More is....well, MORE. On some of the most popular sites, you have the opportunity to link from one item to a list of all of your items. That right there is your opportunity for exposure.
Do not limit yourself to one or two sales a week, testing the water. Expand your repetoir, SELL MORE. The more items you are selling, the more people will see them. When more people see items, you have a better chance of making a sale.
If you cannot make the investment to sell big ticket guns, then find other items to sell that are related to the guns you are selling. Even if you are selling lots of items at almost no profit, you are increasing your chances of someone clicking... see more from this seller. When they do that... you get to make the BIG sales that bring you the BIG bucks.
So find a way to sell a lot. Sell empty shells, sell tents, sell hunting gear, sell Swiss army knives, just sell. The more you sell, the more people will buy.
Now, pricing and everything else comes into play, but that is for a later day.