M&P 15 firing pin spring

[Nelly2014]

New Jard trigger fitted a while ago then I had a broken firing pin fsr. Replaced it with a pin a friend gave me and found I was experiencing multiple 'light strikes'. I ordered another new pin and spring from Shield and still getting light strikes ffs.
I took everything apart and thoroughly cleaned the area. On reassembly I noticed for the first time that the spring (and it's new replacement) has a reduced diameter on one end so that it can be fitted loose or tight push-fit on to the firing pin. Re-assembled with the spring tight fit and since then no light strikes.
Some forums advise lopping a bit off this spring if light strikes after an after-market trigger so if I get any more occurrences I will do that.

[Blackstuff]

Thanks for the info.

I took my bolt apart for the first time when I last cleaned the rifle last week and did pay any attention to the spring so I'd best get it pulled apart again and check which way its in there!

Which way around 'should' it go?

[Nelly2014]

Thanks for the info.

I took my bolt apart for the first time when I last cleaned the rifle last week and did pay any attention to the spring so I'd best get it pulled apart again and check which way its in there!

Which way around 'should' it go?

Not being funny but I don't know how I can describe it any clearer than I already have done apart from that if the spring feels loose on the pin then turn it round so you have to push it firmly to get it on again.
I must also stress that my rifle seems to work better this way but I'm not sure if it is the 'official' way of assembling.
I was hoping tbh that some M&P expert would see this and confirm my suspicions.

[DL.]

I had that on a Marlin, one end of the spring was flared so fitted on easily, yet the other end was considerably tighter.

[BamBam]

Sorry no help here, had CMC trigger for around 10K rounds and issues to report.

[Blackstuff]

Ah so there isn't a visually noticeable small/large end, its just 'feel', got it

[Nelly2014]

After speaking to Graham at ACP it appears the tight end of the spring pushed onto the firing pin is the correct 'factory' way. He disassembled a new one while I was on the phone to prove it.

[Blackstuff]

I took mine apart last night and I had put it on that way around It makes sense when you think about it that the more tensioned end is the furthest away from the bolt. Its good to know anyway for the next time I take it fully apart for a good clean.