Hard primers in Hornady?

[adamsredlines]

had a similar problem with a 308, extractor had 2 o-rings instead of 1 and was tearing tiny flakes of brass off that were sticking to the face of the bolt. removed the extra o ring and cleaned the brass flakes off the bolt face and it's been good to go since

Swapping parts gets confusing haha.
I don't think it's the upper because it ran on his Smith and Wesson lower....The smith lower works fine with both uppers...full function.
This (Anderson) lower only works on his 300, not 556.
So there's something about that combo or the ammo that doesn't jive.

 

[lasher]

ok, lots of folks put the hammer spring on 180 degrees out of whack, that would be the first thing i'd look at

 

[tRidiot]

Why not swap in a different BCG and see if it works?

 

[Pokinfun]

ok, lots of folks put the hammer spring on 180 degrees out of whack, that would be the first thing i'd look at

This is what I was thinking while I was reading about the issue.
My son in-law made this exact mistake when he built his lower. It ran fine with some ammo, at first, then started to have misfires.

 

[NikatKimber]

Also, may not be relevant here, but if someone else is reading this (now or later), if you put in low power springs (like the JP), then certain combinations of lube/cold can cause issues with igniting harder primers. I encountered this with JP springs, motor oil, and CCI #41 primers. Ran fine until I shot it in the cold once - high 20s low 30s was enough to cause a significant issue with detonation.

I have also done the backwards hammer spring.

 

[Shadowrider]

Also, may not be relevant here, but if someone else is reading this (now or later), if you put in low power springs (like the JP), then certain combinations of lube/cold can cause issues with igniting harder primers. I encountered this with JP springs, motor oil, and CCI #41 primers. Ran fine until I shot it in the cold once - high 20s low 30s was enough to cause a significant issue with detonation.

I have also done the backwards hammer spring.

When running reduced power springs the hammer needs lightening. Most use a cutoff wheel on a dremel and cut the "tail" off the hammer making the back side edge straight.

Also stay away from vegetable based lubes like froglube and fire clean. They're not stable over time and will turn to a sticky mess even without cold weather.

 

[NikatKimber]

When running reduced power springs the hammer needs lightening. Most use a cutoff wheel on a dremel and cut the "tail" off the hammer making the back side edge straight.

Also stay away from vegetable based lubes like froglube and fire clean. They're not stable over time and will turn to a sticky mess even without cold weather.

Yep, learned that the hard way. All my hammers are now speed cut.

I remember reading your report on those.

 

[adamsredlines]

Good to know on cutting the hammers. I'm not a big AR guy (have a few but they're far from my favorite rifle). I'll check the spring and hammer on this one.

In other news...he didnt wanna screw with it so I bought the complete lower from him so its my problem now.
Got a 300AAC upper from a board member this morning and will put it on this lower and see what happens.
Will take my other 300 with me when I go test this out as to have combos to try if any issue does arise.

 

[adamsredlines]

And i dont think this lower had the reduced power springs, and I cannot vouch for what oil he used.

Under my care it will have Slip2000 EWL on it. If it functions good I'll probably do a spring kit and cut the hammer as mentioned above.

 

[NikatKimber]

Yeah, since you mentioned complete lower from FBT, I didn't think it would have the JP (or other) low power springs in it, but was just mentioning.