Of endoscopes, lapping bullets, and accuracy mysteries.
- Thread starter Ian
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freebullet
Guest
Looks a lot better. Man that's like 15-20k worth of Jax shooting for that much break in. Really neat tool to be able to monitor the progress like that. Curious what she'll do now!
The biggest challenge I've been having with the cheap bbl is short chambers. The bores look reasonable, shoot ok or better, but won't chamber anything short of small base die sized. Have 2 keepers but guna have to lengthen the chambers. One marked wylde one 5.56 neither chamber 223.
Thinking about buying the ptg pull through chamber finisher in 5.56.
The biggest challenge I've been having with the cheap bbl is short chambers. The bores look reasonable, shoot ok or better, but won't chamber anything short of small base die sized. Have 2 keepers but guna have to lengthen the chambers. One marked wylde one 5.56 neither chamber 223.
Thinking about buying the ptg pull through chamber finisher in 5.56.
Ian
Notorious member
I used oure lead laps previously (months ago) and when starting back at this again I used some 50/50 bullets already cast. The 40 rounds I put through it today were cast of wheelweight alloy because it was in the furnace and I wanted to use my NOE MX3 bullets for more bearing surface...but I shot them within two hours of casting and they were quite soft.
The throat end of the barrel was tight because the barrel is thicker there, but also it gets cut more on the breech end because the carborundom is coarse at first but gets fractured under pressure into finer and finer particles until it basically is only polishing. In a barrel which is uniform in diameter from end to end, the idea is to firelap it until the wear advances to just inside the muzzle and then STOP. The result will be a taper and uniform land width which is ideal for cast bullets. It is difficult to achieve a smooth taper and still have uniform land width when using a cast lap.
The throat end of the barrel was tight because the barrel is thicker there, but also it gets cut more on the breech end because the carborundom is coarse at first but gets fractured under pressure into finer and finer particles until it basically is only polishing. In a barrel which is uniform in diameter from end to end, the idea is to firelap it until the wear advances to just inside the muzzle and then STOP. The result will be a taper and uniform land width which is ideal for cast bullets. It is difficult to achieve a smooth taper and still have uniform land width when using a cast lap.
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Jäger
Active Member
A little late to this party, but I just finished a bit over six months getting the carcass of what was Montana Rifle Company up and running again - at least the barrel making side.
So on the one hand, I hand lapped my first rifle barrel for cast bullets back in the late 1970's, using printed instructions on how to pour a lead lap, etc as my guide.
And then for the last half or so of this year, I was the ops manager (and learning) the process of making and finishing rifle barrels starting with 12' long bar stock. Troubleshooting the Pratt & Whitney drills/reamers, I looked through bore scopes at lots of just drilled but not reamed barrels, drilled and reamed but not rifled barrels, barrels that were rifled but not yet 'hand lapped' (that means scrubbed with medium steel wool), and finally, finished and inspected barrels ready to ship to the rifle manufacturer who ordered them. Also some custom barrels from high end custom barrel makers to have as comparative examples.
All of them - except for a couple of example barrels from a few of the high end makers - had perpendicular tooling marks at least in the bottom of the grooves.
So for starters, there's a lot of truth in those who say "You'll wish you never used a borescope"... Post Traumatic Borescope Syndrome often occurs". I also believe that in some things borescopes are useful tools. Even after suffering Post Traumatic Borescope Syndrome myself.
Relating to the pic above, the most anal, exacting hand lapping job I did was on the barrel of my pick of the litter 1950 Long Branch No. 4 Mk1* Lee Enfield.
I had my bullet bonus and mortar money burning a hole in my pocket just before I was ready to return home from a Bosnia deployment in the early 1990's - I think it was a Shotgun News that my family sent me in a package of magazines and newspapers when I saw an ad for crates of 10 Long Branch's for sale after being returned from Belgium. I bought two crates; when I got home, I spent my post deployment leave unwinding and cleaning all those rifles of their storage grease, then one by one installing an S&K no gunsmithing mount, then firing a few fouling shots followed by a ten shot group with Greek HXP ball at 300 yards.
I kept the pick of the litter, gave second and third place to my younger brother gun nuts, and sold the rest at a tidy $50 profit each. That sale was the dumbest gun thing I've ever done, looking at what new Long Branches sell for 30 years later.
