m305 index is fine but my sight is not?

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Rob_man587

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iv been trying to keep myself informed about all the little things that can go wrong with my rifle, I.E index, gas tube shims and what not.
as for the index my rifle seems to be spot on, but i noticed that my flash hider is still crooked as well as my sight is hard to the left. if i purchase lets say a muzzle brake from armtec and a new iron sight, will this solve the problem or is the same thing going to occur?

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The splines on the barrel that the flash hider slides onto could be cut at a wrong index.

Does it shoot on target with the sight like that?

If so, you might have to get a muzzle device/sights that do not use the splines for index.
 
Rob_man587 said:
yes the whole front flash hider seems to be slightly to the left.
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In the 2nd pic you provided it looks to me like your barrel is over indexed (Tightened onto the receiver a bit too much). Try and get to one of Hungrys clinics as it can be easily fixed using a barrel vice and a couple straight edges. If you plan on just using optics on the rifle don't worry about it.
Hungry is coming here (Petawawa) to have a 2 day clinic with access to a 600 yard range Oct 19-20
 
chalkriver said:
In the 2nd pic you provided it looks to me like your barrel is over indexed (Tightened onto the receiver a bit too much). Try and get to one of Hungrys clinics as it can be easily fixed using a barrel vice and a couple straight edges. If you plan on just using optics on the rifle don't worry about it.
Hungry is coming here (Petawawa) to have a 2 day clinic with access to a 600 yard range Oct 19-20
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ok that sounds great, i live half hour from barrie so ill wait till he has another clinic there.
 
just so everyone knows this rifle is not new iv had it for 2 years and shoots great, but im trying to up grade it so its better, like usgi parts and what not. I just put a black feather stock on it and im waiting for my butt stock to come in. its gonna be a $1500- $2000 when its done so im trying to make it %100 worth every penny, this is why i want to know if i need to fix the index or if its just a messed barrel. (i hope not cause the black feather op rod guide doesn't fit the usgi barrel from what im aware of)
 
How is the op rod alignment with the gas cylinder?

So far it looks like the rifle may be slightly over indexed based on the feed ramp. Keep in mind that not all properly indexed barrels will have the feed ramps lined up. If the barrel splines are mis-timed with the feed ramps, you will need to rely on indexing using your gas cylinder and op rod alignment. If your sight is still off after all this is re-aligned, its also possible that your flash hider could be out of spec.

Here is a pic of one rifle from 2011 that had such an issue with the feed ramps being off from the splines. The barrel here was over indexed, but the feed ramps were perfectly centered on the back of the op rod spring guide. If your flash hider is properly to spec, this is one way you can check indexing.
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Wildcard91 said:
How is the op rod alignment with the gas cylinder?

So far it looks like the rifle may be slightly over indexed based on the feed ramp. Keep in mind that not all properly indexed barrels will have the feed ramps lined up. If the barrel splines are mis-timed with the feed ramps, you will need to rely on indexing using your gas cylinder and op rod alignment. If you sight is still off after all this is re-aligned, its also possible that your flash hider could be out of spec.
Click to expand...

how do i tell if the op rod guide is alined properly?
 
Rob_man587 said:
how do i tell if the op rod guide is alined properly?
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If you suspect that your flashhider is out of whack, barrel index can also be checked using the following methods. Otherwise, a leveling bar clamped to the front sight and another one behind the rear sight will help to determine indexing.

I'm sure others will chime in, as there are many methods to check this. Essentially, you are looking to see whether or not your gas cylinder is perpendicular to the axis of the barrel and stock "ie 6 O'clock position".

One method is to remove the piston, keeping the gas cylinder on the barrel. Turn the action up side down. Find a properly sized allen key, or straight wooden skewer and stick it into the gas port located on the gas cylinder. With a flashlight ensure that the allen key is making contact with the inside of the barrel and is centered properly with the barrel. Now observe the allen key/stick in relation to the rear lugs. If your rifle is not indexed properly, the centered allen key/stick will not be parallel with the rear lugs and will not be centered along the op rod when you look down the action from the muzzle.
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Its very rare that the feed-ramps/ op rod guides are mistimed from the cut of the flash hider and gas cylinder splines, but it does happen once in a blue moon on the norc's i've seen. If this is the case, you might also see a misalignment with your oprod guide and oprod with the gas cylinder. In this case a visual inspection of the contact between your piston and oprod will not be a straight line. These two contact points should be centered and not to the left or right. Here are photos of what it should look like. (Ignore the copious amounts of grease on the op rod)
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Needless to say, if you're shooting with a scoped optic, indexings is not really a big issue.

Based on your pics, I'd agree with the possibility that your barrel is most likely over indexed, and these methods might help to confirm that.
 
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My fav way of determining index is to have your M14 here in my workshop (where I have all the tools) or the upcoming 19-20 Oct 2013 Petawawa M14 clinic. :D

What I do is BEAT/Whack/Pound/Hammer off that Zhinese flash suppressor, understand that most if not all the Xhinese units are out of spec or out of whack. Then I slide on an M1A flash suppressor or a USGI if I happen to have one. Then I clamp the parallels on to see if things are out of index. :)

All kinds of other means are not always terribly reliable. :evil: Don't beat yourselves up over this issue. It's easily fixed by visiting me with a bottle of JLohr Cabernet! :cool:

No kidding! It's that simple! :dancingbanana:

We just did Odd Shot's rifle here tonight! Took only a couple of minutes. Even he is surprised! :pirate:

Cheers and keep helping the nooobs!

Barney
 
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