NEITHER HUNTER was happy about where they were going, although both would have grabbed at any excuse for getting out of the office on such a sunny and mild March day.

They were headed for Merrimac Farm, a 500-acre shooting preserve near Nokesville (between Manassas and Quantico) where pheasant, quail and chukar partridge are pen-raised for gunners to kill.

Both men are transplanted country boys who had drifted away from hunting when they moved to town and have taken a lot of flack from their wives and other friends for their recently renewed fascination with blood sport.

They were on their way to Merrimac Farm because, if you live in the city and are not a person of leisure and means, slay-for-pay is about the only practical way to go after upland game birds. For $30 per person, preserve owner Mac McDowell provides a guide and dogs for a half-day's shooting. The fee lets a hunter take three pheasant, four chukar or six quail.

It didn't sound very sporting to the men, who had never visited a shooting preserve and had the vague idea that the birds were released from boxes on command or something. They had opted for pheasant, because neither had ever had a chance to hunt them and because the bigger birds promised to be more imposing on the table as well as easier for inexpert shotgunners to bring down (they had spent the morning missing clay pigeons at the Clark Bros. gun shop in Warrenton).

McDowell was in the field when they arrived, which was unfortunate because it gave them time to look over the pens. The pheasants seemed very large and, in their iridescent rainbow plumage, more beautiful than peacocks. They flew and ran to the far ends of the pens when the men approached; if they had clustered at the fence like chickens looking for a hand out the hunters would have left McDowell his money and gone home.

Beside one of the long pens was a varmint trap in which a sparrow had managed to imprison itself, and the men were not unconscious of the irony as they released it.

All hesitation vanished with the appearance of McDowell, a retired light colonel of marines who still looks trim and tough enough to lead the boys ashore at Tarawa. He shaped up the two former enlisted men and had them moving out in minutes behind Abbie, a Brittany spaniel whose joyous energy in the hunt is irresistible.

McDowell had selected Abbie because she works close, which helps in keep command of the situation when he's out with clients he doesn't know. In minutes she was pointing at a clump of seedling cedars, and both men fired togethr as a hen pheasant came pounding up almost at their feet. They shot too soon, with thebird not more than 10 yards away, and if both had not half-missed, the superdense shot patterns would have left little but feathers and pheasantburger.

Quarter the brushy abandoned farm field as she would, Abbie found nothing more than a half-dozen clumps of quail feathers, the remains of released birs hunters had missed but hawks had not.

"Sometimes I feel like what I'm really doing here is just feeding the hawks," McDowell said as he led the way to another field. "That big redtailed hawk that flew over us on the way in got so fat on my birds, and there are Coopers all around here that come down on quail like dive-bombers. It's something to watch them stooping on the birds, even if they are picking my pokcet."

What with hunters and hawks and other predators, few chukar or quail get away, but pheasants have at least a sporting chance, McDowell said.

"Some survive several seasons, and a few of them manage to breed. The state of Virginia is working with some wild strains that are extending the breeding range considerably south of the Mason-Dixon Line, and a couple of years ago, when the winter must have been just right for them, several dozen young made it to maturity here. We've probably got a fairly sizable wild population developing between here and Quantico. I know there are a few in my swamp."

A second pheasant, a cock, was flushed while McDowell was dealing with hunters who had strayed out of their assigned area in pursuit of a crippled hen. The cock had gathered considerable speed and distance before one of the hunters got a clear shot. It fell, but not killed cleanly, and Abbie had to run it down in the briars.

"They're tough birds, something like a turkey, and a lot of the people who come here don't load heavy enough," McDowell said as he dispatched the struggling bird. "They use quail shot, or even skeet, when it really takes No. 6s or 7 1/2s to get the penetration you need."

The next four pheasants turned up quickly, only one cock running far and fast enough to extend Abbie and her followers. It beat one hunter's chest and face with its wings as it flushed in tangled brush, and he still was thinking about the feel of the feathers when his companion shot it over his head.

Scarcely an hour had passed. Six birds had been put up and put down, too many in too short a time, too much success for such bad shooters to have earned, even though some outdoor writers claim that the only difference btween the flush and flight of penraised and wild pheasants is that the "natural" birds are fewer and farther between.

McDowell guessed, and examination of their crops later proved, that two of the six birds had been in the fields for some time.

The hunters wanted to stay out, although they already had what seemed to be an indecent number of big dead birds in their game bags. They wanted to get tired.They wanted to hunt more and not find so much.

McDowell is always willing, for $9 per "extra" pheasant, to let hunters go searching for the warier and more scattered birds that have been out for days or weeks. The seventh of the day, a hend, was sniffed out by Abbie in an overgrown swale while McDowell was heading back to his truck to exchange the exhausted but still eager dog for a farther-ranging animal.

The shot was easy, and the hunter to whose side she flew would rather have passed; he fired anyway because when you pay a man to produce birds and he produces them you take them. Later he came to understand that McDowell is more or less indifferent to how many times a client misses or passes; one gets the impression he runs the farm as an excuse to get out in the field and see if this time he can work up a sweat - like those second lieutenants who lead marches in basic training, he doesn't seem to have any sweat glands.

Impressions are important when hunting with the Colonel because he is a friendly but not a forward man who cheerfully answers questions but doesn't chat.

He apprarently would have been content to go on hunting until dark, and he led the hunters over what seemed like miles or rolling ground and marshy creek bottoms. The slanting sun and the suet of civilization soon had the clients soaked and wishing a pheasant would attack them so they could call it a day and go find a drink of water.

It took two hours of chasing the dog to find the final bird, a cock that flushed a hundred yards away, high and far and free int he swamp, when the winded hunters failed to get up to the pointing dog in time. The bird went to ground inthemidst of thorns and sucking mud, and then ran the dog and the hunters bowlegged over several acres.

Cornered along a creek, the cock flushed while the dog still was trailing, when one of the gunners was screened by a tree and the other had his back turned and was picking thorns from his thigh. The bird fell dead on the edge of the impenetrable tangle he was trying to reach; the hunters were sorry he hadn't made it, and glad they had come.