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1/27/2021 11:01:57 PM
1/27/2021 12:46:26 AM
Posted: 3/10/2005 5:07:40 AM EST
I have an ARMS 40 Backup sight, the older larger version, maybe a 2 years old.  Anyway, I used it for the first time and I was having poor results out of a new gun.

It had an LMT M4 Upper and was group 2 inches or so at 25 yards.  Only got worse farther out as expected.

Anyway, when the sight is deployed.  There is a significant amount of twist of the sight arm.  Its not huge, but significant by sight standards since a little movement can go a long way.  Is this normal or heard of before?
Link Posted: 3/10/2005 6:09:40 AM EST
Mine are solid when deployed, so it sounds like a problem.
Link Posted: 3/10/2005 10:33:28 AM EST
Mine is also a rock when put down or up.  No play whatsoever, solid as hell.  
Link Posted: 3/10/2005 11:16:50 AM EST

Quoted:
Mine is also a rock when put down or up.  No play whatsoever, solid as hell.  


+1
Link Posted: 3/10/2005 9:58:58 PM EST
huh, so with sight deployed you cannot twist it back and forth in a clockwise-counterclockwise motion?

I was using XM193.  I have used it with no issues in a 20" barrel.  Could the shorter M4 barrel give me issues?

I am going to try to get back out this weekend with more ammo choices and an eotech to throw on top to isolate this issue.
Link Posted: 3/11/2005 3:35:12 AM EST
In other words, if you are looking down at your rifle from the top with the sight deployed you can actually twist the sight aperture?

Forgive me, I'm trying to visualize what you are doing in an effort to duplicate the problem
Link Posted: 3/11/2005 5:19:48 AM EST
not just the aperature, but the entire arm that can swing up and down.  When deployed in the upright position, it can be twisted back and forth.  Maybe a millimeter to a millimeter and a half tops.

Not so much side to side as it can be slightly rotated back and forth.
Link Posted: 3/11/2005 5:37:46 AM EST

Quoted:
huh, so with sight deployed you cannot twist it back and forth in a clockwise-counterclockwise motion?


Nope.
Link Posted: 3/14/2005 8:49:52 PM EST
maybe the barrel just needed to be broken in.  Went to the range yesterday with an EO Tech and the groups were the same as before.  After a couple of mags, the bullets starting grouping really nice at an inch easy for XM193 and IMI .223 at 50 yards.

Some heavier grain stuff was maybe 3/4 of an inch, same distance.  Didn't try the iron sights again since I ran out of time, the direction they move is rotational so its probably not a big accuracy impact.
Link Posted: 3/15/2005 3:56:16 AM EST

Quoted:
not just the aperature, but the entire arm that can swing up and down. .



The entire arm should be able to swing up and down.  The spring holds it upright an in position.  Should you drop the rifle it allows the sight to fold up rather than snap off.  Note when you pick the rifle up it will go back into position.

Never been able to 'rotate' mine though....
Link Posted: 3/15/2005 4:13:55 AM EST
duuuuhhhh....
Link Posted: 3/15/2005 4:24:12 AM EST
Ya I thought mine was bad too but then I realized I was an idiot and didnt have the mount on correct.  Contact ARMS
Link Posted: 3/17/2005 10:49:21 PM EST
yeah...  my FN 1/7 barrel was good to go from the first round...  This is actually the first time I have seen such a break in difference...
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