who doesn't like to hit the big weights? As long as it's within capacity, especially challenging bigger weights gives a more pronounced pump. Training exceptionally well in the moment, and then when the engorgement has passed, nothing seems to change in arm circumference?

Arm growth is supposed to be a long process and big weights ≠ big arm circumference. If you ignore technique, big weights will only increase the risk of injury, especially when training triple head.

the triceps consists of three muscle heads: The long head, the lateral head and the medial head. When these three heads develop evenly, they create a horseshoe or inverted u-shaped appearance when flexed.
Many little ones who want to increase their arm circumference should focus on compound and isolation movements that target the triceps, rather than the biceps.
Triceps are primarily trained by pushing up and elbow extensions stimulated by movements that can be performed in either the vertical or horizontal plane, and a balanced physique requires an awesome pair of triceps.

the barbell narrow grip bench press is a compound push movement that targets the triceps and trains the long, medial and lateral heads of the triceps. The anterior bundle of the pectoralis major or deltoid as well as the sternal and clavicular heads play a role as secondary muscle groups during the movement.
The auxiliary muscle groups assist the target muscle group during the movement. The short and long heads of the biceps play a stabilising role in this movement. The stabilising muscles help to maintain posture or protect the elbow joint by contracting.
The barbell narrow grip bench press consistently ranks high among the best compound movements for increasing triceps muscle and strength.

how to perform the barbell narrow grip bench press?
Choose the right training weight. Make sure you add an even amount of weight on both sides of the bar. Don't put 75lbs on one side and 100lbs on the other. Unbalanced weights will not improve the effectiveness of your workout and can lead to injury.
If this is your first workout, then choose a conservative weight that allows you to safely push up 8 to 12 reps. When the number of reps is the same as the flat bench press, the weight chosen for the narrow grip bench press should be lighter.

choose the right weight for the exercise by placing your feet flat on the floor and lying backwards, face up, so that your head, upper back and gluteus maximus are close to the bench. Keeping the chest up and shoulders sunk, grasp the barbell with a traditional solid grip (thumbs wrapped around the knuckles and palms, palms facing out) that is slightly narrower than the shoulders.
A grip that is too narrow will reduce range of motion, internally rotate the shoulders and place unnecessary stress on the wrists. A grip that is too wide will shift pressure from the triceps to the pectoral fibres.

with a firm grip on the barbell, take a deep breath, tighten your abdomen and or raise the bar with the help of a partner. Raise the barbell to a position where your arms and shoulders are vertical.
Lower the barbell towards the chest under muscular control. When lowering the barbell, ensure that the elbows are close to the body, lift the chest and lower the shoulders and squeeze the shoulder blades in the upper back. The barbell reaches the desired height (in most cases it will touch or be slightly above the lower part of the pectoral muscles) and hold for 0 to 5 seconds. After holding for a few seconds, push upwards until the arms and elbows are straight (but not hyperextended).

the barbell should be lowered and pushed up in the same pattern of movement. If you find that your elbows are open, then the weight may be too heavy. Some partners choose to exhale between pushing up on the barbell or between the two movements, just choose the breathing pattern that feels most natural and comfortable.
Movements can be done using pre-fatigue sets, decreases, rest-pause sets, supersets, giant sets, halfway moves or slow centrifuges. As with other movements, the two most important parts of the movement are quality posture and continuous improvement of the movement. Movement improvement can take many forms (e.g. Increasing the weight, number of sets or reps, shortening rest periods, improving the quality of the movement, etc.).

tips for the narrow grip barbell bench press
1. Keep tension at the lowest point of the movement. To increase the intensity of the movement, try holding the barbell at its lowest point, touching or slightly above the chest, for 5 to 10 seconds. Never relax your muscles so that the barbell simply touches your body; this is a movement that causes serious injury.
This hold not only stretches the triceps but also increases the amount of time the muscle is under tension. Increasing the amount of time a muscle is under tension is a great way to regulate progressive overload and enhance muscle growth.
2. Keep tension - keep tension throughout the movement to minimise the possibility of injury. If you've seen someone lose tension during the push up or lowering phase of the bench press, you know how serious the consequences can be. Before you start the bar, maintain tension from the correct starting position, keep your elbows close to your body, lift your chest and sink your shoulders, and squeeze your shoulder blades as hard as you can.

these techniques, combined with deep breathing and tightening the abdominals the moment you start the bar, will ensure that the triceps, shoulders and pecs remain consistently healthy.
3. Avoid borrowing - the narrow grip bench press is very effective when it is done under muscle control. Don't immediately attempt a 100kg narrow grip bench press either if your max weight for the flat bench press is only 60kg.
Rest your head, buttocks and upper back on the backrest and do not allow the barbell to bounce at the lowest point of the movement. This momentum significantly increases the likelihood of injury and minimises stimulation of the target muscles.

4. Do not use an empty grip - do not use an empty grip (thumb and fingers wrapped around the same side of the bar) unless an injury makes it impossible to use a traditional solid grip (thumb wrapped around the knuckles). It is possible to increase the weight pushed up slightly by using an empty grip, but there is a great risk that the barbell will roll off the palm of your hand. If you must use this unsafe grip, make sure your partner is nearby in case the barbell is out of control.
5. 5 points of support - during a full push up, the feet should be flat on the floor and the head, buttocks and upper back should be supported on the plates. 5 points of support with stable contact will help maintain tension and complete a quality movement.

the method must be practical and reliable, with 5 points to look out for in one movement, avoiding the risk of injury and also making the results of the training visible. Next time don't rush the weights blindly!