.243 Win 700 Remington

[Wallyl]

I have a 1977 .243 Win 700 that I shoot fairly often with mostly cast bullets. In the 40+ years I have shot 1,000 + Jacketed bullets through it and well over 10,000 Cast bullets (95 SP-GC RCBS). I have noticed erratic groups that have been getting worse. So I took a fired case and crimped the case mouth, inserted a 105 grain j-bullet base first, loaded long to determine the distance from the case mouth to the leade---it was at .394". I would guess that the throat is "shot out" and it would be best to rebarrel it. Can anyone tell me that has a 700 in the .243 Win what there "leade distance" is?

Thank you....

 

[CZ93X62]

Leade clearance is a more complex subject than can be determined by use of a reversed flat-based bullet of proper caliber. The "freebore" measurement you are trying to determine can only be accurately determined by involving the bullet or its ogival duplicate with the leade origin engagement. I have a Sinclair (now sold by Hornady) Tool for this purpose. It uses a drilled & tapped case of the proper caliber to "soft-seat" an exemplar bullet into the leade origin, from which an OAL measurement can be derived. In most cases, I want about .025"-.035" of freebore in my jacketed-bullet loads, and a "soft kiss" of the bullet into the leade origin with my castings. Barnes Bullets recommends a minimum of .050" of freebore with their all-copper "Condor Cuddler" bullets.

More complications--and you just KNEW there would be some. Magazine dimensions can influence OAL considerations. If a rifle is a repeater, you likely want it to feed from the magazine, and this goes double for self-loaders. OEM big-maker barrels of recent times have very deep throating, and are made that way to guard against some newb refiller pouring in an Internet-derived max powder charge with "x" bullet and jamming its ogive into a leade and lighting off a bomb. My experience with the Rem 700s of the mid-70s to mid 80s is that their throating was of reasonable depth to fit most commercial loadings in their respective calibers. My calibers among that population/experience were 222 Rem, 223 Rem, 22-250 Rem, 243 Win, 308 Win, and 30-06 Sprfld. Given one caliber of seating depth, most (but not all) bullets in medium weights gave sufficient safe leade clearance in most rifles.

One particular Rem 788 x 22-250 I bought c. 2005 illustrates an example of an assertion I'll make here that will get the benchresters into vapor-lock most ricky-tick. Assertion--leade clearance a MUCH MORE a matter of safety cultivation than of accuracy pursuit. It is a TWEAK--not a basic foundation. Here goes--I bought the 788 from a guy in Ventura with full disclosure by him that its barrel had A LOT of miles on it. 22-250s can get shot a lot, and that cartridge has a large boiler room on contrast to its bore size--lots of propellant gases going down a small hole at high pressure and great heat will wear things out, sometimes in a hurry. The rifle's price reflected that reality, and I was cool with that--I was buying it for its action to re-barrel.

I get it home and start running my usual Tale Of The Tape on the internals. "Worn" was a good descriptor, to say the least--basically, it was a "Weatherby"--lots of freebore, on the order of .150" with the Sierra 60 grain HP seated at max-spec 2.350" OAL. The mag would allow for 2.400", and not a tenth more. Aight.

I did a pound-slugging on the throat--.225" + a couple tenths. Yeah, it has some miles on it. Aw, WTH--let's make some ammo for it and see what it does. Mild load, 60 grain Sierras atop 34.0 of H-380 and WLR primers in WW cases, 2.395" OAL. To the range......and I'll be da--ed, it shot GREAT. A whole bunch of sub-1" 5-shotters. Stepped up to 36.0 grains (book max), and The Song Remains The Same. I hunted that rifle as-is for 8 years until I finally broke down and re-tubed the critter in 2013-14 (it took a while to get it back. Long story). And worth the wait. This barrel shoots great as well.

