The Armed Forces have their salaries restricted for their contribution; and as a teacher I paid in my contributions. The employer (HMG) chooses not to put our money aside to fund our pensions from our contributions, but to spend it on other things.
If HMG tries to reform public sector pensions for those approaching retirement, they are going to get sued, and it will cost more in the long run.
For some sections of the public sector there is a mandatory retirement age (for the Armed Forces, it is according to rank)and when you reach that age you go. I would love them to raise the retirement age for the RN, but I can't see it happening.
You also need to consider the physical aspects of a job - I would not want to teach past 60, and I think some nurses would have problems going on longer with the physical demands of lifting.
The Armed Forces scheme has already been altered in 2005, so it is less generous for those who chose to move on to it. Those who stayed on the old scheme will eventually die off, so there are diminishing numbers there.
I have a problem with capping pensions in general; if an individual is saving for retirement and can afford large contributions to fund retirement, and not claim from the state, then good for them.