First time barrel fitting

[tturner53]

I fitted my first barrel! Thanks to this site's instructions. A 22" .243 barrel I got here too. Great site. Thanks guys. (As soon as I got it I put it on a SB1 frame, then realised that was a big mistake, had to fit it to  my rifle frame).

[briannmilewis]

Out of curiosity, did you have any previous smithing experience or mechanical background?

[tturner53]

Not really, just a hobbyist gunsmith. I have done a few home gunsmithing projects. Everyone of them intimidated me before I started but turned out ok. The best advice on each one was to go slow, figure it out as you go. I think that's the big difference, a real gunsmith knows already what he's going to find and do, we have to feel our way along. The upside is building a good familiarity with your gun. When I put together my first AR it seemed hard, but now it's easy. The FAQs here gave me the confidence to try it. Test fired today, 3 factory rounds, all is well so far, next is accuracy testing. The mixed reviews here on the .243 barrels have me wondering. The ultimate goal for this barrel is shooting cast bullets. I probably got lucky with an easy one to fit, that helps! Just kept taking down the top of the shelf 'til the latch would close. It's not as good a fit as a factory job, none of those have any visible gap between the barrel and receiver at all. If you're thinking of fitting one go for it, not much to lose if you muff it.

[tturner53]

Update and range results; I shot it today at the range. Lock up is good, accuracy looks promising, I think it will go moa no problem with a little developement. But... misfire city. The firing pin is not getting a good hit. I need to close up the barrel/frame gap I think. It will close and lock up on a .006 feeler gauge, but it's darn tight, can't pull it out no way. There is a visible gap you can see if you hold it up to the light. I suspect this is the cause of the misfires. I know the frame is fine, it shoots 100% with other factory fitted barrels. My plan is to follow the instructions on the FAQs and close that gap up.

[wreckhog]

That is a big gap. Try a smaller shim.

[gcrank1]

A feeler guage that wont 'pull' is not going to tell you the clearance. As you noted, its locked in so your headspace is something less. Now, an average human hair is .003-.004, your HS could be .004-.005, close to 'a hair'. The firing pin protrusion should be working for that, so your misfires are something more than HS. Watch your trigger pull through (per the FAQs) or do you have a hammer spur on it, which has slowed the hammers on others enough to cause it.
Most of us like a tight (often mentioned 'tinfoil') HS but a number of vintage single shots are .003-.005. I dont really like more than that, but if thats what you have and it locks up good and groups so be it. You could have some resizing issues for you brass at that, so match the sizing to the chamber/HS to minimize overworking the cases and keep the brass for that rifle separate.
*an afterthought* you arent getting the feeler guage down so low as to be caught in the extractor/ejector, are you?

[tturner53]

Thanks for the input guys. It is a little puzzling. When I shoot any other barrel on that frame there's no misfires, so I'm assuming it's not the trigger pull through thing. The reason I used the .006 feeler gauge is that's the thinnest I have on hand, I'll get a new set that goes down to .001/.002. I was very careful to hold the gauge just above the firing pin when I closed the gun on it. I do believe saving the brass for this gun only will be the hot set up. Those were factory loads I tried shooting, next I'll use some handloads with used brass and see if that helps. Also will do the shim thing, try to close up the gap.

[wreckhog]

Cheapest feeler gauges are from Harbor Freght, then the auto places like Napa and Advance.

Coke can is about .002. V8, Arizona ice tea, etc are somewhat more. You can also fold them over for more fun. Gives you something to play with til you buy feeler gauges.

If the thing is just loose, but locks up, then it will take a shim. If it won't lock up and you see a gap at the top of the barrel, it is probably too tight and not closing all the way.

[tturner53]

Another important piece of the puzzle wreck. Now you have me thinking. The gap is Very slightly wider at the top than below. Have to hold it up to light and look close to see it. It does lock up tight as a drum now, I honed the barrel latch shelf down 'til it would just barely lock up. The lockup conforms ok to all the checks in the FAQs now. But, the firing pin strike on the primer is off center, a bit high, weak, and looks to be angled down just barely. When the factory rounds did go bang there is a very slight cratering of the primer, which I don't think is caused by high pressure issues. When it's closed the barrel is solid, no wiggle any direction at all. I did notice the barrel latch shelf(I hope I've got my terminology right) is not level or cut evenly, one side is thicker or higher than the other. When smoked and closed I can see the latch is only contacting about 1/3 of the side to side area and is now engaging about maybe 1/8th inch, probably less, didn't try to measure it. Also, when closed, the top of the chamber is below the top of the frame, similar to factory fitted barrels I have. Now you got me thinking maybe the problem is the exact opposite of what I thought before. Maybe I need to relieve the pivot pin notch to allow the barrel to come down a tad more. For now I'm not doing any fitting 'til I get 'er figured out.

[necchi]

Cut a slice of soda can, as wide as the pivot pin about an inch long. Roll it across a table edge so it rolls it's self into a circle.
 Now fit it around the pin and put the barrel on it and try to close the barrel. You'll know right away if it works.

[quickdtoo]

But, the firing pin strike on the primer is off center, a bit high, weak, and looks to be angled down just barely.

