'03 bbl installation

[mike in co]

i got the old bbl off with no issues, but the new one will not turn the last 1/4 inch or so. these bbls are pre-fit by uncle sam...with witness marks to insure correct installation.

ra 44 bbl on a smith corona recvr( the take off was a ra also).

i have always got bbls on and off with just vise bbl jaws, not a full blown bbl vise.

so is there an issue with 03 bbl intallations...or do i just need to spring for a bbl vise ?

mike in co

[leftiye]

You may have already tried this, but I'd try "working it on" first before buying a wrench and vise (they're costly). Maybe even lapping with abrasive compound on the last few threads next to the shoulder on the barrel. Another approach would be a die, and chase the threads on the barrel (if such die exists). It kinda seems that the barrel is more likely the culprit than the reciever (as the reciever had a barrel in it previously). With the right lathe a good machinist might clean up the threads without making them too lose. Or he might ruin the barrel. Not much help, I know.

[mike in co]

i do have a lathe, but it want to get some user input before i take any metal off. could reshoulder the bbl, lap fit, re thread...its a square thread, but shallow...not sure if it is acme or not.


still listening

mike in co

[leftiye]

I'd be cautious too. Matter of fact, I'm really leaning towards some sort of abrasive (even if only oil on the threads and screwing it together and apart) fitting or lapping approach. If you can rule out the diameter as interfering, then all that should be further necessary would be to relieve one side (front or back, not both) of the thread on the barrel. You might even be able to hand reduce the thread in this manner with sandpaper. I guess I'm hinky about taking too much, though screwing in easily isn't necessarily a bad thing more looseness than that is bad and may affect accuracy. Another vote for standard threads - they self center even when loose. Do you get any indication as to where it is interfering from rub/shining?

[Frank46]

Mike, try either never sieze paste or dow cornings assembly paste. The never sieze is used on threaded fittings to keep the parts from galling. The dow corning assembly paste is a moly compound and is highly reccomended when assembling close fitting parts. What you might try is coating the threads with either compound and run the bbl in till you feel resistance, back out and do this again. repeat until bbl is screwed in all the way. Sounds like a lotta work and i agree but better this way than running the risk of jamming things together or ruining the threads. Plus there would be less stress on the bbl threads or receiver. Just a thought. If all else fails, then polish the first threads with an abrasive cloth (silicon carbide wet or dry paper) and go through
the grease procedure. The grease or assembly paste will act as a lube and should help things along. I used to work on double acting recriprocating steam pumps. All studs on the steam cylinders got a healthy coat of the assembly paste and after running and then taken down for repairs the studs were always easier to get out. Break off a stud and you got problems. Usually drill out and heat the area around the stud while sticking in an eazy out and hope it will come out. Sometimes they did and sometimes they didn't. That was usually when the fun started. hope this helps. Frank

[mike in co]

TO clear up a common question, the bbl screws on all the way...shoulder to shoulder, but with my current tools, i cannot torque the last 1/4inch of rotation to get the witness marks to line up. the precut extractor groove is posistioned based on the witness marks. my issue with lapping the threads is it would remover material from the recvr...not my first choice.
i can chuck the new bbl in the lathe and recut the shoulder .

anyone know for sure that the thread per inch is on this ? it looks like 10 per inch, but need to be sure to calculate how much material to remove( if i go that way).

thanks
mike in co

[exblaster]

An old gun smith I know fits Springfield and Enfield barrels by using an oil stone on the fount of the action. He just polished the tool marks out and used a cold blue to color the bright area. The barrels were made to have a crush fit and require quit a bit of force to seat. JUST USE CARE TO KEEP THE JOINT PLUMB OR YOU MAY HAVE A VISIBLE GAP.

Exblaster

[leftiye]

Exblaster
Super solution! I did read Mike's first post wrong. And lapping the threads in that case might work, and again, might only loosen the threads, something that it is now aparent is not needed.

I work on old pocket watches, and have seen threads "work in" so that they are smooth, but not be possible to turn any further (when I was trying to get a pattern to align on a watch case) than a finite point.

More torque, or stone down the shoulder on barrel, or the front of the reciever until you can turn it in to the reference mark.

[RayO]

The threads on the Springland are 10tpi-square.

[Pepe Ray]

Would you tolerate a SWAG from a novice?
Chill the receiver and heat the bbl. line up and turn to right. :?:
Pepe Ray

[MtGun44]

Wouldn't that be heat the receiver and chill the barrel???

Bill

[mike in co]

Wouldn't that be heat the receiver and chill the barrel???

Bill



yes but he did say he was a novice...lol

[Larry Gibson]

i got the old bbl off with no issues, but the new one will not turn the last 1/4 inch or so. these bbls are pre-fit by uncle sam...with witness marks to insure correct installation.........

mike in co

Not quite mike. The witness mark is put there so when lined up to the one on the reciever the sights will be square ith the reciever and the extractor cut will line up with the bolt face. A new '03 barrel that has never been fitted to an action needs the face of the barrel shoulder turned down (just a tudge) untill the witness marks line up. They did use humongous action wrenches to tighten the barrels in back then. It is not really necessary.

Tighten the barrel in until the shoulder is just snug against the face of the action. Make a pencil witness mark on barrel and reciever with a sharp pencil. Then tighten the action onto the barrel (if your vise is big enough, is padded with lead jaws and you are using an action wrench then that may suffice - a proper barrel vice and action wrench are always best) as tight as you can. Put a new witness mark on the reciever lined up with the pencil one on the barrel.

