two 2 rods barrel timing technique

[Kilowatter]

A while back someone posted that their "Uncle Buck" told them to use two 3'rods to time the barrel. Lay one across the receiver flats and one through the hole in the gas block for the handguard screw and when both were parrallel, the barrel was "timed". Well, guess what, it works! I used two 30" pieces of 3/16" O.D. brake line and when they are parrallel, it's timed.(brake line is kinda flimsy,so I'm going to local hardware this week and buy two 3' pieces of 3/16 all thread or drill rod) I used it on the R1 I built Sunday and a Stg yesterday that I'm starting on. It works GREAT! Thought I would pass this tidbit along. Hope you find it helpful. (see pics)

(Photopoint on the fritz?)
http://albums.photopoint.com/j/View?...693&Sequence=0

(Photopoint on the fritz?)
http://albums.photopoint.com/j/View?...069&Sequence=0

[This message has been edited by Kilowatter (edited August 16, 2000).]

[ December 22, 2001: Message edited by: EMDII ]

[ December 23, 2001: Message edited by: gary.jeter ]

[gunplumber]

great - very similar to the Imbel factory method. A t-handle screws into the fropnt sight, and a bolt carrier with T handle on top goes in receiver. Barrel is tightend until handles align. Am working on getting a set for state-side duplication. Assuming your rods are straight, you way seeems better because the longer rods make small errors more visible.

------------------
T. Mark "Gunplumber" Graham
gunplumber@arizonaresponsesystems.com
Arizona Response Systems
5501 North 7th Avenue, Phoenix, AZ 85013
623-873-1410 http://www.arizonaresponsesystems.com

[K. Funk]

It wasn't my Uncle Buck, it was a poster here (or on the old board) that went by the handle Uncle Buck. I just got done barreling my HB, which is my 2nd FAL project, and this method has worked for me. I'm glad that someone besides my ignorant self tried it and confirmed it!! And now for my third trick...R1A1 maybe??

krf

[Kilowatter]

Originally posted by K. Funk:
It wasn't my Uncle Buck, it was a poster here (or on the old board) that went by the handle Uncle Buck. I just got done barreling my HB, which is my 2nd FAL project, and this method has worked for me. I'm glad that someone besides my ignorant self tried it and confirmed it!! And now for my third trick...R1A1 maybe??

krf

Well, thank you Uncle Buck, where ever you are, and thank you K. Funk for passing it along! It works like a charm.

[hsp223]

Thank you both Uncle Buck and Funk for this neat little trick.

[Uncle Buck]

*Blush* Thanks, but credit where credit is due: This is an ancient method for aligning anything and it is described in many old gunsmithing books, like Roy Dunlap's and even newer books like Jerry Kuhnhausen's. I checked this method against my Starrett machinists level (not a cheap bubble level!)and it is good to a few tenths of a degree with 3 ft rods. (I did this on a M14, since there is no convienient place to hang a level on the FAL barrel.) It is satisfying to know that for under $1 and 1 minute time you can accomplish something with precision.
UB

[Phil Messer]

Will try this myself nextime.

[Snapper]

Looks Good!
I have two to build soon....I'm gonna try it.
(also going to use the barrel in the freezer "trick")

[Uncle Buck]

BTT

[Sumoj275]

When newFALguy and I put my rifle togeather this is what we used. It seems to work for mine.

[ulfrikr]

Barrel in the freezer trick?

Does 0 degrees F really make enough size difference to help installing the barrel?

If that's good, what about getting some dry ice and chilling the receiver end of the barrel?

~Rick

[Augie]

Does any one have some pics of this I am a Visual person.

[Aifwikir]

The "2 rod" method works great but I found it awkward trying to hold the rod on the receiver flats. If you insert the bolt carrier, you can put the rod under the rat tail to hold it steady while your timing it. Just mentioning this for posterity.


Aif

[ December 23, 2001: Message edited by: Aifwikir ]

[Batman]

Originally posted by Aifwikir:
The "2 rod" method works great but I found it awkward trying to hold the rod on the receiver flats. If you insert the bolt carrier, you can put the rod under the rat tail to hold it steady while your timing it. Just mentioning this for posterity.
[ December 23, 2001: Message edited by: Aifwikir ]

Good idea!

As a double check, once I figure that my barrel is timed right using the two rod method, I then insert the gas piston and spring and using a pencil push the piston back and forth to ensure that there is no binding in the receiver. After 6 builds this total method works great!

[W.E.G.]

Here are the pics!

[ric44]

Hey Jeter, is that one of the little bead blast cabinets from harbor freight in the bottom pic? Been wanting to pick up one and just wonder what kind of job it does? Thanks,ric.

[Atarget]

ric44,
The blast cabinet works good,but leaks air and some media near the door seams.

[W.E.G.]

Can't vouch for anything except the procedure in the pics. I ripped 'em off a long time ago. Think Kilowatter mighta been the mark.

[1911NM]

I had a machinist friend make me a block which fits on the front sight/gas block and is held in place with a screw which tightens into the front sight hole. The block is grooved for an 18" piece of ground flat stock. A bar is placed in the groove and another bar is placed across the rear of the receiver. Very precise.

[Sumoj275]

1911NM, I like that idea of yours. Do you use a level to check the eveness?

[Mr. Pink]

1911NM now that's a good idea using bar stock. I'm too lazy to machine out the adapter so I'll just use bar stock on the rear and drill rod through the sight/gas block. I highly recomend getting some drill rod for this method instead of all-thread. The drill rod is much stiffer and can be bought in sizes within a few thousandths of the size of the handguard hole.

For you skeptical people out there if you use 3' long sections you'll have 18" sticking out each end. Using a little trig (sin theta = opp/hyp where theta is 1 degree and hyp is 18") we find the difference in height between the two 'rods' for a 1 degree difference will be .314" or about 5/16 of an inch at the tips. So the average FALer should easily be able to time to less than a 1/2 degree (about .157 or 5/32 difference) using this method.

For you gun-ho people remember that this method relies on the receiver rails being square, the rods being straight, the gas block hole being square and clean of debris or burrs, and the user being able to see when the rods aren't square.

[1911NM]

A pair of Starett machinist levels can be used with the two bars but it isn't necessary. The human eye can easily distinguish very tiny amounts of misalignment. This is the method I was taught when I built National Match M-14s for the military. The ground flat stock doesn't sag like cleaning rods or drill rod. The screw that holds the block on the gas block was made from a screw blank and and the threaded end of an original front sight brazed together. I'm working on a modification for inch pattern barrels. Sight ears are higher and the thread is different. I may be able to use the same block with a different screw.

[Gavin]

Whats the thread pitch of the front sight hole?
Gavin