Timing Barrel ( two rods discussion )

[Light Fal]

Question for gunsmiths. Will this work? place barrel in visce and put torpedo level on front site and level it. Then install barrel and level the reciever also. Then check to be sure that they are both level at the same time. Would this method work? Thanks

[ September 09, 2001: Message edited by: gary.jeter ]

[stimpsonjcat]

Sounds good to me.
Just be sure to check both levels often when trying to time.

peace!

[rMac71]

I use laser boresighter, just align rear sight and front sight to laser at 25 feet. So far, this has been a good method for me.

[Dirtfarmer]

Originally posted by rMac71:
I use laser boresighter, just align rear sight and front sight to laser at 25 feet. So far, this has been a good method for me.
..ooohhhh!... gotta like that.
Good one,
Goodwill,
-Dirtfarmer

[W.E.G.]

Another very effective, simple method is the "two rods method" at http://www.fnfal.com/forums/Forum10/HTML/000017.html

A good source for some sturdy metal rods is the heavy wire political-placard supports you see by the side of the road around election time. I'm sure one of your "favorite" candidates will be pleased to donate some rods for your next gunsmithing project.

[RThomas]

I tried the two-rods method and it didn't work. Problem was the R1 gasblock hole was worn from many years of assembly/disassembly and the rod did not sit "flat". It was off just enough to be visible, and proved to be off upon attempting to sight in. I have returned to the "eyeball+testfire" method after encountering a slightly tweaked gas tube on an STG barrel. The laser boresighter may be the most accurate method mentioned so far. I am curious as to how the 'smiths really do it. RT

[W.E.G.]

btt

[gumby]

This method didn't work for me either. There's just enough play in the gas block hole that you need to make sure that the rod is equally spaced on each side of the gas block. Kinda of a balancing act. I concluded that the eye ball approach was just as good.
BTW, finding a truly straight rod isn't easy either.

Using a visible light laser sounds interesting, especially if it could be mounted inside the threaded handle hole.

[Gaspipe]

Regarding the 'two' rods method...

The holes on my gas blocks measure out at 0.190 - 0.195, depending on origin, I guess. Rather than goof around with smaller diameter rods from various sources, I bought a few different diameter water hardening drill rods from McMaster-Carr. They range in price from about $1.85-2.00 each. I bought 0.188 - 0.192 for a close fit in the gas block hole. I cut them down to 2 feet in length, and they remain straight and droop free. I use one rod through the gas block hole, and another on the receiver. I haven't had this method fail me yet, but it does take a few tweaks to torque, eyeball, torque, eyeball, etc.

If your gas block hole is all caddy-wompus, this won't work properly, so you'd best go to an alternate method.

Ciao,

[W.E.G.]

I just wrap some WECSOG tape around the midpoint of the rod so it fits more snugly in the gas block hole.

While the rods may not work out to parallel when the barrel is properly indexed, the one thing that's for sure is they give you a good way to gauge the amount of any correction you might make when you tinker with the barrel timing.

I have a Chilean IMBEL kit on an IMBEL metric receiver. The rods are parallel. But, it looks like I'm gonna need to loosen the barrel about two degrees. Its shooting about 10 moa to the left when the rear sight is at mechanical zero.

[Derby FALs]

Don't you need to tighten, gary?

[W.E.G.]

Uh...yeah...tighten!!!

That's what I meant to say.

Thanks!

[FNfreak]

Lasers, rods...these things sound neat but in practice they are just gimicks...I FAL is TIMED properly when the gas piston is aligned between the gas block and the reciever.The piston will "BIND" and not slide freely in the gas tube. It is easy to check, just get the barrel close to TDC then assemble the gas tube, gas tube lug and insert piston WITHOUT spring. Push the piston through until enough of the rod sticks out of the reciever to grasp. Pull it back and forth a few inches while timing the barrel and you will feel it suddenly go FREE....it will slide with almost NO effort....this is TDC and all the other ways are based on aligning EXTERIOR parts of the gun...these exterior parts can be off/out of spec. for hundreds of reasons. Rods and lasers work...I KNOW because I have tried, BUT I have had to go back and re-time several barrels because the rods and lasers just didn't match up with what the gas piston NEEDED the barrel to time at, thereby increasing drag and friction on the piston causing FTF and guns that would only function with the gas regulator setting fully closed.
(My humble .02)
;)

[CITADELGRAD87]

Piston method is not foolproof.

My Imbel on an Ent Type 3 had almost 2-3 degrees EACH WAY from TDC before ANY noticeable bind in the piston.

[Rich@CGW]

While this is not the most accurate method,,
You might be amazed at how accurate it can be if you have a good eye..I`ve found it particularly usefull when performing a quick diagnosis with home or CAI built rifles..
http://www.centurygunworks.net/techinfo.html " Understanding Barrel Timing "

gas tube alignment method does have some draw backs.. They can, quite often be bent off aligment.. If you have a striaght one, then it works OK. As it should be aligned down the long axcess with barrel and receiver.

