Rebarreling a 243 - rifling twist considerations

[Wapiti]

Hi all,
Wanted to pick some brains here. I am about to order a TSE barrel in 6mm, for a 243.
I believe the standard for the last 1000 years for most brands in this cal is 1-10" but I think this is a bit slow even for 90gn bullets. They might stabilise but back in the old days, 80gn was standard when 1-10" was standardised. But what I think and the reality might be two different things, it doesn't matter.

I'd like to be able to up the weight of projectiles and also play around with long copper bullets, the cartridge case itself is perfect for this and I might just look at an AI version too when I get the reamer. Cases everywhere, and cheap.
But I would like advice too, would a faster twist stuff up the ability to shoot the lighter bullets well? They really teach fawn-pecking crows turn back into their individual atoms, the huge open hollow-points stepping one-up on the 22-250 for feather clouds.
And no, I am never going to ever be interested the 6mm Creedmoor case. This "groundbreaking" must-have "new" cartridge has up to 5gns less capacity than the old .243 depending on case brand.

What do you reckon? 1-8" twist? 1-7"?

[deye243]

I absolutely love the 243 as I consider it the best varmint cartridge ever developed if I was building one would be a one in 12 to shred critters in the paddock but up where you are I do believe I would not entertain the idea of having a 243 unless it was a one in eight i also like knocking off stuff at the longer Ranges than the average person but there are a lot of really good 100+ grain bullets on the market and also slightly lighter monolithics that need the extra twist just my waffle.

Now after all that I'll ask the proper question I should have asked at the start what are you using it for and what's your favourite projectile for the job

[Wapiti]

Thanks for that info mate, I also think the 243 is one of the best varmint cartridges, and it's also really flexible.

But I've been real interested in Outer Edge copper bullets in the 80 and 90 grain weights, they say for the 90's a 1-7" is best, there's the Hornady ELD-X Hunting 103gn, Bergers up to 120 etc. Does not work whatsoever in the twist in the Howa I have.
In fact that rifle is very fussy, HATES any powder except for 2208.
I use Atomic29 Aussie-made copper projectiles in a Sako .300 and it will one-hole 3 shots with 155 and 175gn projies, it's that performance that I'd like to see in the 243.

I also had a play with making copper bullets myself, but it's not economical in fact I never saved any costs with purchasing small batches of copper round bar. The main thing was, could I do it. Way less trouble than copper cups, swaging etc. but taking account of deflection was a learning curve, only took a few but means making only ones at a time is time consuming.

Anyway, primarily it's for dogs and any pigs I come across, I reckon the little Speers I've been playing with are a bit light in fact the barrel on this rifle LOVES them but just will not tolerate the 90 and 100 Hot Cors as far as a good group goes no matter what I do. Twist?
Yes I could grab one of our light accurate 308's for this which does everything here with absolutely no fuss but now I know the 243 can be improved, it's something I'd like to try.
Just wondering though whether or not a faster twist will destroy the possiblility of using 70-75gn bullets.

[deye243]

That's the thing with barrels sometimes you will have a barrel with a twist that will overspend a light projectile and it will Group dine sometimes it won't generally speaking though short bullets in fast twist barrels if they won't gfoup fast a lot of the time they will when you slow the load down a little bit since you've mentioned pigs and dogs I would just go the 1:8 or if you can find one and use your heavies you're 90 to 108 plus with 2209 should come up pretty good

[GQshayne]

I think you have described an issue with your rifle. This could potentially be rectified with a new barrel, in 1:10. The fact that it does not like 2209 is unusual, as is not being able to group 90gn projectiles. That is pretty standard fare for most .243 rifles.

[morerams]

The only reason to go with a faster twist than1 in 10 is if you want to use the long match bullets like the Sierra 107, or 110 HPBT or the Hornardy 108 ELD. 1 in 10 will handle anything else.

