Here in the UK, shotguns are relatively easy to obtain, and ammunition is plentiful.
Lawful private ownership of rifles is rare, and lawful private ownership of handguns almost unknown, so ammo supplies not relevant.

Moving to other supplies there are still local shortages of toilet paper, cleaning products and some canned goods. No generalised shortage though.
Turkeys are very commonly eaten at Christmas, and some reports suggest a glut of these birds (fewer large family gatherings) whilst other reports suggest a shortage for some not clearly defined reason.

Firewood is in short supply and expensive. Propane is much less used here than in the USA but supplies seem adequate. I purchased three large portable cylinders each of 19 kilos without problems.
Coal is less used these days, but is readily available.