Local Gun Shop has a Vision Defense 308 AR that has lite primer strikes. Externally the weapon follows DPMS pattern but once I pulled the BCG that's where the train derailed.  The firing pin fails protrusion with a USGI M14 firing pin gauge.  I would just replace the firing pin but the pin looks to be a crossbreed between Armalite and DPMS. Unknown FP on left DPMS on right (See Photo)  I tried a spare DPMS factory firing pin and it will not go in, the actual firing pin pin is larger than the firing pin from the rifle.  Vision Defense looks to be out of business or I'd just give them a call and see who's BCG they are using.  If anyone can ID this BCG and or firing pin that would be a great help as too how to repair the rifle. The only marking on BCG is acid etched MP on Bolt head (See Photo)

Is it the same length as the DPMS ?  Looks like it.
If so, then measure the tip diameter.
Armalite pin tip is smaller diameter (.071" vs, .078"), and over all length is shorter by approximately .165".

Some of these fly by night manufactures play with tolerances, or are just bad about holding them.

Maybe they drilled the bolt for an Armalite, but used the DPMS length.

Overall yes within a few thousand of a inch.  The offending firing pin is shorter by about 0.006 from the stop to the top of the DPMS.  

I edited my post, hoping I had time before you seen it.

It could also be that just the tip diameter is not cut far enough back.
Does the pin contact the back of the bolt where it is supposed to stop at, or is there a gap there ?

Even within DPMS generation 1 bolts, there are two different firing pin tip diameters.  There's a standard version, and there's a smaller diameter version often labelled as "high pressure."  

I have a bolt carrier assembly which has identical carrier exterior contours, firing pin shape, and solid long firing pin retaining pin as your picture.  I got it from Brownells in their packaging, but I don't know who originally manufactured it.  Mine has the smaller diameter firing pin tip, and I did just measure it as 0.006" shorter OAL than a DPMS brand reference.  But mine hasn't had any light strike issues and has been used in two different barrels.  

I don't know if the high pressure bolts have a different protrusion spec.

I did have a problem with the gas key bore being too small, preventing it from closing easily over the gas tube.  I returned that original bolt, and the replacement hasn't had any problems.  I would check gas tube fitment on your bolt.  Possibly the light strikes are from the bolt not going fully into battery.

I would also check headspace in case it's grossly excessive and the round is sitting too far forward of the firing pin.  Although that seems very unlikely.

Mine also came with and extremely stout extractor spring setup -- two nested springs and two O rings.  Possibly the very stiff extractor is providing resistance to snapping over the round, stopping the bolt from going fully into battery if the charging handle is ridden forward gently.  Again, unlikely as an explanation.

 
Good information but I did check protrusion with a GI M14 Go/No Go gauge and it failed that.  I'll hand cycle the bolt carrier unassembled to see if there's any binding but assembled it seemed to hand cycle smoothly.  

I think Heart got me where I needed to be, I did a search for "High Pressure" 308 firing pin and the only one that matches the profile of the pin I have above is the KAK.  BCG matches too in look and finish.  I'll order a replacement and see how that works, at least it will give me one that I can machine if I have too with out damage to the original.  https://www.kakindustry.com/lr-308-parts/308-upper-parts/308-bcg-and-spare-parts/kak-bcg-fire-pin-mag-hp

I was on a different board and happened to come across a post about M14 firing pin protrusion.  Notice the spec is different than for other .308 platforms.  And the spec for .223 ARs is significantly shorter.  I don't know what the spec for a .308 AR would be, considering there isn't really any standardized spec for any part of these guns.  I also wonder if the narrower firing pin is intentionally made with less protrusion to further lessen primer flow.  (That's just a guess; I don't know if that would make any difference.)

A copy-paste from someone's post.  I haven't verified any of the measurements given:

"
Below are the dimensions from actual US GI gages:

M1 & M14............ Min. .044...............Max. .060
M16 ......................Min. .028...............Max. .036
M60 ......................Min. .035...............Max. .043
.30 BMG...............Min. .060...............Max. .068
.50 BMG M2........ Min. .073 ..............Max. .080
M203 G/L............ Min. .032 ..............Max. .047
"