[Wapiti]

Perhaps it is the barrel, and maybe I'm expecting too much also.
I have only ever had three .243's, and all of them preferred the lighter end of bullet weight. When I talk about doesn't like, the results are not what I have been getting very simply with other cartridges.
It's not about using the target bullets, that's not on my radar but I would like to use more copper bullets and it seems that light/long for diameter needs to be spun a bit faster. And improved the results on the 90-100gn loads.

But the other evening I banged out 50 handloads using a Lee 4-die set, the Ultimate set with the collet neck die and crimp die.
I only use Lee dies for 223 and 243 but everything else larger, I take very seriously and use Redding bushing and competition dies and that might be why I get such good results easily for my larger firearms?
I just run an eye over each and I can see noticeably mega projectile run-out, and if I roll the cartridges on the flat 12mm steel benchtop, the runout is absolutely insane.
This might be a big problem, these f**ken dies. I can see the runout without even using gear to check. This will not be helping my load development.
This was with NEW cases, FLS to the rifle's chamber crush feel, done to uniform them all for first firing, neck dents in new brass etc and to be reliable for what I was going to do with the cartridges.

I've walked away from everything until I get more time to check using some V blocks and a dial indicator, but I know it's unacceptable already.
Might be buying some more dies.

[bladeracer]

Hi all,
Wanted to pick some brains here. I am about to order a TSE barrel in 6mm, for a 243.
I believe the standard for the last 1000 years for most brands in this cal is 1-10" but I think this is a bit slow even for 90gn bullets. They might stabilise but back in the old days, 80gn was standard when 1-10" was standardised. But what I think and the reality might be two different things, it doesn't matter.

I'd like to be able to up the weight of projectiles and also play around with long copper bullets, the cartridge case itself is perfect for this and I might just look at an AI version too when I get the reamer. Cases everywhere, and cheap.
But I would like advice too, would a faster twist stuff up the ability to shoot the lighter bullets well? They really teach fawn-pecking crows turn back into their individual atoms, the huge open hollow-points stepping one-up on the 22-250 for feather clouds.
And no, I am never going to ever be interested the 6mm Creedmoor case. This "groundbreaking" must-have "new" cartridge has up to 5gns less capacity than the old .243 depending on case brand.

What do you reckon? 1-8" twist? 1-7"?

No, a tighter twist rate won't ruin your lighter bullet accuracy, though it might be possible to find a bullet that doesn't like a tighter twist rate I guess. If you want to shoot heavier bullets try the 100gn Interlock round-nose, at under an inch long it stabilises in 10"-twist.

Bullet weight isn't relevant, bullet length is what matters. You can shoot round-nose flat-base 100gn bullets in a 10"-twist, but it won't stabilise the 73.5gn OEP target bullet or their 72gn ball bearing bullet.

If you want to shoot longer copper bullets, that are also heavy, then you'll want very tight twist rates. With copper bullets you can generally drop back a few steps in weight, to allow short enough bullets to stabilise, without losing anything at the target because of the better engineering of the bullet.

For general use I'd go 8"-twist, you don't need 7"-twist until you get up around 1.300" in length. I tried the OEP bullets in 7mm and didn't like the design, though they were accurate enough. I found the TSX and TTSX better to work with.

[bladeracer]

Perhaps it is the barrel, and maybe I'm expecting too much also.
I have only ever had three .243's, and all of them preferred the lighter end of bullet weight. When I talk about doesn't like, the results are not what I have been getting very simply with other cartridges.
It's not about using the target bullets, that's not on my radar but I would like to use more copper bullets and it seems that light/long for diameter needs to be spun a bit faster. And improved the results on the 90-100gn loads.

