What length and weight bullets for the 9.25 twist barrel in the .243 Win?

[MacDR]

Back to the original subject :rolleyes:. Berger bullets has a stability calculator on their website that may help explain why the 9.25 twist rate. Punch in the available bullet specs for the .243 and I think you will see this twist has good coverage.

[mikein]

MacDR, yesterday I ran 10 of my bullets through the Sg calculator, from 58 to 100 grains. Two of the 100 grainers did well (I define "well" as scoring between 1.4 and 2.0 on the stability scale); the rest of them bounced all over the place, from the high 2.5's to a low of 1.2. Having used the stability factor many times before, on many different bullets, I have concluded that it is a good place to start, but is not necessarily the final word on bullet selection, since there are so many other variables to consider. I have a lot of "pet loads" that don't fall within the recommended Sg range. There's a lot more to ballistics that I may NEVER know, and even the professional ballistic folks say it's part science and part magic!

[mikein]

Guess what, gang? I just got a response from Savage! They recommend the 70 grain Nosler BT, at least in factory fodder. Here's the reply:

Debra Roberts (Savage Arms, Inc)
Dec 06 09:18 am (EST)
Hi Mike,
You are correct. Our engineers recommend 70 grain – Federal Nosler Ballistic Tip
thank you

Now if we could figure out what powder and primer Federal uses. . .

[fgw_in_fla]

Cool.
I use a lot of 70's in Nosler BT and Sierra MK.

Good stuff.

[mikein]

I've just spent the last half hour trying to find a box of these bullets to order; nobody seems to have them! I then tried to order a box or two of the factory ammo; nobody seems to have them! Frustrating!!

[beartooth91]

My AccuStock sporter shoots lights out with the medium bullets (Nos 80BT and Hdy 75 V-Max), with a variety of powders. But, drop the bullet weight to the Nos 70 BT or Sie 70 MK; it gets finicky real quick. With these, I've had good results with only IMR-3031.

[mikein]

Thanks, beartooth; I've got a pile of 3031 to work with!

I went to Nosler's site and found the following information:
Their test rifle had a Lilja, 24 inch barrel with a 1:10 twist
Their most accurate loadings were with Varget
Their most accurate Varget loading was with 42.0 grains which gave them an MV of 3616
Their 70 grain BT is .910 inches long
I get a Stability Factor (Sg) of either 1.97 or 2.1, depending upon which of the models I use

I'd definitely like to try these bullets, so if anyone out there in SavageLand can tell me where I can buy some, I'd sure appreciate it!

[mikein]

I just got this from the Berger Bullet Tech Support Team, answering my question about the best ones of their bullets to use in the 9.25 twist barrel:

Hello Mike,

Thank you for getting with us at Berger Bullets. We have checked that you will be able to work with any of our bullets from the 90 grain BTHP, and lighter, and you will be able to stabilize the bullets well. You might be able to stabilize the 95 grain bullet, but is will be very marginal for its stability. The only way you would find out for sure, would be to test with them. We are supplying a link of http://www.bergerbullets.com/litz/TwistRuleAltWP.php, so that you can get to our stability calculator, so that you can run the numbers from your rifle. We are also including our link of http://www.bergerbullets.com/pdf/Quick-Reference-Sheets.pdf, from our website, so that you will have access to our bullet specifications, since you will need the bullet OAL to enter into the stability calculator. Please do not hesitate to get back with us if we can be of further assistance for you.


