What happens if Barrel Index is off?

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Gasanwu

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Noob question here... Just got my hands on a M14s, this is my first "battle rifle".

So I've been reading about M14s here, but still don't get what happens when indexing is off besides the front sight being misaligned.

If I need to get it fixed, what's a good place in the Lower Mainland to get it done?
 
West Coast CLinic

The best way to fix and learn about the m-14 is to come to one of 45APCKing's clinic's. I don't thing there is going to be another one until Nov or Dec.

The reason you want is indexed is to make sure that the Op-rod is not binding in the guide. Everything strait= smooth cycling. Another thing you want to do is to shim the gas system to ensure that it will cycle the action properly.
 
Poor barrel indexing is observed from time to time. Don't assume that a M305 will automatically have the problem, though.
To correct it, you will need a barrel vice, an action wrench, and a means of checking for index. Hungry uses straightedges, I use a machinist's level, don't know what 45ACPKing uses.
Getting the stupid lockscrew out of the receiver can be the biggest pain in the whole operation.
 
Well I'm pretty sure the barrel indexing is off as the front side leans left. as does the barrel shroud... So how do you get that PITA lockscrew out?
 
Motorcycle mechanics have a tool called an IMPACT DRIVER ... basically a bir screwdriver that takes interchangeable bits.

First, you grind down a slot screw driver bit to fit exactly that PITA screw, then you [place the bit into the driver and into the screw, and then you tap the driver with a hammer. This turns the bit AND jolts the screw at the same time.

The last one I did actually came out by hand, with no effort at all ... but the one before it ... that was FUGLY!!! required a vice, a drill press, a carbide bit to DRILL the @#$$%^&^ thing out.
Good luck!
LAZ 1
 
If you examine the set screw, you may see that the receiver metal has been upset into the slot, to keep the screw from turning. I use a tiny cold chisel to tap the metal back from the slot.
I have yet to find an easy one, and a couple have been pigs, requiring the drilling technique.
 
Is it over torqued or under torqued.. might wanna watch that and make sure that your head space is ok...

Mine came over torqued by about 1 degree and I cant index it back or I lose my head space. Gonna bore out the splines on the flash hider and reset it and then silver solder it.. at least that's the idea...
 
Barrel shank threads are 10 t.p.i. One degree of rotation would result in 1/360 times 0.1000" of headspace change. That is less than 3 ten thousandths of an inch. Ten degrees of rotation would change headspace by less than three thousandths. Essentially, there is no headspace issue when an indexing problem is corrected.
 
My sight is leaning to the left, so i guess that would make it over torqued... I took a look at the screw... it's in there pretty good. If I do manage to get it off, and index the barrel.

Would it become loose if I have to unscrew it like 10 degrees?
 
i'm no expert but correct me if i'm wrong:
the gas tube assembly is cast poorly and the front sights are not true/level.
if you look at the sight you'll see what i mean.
to take out a dificult screw you can also use a device called a "woodpecker".it's a screwdriver bit connected to an impact/rivet(aerospace) gun with a handle welded (or threaded) to the side.a little bit of "valve grinding compound" on the screwdriver bit would help.using MINIMUM power/pressure i'm sure a screw would come right out.the valve grinding compound works wonders on stripped/oily/damaged screws.
 
And before we changed that barrel I shot the gun for a whole year without worrying about the fact that it was indexed to far to the left. :D
 
Gasanwu said:
My sight is leaning to the left, so i guess that would make it over torqued... I took a look at the screw... it's in there pretty good. If I do manage to get it off, and index the barrel.

Would it become loose if I have to unscrew it like 10 degrees?
Click to expand...

I have never seen a barrel over rotated by 10 degrees. That is a LOT. Generally if one has been overtightened, just back it off and pull it to index.

IF there was not sufficient torque when the barrel was brought to index, the standard remedy is to upset the barrel shoulder slightly. This can be done with a rolling tool, or with a light hammer. In extreme cases a breeching washer could be fitted.
 
tiriaq:

Thanks for the encouragement. That's exactly what I've done in the past. Other CGNutters have sent me their barreled actions (stripped of all the parts, including front sight) and I've re-indexed them inside 5 minutes and then returned them to the owners in less that 24 hours.

It's all good !! :D
 
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