But the other evening I banged out 50 handloads using a Lee 4-die set, the Ultimate set with the collet neck die and crimp die.
I only use Lee dies for 223 and 243 but everything else larger, I take very seriously and use Redding bushing and competition dies and that might be why I get such good results easily for my larger firearms?
I just run an eye over each and I can see noticeably mega projectile run-out, and if I roll the cartridges on the flat 12mm steel benchtop, the runout is absolutely insane.
This might be a big problem, these f**ken dies. I can see the runout without even using gear to check. This will not be helping my load development.
This was with NEW cases, FLS to the rifle's chamber crush feel, done to uniform them all for first firing, neck dents in new brass etc and to be reliable for what I was going to do with the cartridges.

I've walked away from everything until I get more time to check using some V blocks and a dial indicator, but I know it's unacceptable already.
Might be buying some more dies.

I stick with Lee dies, though I have acquired other brands over the years - RCBS, Lyman, Redding, Simplex. Lee dies lack nothing I need from my ammo.

[Wapiti]

Hey mate, there is a place for precision equipment.
For some, not all. fair enough.
That when something is 1/3rd the price of "more precision stuff, even 1/4 the price, there is always a reason.
Thing is, i never ever checked the quality of the ammo I made on the 223 and 243 dies, because to me it was nothing precision. 223 ammo I almost exclusively use ADI factory because I don't have a need for a 223 often.
But this particular die is seating bullets crooked, some more than others.
I do know how to properly adjust dies, and although some who haven't tried more precision dies will never know the benefits, they will never see the need. Cheers to them. You will not see it until you take the trouble to see how variations cause the same thing on the target, variations.
When you as a handloader who is trying to get the most from your gear starts actually running measuring equipment over the results, understands how you'll never get the best from your stuff when your projectiles hit the rifling at 1000mph on an angle, this one up, next down, next to 10 oclock well, you will never get the best that your work time provides. For the same effort.
Some care, some don't.
When I get the time I will report here how much runout these loaded rounds have. People who place importance in consistency might get something out of it.

[bladeracer]

Hey mate, there is a place for precision equipment.
For some, not all. fair enough.
That when something is 1/3rd the price of "more precision stuff, even 1/4 the price, there is always a reason.
Thing is, i never ever checked the quality of the ammo I made on the 223 and 243 dies, because to me it was nothing precision. 223 ammo I almost exclusively use ADI factory because I don't have a need for a 223 often.
But this particular die is seating bullets crooked, some more than others.
I do know how to properly adjust dies, and although some who haven't tried more precision dies will never know the benefits, they will never see the need. Cheers to them. You will not see it until you take the trouble to see how variations cause the same thing on the target, variations.
When you as a handloader who is trying to get the most from your gear starts actually running measuring equipment over the results, understands how you'll never get the best from your stuff when your projectiles hit the rifling at 1000mph on an angle, this one up, next down, next to 10 oclock well, you will never get the best that your work time provides. For the same effort.
Some care, some don't.
When I get the time I will report here how much runout these loaded rounds have. People who place importance in consistency might get something out of it.

Agreed absolutely. I haven't had any concentricity issues with Lee dies, and I have lots of them. Perhaps you got a bad set though.

The main reason I see for similar products varying wildly in price is marketing, not quality.

[bladeracer]

Hey mate, there is a place for precision equipment.
For some, not all. fair enough.
That when something is 1/3rd the price of "more precision stuff, even 1/4 the price, there is always a reason.
Thing is, i never ever checked the quality of the ammo I made on the 223 and 243 dies, because to me it was nothing precision. 223 ammo I almost exclusively use ADI factory because I don't have a need for a 223 often.
But this particular die is seating bullets crooked, some more than others.
I do know how to properly adjust dies, and although some who haven't tried more precision dies will never know the benefits, they will never see the need. Cheers to them. You will not see it until you take the trouble to see how variations cause the same thing on the target, variations.
When you as a handloader who is trying to get the most from your gear starts actually running measuring equipment over the results, understands how you'll never get the best from your stuff when your projectiles hit the rifling at 1000mph on an angle, this one up, next down, next to 10 oclock well, you will never get the best that your work time provides. For the same effort.
Some care, some don't.
When I get the time I will report here how much runout these loaded rounds have. People who place importance in consistency might get something out of it.

