2009 Polytech flash hider or barrel indexing?

98%Brent

98%Brent

Regular
EE Expired
Rating - 0%
0   0   0
Location
Heehaw
I have a 2009 Polytech and my front sight is canted to the left ~5* and see the operating rod is not lining up with the gas cylinder. Too me this looks like it would be correct if the barrel was lined up or indexed right. Initally I had though the flash hider might have been installed incorrectly but the op rod to gas cylinder is cocked about the same amount as the sight which is leading me to believe this is a worst case scenario.

Can I get some of your opinions on what my my alternatives might be to remedy this situation? I'm not sure when the doctor is coming to Winnipeg but I doubt anyone would do this type of work locally. My intention is never to scope the rifle so iron sights that function is important.

Pablo_455
DSC07341.jpg

DSC07326.jpg

Pablo_455

Pablo_455
DSC07343.jpg


Thanks for having a look!

Brent
 
Looks to me that the flashider itself is the issue , the top of the flashider should have an open section at the top center under the screw . It looks to me in your 1st pic that the flash hider itself has the base of the sight milled offset at an angle.



IMG_1861a.jpg


Spcamno has a replacement Springfield brake for sale on the E.E , I have a couple of them on mine.

And is the op rod guide itself loose (move from side to side at all ) ???.....thats the piece that goes around the barrell , as that will throw off the alignment of the gas cylinder as well .
 
Last edited:
Chalk, now that I see your picture I see that my set screw in the flash hider is off as relative to the open section. The op rod guide was tight but was able to persuade it over with the end of a soft screwdriver handle. Now the operating rod is perfectly lined up. My thinking was it might indicate an error in barrel to receiver index but it is straight now.

What can I do to fix the front sight and will leaving it the way it is effect accuracy? I reversed the front sight and that took out most of the left leaning angle but can now tell for sure the flash hider is installed off center.

Thanks
 
You can get a new USGI spec flash hider from keepshooting.com for $25.00 out of the USA, and it's only $27.50 to ship it! I got mine and it's pretty ###y, or foxy I should say

funny-gif-fox-jumping-snow.gif
 
chalkriver said:
Looks to me that the flashider itself is the issue , the top of the flashider should have an open section at the top center under the screw . It looks to me in your 1st pic that the flash hider itself has the base of the sight milled offset at an angle.
Click to expand...
Have to dis-agree with this statement. As yes the flash hidder is garbage but there are 2 other factor's at play here and they are...
  1. The gas system doesn't line up with the op-rod shown on the 2nd to last pic.
  2. The off angle gas vaule on the last pic.
 
I think the only way to know for sure is to check whether or not your feed ramps line up with the center of the op rod spring guide's rear notch. I thought I had a barrel indexing problem and it just turned out that my barrel did not have the slines cut at the correct angle. Subsequently no amount of twisting of the barrel would line up the feed ramps and the sights.
 
I took some pictures of the feed ramp and the op rod guide is a little loose as it went back into out of adjustment with a few taps with the hand.


feed ramp
DSC07358.jpg


op spring guide
DSC07366.jpg


top view (black shadow under barrel is the gas cylinder not shadow)
DSC07367.jpg
 
Thanks Chalkriver, Wildcard91, Satain, Rocket Surgery, and Hungry for posting your comments! You're all a bunch of stand up guys and really do appreciate your advice. I will also be sure to pass this along down the line, that you can count on.


Just for others searching through the forum, could you just use the feed ramps to determine correct barrel indexing?
 
Last edited:
After looking at your feedramp, it seems to confirm that your barrel needs to be indexed. This will probably end up aligning your op rod as well.
 
You must log in or register to reply here.
Back
Top Bottom