[Uncle Buck]

Nothing is fool proof, but the parallel rods method for timing barrels comes close too it. Probably the trickiest part with FALs is carefully balancing the rod in the hole in the gas block. You need to make sure that the hole is clean and free of burrs and dings. I have never seen one of these holes that is drilled off line, but I have seen loose or misaligned gas tubes. It is always a good idea to double check. If the hole in the gas block is messed up, you can mount the front rod across the top of the sight ears with a small magnet, but this isn't the easiest or most accurate place to mount it. A cheap and easy way to double check is to bore sight it. Clamp the rifle in a vise or other mount without the bolt/carrier or top cover. Signt down the bore with a mirror at an object about 50-100 yards away and then step back and see if the sights are at least aligned vertically with where the bore is pointed. The long, 3 ft rods make it much easier to eyeball barrel timing accurately. It is typically good to about 0.2 degree or +/- 1 inch left or right at 100 yards.

[Bryan]

I tried to use the piston alignment method to time my rifle. It seemed that everything was perfect. I had it so the piston was gliding perfectly. Took it to the range and tried to sight it in at 25 yards... shooting to the right of paper so I adjusted the rear sight. I ended up with it still shooting 4" left of center with the rear sight maxed out. Apparently the piston method had allowed me to over time the barrel, which caused it to shoot right. I got 2 3/16" (3 ft. long) rods and checked it. it was overtimed a bit. I loosened the barrel a bit and retightened it until the rod in the front sight hole and the rod laid across the top of the receiver were perfectly aligned. Checked the piston and it still mooved freely... took it to the range with the rear sight centered again. It now shot only 1" right and was easily adjusted onto center using the rear sight.

It seems to me that the piston method allows for enough variation to cause a bit of error in timing. I was using a Imbel kit in excellent condition with a new DSA piston so I don't think that there was any excessive piston wear to exaggerate this variation... ti just seems to be the nature of the piston method. I would suggest the rod method as it cost me only about $2 for the rods and would have saved me the headache of not having to rebarrel. Fortunately it did not seem to affect the headspacing enough to require a new Locking shoulder.

[Bruce Allen]

I recently swapped barrels on two of my rifles and used the two rod method. One timed up perfectly - I mean 1/2 of a turn of the rear sight from mechanical zero to obtain true zero was all that was needed.

The other the gas block is off somehow. I used the two rods and set the rear sight to zero and took her to the range. Shot to the right - under timed??
Came back and rechecked it. Found I had indeed undertimed it some and found unless I had the gas block perfectly straight up the rod wobbled alot.
Shot it again. Was still under timed.
Have now over timed it slightly and am waiting to get back to the range to find out how she does.

From the several times I have used the rods it is easy to see visually what you have in reference to the barrel and receiver indexing and from that can figure what you need to do.

[Timber Wolf]

Used the piston/eyeball method on my first one and the rod/eyeball method on the rest. Use two brass brazing rods, get a lot of rod sag. They both sag the same so now I compare two arcs instead of two parallel lines, works fine. Must balance rods though. The problem is that my big vice is down in my unfinished barn. I have to stand with one foot in an old tire and stradle a hydraulic piston and lean on a old chevy truck inner fender to work the vice. Then I have to crawl out of the barn and walk around and sight the rods from outside. Good thing the walls of the barn are not finished. I'm glad Casey can't see how I use his beautiful wrench. :D

[LooseCannon]

Hey guys, long time since my last post.

I use a combination of the rod, gas piston and calibrated eyeball methods. First the two rod method, followed buy making sure the piston didn't bind, then checking with the eye to make sure it looked reasonable.

A laser bore sight would be a addition.
Where do you buy those, and how accurate are they?

Dave

[Bubba]

I have had success several times with the "Two Rods" method!
Any rod will work on the receiver. I wrap masking tape around the receiver and the rod to keep it in place when cranking the tourque. For the front rod I have used gun cleaning kit rods. On my latest, they didn't fit so I uses a welding rod. You can get welding rods in a bunch of differant diameters.
The first time I tried it the barrel timed perfectly. The last one I timed, I didn't tighten enough for perfect. I had to adjust the rear sight about 1/8" to the right. Still pretty good for WECSOG.
Two rods is the way to go.

[Fred]

Just to add my two cents worth.

I have been using the two rod method for some time now but with a slight twist. I too have found that the rods do not like to lay flat within the gas block hole. To solve this I use a couple of rubber bands to apply tension to the rods, pulling to the bottom side of the barrel. I add a cupped wooden block to the bottom of the barrel to increase the stress and to allow the bands to be drawn out away from the gas block. This provides a very tight bottom referenced location for the front rod. On the rear rod I again apply rubber bands to tension the rod to the receiver top flats. I have found that this works every time as testing at the range shows no pull to either side.

Good luck,

Fred

[W.E.G.]

I tried to crank two degrees more onto a WECSOG creation last night. I could hardly tell if I had moved it. The two rods seemed to show a change. We'll see this weekend.

[TooTech]

Not originally my idea but...

Put an EMPTY mag in your FAL. Find a flat surface, place your FAL on it upside down, and balance it on the front sight ears and the back sight. Now check to see how close to verticle the mag is!