As some may have read, I have a problem child rifle that I mess with periodically when I am needing a lesson in patience.

Well, I got the barel off and chucked up in our old lathe. I cut about 1" off the end and crowned it...square crown...and polished out the tool marks with an old hard knife sharpening stone. Finally I broke the sharp muzzle/crown edge with a rounded brass rod and lapping compound. Here's the result:





Now I truck down to the range. 4 shots to get on paper and I'm off to the 100 yard line. As you look at this target, keep in mind that this is 4 seperate 3 shot groups at the same aim point with about 10 minutes of cooling in between. The flyers were shot #1 group 2, and shots #1,3 group 3 (high), shot 2 group 4 (low). None were obvious 'called' pulls.





The barrel is floated from about 2" in frount of the receiver. I redid the bedding with marine tex. You see the crown. The center group is/was normal before I started screwing with it a year or so ago...so what's up with the flyers?

Time to quit screwing around and rebarrel?

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Time to quit screwing around and rebarrel?

I would say it is probably time to let a professional have a look at it.

it almost looks like you're using bullets from two lots.....one good bullets and the other lot of lesser bullets.....

What bullets are you using?.....Go out and buy a fresh box of Ballistic tips.....see if this schneganance continues.....

Hey CDH, If it was mine, I'd try a different bullet weight before doing anything else. Sometimes a rifle just doesn't want to shoot a specific bullet weight.

I may be getting in late. What is the action, barrel and caliber? What are you shooting in it? I can see from your photo's that the bore is dark and can see a good amount of copper in pic #2.

DFC, this is a 1908 Brazillian Mauser in .280Rem. The barrel is of unknown vintage, being obviously not original (decent bluing vs. unblued action), stepped 'military style', and looks like it was done with a rough tool (spiral grooves parallel to rifling the full length of the bore). No markings besides proof marks.

Malm, this is a 'can't hurt it' type project. The keys are low budget (new baby, wife not working, and I like to tinker) and hobby, as well as educational. I expect that eventually I will get it to a 'smith for a rebarrel, but for now I would like to take it as far as possible myself. I'm an engineer, BTW, and figuring out/fixing stuff with my own hands is a passion of mine. To a point.

Loads are from a new box of Remington PSP-CL green box 150 grain ammo...I've never reloaded for this particular caliber. All of the 140-150 grain PSP-CL Rem ammo has given similar results, and similar to the 150 grain Federal NP load I also like, for much less money/shot. My favorite (and normal WT deer hunting) load is the Win. Ballistic Silvertip 140 grain load...but it is REAL pricey for testing at this level. It is much more accurate too, but still just a 1-1.5" gun. Good enough for what it is used for...backup and loaning. I have another favorite rifle that does most of my hunting now.

Fouling...long story. The real start to this saga was when I decided to clean the copper/Lubalox from a couple of hundred rounds worth of the 140 grain BST loads (previously with only basic powder fouling removal) Sweets. The rifle immediately went from 1" to 2". Okay, some shoot better fouled. I never got the original accuracy back, so I started tinkering. Pitted crown was obvious...so I recrowned (1st time). Instant 6-12" gun. I rebedded. No help. I recrowned again, with the results you see here. I haven't cleaned it thoroughly since I started this mess because of the original issue.

As some of the others, I'm new to this conversation too. But, it almost looks like a scope issue???
From your description, though, you've been having issues with this rifle for a while. Is there any possibility the scope is taking a dive?
You mentioned the groups opening up after you cleaned it thoroughly. I agree, most rifles shoot more consistently with a fouled bore, but your descriptions of the fliers doesn't fit that explanation.
Without the fliers, that's a good looking group. Ammo could bear the blame, but I wouldn't bet on it.
I still can't get away from the scope/mount explanation.

Before I did anything else I would clean out all the copper and then polish the bore with JB. Have you considered trying any other type ammo?