Moral of the story--if a load goes south all of a sudden, I doubt that throat depth from flame-cutting is the sole or even primary source of accuracy fall-off. There are a lot of "moving parts" in a reloading circumstance, Bullets change--alloys change--powders change--primers change--cases change. In my case, The Nut Behind The Stock changes--brought on by aging and the ravages of same. There was no particular "need" to re-barrel that 22-250, from the standpoint of pure accuracy. I DID pick up about 125 FPS of velocity in any given load because the barrel (Pac-Nor, 1-12" twist) is tight in all respects. But the rifle's accuracy is undistinguishable between barrels.

Just my 2 cents.

 

[462]

Might want to inspect the muzzle.

 

[Wallyl]

I only load single shot...I insert the loaded round manually in the chamber. The cast bullet's nose makes no contact with the lands when loaded long and chambered, BUT is very hard to insert into the muzzle...a sure sign of erosion. Also J-loads fired today have hundreds of FPS loss in velocity compared to when I fired them in the 80's. I guess I better rebarrel.

Leade clearance is a more complex subject than can be determined by use of a reversed flat-based bullet of proper caliber. The "freebore" measurement you are trying to determine can only be accurately determined by involving the bullet or its ogival duplicate with the leade origin engagement. I have a Sinclair (now sold by Hornady) Tool for this purpose. It uses a drilled & tapped case of the proper caliber to "soft-seat" an exemplar bullet into the leade origin, from which an OAL measurement can be derived. In most cases, I want about .025"-.035" of freebore in my jacketed-bullet loads, and a "soft kiss" of the bullet into the leade origin with my castings. Barnes Bullets recommends a minimum of .050" of freebore with their all-copper "Condor Cuddler" bullets.

More complications--and you just KNEW there would be some. Magazine dimensions can influence OAL considerations. If a rifle is a repeater, you likely want it to feed from the magazine, and this goes double for self-loaders. OEM big-maker barrels of recent times have very deep throating, and are made that way to guard against some newb refiller pouring in an Internet-derived max powder charge with "x" bullet and jamming its ogive into a leade and lighting off a bomb. My experience with the Rem 700s of the mid-70s to mid 80s is that their throating was of reasonable depth to fit most commercial loadings in their respective calibers. My calibers among that population/experience were 222 Rem, 223 Rem, 22-250 Rem, 243 Win, 308 Win, and 30-06 Sprfld. Given one caliber of seating depth, most (but not all) bullets in medium weights gave sufficient safe leade clearance in most rifles.

One particular Rem 788 x 22-250 I bought c. 2005 illustrates an example of an assertion I'll make here that will get the benchresters into vapor-lock most ricky-tick. Assertion--leade clearance a MUCH MORE a matter of safety cultivation than of accuracy pursuit. It is a TWEAK--not a basic foundation. Here goes--I bought the 788 from a guy in Ventura with full disclosure by him that its barrel had A LOT of miles on it. 22-250s can get shot a lot, and that cartridge has a large boiler room on contrast to its bore size--lots of propellant gases going down a small hole at high pressure and great heat will wear things out, sometimes in a hurry. The rifle's price reflected that reality, and I was cool with that--I was buying it for its action to re-barrel.

I get it home and start running my usual Tale Of The Tape on the internals. "Worn" was a good descriptor, to say the least--basically, it was a "Weatherby"--lots of freebore, on the order of .150" with the Sierra 60 grain HP seated at max-spec 2.350" OAL. The mag would allow for 2.400", and not a tenth more. Aight.

I did a pound-slugging on the throat--.225" + a couple tenths. Yeah, it has some miles on it. Aw, WTH--let's make some ammo for it and see what it does. Mild load, 60 grain Sierras atop 34.0 of H-380 and WLR primers in WW cases, 2.395" OAL. To the range......and I'll be da--ed, it shot GREAT. A whole bunch of sub-1" 5-shotters. Stepped up to 36.0 grains (book max), and The Song Remains The Same. I hunted that rifle as-is for 8 years until I finally broke down and re-tubed the critter in 2013-14 (it took a while to get it back. Long story). And worth the wait. This barrel shoots great as well.