Off center pin strikes are common, as long as it's not way out on the edge, it will be fine as long as the primers aren't too hard, CCIs may cause a problem. Check the pin protrusion by holding the trigger back and slowly lowering the hammer all the way, don't release the trigger and the pin will stay out, a good length is .050"-.060", remove material from the face of the hammer were it rests against the frame to increase pin protrusion. The firing pin is angled down... a lot, look at the owner's manual or compare the front and rear height. You may also need to replace the hammer spring, Wolff makes heavy replacement springs available from them or Midway, you want the single coil.



 

Also, when closed, the top of the chamber is below the top of the frame, similar to factory fitted barrels I have. Now you got me thinking maybe the problem is the exact opposite of what I thought before. Maybe I need to relieve the pivot pin notch to allow the barrel to come down a tad more. For now I'm not doing any fitting 'til I get 'er figured out.

The slight gap at the top of the barrel indicates to me that either the barrel face needs to be trued if you can per the FAQs, or you need to deepen the pivot, not shim, working the latch shelf before getting the barrel face gap to zero is not the way to do it, you do that last, if not, you may end up with excess latch engagement.

Tim

[tturner53]

Thanks for all the help guys. I'm gonna study on this a bit to be sure I'm seeing it right. Did try a double thick aluminum foil shim on the pivot pin, didn't help. It's looking to me I need to go the other way, move the barrel lug forward to allow the barrel to come down in back a little more. I'll reread the FAQs, study some, and then proceed. Thanks again. I have a good feeling this barrel will be a shooter. I'll get that Wolf spring for sure.

[tturner53]

Update. Made some progress. With a Coke can shim on the pivot arm it will not come close to closing. I was thinking I may need to actually go the other way, deepening the pivot notch. Then it hit me the ejector is protruding a little more than the barrel that works good. I measured them, quite a difference. I took down the back surface of the ejector, the part that contacts the frame when you close it, the barrel gap reduced visibly and now I can just barely get a piece of Coke can material into the top of the gap, maybe goes in 1/8th inch. I'm stopping there for now pending further test firing. I got a feeling this will do it, no more misfires, we'll see.

[zoner]

when the barrel is closed if you have a wider gap at the top it usually means you need to hone the pivot a little. When the barrel,breach engagement is right and the barrel still won't lock up,then work the latch a little.

[tturner53]

Well no joy yet. Reduced the barrel gap a little, still misfire city. The firing pin leaves a pretty good ding on the primer but no bang. Tried a different load, Hornady factory load this time. I've decided to hold off anymore fitting 'til I get my other frame back from H&R. They have it to fit a .444 barrel. Maybe my .243 will fit right up on that one and work great. If so that's great, if not I'll continue fitting program.

[bilmac]

I'm definately no expert here, I've only done one, but I don't think you can make one barrel fit 2 different frames, you might, but it would be just dumb luck. I would stop all fitting until you hear from someone more knowledgible.

[zoner]

if you have another frame available i'd wait and see if this barrel fit's that frame

[MSP Ret]

I second that, don't rush and wait for the other frame to return to try it on....<><....

[gcrank1]

And since the breech is not way loose and a huge gap the misfires are a different issue than the barrel fit to the frame.
What headspace do you have now?
Are you using a hammer extention? If so remove it.
Have you sprayed some lube down into the works? If they are dry it may be slowing the hammer fall.
Yes, a barrel can fit more than one frame, its the luck of the draw so you do want to try a barrel on all the frames you have to know what fits and whats best.

[tturner53]

Thanks guys for the support. I am putting this project on hold pending arrival of my other frame back from H&R.  I'll be a busy bee for a while, that will be 3 new (to me) barrels in just a couple months. There's a .308 on the way, can't wait to see how the fit will be. I shoot about 90% cast bullets and will do so in these barrels too. The handiness and cost effectiveness of these barrels allows me to play with more cartridges. All 3 barrels cost less than one decent bolt action. I'm used to a challenge because my other weakness is shooting cast bullets in military surplus rifles. I'd like to have a Handi in 7.62x54R, did they ever make those?

[nova71]

I agree with waiting and trying it on another frame. I recently got a 204 Ruger barrel and tried it on my frame, terrible fit, wobbled up and down and side to side when latched up, took it off and used another frame and it fit great, couldn't ask for anything better. Didn't get to shoot it this weekend, weather too nasty, but I will this coming week 

[tturner53]

More fitting news. I just got my other frame back from Remington with a new .444 barrel on it. The used .243 barrel is not locking up on this one. But, the used .308 barrel I just got fits like a factory job! Sweet. While I was on this binge I also bought a complete 7.62x39 Handi, which is on the way to my ffl. So I'll have one more SB1 frame to try the .243 on before I do any more fitting. I think I'm now a Handiholic.

[necchi]

So I'll have one more SB1 frame to try the .243 on before I do any more fitting. I think I'm now a Handiholic.

Uhmm,,the sb1 isn't rated for the pressures the 243 has,,so your outta luck there.

But you defenatly got the holic' thing goin on

[fredster22]

 Isn't the 762x39 on a SB2 frame?

[tturner53]

OOPS! No it's not a SB1 frame, my mistake. Brain fart! It's a complete rifle with the original barrel on it. Still, it's good to know you guys are lookin' out for me. Thanks.