Just for the heck of it try to put a forend pressure point (tape in a piece of credit card or something similiar) about 1/2" back from the forend tip. It looks like all your fliers are vertical so this might give you somethng to try.

quote:

Originally posted by CDH:
DFC, this is a 1908 Brazillian Mauser in .280Rem. The barrel is of unknown vintage, being obviously not original (decent bluing vs. unblued action), stepped 'military style', and looks like it was done with a rough tool (spiral grooves parallel to rifling the full length of the bore). No markings besides proof marks.

Malm, this is a 'can't hurt it' type project. The keys are low budget (new baby, wife not working, and I like to tinker) and hobby, as well as educational. I expect that eventually I will get it to a 'smith for a rebarrel, but for now I would like to take it as far as possible myself. I'm an engineer, BTW, and figuring out/fixing stuff with my own hands is a passion of mine. To a point.

Loads are from a new box of Remington PSP-CL green box 150 grain ammo...I've never reloaded for this particular caliber. All of the 140-150 grain PSP-CL Rem ammo has given similar results, and similar to the 150 grain Federal NP load I also like, for much less money/shot. My favorite (and normal WT deer hunting) load is the Win. Ballistic Silvertip 140 grain load...but it is REAL pricey for testing at this level. It is much more accurate too, but still just a 1-1.5" gun. Good enough for what it is used for...backup and loaning. I have another favorite rifle that does most of my hunting now.

Fouling...long story. The real start to this saga was when I decided to clean the copper/Lubalox from a couple of hundred rounds worth of the 140 grain BST loads (previously with only basic powder fouling removal) Sweets. The rifle immediately went from 1" to 2". Okay, some shoot better fouled. I never got the original accuracy back, so I started tinkering. Pitted crown was obvious...so I recrowned (1st time). Instant 6-12" gun. I rebedded. No help. I recrowned again, with the results you see here. I haven't cleaned it thoroughly since I started this mess because of the original issue.

Well then, judging by the pictures, you might try recrowning the muzzle a third time. Cut the crown from the center out. Leave the lands and grooves sharp and clean. Don't round or lap anything. Look the bore over good, particularly in the throat area. Using your engineering eye's, see if the lands appear fairly sharp, or, are they kinda washed out ahead of the chamber.

If the bore etc. looks good, then now might be the time to start thinking about reloading for this gun. Apparantly it doeasn't like factory stuff. Slip some business cards under the barrel to apply pressure. Vary the pressure by adding and subtracting cards. If the groups come in with the pressure. STOP! Send me a PM and I will try and talk you through how to determine the exact amount of pressure so you can repeat it with a more permanent bedding solution. Keep the faith, or, start saving towards that new barrel.

If I may throw out a couple thoughts:

Is there a chance your 280 was rechambered from a 7x57 using an original military barrel? If so, have you slugged it to determine if it is the proper bore diameter or not?

Also, as I remember reading one gentleman's comments on a 7x57 -> 280 Rem project he'd just completed, I remember him writing that he found the twist rate in the military barrel to be problematic with the 280 loads he was firing. It seems that the barrel didn't like light bullets and didn't like fast loads - because of the twist rate. Could this also have a bearing on your problem barrel?

I could be completely off base here, but I thought I'd chip my $.02 anyway.

Good luck with this and I hope it's shooting well soon. Nothing's worse than an inaccurate rifle.

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Is there a chance your 280 was rechambered from a 7x57 using an original military barrel?

an excellent observation...this is likely.....

Hmmm...I haven't slugged the bore, but my handy calipers measures about .2845-.2850" at the muzzle.

It is very possible that it is a rechambered 7x57. I did the 'mark a rod' twist rate measurement a while back, and IIRC it came out to 1:9.5". I don't know if they stamped proof marks on barrels back then, but would a 'smith normally polish and re-blue a military barrel as part of the rechamber?

The rifling looks okay at the throat. The person doing the chambering job didn't spend much time polishing the chamber though. It shows some fine toolmarks...distinct but fine (small). I don't have the tools to evaluate it much further...but it's visibaly rougher than my crown finish for sure.

