Home Forums Hunting & Shooting Ask The Gunwriters 220 Swift headspace

So with my current lack of reloading and hunting, i've been doing a considerable amount of reading on those subjects.

Was reading a article about belted mags, and my wheels got to turning. After a couple quick google searches and some wikipedia education it led me to a question about my 220 swift and headspace. Since the 220 swift is a archaic 'semi rimmed' case, does it headspace off of the shoulder like a 308 or does it headspace off the rim like a 303 Brit?

Shoulder

Ok, well that leads to question number 2.
-WTF is the point of the semi rim besides [bleep] up feeding from your magazine? I know the cartrige is based on the 6mm Lee Navy or something like that? Is it b/c of the rifle it was chambered in?

Yep, 6mm lee navy is the parent case. Rumor has it from some old, old gun gurus that the original designer of the cartridge went to Winchester with his idea and they liked it. Problem was that they didn't own the rights to the case he designed it from. So it seems they had the tooling and left over brass from the Lee Navy, when necked down to 22 caliber it had a little more case capacity. It was a new cartridge for a new model rifle. At least that's what the gun gurus of the late 30's and 40's stated in their books on Winchester.
In 65 IIRC Remington brought the original Swift out of being a bastard child, and called it the 22.250.
The semi rim is just part of the original Lee case, and why it wasn't changed is lost to time. As the people involved are no longer with us. And it headspaces off the shoulder.

Hell, why did they saddle the 250 Savage with a 1-14" twist?

Better yet, why the hell do 'they' saddle the Swift and 22/250 with a 1-14" twist in 2013.

Thanks for the input so far guys. But im still wondering- What is the point of a semi rimmed cartridge? What was the point of it in the Lee Navy?

The rifle it fit and likely a better fit for the stripper clips. Rims didn't overlap in the 1895.

Have run a pre-64 Mod. 70 for about 25 yrs. in the Swift w/o a SINGLE feeding issue!
Cheers

Believe you are mostly correct on this, but another reason may have been that machine guns of the day used rimmed and semi rim ammo, and the 6 mm Lee was to be used in machine guns also. As for twist, who knows why.

The original 6MM Lee Navy case head was a little too small (.448) to fit the standard .473 bolt face so Winchester made it slightly larger to fit existing bolt/extractor systems.

The case head area was also strengthened.

The .22/250 case was not adopted by Winchester because it could not safely obtain the marketing goals of 4000+ FPS with 1935 technology.

The .22/250 champions were not happy that Winchester did not adopt their design and spent the next 30 years bad mouthing the swift design......

Remington adopted the '250 in 1965.

Swifty52-
Your post includes several points that are worth comment.

In 1933, Grosvenor Wotkyns, a gunwriter and experimenter who had played a major part in the commercialization of the Hornet, took his version of the 22-250 to Western Cartridge Co., furnishing them with both his rifle and ammunition for testing. Western was able to obtain 4000 fps with the cartridge, and were so impressed that after some months they passed the rifle and cartridge to Winchester, an Olin/Western subsidiary since 1931. After more tests, Winchester decided to bring out the cartridge and rifles for it.

Wotkyns's Swift was based on the necked-down 250 Savage case. My understanding was that Winchester management absolutely did not want to produce a cartridge based on a case from a competitor's cartridge. When asked by Winchester to recommend a substitute, Wotkyns suggested the Lee Navy case. Is there any published information about "the rights to the case" preventing adoption by Winchester?

This rumor about the reasons for the adoption of the Lee case has been circulating for a while. Because the 220 Swift case differs internally and externally from the Lee case, reworking leftover 6mm cases would be unlikely from an engineering view. Again, is there any reliable published foundation to this rumor?

You're correct that the Lee and Swift cases have somewhat greater capacity than the necked-down 250 Savage case.

The 220 Swift was first offered for sale in the Model 54, which was not really new, having been on the market for about ten years. It was one of the first chamberings offered in the Model 70 a year after the cartridge was offered publically.

