tubbs final finish bullets

Unclenick,

I'm not aware of any military arsenal made Garand barrels that were button rifled. They were all broach rifled after being profiled or contoured as far as I know.

Those made at the end of the broach life had the smallest groove diameters and were the most accurate.
 
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It that unevenness uniform all around?
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Yes. I did not, however, seat the bullets any closer than what a standard COL at the lower powder charge recommended.

Sorry--I double-checked the remaining kits I have and all the bullets appear to be the same type (though I did get a .308 in the .338 kit). I was in error that there were different types of bullets across grit sizes.

I tried out the 280 AI barrel today with regular factory ammo, the results being rather poor (I suspect from the damage in the muzzle area), though I really wasn't expecting a miracle. The .338 LM I don't have any bullets smaller than 270 gr eld-x's (the Tubb bullets are 250 gr and look like matchkings) but will start with some lower power charges hopefully this weekend, though we are having some pretty unstable weather.
 
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I put new batteries into my Hawkeye--the pictures above were taken through my Teslong which does not have as high resolution as the Hawkeye.

Long story short--it's obvious I completely goofed up my interpretation of what I was seeing now that I have a much clearer picture! My sincerest apologies for misleading everyone, I didn't do it on purpose.

The long pointed black streaks the Hawkeye reveals are actually crud streaks to the sides of the grooves, the Hawkeye reveals the groove ends themselves are intact and even. Unfortunately I can't really get a good picture through the Hawkeye--that requires the skills of a heart surgeon using just a bracket holder.

Excuse me while I go have dinner--crow.:o
 
Funny that military rifles don't get special treatment lap wise and they shoot fine.

If it bothers you, buy a gun that is hammer forged. Those are smooth. They may not shoot for diddly but they sure are smooth.

Any cut rifled or button rifled barrel is going to look bad. Its how it shoots that counts.

All the lapping in the world is not going to make a poor barrel shoot good.

You want a clean barrel then get Carbon Killer 2000 (and the right procedure) and or Bore Tech Eliminators. I have WWI barrel that are bright. Look at them with a boro scope and you want to throw up.

You want a good barrel buy it from Shilen, Criterion, Bartlein etc. Tubbs is a shooter, he is not a metallurgist nor a barrel maker (Shilen does thousands of barrels and they know what works by combination of metallurgy and experience)

If the so called fire lapping makes one barrel better, it can make 10 others no difference or worse. Crap shoot.

A boro scope for a day in day out shooter is good for one thing, it tells you if you got it clean (see paragraph above - it still takes technique)

A gun smith uses a boro scope to asses barrel issues. He has the training and experience (hopefully ) to know what he is seeing.


I had one barrel you could feel the drag and was harder to clean. 500 rounds and can't tel the difference between it and the Shilen.

Nothing pretty about the WWII JA barrel but it shoots just fine. Probably only proof fired from the looks of it.

What works is a clean barrel and load development (and don't forget the shooter). There are no magic elixirs.
 
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I haven't really had a chance to test the results thoroughly, though I did put some cartridges through the 280 AI and it still shoots like crap--but it did so before the fire-lapping as well as it has a very deep gouge right around the muzzle. My model 70 has a long spiral gouge, and I didn't notice any change at all with it after the treatment, so I guess that's also a "draw."

I was hoping to get a good test of my 338 lapua, but I only could sneak in a few shots between rain showers. Here's 5 shots of a low-end charge--93.3 grs of LRT driving a 270 gr eld-x at 235 yds; would have been a pretty nice group had I not pulled the shot a bit on the bottom. Hopefully faster charges will tighten that up. The barrel is definitely a lot easier and quicker to clean.

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I've noticed the loopy 5 HD tends to "drift" the side focus dial a bit upon sustained shooting with the 338 LM, hopefully I can tighten that up just a hair.
 

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I went through the Slick 50 craze. Years latter I became the designated facility engineer (no letter attached to the title) on machinery issues (well everything but that was my experience base)

What I learned was that magic elixer stuff does not exist for a reason for machinery anyway (won't comment on other aspect)

If you recall, there was this wonder stuff that you could treat the engine oil and then run it without oil and it would last hours and hours. Actually that part was true.

The Hammer was, it destroyed bearings in short order. How often do you loose all the oil in your engine? Ooops, guaranteed to destroy the engine though. Guaranteed loss vs no gain.

That was all based off WWII Aircraft engine research (no they did not figure it out themselves) based on Chlorine based oil. They had an abiding interest to see if you could get a plane home sans oil of course.

So, yes you could and you got a couple of missions before the bearings were destroyed.
A gain sometimes, 90% guaranteed loss.

As they usually got 500 -1000 hours out of an engine? Yep, pretty soon all your freighters are hauling new engines and no food, gas or ammo.

Slick 50 was not alwyas harmful but in the tight design engine (4 cylinders ) it could plug up the smaller oil passages. Yep, there goes your engine.

So, yes you can smooth a barrel out, that does not mean its going to do you any good.
If its does not shoot smooth is not the issue.

Smooth is easier to clean and if that is the goal, cool. I don't know you can wreck a barrel either (maybe if you really overdue it). Or you can shoot the barrel till its smooth and use the good cleaners.

If its a problem barrel you need a new barrel.
 
Bart,

Yep. I know. But this barrel was military (the one I got through the DCM ages ago) and it definitely had contour-corresponding bore narrowing. My speculation is the broach was getting dull and that stressed it, but I don't know for sure. War production can be hasty and drilling and reaming too fast would add to surface stress, too. All the other military barrels I've had were old club gun barrels that were so badly shot out I never considered doing anything but replacing them. Maybe I was too hasty. David Tubb seems to think you can bring a shot-out throat back with lapping bullets. Anymore, though, popping one of the Criterion barrels on is just too easy and saves a lot of time that might turn out to be a fruitless effort.

When NECO first developed their firelapping kit, they got a university smallbore team's rifles to lap, and IIRC, got no change in accuracy on about half of them and an average improvement of something like 15% reduction in group size with the other half. That pretty much echoes my experience with rifle barrels. About half the time it has no effect on accuracy and about half the time you get a modest improvement, and they are always way easier to clean afterward. Though, in the case of the Garand barrel, it stopped losing accuracy after 40 rounds, so I could get through a match with it. You could say it improved accuracy beyond that 40-round point but not before.
 
called them today. They said my results were odd and the barrel should be mirror polished unless the machining was super rough to begin with. Didnt really comment on the lands. Was able to send picks, Bryan said he would try to get back to me tomorrow on them.
 
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