Barrel wear

[smylee grouch]

It sounds like you have some money invested in your gun, not to mention your time so if it were me I would not take any chances with my health or the posibility of damaging the rest of my gun thus wasting your money and time. I would replace the barrel.  Its your call but you will want to think it over first.     Gary

[SPG]

I would slug the barrel. Mark the loose spots on the rod as you push the lead slug through the barrel. Using a lead slug is much more precise than using a patch and jag. If the loose spots correspond with the dovetails I would re-barrel. At the very least, loose spots are not going to help accuracy. At the worst, something is going on that is not good. Barrels are cheaper than fingers.

Steve

[bama]

I have posted this before but I will do it again. The only barrel I have ever witnessed bursting was at the front lug dovetail. Fortunately for the shooter and the rest of us on the line nobody was hurt. The rifle was a custom job by a good builder that knows his stuff. The barrel was a good barrel by a well known maker. There was no prior damage to the rifle barrel as it was realitively new.

What happened was opperator error that can and probably has happened to anyone that shoots BP. The opperator was talking more than he was paying attention to his loading and he short started his load. The short started load just happened to be over the front lug dovetail. When he touched the round off the report was a very strange sound and everybody looked around to see what had happened including the shooter.

The last 6" to 8" of the barrel had burst and split right at the dovetail. Thank goodness the barrel stayed together but the forestock splintered and sent pieces flying.

I like slender rifles as much as the next guy but if I am going to be shooting 100+gr of 3F with a tight patch it will not be in a B weight barrel.

Take care my friend and be sure your short starter seats the ball to the breach side of the front lug to be on the safe side. Enoy your rifle but please always keep safety first.

[KNeilson]

Gentlemen, thx for all the advice. Since I last posted a couple more questions were asked...
Gaeckle,

I wonder if the hole for your pins is just but a hole in the barrel lugs

The lug is/are slotted, first pic was when I just put them on the barrel (Dec 09),
Snyder,

105 of 3F would be getting to the level of unpleasant for routine shooting.

I developed the load to hunt with, and have adjusted the sights for that amount. I have only "routinely" shot it at a club function twice now and I sure wouldn’t want any more for that purpose. I tried dropping 20G, but my accuracy went out the window with it. I once again had trouble with the sight picture. At 105G it hits what I point at from 25- 100 plus yards...same sight picture. A little higher close in, a little lower farther out. And, fwiw, I will unbreech and look as you suggest. However I feel pretty confident now they are slick spots as opposed to a bulge.
SPG,

"I would slug the barrel"

I will try this when I unbreech it, both to try as you suggest and also just for the experience of doing it..

bama,
 I have been very careful not to short start, and never have done so yet (knock on wood). I understand the mechanics of this and do not want to witness what you are describing..
Another possible thing maybe.. It was asked/suggested that I may have done something different recently that may have contributed to the cause... something like abrasive patch’s or change in lube, and I may have "fire lapped" the bore.  So I wonder what I’ve done, and realize I used a different lube for the first in a long time. For the majority of the time I use a Dawn/water/ veg oil mix...  to hunt I have been using TOW mink oil, and only 25 rnds or so with this trying it out. But, on Sunday I used a commercial product for the first time... Hoppes No9 BP solvent/patch lube.  It seemed to work OK, but a couple times I remember thinking this stuff is a little squeaky (like nails on a chalkboard) as I could feel the vibrations on the rod...maybe this is a possibility also.

Again, thx for all the well informed responses. What a wonderful resource this place is........ thx to all.. Kerry

[Roger Fisher]

Not to beat this to death; but it is important.   We asume you will check that short starter length to be certain it will push the patched ball beyond your lug notch and of course the frt sight notch.   I know I changed mine.

I wonder about that 'spot' you described "near' the breech, we wonder how close to the breech it is  I doubt that your rear lug (or sight for that matter) would be this close----fouling ring---that as your cleaning patch passes over the ring it feels like a bulge on the breech side of said ring fooling you in to thinking it is in fact a bulge.?     Can't imagine a bulge in that heavy section...

BTW no way would a barrel 'wear out' with decent care in several thousand rounds, at least to my knowledge....  If that were the case, I'd be knee deep in worn out barrels

[KNeilson]

Roger, thx for the interest. Yes, my short starter is well past the sight and front lug.  I just put a new rod in it as it was starting to get too short for me. As for the spot near the breech, its harder to find, but there, and it corresponds with the lug also. I dont have the barrel in front of me but my guess is about 10 in.. Ive also done a bit more, and I now dont think there is/was any bulging.
To continuue what Ive tried, .. I upset some balls to a dia of the bore+rifling (.065 first 3 in pic), drill a pilot hole, and drove them into the bore with a block of wood and a mallet. Grabbed them with a screw on a 1/2 alum rod, and pushed them to breech and then pulled them out. After looking at the slugs I decided to try a bit bigger to get more contact. I went to .080 (4 in middle), and did the same thing. I could not feel anything using the lead balls in this manner. However, I did get the same feeling once while scrubbing and cleaning the bore between slugs.
I appreciate what you guys have suggested, and by doing all this I now feel quite confident the bore is round, and not swollen or bulged in any way. There is gotta be a surface difference in some way but I am going to let this go now. Like Roger said...

Not to beat this to death; but it is important.

  I will still try to get a mechanical measurment of the bore, and when done will report the results. For now I feel a little puzzled, but not in danger..........   Thx.  Kerry

[tpr-tru]

Back at reply #9, Pratt goes into some measurements, bringing wall thickness to about .100".  Is there a minimum
wall thickness from the breach plug face forward for smooth 20 gauge, or rifled in any caliber ?   On a taper or swamp the breach end may be 1 1/8 for 12" as an example.  If the front lock bolt needs clearance via file a notch in barrel what is the minimum wall allowed ?  Two questions but both are the same.  

[bgf]

Back at reply #9, Pratt goes into some measurements, bringing wall thickness to about .100".  Is there a minimum
wall thickness from the breach plug face forward for smooth 20 gauge, or rifled in any caliber ?   On a taper or swamp the breach end may be 1 1/8 for 12" as an example.  If the front lock bolt needs clearance via file a notch in barrel what is the minimum wall allowed ?  Two questions but both are the same.  

I belive I've seen 0.100" as minimum from bore (if smooth) or bottom of groove (if rifled).  Being cautious, I try for at least an 1/8 (0.125") to allow margin for runout, imprecise measurement, etc., but I haven't used a light tapered barrel.  Hopefully someone will have a more authoritative answer for you.  I would rather my dovetails fail from being to shallow (which doesn't seem to be a serious problem) than the barrel fail.

[smylee grouch]

If there is a minimum wall thickness figure, it might be different for a lug at the waist and a front lockbolt grove as the pressure at the front lockbolt would be higher,( I think).     Gary