Ive found very little info about these, but I did find this on 24hourcampfire...
The NORMA TRI-CLAD Bullet is specially designed for maximum effect against tough game. It consists of a lead-antimony core, surrounded by a unique jacket design. Starting from the core, this jacket has an inside layer of gilding metal facing the lead. For maximum killing power, it is important to keep the jacket from folding too far back when the bullet hits the game. The next jacket layer in the NORMA TRI-CLAD bullet solves this problem.
It consistsof a special soft, but still tough, Swedish steel, which is strong enough to hold the strips of the expanded jacket out at an angle - providing a strong support for the mushrooming lead. The perfect timing and degree of expansion is obtained by internal grooves swaged into the jacket during the manufacturing process. The reinforcing steel layer is protected by an outside (third) layer of gilding metal - which at the same time provides the correct grip for the rifling lands and reduces friction, exactly like a regular all-gilding metal jacket. Actually, less pressure is exerted on the bore walls by the TRICLAD bullet than by one with an all-gilding metal jacket.
The inside steel reinforcement makes the TRI-CLAD bullet more resistant to upsetting in the bore - (higher longitudinal stiffness) which results in lower combustion temperature and consequently less erosion in the forcing cone and rear part of the rifling.
The three layers of the TRICLAD bullet are welded together and hot-rolled to form a solid sheet of material. It will not come apart even under the highest temperatures and velocities. As a matter of fact, the TRI-CLAD bullet can stand higher velocities without stripping the barrel lands or splitting jackets after leaving the muzzle, than a bullet with an ordinary gilding metal jacket.
So it is a steel jacket, but im doubting it'll harm the bore of my carbine.
Good thing too, i already went and loaded them!
