Firstly, please forgive my astonishing ignorance of ALL things African rifles and calibers. Not to mention hand loaded cartridges for same.
Through happenstance and inheritance I happen to own an African dangerous/big game rifle; an FN (Fabrique Nationale) Belgium made 450 Ackley Magnum. I assume it is a “magnum" and not an Ackley “Improved" since I don’t see any makers marks on the rifle to that effect. Heck, for that matter I don’t see Magnum indicated on the rifle either. However, the RCBS reloading dies that came with the rifle do indicate magnum. Yes, confusing.
I have two questions that I am hopeful someone, anyone, Ferris? Buellar? Can answer.
- I'm curious to know how to find out the model of this particular rifle as it isn’t indicated anywhere? I suspect it rolled off the factory floor in Belgium prior to 2000. Yet again I don’t know that for certain either. Sure, I could contact FN and provide a serial number but that might take some time and be onerous as well. Besides, I'll take my chances with an "internet expert."
-The second question relates to how many rounds I can realistically put through this instrument of the Devil before the mount, rings, or more likely, the scope fails? A little background history is in order so I'll describe the one and only time I fired this rifle. This, about 3 years ago.
Quite frankly, and with brutal honesty I was terrified to put this rifle to my shoulder and shoot the rounds that I was in possession of.
The hand loads that came with this rifle consisted of the following; Norma cases stamped Norma SPECIAL Re on the case head. The cases are filled with 82 grains H4198 powder propelling, I believe, 350 grain flat base round nose bullets of unknown make. I simply assume a magnum primer had been utilized to ignite the cartridges. I elected to shoot the rifle from a Caldwell lead sled. This Caldwell device has saved my shoulder when working up loads for my .300 Weatherby magnum as well my 7mm Remington magnum. I knew it would be absolutely necessary for shooting this .450 Ackley. Yup, ima Sissy!
After checking the screws that held the, “Redfield" base down, and then checking the scope ring screws as well and the two rear adjusting screws on the bridge mount I decided that things appeared... ok. Tight and secure. I function checked the action by inserting cartridges into the magazine well and worked the bolt to pick them up and cycle them into the chamber and then extracted them. No issues there.
I also grabbed the rifle by the scope and gently shook it to feel or hear if anything rattled or shifted. Nothing did. Either scope or rifle parts.
I then proceeded to shoot, one cartridge at a time, three cartridges. Upon shooting the fourth round things went awry!

Namely, I noticed immediately that one of the rings was askew and the scope had come out of it. The scopes internals were now rattling as well. It was an old Weaver scope to the best of my recollection. I also noticed the Redfield bridge mount was loose but had not come apart from the rifle. Yet. So I called it a day before I injured myself. I was alone at the time. In the middle of nowhere where I shoot without distractions.
Admittedly, it is difficult for me to get my brain around the staggering forces and energy generated by this class cartridge! And here I thought break barrel air guns were tough on scopes and rings.
That said, fast forward 3 years.
I have cleaned, de-greased and inspected the steel Redfield mount and put it back on the rifle with brand new (degreased) mounting screws using blue Loctite. I also used a Q-tip with acetone or rubbing alcohol to prep the holes on the the rifle to accept the screws. Cannot recall what those holes are called. Drill and tap something or other…? Screw holes?
Regardless, the scope mount now “appears” and feels solid on the rifle. I then purchased brand new Leupold steel dovetail rings that matched the mount, and then attached an admittedly cheap Bushnell Banner Dusk and Dawn, 1.5-4.5x32 scope within them. I think this scope cost $80.00. Brand new.
I figured that I can afford to sacrifice this scope before putting something more expensive and “elegant" on the rifle. On the other hand it probably doesn't matter because of this particular caliber. This thing must be generating 60-80 foot pounds of recoil. I shudder to think how I’ll handle it when a black bear walks by me some day in a berry field we’re both occupying. Probably the only instance that I will EVER use this rifle. It will then be given away soon after I roll the bruin.
Moving on, I inspected the Ram-Line plastic stock this rifle wears especially where the recoil lug fits. No apparent incipient cracks or… anything worrisome found. That stock certainly won’t be affected by the temperature or humidity changes here in Washington State where we live and hunt.
Accordingly, everything appears ready for my next shooting session.
I am grateful for any thoughts, opinions or advice on the subject, as well any cogent answers to my two inane questions above.
Thank you.
Kindest regards,