I digress. I intended to use that rifle for heritage rifle matches, cast bullet association military rifle matches, etc. So I hand lapped that barrel under the watchful eye of my benchrest shooting and hunting and fishing buddy eye gunsmith to what he assured me was as close to perfection as a reasonable person could hope for. Didn't have a borescope back then, nor the WWW. Fidonet, that was it. But it felt as uniform as humanly possible by the end of the last grade of clover compound. It was a long day's work in pursuit of perfection.
That rifle is still so accurate with both the right ball ammo (or handloads) and the right cast bullet that I'd rather not say how accurate because I don't like being called a liar. It was a tiny bit more accurate with the Greek HXP ball after lapping, but now that the scope is permanently off of it and the Parker Hale vernier rear sight is replacing it, shooter error makes it irrelevant. I never tried cast before lapping, so I can't say about that.
And despite a full day of lead lapping to remove any and all tight spots from throat to muzzle, when I finally stuck a borescope in my rifle to look at it years later - there's STILL cross hatch tool marks visible in the bottom of the grooves, none on the top of the lands. Because depth perception through a borescope is hard, I can't say just how deep those marks are, but obviously they aren't causing harm. The barrel doesn't copper foul, and it didn't foul with cast bullets.
The perpendicular tool marks being in the bottom of the grooves (and not knowing whether Long Branch cut rifled, button rifled, or broached) I don't know which rifling mechanism put them there. But they're still there after all that lapping. And probably 2000+ FMJ rounds and at least as many cast bullets.
I also have my Grandpop's 1895 Winchester chambered in 30 U.S. aka 30/40 Krag, handed down to me after my Dad's death. He bought that rifle before the turn of the century and no doubt shot a lot of corrosive ammo through it before things changed. I don't know what the rifle barrel was when he bought it, but slugging the bore now shows that it has dimensions that would better fit a .303 British.
And when you look at the bore with a borescope, it takes a while to decide whether there's anything left for rifling of any depth or not. Which might be why the best it can do with any kind of 30/40 jacketed ammunition could be charitably called an 8" group at a hundred yards, even with the aperture sight on the rear and that long, long sight radius. Properly fitted cast bullets from my Accurate moulds for that Long Branch - and after much trial and error, it's just a tad over 2" groups at a 100 yards. And that's with a bore that looks like the inside of a sewer pipe through a borescope.
I am deeply tempted to take some medium steel wool to the bore for some lapping every time I look in that bore through a borescope. But then I remind myself this rifle's main purpose is hunting elk and deer in the thicker stuff as my Grandpop did, and I already have perfectly good 2" hunting loads with cast bullets in this rifle. And remembering the Long Branch, there is absolutely no guarantee that any kind of lapping will make any kind of significant difference.
Just some observations. I've never tried the NECO/firelapping thing. The commercial kits didn't exist when I first lapped, and my lapping days are probably behind me now. I do know that it takes a hell of a lot of lapping, even when doing it with medium steel wool, to remove all tool marks in a barrel. And just because a barrel looks terrible through a bore scope, doesn't necessarily mean it won't shoot well.
So I guess what I'm trying to say is that finding a definitive answer concerning lapping and/or bore condition is kind of like trying to nail Jello to a wall.
So on the one hand, I hand lapped my first rifle barrel for cast bullets back in the late 1970's, using printed instructions on how to pour a lead lap, etc as my guide.
And then for the last half or so of this year, I was the ops manager (and learning) the process of making and finishing rifle barrels starting with 12' long bar stock. Troubleshooting the Pratt & Whitney drills/reamers, I looked through bore scopes at lots of just drilled but not reamed barrels, drilled and reamed but not rifled barrels, barrels that were rifled but not yet 'hand lapped' (that means scrubbed with medium steel wool), and finally, finished and inspected barrels ready to ship to the rifle manufacturer who ordered them. Also some custom barrels from high end custom barrel makers to have as comparative examples.
All of them - except for a couple of example barrels from a few of the high end makers - had perpendicular tooling marks at least in the bottom of the grooves.
So for starters, there's a lot of truth in those who say "You'll wish you never used a borescope"... Post Traumatic Borescope Syndrome often occurs". I also believe that in some things borescopes are useful tools. Even after suffering Post Traumatic Borescope Syndrome myself.
