.243 barrel twist question.


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nekwah
February 15, 2009, 12:12 AM
Ok so i have a Savage 10 in .243 and i hearing that theres a big difference between the rate of twist for heavy loads and light loads. As in it will be very unaccurate using a different weight load than what the barrels twist was designed for. Is there some way to find this or am i gonna have to screw around measuring it. There was a thread somewhat like this but cant find it. It was for remington too i think. Wondering if there was something stamped on them that would tell me?

Another question completely off topic. Could you reload a .222 cartridge with a bullet labeled for .223?

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nekwah
February 15, 2009, 12:33 AM
a link to a thread explaining this could be helpful if there is one. thanks

Sunray
February 15, 2009, 12:54 AM
The rifling twist is about the bullet weight, not how hot the load is. Has to do with stabalizing the bullet. Can't say as I've ever seen a really good site that explains it well. Suffice to say heavy bullets prefer a fast twist. Light bullets a slower twist.
Savage uses a 1 in 9 1/8 twist, as I recall(their site is currently down). Your rifle will prefer heavy bullets(85 grains and up), but won't be inaccurate with lighter bullets.
Most .243's are rifled for deer sized game. Even heavy varmint barrels.
The only important thing is if you're deer hunting, most light bullets are varmint bullets and aren't suitable for deer sized game. Varmint bullets are made to expand rapidly upon impact with little penetration. Deer sized game bullets penetrate then expand. Using deer bullets on varmints is fine. What a Speer 105 grain SP does to a ground hog is astounding. A varmint doesn't care what the bullet weight kills it. Hunting varmints with your deer rifle and load is fabulous practice too.
"....222 cartridge..." It uses .224" bullets(so does the .223 Rem). There are lots of 'em from every maker. A .223" bullet will work, but it won't be as accurate.

interlock
February 15, 2009, 07:31 AM
Sunray is right on. with the .243 analogy. My ruger 243 with 1 in 9 twist really struggles with 100gr or more. it does like speers 90 gr hotcor. I use my 7mm08 for deer hunting or my 30-06 sprg.

interlock

Jim Watson
February 15, 2009, 10:40 AM
As in it will be very unaccurate using a different weight load than what the barrels twist was designed for.

B.S.
Gunshow Commando B.S.

Within the normal range of commercial hunting ammo, the different loads and bullet weights (actually bullet lengths) have an equal chance of good accuracy in a standard barrel with the standard rifling twist. I would expect your Savage with its 9.125" twist to shoot anything from an 87 grain varmint bullet up to a 105 grain deer load. Might even go down to a 75 grain varmint load. I don't know about the weird little 55 grain screamer, but if you want to try it, no reason not to.

True, your factory barrel might not handle the 107 grain SMK, and surely not the 108 grain VLD or 115 grain DTAC, but those are long range specialty target bullets, and if you take up the 1000 yard game you will just have to specify the correct aftermarket barrel.


As to bullet choice, the name of the cartridge does not necessarily specify the diameter of the bullet it shoots. For example the .218 Bee, .219 Zipper, .220 Swift, .221 Fireball, .222 Remington, .223 Remington, .224 Weatherby, and .225 Winchester have in common that they ALL fire .224" diameter bullets. (But the .22 Jet is really a .222" and the .22 Savage Highpower is really a .227".)

Art Eatman
February 15, 2009, 11:02 AM
My old Sako .243 has a 1:10 twist. Very tight groups with 85-grain and under. I only tried once with 100-grain Noslers, but it was more a pattern than a group. Damfino.

From numerous threads and commentary, the .243 seems to do best, overall, with a twist around 1:9.

Ben Shepherd
February 15, 2009, 11:08 AM
Faster twists will slabilize bullets on the lighter/shorter end of a calibers range. But the oppisite isn't true, a slow twist barrel won't stabilize long/heavy for caliber slugs.

You may have your info just a bit twisted-The whole reason that the 243 winchester is popular and most folks don't have or haven't heard of a 6mm remington is factory barrel twist.

When the 6mm rem came out most barrels were 1:12 IIRC. This was fine for lighter varmit slugs, but when folks tried to push it into larger game territory with heavier bullets, accuracy suffered due to the slow twist rate. The 243 win came in 1:10 or faster barrels that would stabilze the heavier tougher slugs needed for medium game. Too bad really, as the 6mm rem holds an edge in ballistics with its slightly larger case capacity.

Jim Watson
February 15, 2009, 11:31 AM
Yo, Ben. When the Remington Model 722 rifles had a 12" twist, it was as the .244 Remington. The name 6mm Remington was adopted for the same chamber with a 9" twist after the Model 700 came out. (There are a very few early Remington Model 700s marked .244 with a 10" twist.)

Art's Sako didn't shoot the 100 grain Noslers well because the partition adds to the bullet length and that is what really governs stability. It might have done ok with a simple cup and core 100 grain bullet, which is what Winchester based their barrel and ammo specs on. But that is why Nosler made a 95 grain partition.

A target shooter will be using an 8" twist for 105 grain boattails anyhow. Or more.
Target shooters using small caliber high ballistic coefficient bullets for Long Range shooting with less recoil than the .30s that used to rule, and the US Army trying to make a varmint gun into an infantry rifle have gotten a lot of attention paid to rifling twist. Very little of that applies to hunting rifles and their ammunition.

tango2echo
February 15, 2009, 12:48 PM
I own six different Savage rifles in .243 Win. Savage used a true 1 in 9 twist on the early Model 110's. I believe the 110 E was the last series that had the true 1 in 9. All subsequent models have used a 1 in 9.25 twist.

All six of my Savages shoot great with anything lighter than 105grs, with the exception of the Remington Cor-Loks. I also have two other .243 Win's currently, a Ruger M77 and a Browning A-Bolt. The Ruger shoot very well with the 95gr Hornaday SST or anything lighter. The A-bolt does not shoot heavy bullets well at all. (and will soon have a new owner because of it.)

Honestly, I think most of the talk about ROT in .243 is BS. Any rifle with a twist close to 1 in 9 should shoot well with most, if not all, of the bullets under 105grs.

T2E

jlmurphy
February 15, 2009, 03:43 PM
You can measure the twist. Use a cleaning rod with a tight fitting patch, place a tape flag on the rod, push the rod in and measure how many inches it takes to complete one revolution.

NCsmitty
February 15, 2009, 04:38 PM
Jim Watson and tango2echo have got it right. When Winchester introduced the 243 with 1in10 twist and Remington used the 1in12 with the 244. people bought the 243 because it could handle the flat base 100 gr bullets. The best the 244 could do was a 90gr bullet and the sales dropped because people wanted a combo gun, not just a varmint rifle.

The whole point of this little history lesson is a 1in10 twist will handle a 100gr flat based bullet, but the longer boattail versions will not stabilize in that twist unless driven to velocities beyond the capabilities of the 243.

Most commercial barrels made now are in the 1in9+ range to handle the heavier boattails that are popular now without compromising their ability for the lighter varmint bullets too much.
If you're having trouble with a extra heavy boattail not grouping, drop the bullet weight and/or try a flat base style bullet.

NCsmitty

aubie515
February 16, 2009, 11:25 PM
I have a stock Savage model 12 in 243 and the only bullets I loaded are the Hornady 75gr Vmax. I'm not getting the precision that I was hoping for, but it shoots sub MOA.

I just purchased a McGowen 1:9 twist and I am hopeful that it will shoot the same 75gr load with better results. I will also be looking to load it with 95gr Hornady's for deer.

moooose102
February 17, 2009, 08:10 AM
this might be of help. http://www.6mmbr.com/243Win.html

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