Actually, concentricity and neck tension were the issues I had with the OEP bullets, that's why I preferred the TSX bullets. Also the black crap they coat the bullets with is filthy stuff and takes time to remove.

[perentie]

I bought the Lee Precision seating die for the 223 upper on the Wedgetail. Its only got a 16 inch 1 in 7 barrel but surprised all of us at the last club shoot at 500 yds.
Shooting 80 gn Sierras at only 2600fps. Try 600 next Saturday. I am finding Lee dies OK for that, Its got a floating thing that keeps the bullet centre.
Not much help with the 243 but. Just thought I would chuck it in.
Cheers.
Keith

[Wapiti]

Yeah well, somethings not right with this seating die, I haven't had a chance to check but I bet it's out of alignment internally, or something.
So sure this thing is not going to be used going forward, I've ordered two Redding 3-die sets to replace the 223 and 243 Lee stuff. Nothing flash, no bushing dies with supporting chambers to ensure concentricity, just standard dies. Cos I just don't use dies in those cals enough. But there's no way I'm going to handload ammo where I CAN SEE the crooked projectile sticking off-centre, without even using some v-blocks.
Those of you who have had no issues, I'm glad. I would expect that from a big name. I'm sure it's just a one-off dud.

[GQshayne]

You may be on to something with the dies. It certainly won't be helping.

[bigrich]

i'm watching this topic with interest . thinking of a 6mm for precision range work with occasional hunting uses. i prefer my 308 tikka as a all rounder out bush, but the 6mm has merits for target work , goats and the majority of pigs that i encounter. tikka make a 8 twist 243 now . with regards to dies i prefer decent quality hornady, RCBS or redding . i've used lee dies with no issues , but you get what you pay for quality wise . having said that i had a set of hornady 222 dies that tried to put a belted rim on my 222 brass . bought a set of rcbs dies problem solved . cartridge choice wise i'm on the fence between 243 vs 6mm man-bun . 243 has the runs on the board , but being OCD i can't fathom the short neck and shoulder angle that blow torches the barrel throat . the original warren page 240 super pooper used the long neck and shoulder angle of the 257 rob/6mm rem , which is close to the man-bun case neck and shoulder, creedmoor case is also a twin to the old 250 savage ackley case invented waaay back when . the wheel has been reinvented quite a few times now winchester chose to stick with the shallow shoulder for ease of brass manufacture and smoother feeding with their 243 case. in a tikka t3 feeding would not be a issue with a single stack mag . am i overthinking the case differences , yes i am . i did mention i'm OCD ... .

30-06 guys once derided the 308 as some reinvented, new fangled upstart , the 6mm man-bun is gaining ground in the USA for specific long range comps , particularly in AR platforms . we'll have to see if it takes hold in OZ, but i'm sceptical as the 243 has been doing sterling service for a long time now . component availability and ammo in the regions is a no-brainer in favour of the 243 , but the big C have stocks of hornady 6mm man-bun ammo, and cases aren't too hard to find in bigger gun shops .

i think twist rates are specific to application , 1-8 in 243 would suit you well wapiti for your intended uses/bullet weights . freebore chamber length might be a issue with case capacity and longer projectiles with a standard 243 chamber. from what i've seen and heard with 243's the 87 vmax is a really great projectile for general use and accuracy , which only requires a 10 twist . i've been told 90gn nosler bt's and 95gn sst's are good for deer and pigs , but i think this is starting to push the boundaries of the 243 in comparison to 308's . having said that , there was a fella on here years ago up in FNQ that only had a 243 and used it on everything up to scrub bulls with head shots . one of you other long time forum members might remember who that was. "daddy bang" i think ? loved 243's as a extremely accurate mild recoiling rifle that did every job he asked of it .