Moral of the story--if a load goes south all of a sudden, I doubt that throat depth from flame-cutting is the sole or even primary source of accuracy fall-off. There are a lot of "moving parts" in a reloading circumstance, Bullets change--alloys change--powders change--primers change--cases change. In my case, The Nut Behind The Stock changes--brought on by aging and the ravages of same. There was no particular "need" to re-barrel that 22-250, from the standpoint of pure accuracy. I DID pick up about 125 FPS of velocity in any given load because the barrel (Pac-Nor, 1-12" twist) is tight in all respects. But the rifle's accuracy is undistinguishable between barrels.

Just my 2 cents.

 

[Wallyl]

Muzzle (crown) looks good.

Might want to inspect the muzzle.

 

[RBHarter]

I have a 7mm barrel that's shot out and y'all ain't even in the same zip code of it . All silliness aside it would chamber the 301618 NOE version of the Lyman NRA paper patch bullet at 2.90 oal . On more or less the same a 280 AI no less . To get a set back and rechamber it would require the whole shank to be removed for the 98' it was screwed to . Rebore to a 338 - 300 Gibbs maybe .

In that vein a set back and chamber ream for an AI if there is such a thing might be more cost effective . It doesn't sound like you have a neck and throat erroded by .016+ so there's hope .

More a geewiz than knowledge . Has anything changed ? Alloy , alloy source , checks or source , mould or sizer wear , brass changes , sizing die wear or new dies , press wear ? Could it be new primers and/or powder lots ? There's been a lot of messing with the old tried and trues the last 5-7 years .

 

[Ian]

If you know someone with a bore scope, inspect for excessive heat checking in the first few inches of the bore, if that looks good make an impact impression of the whole throat area and see what your measurements look like. .243s have a reputation for throat erosion and likely the bore will be too worn for a set-back.

 

[fiver]

10-K cast bullets shouldn't even rough up a barrel let alone burn it out.
unless your doing some of the dumb stuff I tend to do with cast bullets, then 10-K might be stretching some of them.

I would scrub the thing out to 25 caliber with 6 different solvents before I gave up on it.

 

[Wallyl]

Thanks...I did think of that, unfortunately I don't know of anyone with one.

If you know someone with a bore scope, inspect for excessive heat checking in the first few inches of the bore, if that looks good make an impact impression of the whole throat area and see what your measurements look like. .243s have a reputation for throat erosion and likely the bore will be too worn for a set-back.

 

[Wallyl]

That's what I thought, but I have shot 1,000+ J-bullets in it and perhaps that was enough to erode it. I had read that if a load shoots at a greatly reduced velocity, that is inductive that the barrel is done. As mentioned, my best cast bullet loads have many more flyers than they used to. As this is not the case with other calibers that I shoot often, that too seems to tell me it's time to rebarrel.

10-K cast bullets shouldn't even rough up a barrel let alone burn it out.
unless your doing some of the dumb stuff I tend to do with cast bullets, then 10-K might be stretching some of them.

I would scrub the thing out to 25 caliber with 6 different solvents before I gave up on it.

 

[fiver]

it probably is.
I bought a mostly burned out 243 some time back for like 175$ then proceeded to run another 3-400 high speed low bullet weight loads through it.[all it would shoot and at a ridiculously long jump]
one afternoon poof no more accuracy, I still have a hundred or so rounds loaded so I'm debating the same thing you are.
I suggested the super serious cleaning because your alligator throat might be bighting a bullet every now and then.
then the tug of war is over until the next one cleans it out again.
one more thing that might work is to run a handful of Jacketed or Paper patch bullets through it to maybe iron things out again.
I guess it just depends on whether your trying to keep going or if your fully resigned to just re-barreling.