Measure the distance between the two witness marks on the reciever. wWrite that down and erase all the pencil witness marks on barrel and reciever. Measure that distance back from the witness mark on the reciever and put a witness mark with the pencil at that spot on the reciever. Face off the shoulder of the barrel with your lathe until the witness mark on the barrel is lined up with the pencil witness mark on the reciever with the same "snug" fit against the face of the reciever. Then using the wrench and vise tighten the action onto the barrel and the two actual witness marks should then line up.

Harder to explain than it is to do.

Keep in mind the chambers of new '03 barrels are usually .01" short chambered so a finish reamer is required to finish chamber ad properly headspace the chamber to that action.

Larry Gibson

[leftiye]

That was clear as mud. Wouldn't you have to measure the distance from where it is to where it should be (when torqued tight), and measure or calculate the circumference of the barrel at the shoulder. Then find what percentage of a turn needs to be removed from these measurements, and multiply the length of one thread (.100") by that? After that you can pray that your lathe makes that cut and not what it feels like (doesn't slide off, nor dig in as happens with fine cuts). So I'd abrade a thou or two at a time and test if it were me FWIW.

1.20 barrel diameter (just a number for instance) X 3.1416=3.77" circumference. .250 divided by 3.77=.066. This times .100 = .0066" This says you need to remove .0066" If the cut on the rear face of the shoulder is rough, then this may not be much more than smoothing the shoulder. All this changes with your actual barrel diameter.

[Larry Gibson]

Leftiye

Glad to see we're still talking;-)

Larry Gibson

[mike in co]

larry,
this is a new usgi bbl marked '44. the threads show slight wear. as it it was installed in some receiver to check the extractor groove and put on the witness mark on........now why would they go thru all this and not fully cut the chamber ? i guess i'll re do the chamber cast all the way to the cone.
dang....
thanks
mike in co

[leftiye]

Mike, It sounds like that barrel was previously installed. I'm not sure, but I'd bet they didn't install barrels to put witness marks on 'em. Might be correct for headspace. You're only a few thou. from being all the way there as it is. Try a fired case or headspace gauge in it. If it is short chambered, you won't be able to close the bolt.

[mike in co]

it came in gi wrap with heavy cosmoline.........i'm still betting on new usgi( from sarco)....will take the bbl off the revr,and compare dummy rounds in the old and new bbl.

did that,,,,
there is about .020 diff in the height of a dummy round in the old vs new......will have to wait for actual install to do a bolt close check.....

i got 308 reamers and gages, 223 reamers and gages...but nothing for .30'06.......

[Pavogrande]

I agree with Mr. Gibsons analysys. I walked out to the bench and checked two RA 44 barrels that I know have never been installed. Both have witness marks. Remove enough from the shoulder to allow as heavy a crush as you want. It is not exactly a precision cut thread and shoulder by todays standards. War time speed and finish. One of my new barrels even has a slight burr on the outer edge of the shoulder. I would think chucking the barrel up and taking a small mill file to the face to clean it up would get you close. Best o british luck --

[Larry Gibson]

mike in co

it came in gi wrap with heavy cosmoline.........i'm still betting on new usgi( from sarco)....will take the bbl off the revr,and compare dummy rounds in the old and new bbl.

did that,,,,
there is about .020 diff in the height of a dummy round in the old vs new......will have to wait for actual install to do a bolt close check.....

Wrapped in heavy cosmoline and the .020" difference make it a sure bet the barrel was not intstalled previously. May have been tried on a few actions including final check durng manufacture which would account for slights signs of wear.

i got 308 reamers and gages, 223 reamers and gages...but nothing for .30'06.....

Shouldn't be hard to locate an '06 reamer, either to rent, a loaner or to buy. If not let me know.

Larry Gibson

[mike in co]

ok, i ordered a bbl vise from midway on tuesday eve, and it got here today. i cut a set of blocks to match the bbl dia, and guess what ?? it still would not go within .3 on the dia of matching the witness marks.
i chucked up the bbl in 4 jaw with a spyder on the muzzle end( thru the head stock), and dialed it in to less than 0.001. i then did a fine clean up cut and tried the reciever...still not go. so now its time to take some metal off. took three small cuts and was fianlly close enough to go back to the bbl vice and recvr wrench. cycled the two a couple of times and then hit it hard, and then a little harder....lol...its lined up.

the bolt cycled fine, but it will not close on a dummy round, so it is short chambered..just a bit.

its reamer time....

thanks

mike in co

[leftiye]

How much did you end up taking off approx? Sounds like a fair amount?

[Larry Gibson]

Sounds like it was/is a new barrel. Good to see you got it on. Not too difficult to ream. Hope she shoots good for you.

Larry Gibson

[mike in co]

How much did you end up taking off approx? Sounds like a fair amount?

probably less than 5 thou, i did not measure, but was cutting around 1-2 thou each time. was being very conservative.

gonna rent a reamer and gages about 50 bucks for two weeks...plenty of time to get it cut will order for shipment one week from monday..i'm going on vacation for a week!

(someone want to do the math...figure .27 turn ona 1.2 od)

[leftiye]

You might (might)be able to buy a reamer on fleabay for close to that. Just a thought, if you can measure your sized brass for length at the reference line, and your dies are in spec. (or near - not too short). You could chamber to that length - your sized case.

[Morgan Astorbilt]

Mike, I make it a practice, after a few bad experiences, NEVER to lend out reamers. If you manage to buy one, let me know, and I'll lend you a pair of go-no go gages.
Morgan