I have a Ruger 77 MKII stainless .270win and I can tell you that taking the bolt apart and cleaning the inside of the bolt, spring and firing pin is rather easy and I do it once a year. - If you can change the oil in an truck then you have enough technical ability to do this.
1. Use the video posted above to disassemble the bolt and take some good solvent (Hoppe's 9) and a tooth brush and scrub down the entire firing pin/spring assembly.
2. Use a pistol cleaning rod and nylon brush with solvent to clean out the inside of the bolt; and run several solvent soaked patches through until its clean.
3. Spray off all the bolt parts and the bolt itself with gun scrub/ breakfree.
4. Relube all the parts with a LIGHT coat of good gun oil.
If you still have the same problem after you reassemble the bolt then you probably just need a new spring..... Which is $3.00http://www.midwayusa.com/product/541638/...=ProductFinding