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View Full Version : Walking Zero (Imbel on Imbel, IAI build M444)


JohnKSa
December 30, 2008, 02:15
I've got an Imbel parts kit built on an Imbel (Pacific Arms import) receiver. The assembly company was IAI who is no longer in business as nearly as I can tell. These guns were sold marked M444 if that means anything to anyone.

The gun functions perfectly and I can find no issues with the assembly, however the gun has a "walking zero".

Basically, the longer I shoot it (hotter the barrel gets) the farther the zero walks from the point of aim. At 100 yards the point of impact will slowly move down & to the left by around 2 feet in the course of shooting a couple of mags through the gun.

Is there anything besides the barrel that could cause this problem?

Right Side Up
December 30, 2008, 02:42
Kind of sounds like the barrel is moving under heat. Some barrels have stresses in them that cause this. A barrel that has been *straightened* will often do this.

brownknees
December 30, 2008, 10:35
Check the attachment of the handguards at both ends.
It's supposed to be "floppy" to a small extent. If it's tight on the rear ring & gas block as the barrel heats up it will add pressure to the barrel.
Try deliberatel making it loose by a couple of turns backing off the gasblock securing nut & see if that helps.

JohnKSa
December 30, 2008, 12:16
The handguards are very tight. Next time I get a chance I'll try shooting the rifle without the guards in place to eliminate that variable.

fastfreddy
December 30, 2008, 20:08
I was going to mention the handguards also.

If you get a chance, let us know how it turns out.

BTW, the M444 is a fine FAL.

George4
December 30, 2008, 22:39
Roger M 444 being good, they were assembled in Texas. If you need to know company name, no idea if they still exist. PM me.

Andy the Aussie
December 30, 2008, 22:52
My home rolled SLR had a mismatched set of Brit/Kiwi handguards that caused a VERY tight fit when mount (get our bloody minds out of the gutter of Pete sake), as a result I had what could be politely termed "a wandering zero" shot it without and it was fine.

Hope that helps.

Andy

JohnKSa
December 31, 2008, 01:07
Thought I should mention that the handguards on the rifle are NOT the ones that were on it when it came from IAI. I replaced them with some aftermarket US made handguards because the originals were a bit dinged up.

Sounds like I may have caused the problem...

I'll try it with the originals first and then without handguards at all if there's still an issue with the original handguards installed.

Thanks for the replies, I'll post an update when I finally get it to the range again.