As I had posted earlier, the .30-30 Win., has a 1 in !0" twist in Marlin's, and a 1 in 12" twist in Winchester's. The .32 Win. Sp. and .35 Rem. both have 1 in 16" twist rates. In the Speer reloading manual, # 12, data for .32 Win. Sp. states that with it's 1 in 16 twist, the .32 Win. Sp. with even slight barrel wear, due to use or neglect, will be hopelessly inaccurate, while the .30-30, with its faster 1 in 12" twist will still shoot reasonably well. Now I have not put hundreds of rounds thru my .32's, or my .35, and I am very careful to clean my guns after every use, so I don't know if this is true. If this is the case, over the years, I would think gun makers would have engineered a twist rate that would hold up, for the .32 Win. Sp. and .35 Rem.

Actually the reverse would be true.

If the wear was equal, and the bullet diameters / bore size relationships the same, the faster twist would have a harder time 'grabbing' the bullet because it would have to impart more rotational momentum to the bullet.

This is just one of those endless myths that have been propgated over the years by gunwriters who are only vaguely aware of the laws of gravity, and little else in the way of physical principles beyond that.

See Mic McPherson's articles, I believe over on either Leverguns.com or Sixgunner.com, on the .32 Special.

He takes a look at it from basic principles of science, not lore/legend.

Mic suggests that the root of this legend was that Winchester used up some undersized bullets in .32 Special factory loadings that they had made on contract and ended up being stuck.

Whether that's the case or not, I don't know, but you have to work harder to spin a 170gr. bullet in a 1-10" twist than in a 170gr. bullet in 1-16" twist, that much can't be argued with. Just basic physics.

I suppose it could be argued that the .30 / 170gr. bullet probably has more bearing surface to contact the rifling than the .32 / 170gr. bullet, but that fact would still have nothing to do with how much force must be imparted on the bullet to make it spin.

Mike,
Thinks for that info. I took a look at this thread earlier and asked myself, "what's going on?" I worked through the Greenhill equation and found they're all over-stabilized so stability can't be at issue. I, too, have heard this story about the .32 Win Spl but I've never given it any thought before today.
What is the rifling depth on these barrels? I understand the .32 was introduced to give shooters something they could handload because, at that time, they had to use black powder because smokeless was too dangerous for anyone except an arsenal to load. If I was designing a barrel to shoot black powder, I'd increase the depth of the rifling to accomodate the fouling. However, the then new .30-30 may have had deep rifling just because that's how they'd always done it. The other question is, "what was the size of the bullets the .32 was reloaded with?" If it was being reloaded with black powder, the bullets would most likely be cast lead and sized smaller than the groove diameter. I've made the mistake of trying to shoot undersized bullets with smokeless!
Clouded in the myths (mists :) ) of history!

Have read the reports of early war and lack of accuracy in the .32specail (re-published with each new edition of C.O.W.) but haven't hear that accuasation about the .35Rem. The .35's 1:16 twist was also use don some of the rem. 350RM chambers, and as that round is often asked to use even longer/heavier bullets than the .35Rem. believe that if there was a problem, it would have shown up by now.

Are a good number of .35Rem. fans and a few 32specail fans on these boards..so we'll ask: any of you .35/32spec. shooters finding accuracy going to pot after just a bit of wear?


For that matter, the 32-40 shares the same 1:16 twist with the .32Special, but no accusations of slight wear and loss of accuracy found with the 32-40...with the lower vel. of the 32-40 using the same weight jacketed bullets, any problems should have shown up sooner than in the 32special.

I doubt the myth....whay does the blam fall on the 1:16 twist when the same twist using the same weight/diameter bullets in the 32-40 escape unblemished? Was it some early use of non-smokless steel that wore more rapidly?

Consider also... when the latest "ultra short / long benchrest rimless rebated magnum" comes out, what is the first thing that everyone does? Speculate how it would work necking up / down and so on.

The .300 whatever begats the .270 or 7mm version of same... all in the interest of drumming up more sales, though any of the versions will do what the others will do, to a large degree.... how many times do we hear the .270/.280 debate, which amounts to a difference in bullet diameter of just 0.007?" Seven thousandths of an inch.... and it's a big deal!

Oh and we have to make sure the new rounds can't be chambered in any old guns and blow them to smithereens......

Why would people 100 years ago think any differently? The .32 was a popular bore size, and loading high-pressure smokeless rounds in say the existing black-powder .32-40 was an accident waiting to happen. Hmmm... so let's neck up the new .30-30 case and see if we can't drum up a few more sales out of those folks who think that the .30 is entirely too small...

Marketing. Alive today and alive then.

The ever popular .308 is built with different twists also. Some with 1 in 10 and other with 1 in 12. You'd think a standard would've been achieved by now. .308 is over 50 years old!

I know an interesting fellow who shoots competitively with a round ball muzzle loader. Twist is 1 in 38 he told me. His groups are variable based upon fouling. Seems to shoot best after the first 3 shots but before 15 shots. The groups look like fired from a scoped Marlin!

There is a lot I do not fully understand about twist rates.
TR