As pointed out elsewhere on this thread, the Swift case has a semi-rim designed to fit the standard 0.473" bolt face. The Lee case as loaded for the Navy rifle and the M1895 Colt-Browning machine gun was rimless. Here's a case diagram from ammoguide.com:


There exists a rare version of the Lee Navy case in a fully rimmed configuration. The Blake and perhaps other rifles were chambered for this cartridge about 1900. Phil Sharpe's Rifle in America describes this.

--Bob
edited to add machine gun info

"Because." Because they were so set on hitting 3000 fps for marketing reasons they had to drop to 87 grain bullets instead of 100 grain or heavier, and the 1-14" twist pretty much forces you to stick with that weight. I suspect your question was rhetorical, that you knew that answer as well as I do.


Because it is better for varmint shooting. The fast twists are fine for heavier bullets and fine for the more heavily constructed ballistic tip and vmax bullets but if the throat is at all rough, and it will be if you shoot it much, they'll blow up the lighter cup 'n' core bullets unless you download them.

I know as much as the heavy bullet guys want a fast twist, I wouldn't buy a swift with anything faster than a 1-12" twist and I'm perfectly happy with a 1-14". It is right for what I want a Swift to do.

I think today's shooters are generally a bit more sophisticated ... we could handle both cartridges with both 1-14" twists and 1-8" or 1-9" twists with factory loads appropriate for each.

Tom

The reason for the 1-14 twist in both the .250 Savage and .220 Swift is that back when both rounds were developed, most production bullets weren't nearly as well balanced as they are today. A slower twist DID produce better accuracy with light bullets, and light bullets were used because high velocity was considered highly desirable.

Before laser rangefinders appeared in the 1990's, shooters had to guess at range, or at best use a scope's reticle for a rough estimate. Light bullets at very high velocities shot flatter at what were then considered normal ranges, reducing the effect of errors in range estimation.

This trend started as soon as practical smokeless powder appeared. The .30-30 was considered a flat-shooting wonder by hunters who'd been using black powder rounds: You could aim right at a deer's chest and hit out to 150-200 yards! Cartridges like the .250 Savage, .220 Swift and .270 Winchester extended the hold-right-on range considerably--and with lighter bullets were more accurate with slower twists.

In contrast, military cartridges developed in the early days of smokeless powder used faster rifling twists, because at first they used heavy-for-caliber round-nosed bullets such as 156-grain 6.5mm, 175-grain 7mm, 220-grain .30, etc. This was apparently because the black powder cartridges they replaced used heavy-for-caliber round-nosed bullets.

Then Germany introduced lighter spitzer bullets in the 8x57, and everybody else followed that trend--but the twist rates were already established. Only commercial cartridges developed after the military switch to spitzers used slow twists, specifically to shoot very light and fast bullets. And that's the reason .25 and .270 caliber rifles aren't considered as good today for really long-range shooting as 6.5mm and 7mm rifles, which had fast rifling twists to stabilize long bullets.

On a different subject: The slightly larger rim on .220 Swift brass was indeed created purely to save money, rather than using the .448 rim on 6mm Lee Navy brass: Winchester didn't have to machine a slightly smaller bolt-face for their .220 Swift rifles.
However, when necking up .220 brass for handloading the 6mm Lee Navy, the oversize rim doesn't result in any difficulties in feeding or extraction in a Lee Navy rifle. I know this because I have a Lee Navy rifle, and have been shooting it for a while now.

Oh, and by the way, the Lee Navy rifles had rifling twists of one turn in 7-1/2 inches, for the same reason other early military rifles has fast twists: They used long, round-nosed bullets. In fact the first bullet used in the 6mm LN weighed 135 grains, which was eventually reduced to 112.

So if you find a Lee Navy with a really nice bore (pretty rare, since corrosive priming was standard back then) it would be ideal for shooting 115-grain spitzer boattails for long-range hunting.

Great discussion guys. Threads like this are the very best of what The Campfire offers.

Everyone, Especially MD, Thanks for the input!

I now get it!