Fellas. Came across a great deal on a used Remington 700 BDL 243. It’s already heading to the smith to get threaded for my suppressor. And, I want to rechamber it. Question being, what can I realistically change to with a 1-9 1/4 twist barrel? I don’t want to buy a new barrel. Want this to be a cheap, light weight truck coyote/maybe deer rifle. And yes I know, the 243 would do a fine job. But I have a couple already and I want to play with something else. I have a large amount of H4350, H4831sc, Stabll 6.5, Superformance, 8208xbr and RL16. So, 243 AI? 6mm GT? XC? x47 Lapua? What’s my best choice for running 60-90 grain bullets with that twist? Thanks!!
REM 700 243 rechamber
- Thread starter Jchap01i
- Start date
Ha. Found a store in Tulsa Oklahoma when I was passing through that had several 8 pounders of RL16! And an 8 of XBR. Twas an expensive but great day!
As someone who owns a 243, 6BR, 6x47L, and 244AI, I would probably go 6GT or just leave it in 243.
My 243 is a factory R700 Varmint rifle. It seems to get hot quicker and fouls worse than my other guns, but maybe that's because of the factory barrel. Accuracy is decent, averaging around 0.75 MOA with handloads. Powder choice doesn't seem to matter, while velocity changes, accuracy is about the same.
The slow twist will stabilize the 105 Amax at 4000' elevation, has been accurate, but they are not made anymore. The 105 ELD and RDF are too long and accuracy is poor. The 87 Vmax, 95 TMK, and 95 SMK shoot well.
I wouldn't waste your RL16 or 8208 in it. 4831sc is probably a better fit. N540 and 2000MR are powders that seem to burn cleaner in mine. Superformance is one I have on hand and want to try.
My 243 is a factory R700 Varmint rifle. It seems to get hot quicker and fouls worse than my other guns, but maybe that's because of the factory barrel. Accuracy is decent, averaging around 0.75 MOA with handloads. Powder choice doesn't seem to matter, while velocity changes, accuracy is about the same.
The slow twist will stabilize the 105 Amax at 4000' elevation, has been accurate, but they are not made anymore. The 105 ELD and RDF are too long and accuracy is poor. The 87 Vmax, 95 TMK, and 95 SMK shoot well.
I wouldn't waste your RL16 or 8208 in it. 4831sc is probably a better fit. N540 and 2000MR are powders that seem to burn cleaner in mine. Superformance is one I have on hand and want to try.
Thanks! I was leaning toward the AI before reading that it’s not great in shorter barrels and I’d not really gain much. Having a Sandman L that’s almost 9” long is like the barrel 18-20 inches. GT brass seems readily available. Think I may run that race. I have allot of 90 grain TGK’s. Should make a decent coyote getter.
You don't want to spend a lot of money but you are talking about dumping a ton into a cheap factory barrel to change to a caliber that will do nothing more for you than a .243? Think about it and long and hard before doing anything to that besides threading the barrel. Anything more is a waste of money.
I get along pretty well with the local gunsmith. He said he’d recut my chamber to any of those because he has the reamers on hand for 40 bucks since he’s already doing a R709 7mm SAUM for me. Figure try a new cartridge, if I love it then perhaps build out the rifle with a new barrel. So I’d be out the 40 bucks and cost of dies and brass.
He'd have to set the barrel back and rethread also. He won't be able to just rechamber for a shorter 6GT. Might want to check if that's all going to be $40.
243 AI or 6 CM are probably the only options on the existing barrel. You’re twist rate isn’t going to be great for the longer high bc bullets but you’ll definitely grab some more speed.
I have heard it said bullets matter more than headstamps. Simply shoot out your 243 barrel and screw on a 6 creedmoor.
edit: sorry didn't notice how old thread was.
edit: sorry didn't notice how old thread was.
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I’d vanilla .243 and work up a load for 80 TTSX’s and 80 ELD-VT’s and shoot it till the grooves disappeared.
243AI is about your only option unless you want to get exotic with it.
I had an out of whack chamber in a 243 model 700 vls. Local Smith though we could get it to clean up with an AI reamer but it just barely didn't make it on the back end of the chamber. The only thing I found that would completely clean out the old 243 chamber was a 6-284. I didn't feel like sourcing the dies and brass for it so I abandoned it for several years.
Years later I ended up putting that rifle back together and I'm liking the 243AI. Running 85gr bthp gamekings at 3400, and 55gr noslers at 4000 from a 24" barrel.
I had an out of whack chamber in a 243 model 700 vls. Local Smith though we could get it to clean up with an AI reamer but it just barely didn't make it on the back end of the chamber. The only thing I found that would completely clean out the old 243 chamber was a 6-284. I didn't feel like sourcing the dies and brass for it so I abandoned it for several years.
Years later I ended up putting that rifle back together and I'm liking the 243AI. Running 85gr bthp gamekings at 3400, and 55gr noslers at 4000 from a 24" barrel.
That's not a $40 job from any competent riflesmith to change the chamber to another cartridge listed.
The 243 Ackley improved requires the barrel removed and set back one full turn...if the chamber finish reamer neck is the same size or slightly larger then the original chamber...it would be better to cut a new neck in the chamber to clean up nicely and have less firecracking if the barrel has been shot much.
But at least one full turn as the Ackley chamber is slightly shorter than the standard 243 chamber.
