Thank you for your service.
Yes it is possible to get a VA mortgage with a 615 score, I can actually go down to a 600 score on VA and 580 on FHA.
Check out my recommendations here on Trulia from some of my past clients by clicking the following link. http://www.trulia.com/profile/johnburke/#__rec
Call me and I'll go over your options.
Senior Mortgage Banker
Great Plains National Bank
I can put you in touch with a VA loan officer as well. They can provide you with more details.
You can find more info on my website http://www.NOLADreamHomes.org