Gents- Ive recently acquired a FAL built on a DSA receiver and Brazilian parts kit. The gun is shooting WAY to the right. I have the rear site (Para style with ears) MAXED out to get it on paper at 50 yards. Ive looked the sights over 1000 times and nothing looks crooked. Ive tried using strings and levels and a build alignment guide, and everything APPEARS normal. Seeing how you cant just put a straight edge on it, Im assuming Im left to trying a bbl straightness gauge...??? Does anyone have any WESCOG tricks that can help me diagnose or make a tool from common items?
How to detect a bent barrel on a FAL?
ScottD
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Gents- Ive recently acquired a FAL built on a DSA receiver and Brazilian parts kit. The gun is shooting WAY to the right. I have the rear site (Para style with ears) MAXED out to get it on paper at 50 yards. Ive looked the sights over 1000 times and nothing looks crooked. Ive tried using strings and levels and a build alignment guide, and everything APPEARS normal. Seeing how you cant just put a straight edge on it, Im assuming Im left to trying a bbl straightness gauge...??? Does anyone have any WESCOG tricks that can help me diagnose or make a tool from common items?
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Strip the gun down to just the receiver and barrel parts ( no gas assembly so the hand guard ring can get out of the way) On a flat surface clamp the assembly down with the big flat side of the receiver down (will have to move the hand guard ring to the middle of the barrel)
The center line of the bore should be parrallel to your flat surface. This method will show a bent barrel or a cross threaded barrel
The center line of the bore should be parrallel to your flat surface. This method will show a bent barrel or a cross threaded barrel
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90% of the time this problem is caused by an improperly indexed barrel. 5% of the time it's a non-concentric Argentine barrel that's been cut to 18". 5% of the time something else.
To check the first: remove handguards. Look at the barrel/ receiver mating spot, TDC. The scallop on the barrel should be perfectly aligned under the threaded hole. The one below is not, it's an extreme example. 1 degree off equals about 2" off target.
![106181]( "106181")
If your barrel is standard 21" it's not going to have the Argentine issue.
Best way to check sights is with a straight rod set specific to the FAL; one screws into front sight, one slides into the receiver channel. You can drive over and use mine.
To check the first: remove handguards. Look at the barrel/ receiver mating spot, TDC. The scallop on the barrel should be perfectly aligned under the threaded hole. The one below is not, it's an extreme example. 1 degree off equals about 2" off target.
If your barrel is standard 21" it's not going to have the Argentine issue.
Best way to check sights is with a straight rod set specific to the FAL; one screws into front sight, one slides into the receiver channel. You can drive over and use mine.
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Funny I just did this on an FN49...It was over clocking.. I had to add a couple of shims to get the sight strait ..I made the shims out a piece of sheet metal...I used the gas piston / rod as a way to a align the barrel with the receiver ...If the barrel was a little to the left or right the piston / rod would bind...Once I found the sweet spot where the rod would move freely , I staked the barrel in placed.
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Been there.
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It sure looks a hair over clocked, need to use rods, clamp barrel with rod vertical check with level then check level on rod on receive. Arizona response has a great book for building and all the checks to do and gun things.com has tools.My old eyes keep playing tricks on me. The sights look perfect, the FAL specific alignment rods look good. From one angle it looks correct, from another it looks over clocked. What do you guys think?
![Image]()
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Even with the rods in, I, unable to see a vertical cant. Maybe I need to look again and pay more attention. But when viewed from above, it looks perfect, and viewed from an angle at either side, it looks cocked in to opposite direction. My effin eyes are going bad, I swear.
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190 Posts
Definitely looks little more in the center, give me a shout if still running into issue.Tweaked it. (I think.) Does this look better?
![Image]()
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2,425 Posts
It doesnt take much to over time an FAL. It took me a few tries to get mine aligned. Yours looks better now.
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12,249 Posts
Looks better Scott but try it and see if it is hitting better. If you run into troubles let me know I will run up.
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4,144 Posts
I took the gun out today, it was still hitting far right. It was a miserable, 45 degree rainy day today, so I only played at 50 yards. First 3 shots were on the very right of the target. I gave the gun quite a bit of windage and eventually manged to shoot one ragged hole at 50 yards. I was actually impressed how well it was shooting (30 rounds all within a 2 inch group, no stringers or flyers at all)
However Im very concerned whats going to happen when I walk it out to 100 yards. I chose to use a combination of moving the sight base and the windage screw. (I didnt want the rear site totally buried to the left)
This is the current windage: (Im no stranger to building guns, I know FAL's fairly well....but this still seems a bit excessive to me)- but still, at 50 yards I can comfortably shoot the center of the target out....
I guess I wont know until I can shoot it at 100 yards and see if this is the sweet spot.
![Image]()
However Im very concerned whats going to happen when I walk it out to 100 yards. I chose to use a combination of moving the sight base and the windage screw. (I didnt want the rear site totally buried to the left)
This is the current windage: (Im no stranger to building guns, I know FAL's fairly well....but this still seems a bit excessive to me)- but still, at 50 yards I can comfortably shoot the center of the target out....
I guess I wont know until I can shoot it at 100 yards and see if this is the sweet spot.
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Im pretty sure I bought the sight from DSA. I took a few liberties with my 'clone' and I wanted a better rear sight. Installing to original sight to verify never even crossed my mind.
Hopefully Ill get to take it out again soon and take it too 100 meters, because lets be honest, Ill never shoot it past that. Its good to hear that you think its still within tolerable limits though.
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190 Posts
I see you have the receiver wrench so must have other stuff, I have a new set of level rods and some digital box angle levels if you need to borrow let me know, and have Mark’s book and DVD’s. still new as got to many irons in the fire, plus new 1919 that followed me home going to post on for some info.Im pretty sure I bought the sight from DSA. I took a few liberties with my 'clone' and I wanted a better rear sight. Installing to original sight to verify never even crossed my mind.
Hopefully Ill get to take it out again soon and take it too 100 meters, because lets be honest, Ill never shoot it past that. Its good to hear that you think its still within tolerable limits though.
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Badger, I sent you a text.
I didnt even know a digital level was a thing. 😃 Jeebus I feel old sometimes. This isnt my first build, I feel like I know what major errors I should be looking for but I just cant see anything obvious. Like I said, I shot the center out of a target today, so I know the gun is capable, I just need to see if 1) there really is a problem (As Abominog said, its within tolerable specs) and 2, if something IS wrong..is it something I can diagnose and fix. FAL's seem to be like M1 Garands...anybody can build one, but it takes experience to troubleshoot them.
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Scott if I come up your way I have a straigtness of bore gauge that will tell us what we need to know. It is a very hard to find tool and most guys will never see one let alone know they exist but they are quirt handy for things like this and yes I know I am a tool geek. From what you have posted it does sound like it is slightly bent but inspecting it is the only way I can tell for sure.
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