As Ackley designed it, you are supposed to put a factory 243 in the chamber... but have to smack the bolt down pretty good to chamber it.
Otherwise case head separation happens.
Which means you have to recut everything, pertaining to fitting a barrel to a Remington 700...like barrel tennon, bolt nose counter bore depth and dia. and maybe have thread.
Recalculate headspace.
And buy an Ackley go gauge.
Might as well buy a new match barrel in the caliber of choice.
OR leave it a factory 243, it will suit the purpose just as it is...and cheaply.
The 243 Ackley improved requires the barrel removed and set back one full turn...if the chamber finish reamer neck is the same size or slightly larger then the original chamber...it would be better to cut a new neck in the chamber to clean up nicely and have less firecracking if the barrel has been shot much.
But at least one full turn as the Ackley chamber is slightly shorter than the standard 243 chamber.
As Ackley designed it, you are supposed to put a factory 243 in the chamber... but have to smack the bolt down pretty good to chamber it.
Otherwise case head separation happens.
Which means you have to recut everything, pertaining to fitting a barrel to a Remington 700...like barrel tennon, bolt nose counter bore depth and dia. and maybe have thread.
Recalculate headspace.
And buy an Ackley go gauge.
Might as well buy a new match barrel in the caliber of choice.
OR leave it a factory 243, it will suit the purpose just as it is...and cheaply.
Pretty much all this. The 243ai has the most gains of any ackley improved case. When I had a couple ackleys, fireform load shot in the .5s with 105@3080-3100 and the fireformed case would scream 105s@3300+ into bugholes. I worked up some loads for a deployed buddy in his 243 rem varm, 95tmk at 3425(24 or 26" barrel) they worked great for him. H4350 and h4831sc work great in a 243/243ai, with the shortened barrel I would look at rl16 or h4350 since you'll get closer to 100%burn with their faster rate.
Is that 6 comp match or 6creed? Creed would need a setback, if comp match nevermind.
243ai cleans it up nicely, his Smith has that reamer and he's got dies to load the parent case.
It cleans up nicely... if ya set the barrel back.
If your gunsmith doesn't do that it isn't chambered correctly...because the 243 Ackley improved chamber is slightly shorter than the standard 243 Win.
Can not clean up on the standard chamber when its slightly longer in headspace than the Ackley Improved. So ya need to set the barrel back...just the facts.
If your gunsmith doesn't know that, don't have him chamber your rifle....
True, sort of. A 243ai max headspace is right at minimum 243win, or 243 go gage acts as a no go for 243ai. Easy enough to work around as a reloader, seat bullet in 243 long to jam rifling, then set up 243ai sizer to just bump back .001. While you are technically correct, I would wager that most ai chambers are cut on existing parent chambered factory barrels. My 2 243ai were cut on kreiger blanks, so virgin. I remember having this conversation with Smith and yes he knows how to do it, but he also mentioned how a large portion of ai were made and how to reload for those.
Yes, you can do it correctly as it was designed...or do it incorrectly, and work around.
It was designed to shoot factory 243 in the Ackley chamber to fire form 243 Ackley....with no need for false shoulder or jamming bullets ...so when your done ya don't really have a 243 Ackley improved but something else, and the fired cases would not fit in a correctly chambered 243 Ackley....but would fit "Your wildcat" version of "243 improved"...
Factory chambers vary widely, especially in some early rifles .008" is not uncommon, and the no go will sometimes chamber, plus the brass is headspaced quite a bit shorter than minimum chamber headspace specs.
Then what is the neck dia of the orginial factory chamber compared to the chamber reamer.
Why, "If" I were going to change from 243 Win factory barrel to another caliber and "just had to do it" ....it would be a 6 X.284, cause it cleans up everything including firecracking in the throat and down the bore a bit....but I'd most likely buy a new match barrel if it were mine.
The 6X284 and 6X284 improved were popular 1000yd benchrest cartridges back in the day.
I chamber for wildcats and obsolete cartridges.
I do not particularly care how your rifle is chambered, but you should know the difference between a correctly chambered Ackley standardized wildcat or non standard improved wildcat...and don't confuse the difference between standardized chambering and a
"work-around" non standard wildcat...the chambers are not the same.
It was designed to shoot factory 243 in the Ackley chamber to fire form 243 Ackley....with no need for false shoulder or jamming bullets ...so when your done ya don't really have a 243 Ackley improved but something else, and the fired cases would not fit in a correctly chambered 243 Ackley....but would fit "Your wildcat" version of "243 improved"...
Factory chambers vary widely, especially in some early rifles .008" is not uncommon, and the no go will sometimes chamber, plus the brass is headspaced quite a bit shorter than minimum chamber headspace specs.
Then what is the neck dia of the orginial factory chamber compared to the chamber reamer.
Why, "If" I were going to change from 243 Win factory barrel to another caliber and "just had to do it" ....it would be a 6 X.284, cause it cleans up everything including firecracking in the throat and down the bore a bit....but I'd most likely buy a new match barrel if it were mine.
The 6X284 and 6X284 improved were popular 1000yd benchrest cartridges back in the day.
I chamber for wildcats and obsolete cartridges.
I do not particularly care how your rifle is chambered, but you should know the difference between a correctly chambered Ackley standardized wildcat or non standard improved wildcat...and don't confuse the difference between standardized chambering and a
"work-around" non standard wildcat...the chambers are not the same.
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