Twist rate vs. Bullet weight Question

Pruson

Pruson

New member
I own a Remington Model Seven .223 with a 1 in 12" twist. Shouldn't this gun be able to handle a 60 gr. bullet with some consistent accuracy?
 
Some 12 twist barrels have been known to have problems with some 60 gr bullets. You will just have to try them and see.

On the barrel twist on light bullets, my 1 in 8 barrels handle 40gr bullets with no problem at all. 1 in 9 twist barrels prove to be finicky with factory ammo on how it shoots.
 
It's not the pill weight but rather length. Some barrels will handle those pills with a standard twists. Ultimately it comes down to the rifle....Take for instance a 75gr Berger, my 1 in 9 Hart just eats them up but try a 75gr Amax and no dice. You also have to consider the o-give of the pill.

Gari
 
Let me see if I understand this a 1 in 12 twist rate won't stabilize the heavier bullets as well as the 1 in 9 will so is there a disadvantage to shooting smaller grain bullets in the 1 to 8 or 1 to 9 twists. Just confused what would be the best of both worlds
 
Bart,
In my experience 1 in 12's will handle 60/63gr's in factory barrels. Most 9's will shoot anything just fine from 50-69. The only advantage in a faster rate is for longer pills. To shoot any thing heavier than 80gr's one must go to a 8 or even better 1 in 7 3/4. This is the rate preferred by National High-Power shooters....atleast it use to be. I think Jack is up on this he may be more help than I.

Gari
 
courtesy of Shilen

Caliber Twist:


.172
- 9" for bullets heavier than 30gr.
- 10" for bullets up to 30gr.

.204/20
- 12" for all bullets


.222 RF
- 14"* Twist for pistol barrels
- 16" Standard twist for rifle barrels
- 17"* Special twist for rifle barrels

.224 CF
- 8" for bullets heavier than 70gr.
- 9" for bullets up to 70gr.
- 12: for bullets up to 63gr.
- 14" for bullets up to 55gr.
- 15"* for bullets up to 55gr. driven 4,100 pfs or more
- 16:* for bullets up to 55gr. driven 4,300 fps or more

6mm/.243
- 8" Special for VLD bullets over 100 gr.
- 10" For bullets up to 120 gr. and VLD under 100 gr.
- 12" for bullets up to 85gr.
- 13"* for bullets up to 75gr.
- 14"* for bullets up to 70gr.
- 15"* Special for bullets up to 70gr.

.257
- 9" for bullets heavier than 100gr.
- 10" for bullets up to 100gr.
- 12" for bullets up to 90gr.
- 13"* for bullets up to 80gr.
- 14"* for bullets up to 70gr.

6.5mm/.264
- 8" for bullets heavier than 130gr.
- 9" for bullets up to 130gr.

.270
- 10" for all bullets

7mm/.284
- 9" for bullets heavier than 140gr.
- 11" for bullets up to 140gr.

.307
- 13"* Special size and twist

.308
- 8" for bullets heavier than 220gr.
- 10" for bullets up to 220gr.
- 12" for bullets up to 170gr.
- 14"* for bullets up to 168gr.
- 15"* for bullets up to 150gr.

7.65mm/.311
- 10" for all bullets

8mm/.323
- 10" for all bullets

.338
- 10" for all bullets


9mm/.355
- 14" for low velocity wad cutters
- 16" for all other bullets

.38/.357
- 14" for low velocity wad cutters
- 18" for all other bullets

.358
- 14" for all bullets

.375
- 12" for all bullets

10mm/.400
- 16" for all bullets

.411
- 14" for all bullets

.416
- 14" for all bullets

.44
- 20" for all bullets
- 16" for low velocity wad cutters

.451
- 16" for all bullets

.458
- 14" for all bullets
 
I just shot some 40 gr vmax that I reloaded from my Savage 10FP 24 inch 1 in 9 twist. I was very pleased to see a 6 shot,1 inch group at 100yds using 2 different brands of brass and 2 different primers with 25grs of IMR 3031, and an OAL of 2.27. Now if I can get the same results from my NEF handi 223.........
 
Ridge Runner nailed it, overspinning a bullet only makes flaws in a bullet more visible. With quality bullets just not something to worry about unless you are a serious benchrest competitor and looking for that last .010" reduction in group size.

Jack
 
Got a buddy of mine that's shooting the 68 Hornady Match out of a 22-250AI 12 twist, and getting 2" gps. at 300 yds.-- no discernible keyholing. My benchrest gunsmith who's been at it for a longtime (supposedly introduced Greg Tannel to gunsmithing) says that one of the secrets to good grouping is to get the bullet just stabilized.?
 
What does VDL mean? I was looking at JustC's post where he posted the rate of twist from Shilen. Specifically the - 10" For bullets up to 120 gr. and VLD under 100 gr.

Why I ask is because I bought a Remington SPS and I'm going to have it accurized but I'm going to leave the factory barrel on it for a while. It's 1-9 1\8" twist if I remember right. I want to find the lightest load I can shoot with decent accuracy.



6mm/.243
- 8" Special for VLD bullets over 100 gr.
- 10" For bullets up to 120 gr. and VLD under 100 gr.
- 12" for bullets up to 85gr.
- 13"* for bullets up to 75gr.
- 14"* for bullets up to 70gr.
- 15"* Special for bullets up to 70gr.
 
VLD = Very Low Drag. They have more pointed noses and a longer boat tail. They are longer than a regular bullet of the same weight so require a faster twist barrel.

Jack
 
Quote:
I have a Bushmaster V Match 223 with a 1-9 twist. I was wondering what loads out of that gun shoot the best.



If the shots you make are under 300 yards, you may want to try playing with the 60 grain flat base bullets. There is little need for boat tail bullets under 300 yards. The VLD's will work quite well at much longer distances but not neccessarliy with any given twist. The VLD's as Jack mentioned are longer, but they don't neccessarily have more bullet to land contact so barrel configuration plays a huge part.

So given your 9 twist, I would stay more in the 60 - 65gr. area. Keep the speed up and it should be very effecctive on coyotes in the 200 - 300 yard range.
 
Velocity is a factor also. I was told 80 gr JLK's needed a 1-7 or 1-8 twist and they shot great out of my 1-9. The reason was the velocity, they were being push at 3550 fps. It would be easier for me if they would list what rpm range they shot best at and print the formula for rpms on the box. /ubbthreads/images/graemlins/grinning-smiley-003.gif Velocity X 12 divided by Twist X 60 = RPM

3,550 X 12 = 42,600
42,600/9 = 4,733
4,733 X 60 = 283,980 RPM's

2,600 X 12 = 31,200
31,200/9 = 3,467
3,467 X 60 = 208,020

Just My $.02 /ubbthreads/images/graemlins/grin.gif RR
 


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