Quote Originally Posted by Noodles View Post
For what it's worth....

This weekend I tested under extremely highspeed camera (see new avatar) the A5 system vs std and H1 buffers.

The plan was to test it under full auto and get cyclic rate along with bolt bounce and etc. Ran out of time for these tests, and cyclic rate wasn't reliable for number under semi-auto. So all I ended up getting was bolt bounce and carrier movement between the three systems.

Short and sweet, I can easily confirm under every upper I tried, 12.5" DD, 16" with swithblock, etc etc, there was less than zero bounce on the A5 lower. Noticeable bounce on the standard carbine, less on the H1 with the switchblock. This shouldn't be of much suprise to anyone really.

What did surprise me was the amount of movement the carrier had above and below the bore. When the carrier is slighting forward, the is an obvious drop in it's ride height as it passes over the hammer. On the Non-A5 guns, there was noticeably more wiggle in the carrier before resting, the A5 still had a little play just because the carrier is of course under-sized for the upper. I have video, but it's very large and pretty uninteresting so I'm unlikely to post it.

No real amazing conclusions or cyclic numbers (that'll have to wait until next time and). I'm going to try and get that kit installed on a full auto lower, and even then I doubt I'll use highspeed, rather probably just measure the sound and get cyclic rate. Maybe a few weeks at the soonest.

Now, all that said, I don't care about much at all as long as it's not a large amount, I shoot semi only but I do get that the bounce is more indicative of other potential issues (weak action force, FTF?). What I find to be interesting the the extra weight forcing that next round into the chamber, still have testing to do, but as of right now, I really can't see not spending the extra couple of dollars to make a new build an A5. The company I was consulting for pretty much saw the same thing, I suspect all their new guns run A5 from now on, we'll see. Left a kit with them to play with.... So now they owe me a kit :\

As far the seat of the pants testing between a few users... It's close. No one said OMFG the A5 is sooo much smoother. There was a nod to the A5, but with any more than a few seconds between the two guns it was almost too close to tell - as the shooter. One of the guys watching was talking about how the shooter appeared to be under less recoil with the A5, but nothing concrete. I suppose it would be cool to test actual recoil between the two with a better tool than pants.

EDIT: I suppose rather than cylic rate, when I get to re-test this, it will be with carrier/bolt velocity and not RoF. I can't compare the two directly, but velocity between suppressed, not, h3 h4 h5 weights, barrel lengths, etc will be easier.
Thanks for posting this. I would love to see the video. Youtube has no upload filesize limit right now. I uploaded a 2GB 720p video a while back on another forum and it was my first upload. I realize you would have to edit it first.

My first thought about extraneous carrier movement inside the upper is an out-of-spec upper or carrier (or both). Using my finger, I cannot force any wiggle between the carrier and upper in any direction on my BCM 14.5" middy or my wife's PSA 14.7" middy.

Also, to clarify, did you see the carrier being pushed up as the front portion depressed the hammer, or did you see the carrier sink a bit as the front portion made it past the hammer?