Relating to the pic above, the most anal, exacting hand lapping job I did was on the barrel of my pick of the litter 1950 Long Branch No. 4 Mk1* Lee Enfield.
I had my bullet bonus and mortar money burning a hole in my pocket just before I was ready to return home from a Bosnia deployment in the early 1990's - I think it was a Shotgun News that my family sent me in a package of magazines and newspapers when I saw an ad for crates of 10 Long Branch's for sale after being returned from Belgium. I bought two crates; when I got home, I spent my post deployment leave unwinding and cleaning all those rifles of their storage grease, then one by one installing an S&K no gunsmithing mount, then firing a few fouling shots followed by a ten shot group with Greek HXP ball at 300 yards.
I kept the pick of the litter, gave second and third place to my younger brother gun nuts, and sold the rest at a tidy $50 profit each. That sale was the dumbest gun thing I've ever done, looking at what new Long Branches sell for 30 years later.
I digress. I intended to use that rifle for heritage rifle matches, cast bullet association military rifle matches, etc. So I hand lapped that barrel under the watchful eye of my benchrest shooting and hunting and fishing buddy eye gunsmith to what he assured me was as close to perfection as a reasonable person could hope for. Didn't have a borescope back then, nor the WWW. Fidonet, that was it. But it felt as uniform as humanly possible by the end of the last grade of clover compound. It was a long day's work in pursuit of perfection.
That rifle is still so accurate with both the right ball ammo (or handloads) and the right cast bullet that I'd rather not say how accurate because I don't like being called a liar. It was a tiny bit more accurate with the Greek HXP ball after lapping, but now that the scope is permanently off of it and the Parker Hale vernier rear sight is replacing it, shooter error makes it irrelevant. I never tried cast before lapping, so I can't say about that.
And despite a full day of lead lapping to remove any and all tight spots from throat to muzzle, when I finally stuck a borescope in my rifle to look at it years later - there's STILL cross hatch tool marks visible in the bottom of the grooves, none on the top of the lands. Because depth perception through a borescope is hard, I can't say just how deep those marks are, but obviously they aren't causing harm. The barrel doesn't copper foul, and it didn't foul with cast bullets.
The perpendicular tool marks being in the bottom of the grooves (and not knowing whether Long Branch cut rifled, button rifled, or broached) I don't know which rifling mechanism put them there. But they're still there after all that lapping. And probably 2000+ FMJ rounds and at least as many cast bullets.
I also have my Grandpop's 1895 Winchester chambered in 30 U.S. aka 30/40 Krag, handed down to me after my Dad's death. He bought that rifle before the turn of the century and no doubt shot a lot of corrosive ammo through it before things changed. I don't know what the rifle barrel was when he bought it, but slugging the bore now shows that it has dimensions that would better fit a .303 British.
And when you look at the bore with a borescope, it takes a while to decide whether there's anything left for rifling of any depth or not. Which might be why the best it can do with any kind of 30/40 jacketed ammunition could be charitably called an 8" group at a hundred yards, even with the aperture sight on the rear and that long, long sight radius. Properly fitted cast bullets from my Accurate moulds for that Long Branch - and after much trial and error, it's just a tad over 2" groups at a 100 yards. And that's with a bore that looks like the inside of a sewer pipe through a borescope.
I am deeply tempted to take some medium steel wool to the bore for some lapping every time I look in that bore through a borescope. But then I remind myself this rifle's main purpose is hunting elk and deer in the thicker stuff as my Grandpop did, and I already have perfectly good 2" hunting loads with cast bullets in this rifle. And remembering the Long Branch, there is absolutely no guarantee that any kind of lapping will make any kind of significant difference.
Just some observations. I've never tried the NECO/firelapping thing. The commercial kits didn't exist when I first lapped, and my lapping days are probably behind me now. I do know that it takes a hell of a lot of lapping, even when doing it with medium steel wool, to remove all tool marks in a barrel. And just because a barrel looks terrible through a bore scope, doesn't necessarily mean it won't shoot well.
So I guess what I'm trying to say is that finding a definitive answer concerning lapping and/or bore condition is kind of like trying to nail Jello to a wall.