Kind Regards,
Berger Bullets Technical Support Team
techsupport@bergerbullets.com (techsupport@bergerbullets.com)

[MacDR]

Mikein:

Yes Sg isn't the whole story. There is also Sd, dynamic stability. As you are no doubt aware, it relates to bullet shape and other design factors. As a hobbiest and by no means anything but a ballistics novice, I don't pretend to fully understand how Sg and Sd interplay to determine if a given bullet will be stable in a particular rifle. I have also read that alignment of the bullet in the chamber to the bore can affect its concentricity. A misaligned bullet can supposedly get swaged slighly to one side, imparting a serious dynamic/gyroscopic instability. I can't attest to this as I have never recovered a bullet in such perfect shape that I could measure for this swaging effect. I do know the frustration of getting a bullet with a Sg of 1.51 (190 grain Hornady Interlock BT .308 using the JBM calculator) to stabilize in a otherwise accurate bolt action rifle. At anything over 75 meters every second or third shot would keyhole. After 200 rounds and changes in powder and loads as well as OAL I just gave up. During those trials I read as much as I could on stability but in the end my rifle was the definative authority. I have 10 of those rounds in my ammo locker. Since buying my 99f I haven't had the chance to test them out in this rifle. Same twist (1/12) as my bolt action and pretty much same barrel length but a much shorter throat and tighter chamber. If they shoot well in this rifle I am going to revist the alignment theory :o. Ain't reloading fun!

[mikein]

You are so right, MacDR! There's Sg, Sd, I7, G7 and G1 BC's, and MV to consider. Then there's the temperature, barometric pressure, and altitude. Bullet concentricity plays a part, and the alignment of the bullet in the throat of case, the neck tension, seating depth of the bullet, the kind of primer, the burn rate of the powder, the powder lot, the condition of the crown, the cleanliness of the bore, how well the bore was cut, and the trueness of the bolt face all playing into the accuracy considerations. For a simple man who only wants to put all the bullets into one hole at 100 yards, it's a bit overwhelming, but it keeps me searching for the answers!:frusty:

[FW Conch]

So, what's the problem ???? ;-)

[mikein]

FW Conch, I think that the problem really is my diminished (and diminishing!) ability to handle a problem that seems to have more "variables" than it does "constants" in the equation! It's like trying herd cats; or keep all 12 puppies in a box. Or trying to teach my grandchildren to say "please," or "thank you." There's a lot of unsolved mysteries out there for an old man who does not understand most of what's going on around him. I just add ballistics to the pile!:confused:

[FW Conch]

I heard dat !!! ;-)

[shawnhu]

Hi folks, I'm new here and this thread sparked my interest to join and reply.

For those that don't already know, Savage Arms has on their website an electronic version of their rifle manuals. In there, you will find ALL the factory recommended ammo recommended for different calibers. The .243 is in there, and it does state the Federal 70gr Nosler Ballistic Tip as the ammo they will test with.

Same could be said for their Rimfire as well. Separate manuals, but the ammo used is all listed there. Nosler, Hornady, and I think Sierra are the big three.

Hope this helps.

[mikein]

Thanks, shawnhu; that site is where I got my original information for my query to Savage. As a reloader, I haven't used factory ammo for decades, and was just curious to find out what the driving technical force was behind Savage's decision to go to such an odd barrel twist number. And, now that I know that they recommend the Nosler 70 grainer, I can't help but still wonder why they would use that particular weight and length bullet as their key design point? Marginal for anything other than small deer; major overkill for varmints; it seems they selected a bullet that just fell in between 58 grains and 105 grains! It's a great bullet, and Nosler makes a whole line of fine bullets in all calibers. Just can't figure out how, with all the great bullets out there for which to select, that particular one got the call. . . I guess the answer I was looking for from Savage was something more like: "After years and years of lab testing of every single 6MM bullet on the market, we decided that, to meet our customers' needs the best, a barrel twist of one turn in every 9 1/4 inches was the optimum choice."

[stomp442]

Well I think you hit the nail on the head when you said that they picked one that's right in the middle. I'm sure they don't want to spend hundreds of hours and money on testing every bullet they can get their hands on. By choosing one right in the middle and insuring that it shoots well they can pretty much do the rest with math as far as other bullet weights and lengths go. I applaud savage for giving us the 9.25 twist. it opens up a few more doors on the heavy side that you just cant do with a 1:10 twist.

