Home Forums Hunting & Shooting Ask The Gunwriters Barrel and twist for .358 Win?

Mine has a muzzle diameter of .650 - which is what MRC considered to be the minimum they would go.

I have five rifles chambered to the .358 Winchester. Three have 1 in 16" twists rates and two have 1 in 12" barrels. The 1 in 16" guns are all bolt action and the 1 in 12" guns are lever actions. Guess what? The two witht he 1 in 12" barrels are noticable more accurate than the bolt action rifles.
Regarding whether a 1 in 12" twist will affect how well a 180 gr. bullet holds together, I have some 150 gr. Remington bullets that were made for the .350 Rem. mag. and so far I haven't had any come unglued at high velocity, even in the 1 in 12" guns.
I also have three rifles in .35 Whelen, two having a 1 in 16" twist and another, a custom Mauser I picked up at an estate sale has a 1 in 14" twist. All will shoot bullets up to 250 gr. reasonably well. The Mauser is the tightest grouping rifle, but all are acceptable. The next Whelen will have a proper 1 in 12" twist.
Paul B.

It could be that the pointy/longer(?) bullets were on the edge of stability. Certainly other factors could be at play so I won't flog that horse too much. Rotational velocity results in angular momentum and that is where stability comes from. In general terms spitzer forms have more displacement between CG and CP so require more spin. Solid base wadcutters, or better yet, round balls have the two co-located, or nearly so. Idle curiosity on my part, have you shot those little hindenbergs out to the range where they start going sub-sonic, and if so how did they do there? If, and that is an "if" you are on the edge of stability it might show up at that range. Marginal stability does not infer inaccurate necessarily, but it does make the bullets susceptable to the wobbles along the way. Transonic speeds are the realm of maximum pitching moments on bullets.

On a small tangent, sometimes folks confuse velocity with stability, thinking they can overcome marginal circumstance with fps. To a very small degree that is true. The math is rather simple actually. A bullet with a 12" twist at 3000 fps MV is spinning at....drum roll....3000 rps or 180000 rpm. Tighten the twist up to 10" and it's doing 3600 rps or 216000 rpm. Rather than tighten the twist we'll assume that some nimrod wants to achieve the same stability with velocity....he'll need 3600 fps, and that goal is likely not possible due to case capacity or pressure limitations.

Nice hog cannon BTW. Probably a lot of thru and thrus? <img src="/ubbthreads/images/graemlins/cool.gif" alt="" />

Dan,

The "hog cannon" is still unchecked, but as the hogs get closer to being a problem here, that will probably change!

1200 fps is barely supersonic and many would consider that to be transonic, or at least dropping below supersonic speeds pretty quickly after leaving the muzzle. Whatever, it doesn't seem to hurt the accuracy, but I haven't shot them out further than 100 yards.

You asked about "pointy" bullets, here's a picture of Speer 220 gr and Hornady 200 gr in .357 Mag brass compared to a 125 gr.



Since they were seated to the cannelure, they aren't very long compared to the 250 gr. In fact, they look almost normal. <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" /> I shot these much faster than the 1200 fps cast bullet.

"I plan to use this setup for Coastal Elk."

Coho:
Sorry Dude, coastal elk don't like .358's ! Make's em fall down dead ! Good luck with your project and your hunt. BT53

Transonic = Mach .7-1.3 for purposes of this discussion...Mach 1 point of highest drag and pitching moments. Forget the question about longer ranges.

How long are the jacketed bullets in inches vs. the 250 gr lead? You obviously have a great deal more bearing surface with the lead and that helps with concentricity.

Dan, the 250 gr is 1.026" and the 220 gr jacketed is 1.012" long. In this case, the bearing surface is longer, but that's not always the case. A 158 gr 358156 has more bearing area than the longer and heavier 170 gr 358429. That's one of the reasons the 358429 will be faster, with the same load, than a 358156.

A normal 158 gr LSWC non gas check bullet, like Oregon Trails, will produce 1643 fps MV out of the Handi rifle using .38 Special brass and 13.5 gr of Alliant 2400. The same load with a 170 gr 358429 will produce 1742 fps out of the same Handi rifle. Out of a 4" M66-2 the OT produces 1301 fps MV and the 358429 produces 1355 fps. (NOTE: these loads should never be used in anything chambered for .38 Special and probably not even if it's an "N" frame, like a .38/44)

Good to see ya over here Paul.

A faintly educated guess on this leans toward the probability that your 250 gr bullets work better with that twist due to lesser displacement between CG and CP as compared to the Spitzer form due to form despite slightly greater length.

Well Scott, is the CG still treating you well? I know the weather is certainly different up there! Gatorland did have some things going for it. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

Dan, the Speer 220 gr isn't really a spitzer. I would describe it more as a flat point, but irregardless, I thought the low velocity would make it perform more like a cast bullet, due to the heavy jacket material. So, I just switched to a more accurate, for me, heavier cast bullet.