Ian
Notorious member
I HAD to lap that M4-gery barrel, it had a .223 Rem throat and was mellonited even though it is marked "5.56 NATO". When using military 5.56 ammunition the primer pockets would swell so much the primers would fall out and tie up the bolt in the barrel extension. The nitride coating precluded trying to ream the throat with a Wylde or other reamer. The barrel "relaxed" everywhere it was reduced in diameter, particularly after the gas block journal and where the grenade launcher mount was machined; in essence the bore dimensionally resembled a snake full of eggs.
And.....the best it would shoot factory 55-grain .223 Remington ammo was ten into 8" at 100 yards.
So I lapped it with cast bullets embedded with coarse Clover compound (rolled between steel plates) and after many sequences of this finally got the coating scrubbed out and the throat pushed out enough to accept 5.56 ammunition without excessive pressure. Getting the tight spots out was a bonus. Now it's a 3 MOA rifle with factory stuff and about half that with 3,000 fps powder-coated cast bullets.
Was it worth it? Yes indeed. It still looks like a bad road and isn't dimensionally perfect inside but it shoots. Saving the barrel also saved an expensive, suppressor-mount muzzle brake that I pinned and welded per BATFE code of conduct to bring the permanent barrel length into the rifle realm from 14.5", and also saved my JP Enterprises adjustable front sight gas block which otherwise was trapped in the tube by the welded brake.
And.....the best it would shoot factory 55-grain .223 Remington ammo was ten into 8" at 100 yards.
So I lapped it with cast bullets embedded with coarse Clover compound (rolled between steel plates) and after many sequences of this finally got the coating scrubbed out and the throat pushed out enough to accept 5.56 ammunition without excessive pressure. Getting the tight spots out was a bonus. Now it's a 3 MOA rifle with factory stuff and about half that with 3,000 fps powder-coated cast bullets.
Was it worth it? Yes indeed. It still looks like a bad road and isn't dimensionally perfect inside but it shoots. Saving the barrel also saved an expensive, suppressor-mount muzzle brake that I pinned and welded per BATFE code of conduct to bring the permanent barrel length into the rifle realm from 14.5", and also saved my JP Enterprises adjustable front sight gas block which otherwise was trapped in the tube by the welded brake.
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Ian
Notorious member
Not likely to happen here, so fear not. This board exists partly because some of us got tired of being told we couldn't possibly be doing the things we said we were on other boards, even though we explained how and taught others to duplicate our results.
462
California's Central Coast Amid The Insanity
It's not in me to dabble along with the experiments Fiver and Ian have done, nor is there the need to. But I have sure enjoyed the reading of their adventures, over the many years.
By the way, whatever happened to that 2600 fps 6.5 Swede brouhaha?
By the way, whatever happened to that 2600 fps 6.5 Swede brouhaha?
Ian
Notorious member
Some people's personalities got them banned from the entire internet, though I have no specific reason to doubt their veracity. I managed (with ridiculous amounts of time and effort) just barely sub-moa at 2200 fps enough times to say I done it and then me and Karlina signed a truce stating she will group sub-moa to as far as the bullet will travel, while my part of the agreement is that said bullet will be only of the Sierra 160-grain roundnose variety from now on.
Jäger
Active Member
But I cheated to get a head start on all of you. I bought 20 new, unfired rifles, and group tested all 20 with what was considered some of the best military ball match ammo of the day among all the Commonwealth nations using the Lee Enfield for competition. I kept the one that grouped the best.
I doubt many guys looking for cast bullet accuracy started out by test firing 20 new samples of their rifle of choice and then getting to keep the one that grouped the best.
Success is easy when you start way ahead of all the poor buggers whose rifle is luck of the draw, not the pick of 20.
I never did get around to much of that military cast bullet competition stuff. The Residential Sergeant Major arrived on the scene shortly after the rifle, there was a readjustment period to get used to splitting your time away from work with somebody else - and then 9/11 threw ALL the plans in the circular file for the next 15 years or so until I retired.
Now I don't have the hunger to try and wring the tiniest groups possible out of any rifle. Mostly, I just want to go shoot and hunt as often as possible while all my joints and my eyes still work okay. Just keep the dust shot off the rifles I have for however much time I have left.