 

[Wallyl]

I have read read that when a specific load starts to drop 200~300 fps in velocity the throat is shot out and the only solution is to rebarrel. The .243 is pretty well known for being a barrel eater. From what I read the barrel life is roughly 1,500 J-bullet shots. I started keeping track of the no. of shots 21 years ago, but I bought the rifle in 1977....I am almost certain I have fired more than 1,500 J-bullet rounds through it. If one fires many shots through a hot barrel, the barrel life is greatly reduced. I never did much of that kind of shooting with it. But then again I didn't wait 20~30 minutes for the barrel to fully cool down either.

it probably is.
I bought a mostly burned out 243 some time back for like 175$ then proceeded to run another 3-400 high speed low bullet weight loads through it.[all it would shoot and at a ridiculously long jump]
one afternoon poof no more accuracy, I still have a hundred or so rounds loaded so I'm debating the same thing you are.
I suggested the super serious cleaning because your alligator throat might be bighting a bullet every now and then.
then the tug of war is over until the next one cleans it out again.
one more thing that might work is to run a handful of Jacketed or Paper patch bullets through it to maybe iron things out again.
I guess it just depends on whether your trying to keep going or if your fully resigned to just re-barreling.

 

[Wallyl]

I read this on another website....notice it mentions serious issue after only 500 shots!

Burning out a bbl is largely related to throat erosion.

Once a bbl chambered for the likes of a 243, 6XC, or 6.5x284 gets 500 rds thu it, you can borescope the bbl and find:

Cracking in the bbl steel in the first two inches of bbl. Some call this alligator cracking because it begins to look like a dry lake bed or the irregular pattern of skin on an alligator.

The throat (tapered part of the lands) begins to wear/recede from the mouth of the case. That is why you "Chase" the lands with bullet seating as the round count down the bbl increases.

This rough area begins to build up with copper fouling that is torn from the bullet as it passes. This affects accuracy.

The actual land diameter also enlarges/tapers towards the muzzle. Chamber end of the bore will measure larger than the muzzle. If you rechamber a used bbl, you will see that the pilot that fits the muzzle is way too small in diameter for the breach end of the bbl.

Muzzle deterioration/wear comes from cleaning rods and from rounds fired. The high temp/pressure gases do begin to take the sharp edge off the crown after 1000 rds or so. That is why benchresters recrown their bbls to keep that area sharp.

So if you want the high performance cartridges like 22/250, 243, 6.5x284, then be prepared to pay the price of short bbl life. If you are a hunter, this may not be an issue. For us competition shooters (where a lot of rounds are put down bbls each year) it is an expense we have to accept.

 

[fiver]

the competition guys also like to jam the bullet into the rifling to varying degrees.
this will also burn the throat up by increasing heat, friction, and pressure in that area.

I think my best bet is to have mine re-bored to 7-08.
I was gonna go with a 6.5 but that would be a re-barrel the 7 should be easy enough to have re-cut if I can find someone to do that work.

 

[Wallyl]

Great idea....I am not sure how much that'll cost. Looking around, one can get a SS barrel and have it installed for as low as $350, plus shipping. The re-bore may cost more than that. I asked Remington what it would cost to rebarel the 700....still awaiting their response. Their CS is not up to the standards or Ruger.

the competition guys also like to jam the bullet into the rifling to varying degrees.
this will also burn the throat up by increasing heat, friction, and pressure in that area.

I think my best bet is to have mine re-bored to 7-08.
I was gonna go with a 6.5 but that would be a re-barrel the 7 should be easy enough to have re-cut if I can find someone to do that work.

 

[fiver]

personally I wouldn't send it to Remington.
it would be easier to find a pull off barrel for one of them.
I'd still rather spend the extra couple hundred and get an aftermarket rather than going even that route.

 

[Wallyl]

I decided to do some test groups later this month with Jacketed & cast bullets. I Beagled the cast bullets (RCBS 95 SP-GC) that may well make a difference. If I get more consistent groups with them, I'll be plenty happy.