[mikein]

stomp, I can't think of any other reason for them to have made such an engineering change! It's a decision that can't have been made lightly by a bunch of engineers standing around the water cooler. The marketing implications; the tooling costs; there have got to have been quite a few discussions up and down the hallowed halls of Savage Arms before they implemented this change.

[shawnhu]

Thanks, shawnhu; that site is where I got my original information for my query to Savage. As a reloader, I haven't used factory ammo for decades, and was just curious to find out what the driving technical force was behind Savage's decision to go to such an odd barrel twist number. And, now that I know that they recommend the Nosler 70 grainer, I can't help but still wonder why they would use that particular weight and length bullet as their key design point? Marginal for anything other than small deer; major overkill for varmints; it seems they selected a bullet that just fell in between 58 grains and 105 grains! It's a great bullet, and Nosler makes a whole line of fine bullets in all calibers. Just can't figure out how, with all the great bullets out there for which to select, that particular one got the call. . . I guess the answer I was looking for from Savage was something more like: "After years and years of lab testing of every single 6MM bullet on the market, we decided that, to meet our customers' needs the best, a barrel twist of one turn in every 9 1/4 inches was the optimum choice."

I'm very confused and a little upset about discovering this myself. I purchased the model 11 lightweight hunter for whitetail and so far haven't been able to get a decent group with 100 gr soft points. When asked about it, a Savage rep told me about the 70 grain Nosler, and I was perplexed as to why that light of a round for a hunting rifle meant for the mountains. IMO, that weight is not common, because it serves only one purpose, long range varmint hunting. If reloading, the Savage .243 is a bad round to get IMO, better off with the 6.5 Creed.

[bootsmcguire]

stomp, I can't think of any other reason for them to have made such an engineering change! It's a decision that can't have been made lightly by a bunch of engineers standing around the water cooler. The marketing implications; the tooling costs; there have got to have been quite a few discussions up and down the hallowed halls of Savage Arms before they implemented this change.

Yup, I would say that they found a winner with this twist and hope they stick with it for years to come. As to Savage making a change around the water cooler, you may be surprised. A couple of years back Savage decided to change all of the 7-08 barrels over to an 1-11" twist. Not really sure why they did it, but they did. People seemed as whole to hat the slower twist as they couldn't seem to get much over 130gr to stabilize. Well I would say that the shooting community spoke out, and probably their sales did too, because Savage switched back to the faster twist (1-9" IIRC) and now everyone is happy.



I'm very confused and a little upset about discovering this myself. I purchased the model 11 lightweight hunter for whitetail and so far haven't been able to get a decent group with 100 gr soft points. When asked about it, a Savage rep told me about the 70 grain Nosler, and I was perplexed as to why that light of a round for a hunting rifle meant for the mountains. IMO, that weight is not common, because it serves only one purpose, long range varmint hunting. If reloading, the Savage .243 is a bad round to get IMO, better off with the 6.5 Creed.

The one thing I have discovered with barrels of any maker, is that there seem to be two types. Barrels that shoot many different bullets well, and barrels that only shoot a couple of bullets well. I have had 3 different Savage 243 barrels all with the 9.25 twist and all 3 shot the 100gr Sierra SPT's MOA or better. The one I have that was rechambered to 243AI shoots them 1/2 MOA, but seems to hate the Remington Core-Lok bullets in the same weight. My advice is try another brand of bullet or drop down to a 95gr bullet like the SST for example and see how it does. Another thing to consider in your case is you say you have the 11LWH which has a very skinny barrel and will be influenced a great deal by barrel heat, and also let it get a bit dirty and don't over-clean as Savage barrels like it a bit dirty.

[mikein]

shawnhu, before you get too discouraged, do as suggested and play around with a few different brands and weights. If you are a reloader, let me know and I'll share a good recipe for 100 grain Sierra ProHunters with you that really works well in my 9.25 twist. As pointed out, though, some barrels like some recipes; some don't. But this particular load might be a place to start, and it has worked in both my and my son's Savages.