JMHO opinions , from my limited experience , perspective and intended uses time for another coffee .....

[Duramax]

Rich the 6.5 Man bun came with a lot of hype where it is difficult if not dangerous to try and replicate velocities factory offerings from Hornady with their proprietary powders can attain.
I had 243s for years but no more. The 6 Creedmoor with less capacity exceeds 243 velocity in virtually every bullet weight but really shines with bullets over 90 grains. Where the 6mm is different to the 6.5 Man bun is that ADI powders meet and exceed published factory data. My LRP rifle runs 2209 and 107 SMKs at just under 3200 fps in a 26 inch barrel with no case stress issues. The main thing i see with the two 6 Creeds i have and even the 6 x 47 Lapua is that they have wider accuracy nodes. Not saying 243s aren't accurate but the Creed has lower ES that sets it apart at 7, 8, 9 and 1000 yards. Barrel life is somewhat better than 243 but it isn't in the 3K area as it is a hotrod. Not burnt a barrel out yet and am beyond 1500. For general hunting, no idea of barrel life but i suspect it will be like 243s i have had in the past, shot well yesterday and died the next day. Anyones guess.
The 6 and 6.5 Man bun share the same trait that is handy with detachable magazine rifles in that with the long bullets like 103 ELDX the OAL is still able to load and cycle through a standard magazine that i use in both the LRP and hunting rifles i have. Borderline with 243 and some bullets.

[bigrich]

Rich the 6.5 Man bun came with a lot of hype where it is difficult if not dangerous to try and replicate velocities factory offerings from Hornady with their proprietary powders can attain.
I had 243s for years but no more. The 6 Creedmoor with less capacity exceeds 243 velocity in virtually every bullet weight but really shines with bullets over 90 grains. Where the 6mm is different to the 6.5 Man bun is that ADI powders meet and exceed published factory data. My LRP rifle runs 2209 and 107 SMKs at just under 3200 fps in a 26 inch barrel with no case stress issues. The main thing i see with the two 6 Creeds i have and even the 6 x 47 Lapua is that they have wider accuracy nodes. Not saying 243s aren't accurate but the Creed has lower ES that sets it apart at 7, 8, 9 and 1000 yards. Barrel life is somewhat better than 243 but it isn't in the 3K area as it is a hotrod. Not burnt a barrel out yet and am beyond 1500. For general hunting, no idea of barrel life but i suspect it will be like 243s i have had in the past, shot well yesterday and died the next day. Anyones guess.
The 6 and 6.5 Man bun share the same trait that is handy with detachable magazine rifles in that with the long bullets like 103 ELDX the OAL is still able to load and cycle through a standard magazine that i use in both the LRP and hunting rifles i have. Borderline with 243 and some bullets.

i don't mean to derail wapiti's original topic, but thanks for the info , it confirms my research . 6mm man-bun seems to work well with the powders i use in other cals , 08,09 , efficient case design as well . only issue i can see for my uses is the fact that the 6CM is throated for long bullets . in reality the 85-90gn projectiles suit my uses perfectly, hunting/target to 300 meters ,which is also what the 243 is throated for . i wouldn't cry over losing a ADI 243 case out bush either . rather than go through the rigmarole of a waiting on a barrel for a custom build i'm thinking buying a t3 off the shelf and fitting it out with all the good gear currently on my 308 is probably a less painless way (cheaper) of achieving my goal . i haven't fact checked it yet, but tikka list 8 twist for 243 now , not sure if they still sell t3's in 10 twist for 243 . it seems like twist rates are getting quicker for 243 in factory rifles, a recent trend in the US is faster twists for 270win . some companies are starting to make high bc bullets for the 270 now. the one thing i do pay attention to in ballistics is the powder burn rate . i believe cartridges that run medium to faster burning powders are a sign of efficiency for bore size, to a certain degree better barrel life as a benefit. supposedly