can give a 2-3 MOA shift with some RDS, depending on the mount!
But if re-mounting to the same spot, no POI shift detectable even between 20 round precision slow fire groups.

Thought about markings or something, or maybe a "witness" mark on the receiver/mount interface.
Anybody do anything like that?


2/25/2010 6:28:09 AM EDT
[#5]
I dedicate each optic to an complete upper - also helps with the intended use - my SBRs use a reddot or Triji 1.5, my 18" uses a NF scope, etc.

No worries about zero shift, just pull the pins and go.
2/25/2010 4:19:29 PM EDT
[#6]
Quoted:
Quoted:
Several of my platforms have multiple optics, and I swap them on a regular basis.  When uisng a quality QD mount, the POI shift will typically be less than most ammo is capable of.


That's been my experience as well.
However, you do have to be careful what rail spot you occupy on some uppers/rail combinations. Others, it doesn't seem to matter so much.

For instance, when using the "hump" on my KAC RAS II, certainly a more extreem example due to the shotness of the elevated rail, one slot forward or backward can give a 2-3 MOA shift with some RDS, depending on the mount!
But if re-mounting to the same spot, no POI shift detectable even between 20 round precision slow fire groups.

Thought about markings or something, or maybe a "witness" mark on the receiver/mount interface.
Anybody do anything like that?




Agree that maintaining the same rail slot is important to consistency.  Even for the one system that I run three different optics on, it isn't too hard to remember where they each go.  The harder part is remembering the W&E offsets when swapping the 740 between multiple platforms or suppressor POI offsets, but that is what writing stuff down is for.

2/25/2010 7:39:46 PM EDT
[#7]
I'll shoot between ACOG (LaRue mount) and BUIS periodically with negligible effects.
I also remove the optic while cleaning the upper. Just remember which optic goes where.....
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