The 52 gr was developed for benchrest. There were several makers and three comercial makers sierra, hornady, speer. All of them were used in competition and did very well. The 52 gr is made on a 705 jacket.
The best performance was with a core that made the weight come out to 52 or 53 grs. We acheived the best velocity accuracy with this bullet weight in the 222 and 222mag and 2221/2 Those were the popular calibers back in the sixtys and seventys. Most of the shooters had a heavy varmint
in 222 or mag etc for a starter.
No that is not right , the 52 to 53 grain weight came about much earlier than Sierra or any of the other makers designs .
It was guys like Harvey Donaldson and also Fred Huntington of Rock Chuck Bullet Swage ( RCBS )
that swaged 22 bullets from rimfire cases of the day and they came out 52 to 53 grain for the protected point (HP) and up to 55 60 for an exposed lead tip .
People became used to that weight of bullet and tuned loads around it.
Barrel makers made twists around it and so on.
So when companies like Sierra came along they put out new jacketed bullets in this weight to capatalise on the previous history of that particular bullet weight.
Marketing.
The following is from Corbins the bit about benchrest quality is not correct but the history is what we are talking about.
D.R. Corbin writes .
Those fired 22 long rifle cases we usually throw away can be recycled into nearly benchrest quality bullets for reloading standard .224 calibers, in four steps. The fired caseis washed and drawn into a bullet jacket. Then a piece of .185-inch diameter lead wire issnipped off and swaged to precise weight in a simple bleed die. This core, which is now aprecise weight and shape, is inserted into the jacket and seated in a core seating die.Finally, the ogive or nose curve is formed in a point forming die.The bullets can be made in weights from 40 to 60 grains. The typical open tip style bulletwith flat base weighs 52 to 55 grains. You can adjust the weight by using more or lesslead wire, and bleeding off more or less of it in the core swaging operation. Accuracy ofthese very low cost bullets can be outstanding. In 1978, writer Rick Jamison comparedthe nearly free bullets he made using fired .22 LR cases and lead wire with Sierra MatchKing and a number of other quality commercial bullets. The best commercial bullet groupfrom his .222 Benchrest rifle was about 0.21 inches. The fired .22 case bullets grouped atabout 0.20 inches (at 100 yards) for five shots.Using fired .22 LR cases to make .22 centerfire projectiles is nothing new. The very firstcenterfire .22 experimental rounds used .22 LR cases as jackets. Harvey Donaldson, atthe start of the 20thcentury, was experimenting with necked down .25-20 and .25 SingleShot cases chambered in a .22 caliber barrel. Although a few early calibers used .223,.226, and even .228 diameter bullets, the vast majority of all .22 centerfires use an actualbullet diameter of .224. With a typical rifling depth of .004 inches, the actual bore of a.224 would be .216 inches, but more shallow rifling sometimes was used with a bore of.217 or .218 inches. The .218 Bee, for instance, was named after the bore diameter, butstill fired a .224 bullet.
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Modern .22 centerfires including the .220 Swift, .221 Fireball, .222 Remington, .225Winchester and the 5.56mm NATO and 5.7mm HK pistol all fire a .224 bullet.Regardless of the name attached to your modern 22 centerifre, you can nearly alwaysmake the right size bullet for it using a fired .22 LR case and a .224 caliber swage die set.Many shooters have heard the story of how RCBS was launched, with the offer of toolsto do exactly what we’ve been talking about. The RCBS name stands for “Rock ChuckBullet Swage”, even though it wasn’t long before Fred Huntington discovered there was alot more money to be made in reloading dies, and quit building the high pressure tools tocold form bullets at home. Others took over the bullet swaging field, so that by the 1960’sthere were about half a dozen sources of tools, including at least a couple of diemakerswho offered the .22 LR to .224 kits.Some shooters know that Vernon Speer, founder of Speer Bullets, also got his start bymaking .22 LR cases into .224 bullets, and selling the bullets rather than the tools. Fewerpeople remember that Joyce Hornady also launched a bullet business with the sameproduct, and even Sierra bullets has a history that involved fired .22 cases.During the 1940-1960 era, most of the .22 LR cases were primed with a mercuric primingcompound that made the brass brittle. Since rimfire cases were not reloaded, this didn’tmatter to anyone. The mercuric priming was reliable and kept well in less than idealstorage conditions. But using the fired cases to make .224 bullets introduced a problem:the brittle cases flaked off in the barrel, and left worse fouling than a commercial gildingmetal jacket. Shooters soon got the idea that rimfire case bullets fouled bores.Later, as the mercuric priming was discontinued by one rimfire ammo company afteranother, and the non-mercuric rimfires solved the brittle case problem, bullets made fromfired .22 LR cases actually had less fouling than conventional jackets. But the reputationof the earlier era was hard to dispel. Even to this day, some handloaders believe that arimfire case bullet will cause worse fouling than a factory bullet, because they read orheard something about it from the early decades of mercuric priming.Rimfire case jacketed bullets cause less bore wear and less fouling than mostconventional factory bullets for two reasons. First, they typically are half as thick andthus are much more easily engraved, offering less resistance (friction) in the bore.Second, they are typically made of 30% zinc and 70% copper, whereas gilding metaljackets are only 5% zinc and 95% copper. The added zinc makes the metal “slicker” andless likely to leave copper smears in the bore.Why, then, are commercial bullets made with gilding metal jackets (or the cheaper 10%zinc, 90% copper alloy called “commercial bronze” although it is not bronze at all)?The drawback of using the thin, high-zinc content alloy is that it tends to crack andexplode on impact, rather than peeling back smoothly in a classic mushroom. For bulletsto be used on edible game, more copper and less zinc offers better terminal performance.
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But for target and varmint shooting, the highly frangible fired .22 LR case jackets areexactly what a reasonable person wants to use. They tend to explode on impact with theground, instead of skipping off into the hills and valleys. A ricochet is rare with the fired.22 case jacket fired at normal .224 centerfire velocities.So, we have a bullet that is easier on the barrel than commercial bullets, costs only abouta penny if you use lead wire or can be made for nothing if you use scrap lead, and is asaccurate as any of the best commercial bullets on the market (if you make it withreasonable care). It is less likely to ricochet and more likely to blow up a ground hog.What is the downside?Of course, the first obstacle is that you need to make it. Modern tools are available,including a complete bullet making kit. Using lead wire, you can make about 100 bulletsin an hour, which is reasonable production considering there is very little or no cleanupand only minutes setup time. The other issue is velocity. Because the jackets are onlyabout 0.012 inches thick, compared to as much as 0.026 inches in a commercial .224jacket (near the base section), they can’t be driven as fast before coming apart in the air.Depending on the rifling sharpness and depth in a particular barrel, you can load tobetween 2,800 and 3,200 feet per second before the bullet spins apart in mid-air anddisappears in a puff of grey dust.Of course, at 3,000 fps the thin jacketed bullet give you the kind of explosive impact thatyou normally expect at 4,000 fps. And, it does the work with less powder and less wearon your barrel. A 220 Swift rifle shooter can simply load down a bit, and the .222Remington rifle owner can load normally with the same bullet. The trade off is a free ornearly free bullet that performs very well both in explosive effect and accuracy.For more information, log onto
www.Swage.com and download the free technical paperon making .22 rimfire case jacketed bullets.
