fast twist : slow bullet

[1874sharpsshooter]

Speed kills is the mantra nowdays for bullets. In the discussion about twist rate I decided to experiment a little . I chose one of my fast twist guns. it is 1:18 twist. Normally I shoot either a 500 gr lead bullet or a 405 gr lead bullet. For this experiment I chose a 300 gr jacketed hollowpoint, knowing the gun doesnt shoot them very well . But what if I slowed them down some. Would that help.?
I went with loads that according to my program would give me about 1200 to 1300 fps max. ( just a guestimate)
The wind was 19 mph with gusts even higher so I decided to do all the shooting at 50 yards .The gun is sighted in at 100 yards.
The first bullet which was 200 gr lighter than normal and 50 yards closer shot high. That's the top hole on the target.
I didnt want to change my sight so I just held under the orange a hair. it put 2 in one hole



I was shooting without a steady rest, like hunting conditions
the next group wasnt bad but it did have a flyer



then I decided to try 6 shots as fast as I could. , the barrel was really warm. You can see the results



Overall I came to the conclusion that I could shoot even light bullets in a 1:18 twist if I kept them slow . They would still be deadly on game and produce hunting accuracy.
This was all done with open sights. The bullets were .459
Powder was 38 weight grains Blackhorn 209

[flounder33]

Chet, How much is the 38 grains by weight in a volume measure? Or what is the conversion, I just use volume measures myself.
edit: I found it, 38 grains by weight should be real close to 57 grains by a volume measure.

[Boonechaser]

According to my program, that is pretty accurate. Using a 1:18 barrel and 1300fps at muzzle would require a bullett about 1.42" in length to stabalize.

Have you noticed that if the bullet is longer in legth, you can speed it up? According to the program I have the length has more to do with stabilization than does weight.

Thats part of why I do not see a fast twist Knight doing well. In todays world of magnum loads and long range shooting, I don't see the everyday average guy willing to give up the speed, to shoot a fast twist.

Which again would be Knight trying to supply a very small, niche group.

[1874sharpsshooter]

I would think if lehigh made some bloodlines that they could be 300 gr or less and be shot much faster and still stabilize well compared to my lead bullets which need to be up there at 500 gr or so. Just a guess of course. I definitely believe it's length more than weight for sure

[Ridge Runner]

bullets cannot be overstabilized if they are structuraly sound to withstand the RPM's.
velocity mounts to not much as far as bullet RPM's go.an example
12/18=.666x1300x60=52000 rpm's
12/18=.666x1800x60=72000 RPM's

12/21=.571x2200x60= 72000 RPM's
as you can see the same bullet in an 18 twist at 1800 fps spins the same speed as a bullet at 2200 from a 21 twist. my guess is your rifle don't like that bullet, 20 thou rpm isn't enough to blow accuracy outta the water.
RR

[1874sharpsshooter]

Ridgerunner:you are right , it doesn't like that bullet. The gun actually prefers a 405 gr or a 500 gr with the 500 being the most accurate. I just got a couple 405's in so I plan on trying them with different loads and different powders

[Chasam60]

What is the length of a .458/405?

Charlie

[1874sharpsshooter]

Originally Posted by Chasam60

What is the length of a .458/405?

Charlie

only 1.04 inches
checked the 500 gr and they are 1.3
I push the 405 at about 1800fps and it does great.

[builder459]

Originally Posted by Boonechaser

According to my program, that is pretty accurate. Using a 1:18 barrel and 1300fps at muzzle would require a bullett about 1.42" in length to stabalize.

Have you noticed that if the bullet is longer in legth, you can speed it up? According to the program I have the length has more to do with stabilization than does weight.

Thats part of why I do not see a fast twist Knight doing well. In todays world of magnum loads and long range shooting, I don't see the everyday average guy willing to give up the speed, to shoot a fast twist.

Which again would be Knight trying to supply a very small, niche group.

This is exactly why i question this move knight is making in regard to changing the .45 cal twist. the 1:28 & 1:30 twists shoot the 40 cal bullet offerings excellent, with the exception of the 200 gr .40 Lehigh which needs to be pushed to 2300 fps or more in these twists due to it's length being to long.changing to a twist that has a bad reputation deserved or not, for one brass bullet and heavy conicals to me is madness.i have seen tons of testing on bullets for the .45 cal 1:28 & 1:30 and PR bullets has done major testing on the .45 cal 1:20, which doc white shot a 350 gr saboted bullet from accurately..staying with the 1:30 and developing jacketed .40 cal bullets in the .220-.260 range makes a lot more sense and would be a hell of a lot less risky.Knight can't afford two red headed step children ( .52 & 1:20 .45)