Aguila 5mm Ammo: The Only Source for the Rimfire Magnum

If you shoot the 5mm rimfire, Aguila Ammunition has good news: the 5mm Remington Rimfire Magnum (RFM or sometimes RRM) is back in production. Additionally, the company is offering two loads now.


Remington Core Lokt Ultra Bonded in .223

The AR-15 platform has become extremely popular in the past two decades. With it, the .223 Rem rose to one of the most popular rifle cartridges of all time.

In the hunting realm, the .223 has been very popular with varmint hunters. However, many people have felt the .223 cartridge is too small for hunting deer-sized game.

Remington is trying to change people’s minds.

Core-Lokt .223

To help influence the debate, Remington introduced a .223 cartridge in their Core Lokt Ultra Bonded line of hunting ammunition.

According to Remington, the Core Lokt Bonded bullet “…offers the unique combination of excellent accuracy, superb weight retention, and expansion with overall superior terminal results.”

Remington says the bullets retain up to 95% of their original bullet weight, and by using a progressively tapered jacket, the bullets expand reliably at “all practical” velocities. Expansion of up to twice the original bullet diameter is typical with this bullet design.

Remington Core Lokt Ammo

The obvious goal is improved penetration with the relatively light bullet. A bonded bullet enables the projectile to hold itself together when hitting bone and other tissue.

Whether deer hunters will embrace this round remains to be seen. However, Remington’s introduction of their Core Lokt Ultra Bonded bullet in a .223 loading expands the possibilities with this already versatile rifle cartridge.


Caliber.223 Rem
Bullet Weight62 grains
Bullet TypeCore-Lokt Ultra Bonded
Muzzle Velocity3,100 fps
Muzzle Energy1,323 ft-lbs
Ballistic Coefficient.234
MSRP (2021)$38.99/box of 20

The Core Lokt Ultra Bonded line is fairly extensive and covers many of the other popular calibers in both short- and long-action.

Additionally, the company offers these bullets loaded in the 6.8 SPC cartridge, which is another caliber that is very popular with AR-15 shooters. For deer-sized game, I would much rather have the 6.8 SPC cartridge than the .223. It definitely gives the hunter a lot more power for anchoring an animal. 

While you could hunt whitetail with a .22 LR, I still believe in clean, humane kills. Bigger bullets tend to improve the likelihood of this happening.

Another excellent hunting cartridge for the AR-15 platform is the more recent 300 BLK (aka the 300 AAC BLACKOUT) cartridge. This uses a .30 caliber bullet in the same size envelope as a 5.56 cartridge. They even use the same magazines and can be had in subsonic versions for suppressor use. I’ve seen these used on hogs and they are very effective.

Do you hunt deer with the .223? If so, what ammo are you running? Anyone want to offer their review of the Core Lokt ammo in .223?

Last update: June 3, 2021


New Barnes Varmint Grenade Bullets

Barnes Bullets introduced several new bullets at the 2008 SHOT Show. In the company’s very popular Varmint Grenade line, Barnes showed the .204 caliber, 26-grain bullet for the .204 Ruger cartridge and a .224 caliber bullet in 50 grains for .223 Remington/5.56 NATO cartridges.

The .204 bullets and the 50-grain .224 were both developed specifically due to customer demand according to Jessica Brooks of Barnes Bullets. Barnes continues to produce the existing calibers of bullets. 

In other words, the new offerings expand the line – not replace any part of it.

Varmint Grenade Bullet Close Up

Developed for specialized military applications the Varmint Grenade bullet proved to be excellent for varmint hunting in the civilian market.

Made with a powdered copper and tin core with a gilded metal jacket, the bullet achieves high speeds and instantly fragments upon impact. 

Driving small bullets to very fast velocities is a difficult trick. Too often, the bullets tear themselves apart in flight. When your core is not a solid lead or copper, this becomes even more difficult to manage.

Nevertheless, this very difficult engineering feat seems to have been perfected by Barnes Bullets in this line. Many compressed powder core bullets will literally spin apart when driven to high speeds. In small caliber cartridges like the 204 and 223, it is very easy to attain high velocities.

Varmint ammunition is in demand. Other companies manufacture varmint hunting ammo. For example, Winchester has its Varmint X line of ammunition while Hornady offers the Varmint Express ammo.


Barnes has some spectacular videos of these bullets hitting and fragmenting in a seedless grape. Woodchucks and prairie dogs beware! This is the most recent video:

This video is the original one that Barnes published when the bullets were introduced:

Rumor was the second video had been pulled due to the graphic nature of the prairie dogs being eradicated. Truth be known, the scenes in the more recent video are about the same as far as I’m concerned. It’s not for the little kids, but it isn’t anything glorifying killing.

Both bullets are available immediately through Barnes’ website

Commercial Ammo Options

If you don’t load your own ammunition, fear not. Black Hills currently loads the .223 and .22-250 cartridges using the Varmint Grenade bullets.

Currently Black Hills offers the following loads:

.22-25036 grains4,250 fps
.223 Rem36 grains3,750 fps

CorBon once produced ammunition with the Varmint Grenade. However, the company pulled the line with no explanation.

Corbon Varmint Grenade

CorBon manufactured ammo in .204 Ruger, .22-250 and .223 Rem. With the company changing hands, I doubt we will see a return of these products.

Last update: May 31, 2021