Hammer Springs

[prepare]

According the Battlefield Las Vegas armorers, hammer springs are one of the items that regularly breaks. Is this more common with FA or semi-auto as well?

[bamashooter]

Believe that's more of an anomaly than anything. Never had one break on either out of zillions of expended rounds. IMO "regularly" is a complete exaggeration.

[Stickman]

Regularly? Breaking hammer springs? I would like to know what their definition is of “regularly” breaking hammer springs.

Those guys have always been decent to me, and I know the Brownells site has a group that worships them, but on its own without any other info.... something doesn’t seem right.

[docsherm]

According the Battlefield Las Vegas armorers, hammer springs are one of the items that regularly breaks. Is this more common with FA or semi-auto as well?

I would be very cautious how you interoperate their data. Yes, they have a ton of it and they are the pentacle of a TYPE of endurance tests. That being said, you need to understand that they live in a completely different world then 90% of other people.....Including ALL military units.

That place is primarily a bunch of people doing mag dump after mag dump for the sake of doing something cool. It is completely unrealistic that even the top tier one units in the US military would ever shoot that many rounds that fast.

I can tell you that I have shot out (barrel needed to be replaced due to loose of acceptable MOA) 3 issued weapons in the MIL and used the same lower and trigger spring for all of those with no issue. I had the same lower for 11 years and went through 2 triggers. The only reason that I changed the trigger is because I went from a single stage to a two stage. The old one still worked just fine.



The problem of using there data as the standard is that it is like using only top fuel dragster 1/4 mile data for all cars. You would be hard pressed to drive 10 miles to work if that was the case.

[prepare]

Appreciate the input. Breaking hammer springs regularly is not something I have read about or encountered anywhere else.

[lysander]

I would be very cautious how you interoperate their data. Yes, they have a ton of it and they are the pentacle of a TYPE of endurance tests. That being said, you need to understand that they live in a completely different world then 90% of other people.....Including ALL military units.

That place is primarily a bunch of people doing mag dump after mag dump for the sake of doing something cool. It is completely unrealistic that even the top tier one units in the US military would ever shoot that many rounds that fast.

I can tell you that I have shot out (barrel needed to be replaced due to loose of acceptable MOA) 3 issued weapons in the MIL and used the same lower and trigger spring for all of those with no issue. I had the same lower for 11 years and went through 2 triggers. The only reason that I changed the trigger is because I went from a single stage to a two stage. The old one still worked just fine.



The problem of using there data as the standard is that it is like using only top fuel dragster 1/4 mile data for all cars. You would be hard pressed to drive 10 miles to work if that was the case.

I dunno . . .

Their data is roughly the same as the parts breakage data from the Army's "System Assessment for Baseline Reliability and Dust Assessment for the M16, M4 and M249."

After 144,000 rounds there were a combined total of 35 hammer spring broken, this was the third highest part consumed in the test, right after barrels and bolts.

[Clint]

Only 4114 rounds per failure?

Seems low vs a single lower lasting for several barrels, but who knows...

I dunno . . .

Their data is roughly the same as the parts breakage data from the Army's "System Assessment for Baseline Reliability and Dust Assessment for the M16, M4 and M249."

After 144,000 rounds there were a combined total of 35 hammer spring broken, this was the third highest part consumed in the test, right after barrels and bolts.

[titsonritz]

Maybe they get their hammer springs from PSA's seconds bin.

[lysander]

Only 4114 rounds per failure?

Seems low vs a single lower lasting for several barrels, but who knows...

Well, calculating an accurate MRBF from that data is impossible, as the test was 24 rifles each firing 6,000 rounds, but half of them were refurbished, so the total rounds between spring failure on those is unknown. For the new ones, the MRBF was 5142 rounds.

[1168]

With respect, I’m not convinced of a MRBF of 5,142 for hammer springs on .mil guns. That would make this failure quite common. I’m confident that I’ve seen more broken bolts than broken hammer springs. In fact, I don’t specifically remember ever seeing a M4 shit the bed over a broken hammer spring, although I’m sure it happens. Is there a difference between the M4 and M16 here?

Are armorers changing these out prophylactically, and I just never knew? How have I not broken any in my personal guns?

Maybe I’m reading/interpreting this all wrong?