[Audix99]

Hi all,

I bought this WASR-10 a couple of month ago. During the first range trip right out of box, it shot in average 3" 100 yards group (5-shot string), which made me grin ear to ear.
I fired 100 rounds of Golden Tiger ammo and the 3" group was the norm on that day.

But then I noticed that the gas piston was binding a little right before the bolt went into full battery (around the last 1/2").
So I decided to "fix" it, and got rid of the binding by bending the piston rod downward just a little and filed the angled, flat area (don't know what to call this area) on the gas tube where it was pressed down by the gas tube lock lever little bit to ease the gas tube locking tension.

As a result, the binding is 100% gone and the bolt moves to the fully locked position very very smoothly.

But now comes a new problem...
The same rifle that used to print 3" group before the "fix" now does 5" - 6" group with the same ammo after the fix at the same distance.

What the heck happened?
Does bending the piston rod downward and/or filing that area on gas tube affect accuracy of a rifle that much?

What did I mess up???

Your input will be highly valued!!!

Thanks guys!!!

Steve...

 

[303hunter]

shouldn't affect it....clean the bore?

 

[Audix99]

Thanks 303hunter.
But I do clean my gun, including the bore, after every range session.
I'm positive dirty bore is not the issue, I think...

 

[dglockster]

Maybe you some how canted the front sight block. Go here for more info: http://www.gunsnet.net/Linx310/fsbcantfix.htm

 

[LeibstandarteAdH]

What the heck happened?
Does bending the piston rod downward and/or filing that area on gas tube affect accuracy of a rifle that much?

No, never really should. something else is at work

 

[Audix99]

Thanks guys for your input.
I thought of the front sight block. But it is as straight as it can be...
Maybe I somehow damaged the muzzle crown during cleaning?
The crown does seem okay from visual inspection, though...

Another thing I did when I fixed the binding was to replace the lower handguard to a Romy guard with vertical foregrip.
The guard was stiffer to put in than the original guard.
Then I went to the range the second time and noticed the degraded accuracy.

I thought that the stiffer handguard was putting undue pressure to the barrel and hurt the accuracy.
So I put the original guard back. But the accuracy still is not what it used to be...

Man, this is driving me NUTS!!!

 

[LANT]

Bad accuracy

I have found that REMOVING the CLEANING ROD improved the accuracy of my AK by 40% or more. HTH

 

[jjk308 In Memoriam RIP]

Maybe you loosened up the gas tube/barrel/receiver connection, letting the assembly vibrate erratically? Or tightened it too much?

Not too much work has been done on AK accuracy because it's usually not real good but I'd take a look at other autoloaders and see what's been done on accurizing besides the usual heavy barrel/crown/tight chamber stuff.

The Ruger Mini-14 usually has accuracy issues - Gas block attachment is one area that affects it.

Here's links to mini-14 accuracy posts

http://outlands.tripod.com/armory/mini-14.htm

http://www.perfectunion.com/vb/archive/index.php/f-106.html

Another thought: The drag on the piston before it hit full stroke could have stabilized the recoil and dampened the vibration it induced. Maybe you could find a slightly larger piston or smaller gas tube?

 

[El Karang]

clean the gas tube and gas port-you may need to ream the gas port if it is crusty.

 

[Audix99]

Thanks for all your replies!

El Karang: As I mentioned, I do clean my guns after every range session. The gas tube and port (with a Q-tip) do get cleaned in process, and they are clean. So I can't say that's an issue here...

jjk308: That may be a possibility. I may have loosened up the gas tube/barrel/receiver connection when I filed a portion of the gas tube. Although I filed very little, the process could've messed up the "sweet spot." But then, can that have that much of impact on accuracy? I'm not sure. But it certainly is possible. I will play with this idea by placing a shim between the gas tube and the locking lever to see if accuracy improves.

LANT: I think you might be onto something here.
The very first, initial cleaning was done at the range on a shooting bench immediately after the purchase. I hauled all my cleaning gears with me to the range right after the purchase and spent about an hour at the range to clean the rifle inside and out. Then once I finished cleaning the rifle, I fired 100 rounds and got around 2-3" groupings throughout the remaining range sesion.

BUT, it was possible that during the reassembly after the cleaning, I may have forgotten to put the cleaning rod back in and proceeded to firing, which produced really good groupings for an AK.
(I, time to time, do forget to put the cleaning rod back in after cleaning my M-N 91/30 and Yugo SKS)

Since the first range trip with this AK was about 2 months ago, I can't recall if I fired it with or without the cleaning rod in place. But I will definitely try it without the cleaning rod when I go to the range next time, in about 2 weeks...

Also, your 40% gain in accuracy without the rod is about the same amount of accuracy I lost (from 3" to 5").
Hopefully, this is the issue. If it is, then it will be a real easy problem to solve!

Thanks again, guys!!!

Steve...

 

[spacegun]

The M-1 Garand and the M-14/M-1A acheive some of their accuracy by virtue of downward pressure on the barrel applied at the tip of the stock. A barrel tends to vibrate like a tuning fork when fired, and the downward pressure in the middle of the barrel dampens the vibrations. You just removed the pressure on your barrel so it is now free to have the muzzle vibrate up and down...back and forth, etc. If the muzzle is at the far left of it's arc when the projectile leaves the barrel...the shot goes left on the target. Muzzle to the right of its arc and the round moves right on the paper. The vibration is only a 100ths of an inch (like a tuning fork), but the effect is magnified 100 yards down range as your group opens up. Most bolt guns with light barrels will also group better if bedded in such a way as to free float the barrel except for the last inch where the stock can apply upward pressure to prevent the harmonics and vibrations from throwing the shot. You just undid that "dampening" effect on your barrel, I expect....and now the barrel can 'vibrate' freely.

 

[Larithknight]

Check to See if there is still big Groves and Lands, and a crome lined bore. I blew the crome lineing and bore out of a Romy -10. Still shoots but not like my bulgy ak -74's.
My groves look like small lines now.

 

[jjk308 In Memoriam RIP]

The M-1 Garand and the M-14/M-1A acheive some of their accuracy by virtue of downward pressure on the barrel applied at the tip of the stock. A barrel tends to vibrate like a tuning fork when fired, and the downward pressure in the middle of the barrel dampens the vibrations. You just removed the pressure on your barrel so it is now free to have the muzzle vibrate up and down...back and forth, etc.

Actually free floating a barrel will give more consistent accuracy than the upward pressure - - assuming nothing else interfers. Usually the barrel heats and expands at a different rate than whatever's applying pressure - the stock on bolt actions - and with different temperatures the pressure on the barrel and barrel vibrations change, changing the point of impact. It's going to vibrate enough to affect accuracy anyway, unless you've got an ultra thick barrel, and you want the vibration to be consistent.

However gas operated autoloaders have a gas block, tube, piston, rod, handguard, etc... hanging off the barrel too, making it more complicated, Usually the solution is to stake everything in place to get it as consistent as possible, and hope the POI doesn't "walk" too much as it heats up.

I suspect that in this case the work done and the disassembly/assembly has the whole forward part and gas piston assembly too loose and vibrating irregularly.