First and foremost, are you happy and do you see a future for yourself there? If the company's primary focus is software, then defense is less of a concern than if software is adjunct to the core business. Do you drive profit, or are you a cost center?
Are there people there you can learn from? It sounds like the company is doing well ($166k to $500k profit per employee--profit, not revenue), but if you are 2 years in and already the biggest fish in the pond, then you may have a decision to make, possibly based on whether you can get any equity or not. The small size of the company is a plus, particularly if they are software focused.
If you have any ambition or dream to move to a commercial company, now is probably the time. While defense can provide a premium (especially in the NoVa market), it also tends to come with a bit of a stigma around process that can be hard to shake if you are immersed in it too long (both in terms of habits and perceptions those outside the industry can have). Take your experience and make the jump to an industry that suits your tastes. Loving what you do and sticking with it can yield better financial outcomes than can simply trying to optimize a situation that is "just a job".
If your current company is growing, and you are growing with it, and if you see some of the shared upside...then don't worry so much about base rate. Your skills and ambition will keep you a big fish in that pond and you should start to see the upside soon.
1. How critical is your position/situation at the current company ? Is it possible to have a frank discussion about salary with your manager and see where it goes ?
2. Have you tried looking outside just to get an idea of how much someone is willing to pay you ? With 2 years of experience, 75K is not a bad number necessarily but again I know a few 2 years experienced Java devs making more than that.
Bottomline is that it comes down to whatever you can negotiate. Pay attention to the word negotiate again. Thats what it really is all about. If you don't try hard, your employer will obviously not do charity even if they love you. So go out there, talk to current employer and look outside at the same time. You will know where you stand.
If you don't feel confident to go out on your own, or need stability and/or benefits, you can always start shopping around at other places (lots of companies are hiring for your skillsets in the DC area). This can be a good opportunity to practice your negotiation skills, and see how high of an offer you can get (tell them what your current salary is and that you know you're underpaid). Then you can either take the new job or go back to your current company and get them to match.
A quick glance at GlassDoor's salary data is that $75K is pretty typical for someone with your experience, skillset, and location.
100k for 7-10 years seems right for the area, especially if you are in the government contracting realm(contrary to popular belief, government contractors are paid well below market). A company that competed in the private sector could probably pay more. 85K for about 5 years seems a touch low for an average, but no incredibly so. 75k for 2 years is probably a touch above average, although not incredibly so.