At least, new to me, though I had read of its development in a book on stopping power. It's Federal's Guard Dog apparently only in .45 ACP just now.
It looks like an FMJ, but the jacket of the nose has four slits inside it, running up to the nose. The core is lead at the rear, with a wad of polymer in the nose. On impact, it deforms and the jacket splits along the slits. It gives quick expansion, near 100% retained weight, and no problems with a hollow point plugging up when going thru a barrier or through heavy clothing.
UPDATE: here's a review. He mentions one other advantage -- if you are so unfortunate as to live in a state that bans hollowpoint ammo, you can still own this.
Looks like a renamed EFMJ.
Posted by: ParatrooperJJ at November 17, 2011 03:30 PM
This is indeed EFMJ, except the EFMJ (Expanding Full Metal Jacket) is typically +P. I tried it in 9MM and it expands every time. Very good ammo, clean and accurate.
Posted by: Dennis at November 17, 2011 05:00 PM
I had the pleasure of shooting with Peter Pi of Corbon/Glaser in AZ one weekend. The Corbon Glazer Pow'RBall is also similar, perhaps except for the slits.
He stated convincingly that in his research "speed is everything" for stopping power. Lighter bullet = faster bullet.
(Let the debate begin...)
Posted by: Jim D. at November 17, 2011 05:11 PM
A quick Google check for EFMJ tests suggests it might underpenetrate.
That said, some years ago I bought some 200g EFMJ .45 and it shoots well enough.
Posted by: JohnS at November 17, 2011 07:51 PM
(That would, of course, be 'grains' not 'grams'!)
Posted by: JohnS at November 17, 2011 07:52 PM
Federal EFMJ doesn't seem to have the high profile of other premium ammo types. It's been out for some years, and though superficially similar to some other companies hollow-point bullets which use a plastic or polymer forward core, EFMJ seems to use a unique concept of expansion by means of a flattening bullet jacket rather than the more typical expansion by means of a mushrooming bullet core. Very clever.
I would think EFMJ would have less trouble with feed failures than typical hollow-points.
Posted by: Brad at November 17, 2011 11:41 PM
He stated convincingly that in his research "speed is everything" for stopping power.
That can't be literally true if for no other reason that if a high energy (F = mv^2) round goes all the way though the energy (note the squaring of velocity) it has retained up to that point is wasted.
Perhaps his statement is a simplification of a principle that velocity matters a great deal in getting expansion? As far as I can tell stopping power scales with diameter more than anything else at defensive handgun velocities.
I myself am wary of "trick" ammo; i.e. I'm almost* entirely happy with 45 ACP Gold Dot at traditional weight and speed, since we know if a lack of expansion results in a FMJ level of performance that's good enough.
Final comment on feeding: note that it's a flat head round. The ogive doesn't look vastly superior to my 230 grain Gold Dots (although small differences can make a very big difference); I suspect this will be a "your mileage will vary" sort of thing. But it'll probably, in general, feed at least a bit better than hollow points.
* As it turns out, on one of my guns Gold Dot will not reliably feed in the last position of my Wilson-Rogers 47D 8 round magazines.
Posted by: Harold at November 18, 2011 09:28 AM
"...ifyou are so unfortunate as to live in a state that bans hollowpoint ammo, you can still own this."
And is the author eager to bet that a Jersey judge and jury will consider this legal, instead of just another kind of expanding ammunition?
Posted by: DaveP. at November 20, 2011 07:59 AM
Thanks for the link to the review. Very informative.
I was quite disappointed to see how low the level of penetration is with this ammunition. Only the 9mm managed to penetrate as deeply as 12 inches, and that just barely.
Posted by: Brad at November 20, 2011 06:45 PM