5000+ FPS with 22BR Improved and 30gr Berger Bullets
Forum member XmarksSpot has been shooting a wicked fast varmint cartridge that has broken the 5000-fps barrier using Berger 30gr varmint bullets. That’s some serious velocity! The parent case is a 6mmBR, which is then improved and necked down to .224 caliber. XmarksSpot reports:
Some people think 5000+ fps is mythical. Well just thought I’d let you guys know that I got 5239 fps a couple weeks ago shooting 30-grainers with my 224 McDonald, a wildcat cartridge based on an improved 6BR case necked down to 224. (This case is very similar to a 22 Dasher.) The bullet used is the 30gr Berger. (The 40s run fast too — about 4800 fps.) The rig is a Rem 700 with a 30″ Hart barrel. Below is the case before and after forming. As you can see it has a 40° shoulder and far more case capacity than a 22 BR (a 22 Dasher case holds about 41.0 grains H20). My most accurate loads are with 50-52gr bullets, with bugholes the norm at 4200 fps. The 40gr bullets will do 4800+ fps.
This 224 McDonald wildcat was originally developed by Charles McDonald. He has been developing and chambering custom cartridges for years. Editor’s Note: Many folks may not be aware of the little .224-caliber 30gr Berger varmint bullet, Berger item # 22301. This bullet is not on Berger’s current production list but some vendors may still have “old stock” inventory. The little 30-grainer has an 0.119 G1 BC and will work in 1:15″ or faster twist barrels. For more info, visit BergerBullets.com.
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Tags: 22 Dasher, Berger Bullets, Charles McDonald, McDonald, varmint hunting, XMarksSpot
How interesting! I have been curious to know if anybody had/has done this very sort of case reforming, and, if so, the results. Presumably then, a 6.5×47 in the same configuration would do the same if not more so which would be a second great alternative to the 22 CHeetah. Mine, put together some 20 years ago, using the original 308BR brass runs the same if not somewhat faster: 52gr at 4350, 40gr at 4850 (easily), not yet shot the 30gr but may have to now. All things being equal, 5000fps + will be easy. I’m sure XmarksSpot would agree that everyone who shoots varmints hasn’t really shot them until one does so at 4800fps or more. The bullet arrives at the target about the same time as the trigger is pulled. Wild.
Okay, too bad nobody else wants part of this since my last post above. Additional shooting has resulted in 5000+ with 40 gr bullets with just a beginning hint of pressure. I should purchase some of the 30 gr Berger’s to see what my Cheetah can do with them. Of course, the larger case (Rem 308BR) uses more powder than the 22BR, but at 5000 fps who cares.
Wow! What kind of twist rate are you running for a 224 going that fast? Have you had any trouble with bullets tumbling or keyholing targets? I would imagine if the bullet spun too fast it would spin the jacket right off.
I can’t imagine what 5,000 fps does to prairie dogs. And how soon do you have to replace the barrel?
I would think a 30 grain bullet in a .22-250 case would be even faster, with all standard equipment, isn’t its case even a little larger than the improved?
A good example of how a 40 degree shoulder and the name “improved” do not equal “Ackley Improved/AI”. Here the neck shoulder junction is much higher than the parent case.
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“TJ says:
July 13, 2012 at 4:48 am
Wow! What kind of twist rate are you running for a 224 going that fast? Have you had any trouble with bullets tumbling or keyholing targets? I would imagine if the bullet spun too fast it would spin the jacket right off.”
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It’s not too difficult to find bullets that will come apart when driven to too high an RPM. I have done it with .224 bullets (these were factory-labeled with velocity warnings and performed as they should). I’ve also had it occur with lighter-weight bullets fired through a Swedish Mauser. (which generally have a relatively quick twist rate.) Anyway, the concentricity and tensile strength of a bullet is not something that can be ignored.
How does this cartridge surpass 22-250 and Swift velocities by such a huge margin? I understand the longer barrel is going to boost speed but this borders on amazing.
Doing some quick math that bullet is just shy of hypersonic Mach 4.8!! Hypersonic starts at Mach 5.
What’s next? Warping the space/time continuum?
WHY?
I would love to see what those bullets do in ballistic gel.
I built a tactical laser – 186,000 miles/second muzzle velocity; beat that! (;-D
Seriously, however, what is the twist rate? At a nominal 12″, that’s 300,000 RPM – getting mighty close to disintegration speeds. Seems like you’d need permission from Starfleet Command to fire that. When a .22
bullet disintegrates at that RPM, the tangential velocity of the fragments is about 3,500 f/s – enough to cause damage orthogonal to the bullet path over quite a lateral distance. Not safe to shoot if so.
That’s why Barnes make Solid bullets.