J4 Precision Bullet Jackets — 7mm • 1.440″ • 700ct

Making your own match bullets and want jackets that don’t hold you back? J4 Precision Jackets are the standard many custom makers lean on. They’re straight, uniform, and concentric—exactly what you want when you’re chasing tiny vertical and tiny groups.

Why builders choose J4

• Ultra-uniform walls: industry-leading concentricity with wall thickness tolerance around ±0.0003″ keeps cores centered and dispersion low.
• Consistent lots: tight process control means weight, length, and mouth geometry stay repeatable from box to box.
• Easy to work: clean draws and smooth surfaces form predictably in point-up dies, supporting very low TIR when your tooling is right.

Specs

• Caliber: 7mm (.284″)
• Length: 1.440″
• Quantity: 700 jackets
• Use: custom bullet making (varmint, target, hunting)

Shop notes

• Pair with quality cores and well-set dies to realize very low total indicated runout.
• Light oil or a proper lube helps maintain finish during forming.

Jackets only — not loaded ammunition and not complete bullets.