I have a few rounds left from a box of 175 grain Remington round nose ammo I could try again, as well as some of my pricey (Fed 150NP and Win 140BST) stuff. Personally I am of the opinion that I won't reload unless the fliers go away...the $$$ is better spent on rebarreling, and I won't go back to .280 with it. When I run out of ammo, either it's fixed or it gets fixed, if you know what I mean!

I've tried scope changes, remounting bases with red Loctite, re-bedding, new shooter, 4 different ammo brands/types, 2 re-crownings, and all have the fliers to some degree. At least it's improving, so it gets another chance! Dangit...I really saw a .220 Swift in my future...

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Well then, judging by the pictures, you might try recrowning the muzzle a third time.

Honest question...I posted the pictures for feedback...do you see something in my work that looks 'off'? I want the (constructive!) feedback you guys give so generously. I haven't been able to cut without leaving a wire edge into the bore area...hence the lapping to clean it up.

Keep the ideas coming! Beer's on me for the guy/gal who figures out this thing...of course it's in Corpus Christi Texas.

My money is on the barrel, I like Bud.

Likely not the crown, or the ammo. that leaves the barrel of unkown quality.

Since it is a 280, go get another barrel.

I have found the 280 one of th MOST difficult calibers I have found to make shoot well.

1. My very first thought is that the target looks as if the action is slowly setting back into place in the stock as you fire it. That type of issue is why most folks recommend not taking a barreled action out of the stock any more times than you absolutely have to, once it shoots okay. Anyway, POI will definitely change in a rifle until the barreled action reaches stasis in the stock.

By any chance did you have it out of the stock for any reason about the time you cleaned it with the Sweet's?
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2. My second thought is that the crown looks sorta okay at the most important point...right where it breaks into the bore, but it's a bit rough outside of that. Just as a suggestion, when you re-crown another barrel, don't stick a stone of any sort onto the crown. Instead, once you have the crown cut, spin the barrel at somewhere over 500 rpm and take a little piece of 240 or finer grit emery cloth and press it firmly against the end of the bore with your finger for the final breaking/finish. Move it around just a bit. Your eyes and your sense of touch will tell you how to do it. In my experience, that gives both a much smoother break and and a much smoother crown surface....really polishes it up...might work for you too. I also use a very small, very charp, cutting tool (1'4" tool)for doing my 79-degree crowns. Let's me cut right from the outer edge all the way into the bore, without hitting the other side of the bore with the back of my tool.

(Guess I should correct this, as I really cut from the center of the bore to the outer edge of the barrel...keeps from leaving a "burr" on the inside when the last bit of metal is cut away. But anyway, it let's me put the tool in there without hitting the other side of the bore with the back of the tool.)
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3. The folks who mentioned the scope might well be onto something, regardless which brand it is. It sure looks like "something" is moving, whether the action in the stock, the reticule in the scope tube, the scope in the rings, the rings in the bases, something....
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4. Just out of curiosity, is there any chance a sling swivel or sling swivel stud might have been touching either the front or rear bag on some or all shots? If so, that will vary the recoil sufficiently to change impact elevation from shot to shot.
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5. If you are going to check for accuracy, inexpensive doesn't get it as a primary ammo consideration. You need to use whatever it is that your rifle likes. Some rifles, you have to find and build that load, others work out okay with one or a few versions of commercial ammo. Only a few rifles few shoot really well with all factory ammo.

A guy can always go to the cheap stuff for plinking once he knows the rifle does (or doesn't) shoot the way he wants, but if he uses an ammo his gun doesn't like just because it is cheap, he'll never know how accurate it could be...
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6. If it was mine, I would not rebarrel at this point. There are too many basic things left to explore...like bedding, slugging the bore, checking the match of twist to bullet weight (length), trying a known-to-be-good scope on the gun, re-checking the bench technique, etc.

Good luck.