Buffer options for 10.4

[InshallahTech]

Maybe a silly question but when talking about the heavier HK buffer and HK spring is that the same as the MR556 buffer and spring? I've got an MR556 with a 10.4" barrel from HK parts and haven't shot it a lot but so far have not had any issues.

Yes, 416 and MR556 buffers/springs are the same.

[Oicani]

Lots of threads on ar15 about the topic. I guess the 2-3:00 is subject to opinion like 3-4:00 is but haven’t found any other charts but this one:

Also, HK416/MR556 buffet weight is 5.4oz, same as a H3. I run a 4.6oz buffer with a flat wire recoil spring with AGB with good ejection using mostly wolf gold ammo.

Also found this chart as well:

[InshallahTech]

Everybody keep in mind that these charts are most useful for diagnosing parts wear (mostly springs) and the suggestions of adding aftermarket crap should generally ignored.

[Oicani]

HK lacks in the MR556 platform, hence the need for after market crap. You can’t suppress it using the only buffer and spring option they offer. Just sayin’.

[Belted]

Any standard h3 or 5+ oz buffer will suit the piston system just fine. There's no need to spend the exuberant money that an hk buffer demands. I settled on a h3 buffer from dsg and a geissele coiled spring and she's running like a top with a solid 3 o'clock ejection and near perfect linear recoil. Thanks all.

[Belted]

I reckon I could put a dot of red paint on the buffer to suit the masses if that'd help. But for about $60 you can tune a 416 upper to purr like a kitten.
I ran about 200 rounds of pmc 55gr with a suppressor and 30 rounds of 77gr otm suppressed. The 77gr had a slightly noticeable more rear thrust but the rifle ran like a well tuned machine. Bottom line? Heavy buffer.

[jmes731]

So if someone were to cut down an mr556 upper to 10.4, then whomever installs the 10.4 GB would need to change the barrel gas port as well? And if so does it matter if the GB is vented or not?

Yes and yes.

Some people don't know that the 10.4 barrels with vented blocks have larger gas ports so when they modify a 16 down to 10.4 and install a new 10.4 vented gas block, they don't do the port and wonder why things don't work with the factory HK buffer and spring.

Switching to a USGI buffer and spring seems to be a really good way to account for this without changing the gas port.

Ok. To clarify, if I’m having a non-vented gas block installed then I don’t have to modify the gas port. Correct? And if I do, can you tell me what size it needs to be?

[tanodized416]

Do you know if theres any difference between the vented 14.5 GB vs the 10.4 GB? I recently bought a factory 10.4 that came with a none marked 10' vented GB, makes me believe its the 14.5 GB vented version. anything helps. thanks

[yz125racer]

Do you know if theres any difference between the vented 14.5 GB vs the 10.4 GB? I recently bought a factory 10.4 that came with a none marked 10' vented GB, makes me believe its the 14.5 GB vented version. anything helps. thanks

difference would be the size of the port hole and the fact that the 10" is marked. 14.5" is not marked. Someone may correct me if im wrong but that is my understanding. Was it an authentic 416 complete upper or a clone?

[tanodized416]

the barrel and BCG is authentic 416, the GB, not sure since its nor marked 10"... doing research I found that there's non marked vented GB for the 14.5,16 and 20" BBL, based on hkparts.net...