Here’s a bit on wardrobe and more on shooting.

This illustration is taken from the book English Costume for Sports and Outdoor Recreation from the 16th to the 19th Centuries by Phillis Cunnington and Alan Mansfield. Its shows a gentleman wearing a shooting jacket, which evolved from the “frock”.

From 1730, gentlemen who shot wore the frock, which had a small turn down collar, which was often made in a contrasting colour to the main garment, and of course had full skirts. Popular colours for the frock were brown, grey, red and blue.
The frock might be made of cloth, fustian, serge, etc. and breeches made of similar material.

Page 192, as above.

Shooting in England, until the very late 18th century did not involve the “battue”, that is driven birds. The now familiar sight of a line of men, waiting for birds to be driven towards them by a posse of beaters, was a practice introduced from France by Thomas Coke of Norfolk in 1796 ( See page172, The Poacher and The Squire : A History of Poaching and Game Preservation in England by Charles Chenevix Trench).

Prior to this innovation men shot mounted on horses, or on foot walking the ground, accompanied by pointer dogs who would seek out the birds to be shot. The change in the manner of the organization of “shoots” coincided with a change in the clothes worn by gentlemen who shot.

Frocks continued to be worn for shooting, but, from the mid-18th century, they were double breasted. Then, finally, from around the time of Coke’s transformation of the sport, shooting jackets began to be worn: they originated as garments worn by ordinary “country people” but

they gained favour with the sportsman by the end of the century

Cunningham and Mansfield, as above, page 191.

As you can see from the illustration the frock, evolving into the jacket, became skimpier and the full skirts were cut away into “tails”.

The fashionable sportsman also wore “Spatterdashes”: these were long gaiters, and they were usually made of canvas or leather and were fastened on the outside of the leg with laces, buttons or buckles. They were of course, added protection from the wet and cold for the, now mostly stationary, gentleman’s feet and legs. You can see these clearly in the illustration above.

The Beau Monde, magazine published, (in 1807) this description of how fashionable this type of dress was becoming, even for town wear:

Many gentlemen in their morning walks have attempted to introduce a sort of shooting dress, parading in a short coat of any light colour , and with drab coloured cloth or Kerseymere gaiters coming up to the knees.

Cunnington and Mansfield found a record of the cost of these jackets, circa 1798, in a set of tailors accounts found in the Kent Record office:

To a shooting jacket: £1 10 shillings
Page 191 as above

The date the Cunnington/Mansfield book gives for the illustration is circa 1800.