Deadbolt Throws Hard Only When Door Shut After Strike Adjust Decision Tree

Why this matters

You adjusted a strike to fix a sloppy or non-latching deadbolt, and now the bolt throws freely with the door open but drags hard the moment the door is shut. This is the signature of a strike-to-bolt misalignment you introduced or failed to fully resolve, and it is the most common deadbolt callback in residential work. The customer feels it as "I have to lift the door and force the key," which over weeks rounds the bolt nose, scores the strike, and eventually shears the bolt cam. Diagnosing it is about separating four distinct causes that all present as door-shut binding: vertical or horizontal strike offset, insufficient bolt-to-jaw clearance, a door that sags or swells, and a deadbolt installed without enough backset or bore clearance. Each has a clean test and a clean fix.

Symptom presentation

The discriminating observation is the open-versus-shut difference. With the door open, the bolt projects its full throw under finger pressure or an easy key turn. With the door pulled shut and held, the same throw requires noticeable force and may stop short of full extension. The bolt nose or the strike plate often shows fresh bright metal where they are wiping. Sometimes the customer reports it worsened after the strike adjustment; sometimes it appeared only after weather changed. Both clues matter. A bolt that is hard to throw door-open-or-shut is a cylinder or bolt-mechanism fault, not this tree.

Quick checks

• Throw the bolt with the door open, then with the door shut. Confirm the bind only appears when shut. That single test scopes the entire diagnosis to alignment and rules out a cylinder or bolt-mechanism fault.
• Coat the bolt nose with a marker, machinist's dye, or lipstick, throw it into the strike, and read the transfer mark. The witness mark tells you exactly which edge is fouling: a high or low mark means a vertical offset, a mark on the latch-side edge means the bolt is hitting before full throw.
• Push the door tight against the stop while throwing. If it frees up under hand pressure, the door is not seating fully against the weatherstrip and the bolt and strike sit on slightly different planes until pressure closes the gap.
• Lift up on the door knob or pull edge while throwing. If lifting frees the bolt, the slab has dropped on its hinges and the bolt now sits below the strike hole.
• Throw the bolt slowly by hand and feel where in the stroke the resistance starts. Resistance from the first fraction of travel is a vertical or plane offset; resistance only in the last quarter of throw is the bolt nose catching the far edge of the strike hole.

Isolation tree

Branch 1: Witness mark high or low on the bolt nose. The strike hole is vertically offset from the bolt path. If you just moved the strike, you moved it too far or the deadbolt bore and the strike were never coplanar. File the strike hole in the direction the mark indicates, or reposition the plate. Verify the bolt enters centered top-to-bottom with the door shut.

Branch 2: Witness mark on the latch-side edge of the strike (the side toward the door edge). The bolt is hitting before it reaches full throw because the strike sits too far toward the stop, or the door is not closing tight enough to bring the bolt and strike into register. Distinguish: if pushing the door harder against the stop frees the bolt, the cause is a compressed or over-thick weatherstrip holding the door proud (Branch 3), not the strike position.

Branch 3: Door frees only under hard inward pressure. New or swollen weatherstrip, or a misadjusted door stop, is holding the door slab off its closed plane. The bolt geometry is fine; the door simply is not where the strike expects it. Adjust or trim the weatherstrip, or reset the stop, so the door seats fully before the bolt is thrown.

Branch 4: Lifting the door frees the bolt. The slab has sagged on worn or loose hinges, dropping the bolt below the strike hole. Tighten or shim hinges, or replace a worn top hinge, to bring the slab back up. Do not chase this at the strike; you will end up with an oversized hole and a rattling bolt once the door is re-hung correctly.

Branch 5: Bind present at all door positions and lifting/pressure changes nothing. The deadbolt itself is the problem: insufficient backset clearance, a bore that pinched the bolt housing, or a bolt cam binding on the cylinder tailpiece. Pull the deadbolt and bench-test the throw out of the door.

Confirming diagnosis

Re-read the witness mark after each correction. A clean, centered bolt entry with the door shut and the bolt thrown fully under light key torque is the pass condition. Throw and retract the bolt 15 to 20 times with the door shut and confirm the force stays even across the cycle and the door is locked weatherstrip-seated, not forced. On an exterior door, re-test after the door has sat closed long enough to load the weatherstrip, since some binds only appear once the gasket has crept back to its set position.

Remediation

• Vertical offset: file or relocate the strike to center the bolt; on metal frames, use a round file and dress the edges so the bolt nose does not catch a burr.
• Latch-side foul from weatherstrip: trim or replace the gasket to the correct thickness, then re-test before touching the strike.
• Sagged door: tighten or replace the top hinge and shim as needed; re-bore the strike only if the door is now correctly hung.
• Deadbolt bind out of the door: confirm 2-3/8 in. or 2-3/4 in. backset matches the bore, clear any bind on the housing, lubricate the bolt with a dry film, reinstall.

References

• BHMA/ANSI A156.5, Auxiliary Locks and Associated Products (deadbolt throw, bolt projection, and strike requirements).
• BHMA/ANSI A156.115, Hardware Preparation in Steel Doors and Frames (strike and bolt-hole location tolerances).
• Schlage B-Series Deadbolt Installation and Service Instructions (backset, bore, and strike alignment).
• Kwikset Deadbolt Installation Guide (strike adjustment and door-prep clearances).