Maxim roller delay AR9 buffer

[teratos]

Mine is ridiculously hard. I'll take it apart and look at it. Might have to call them....

 

[alucard0822]

Mine is ridiculously hard. I'll take it apart and look at it. Might have to call them....

There were a couple people saying the same thing a couple other places, not sure why, but seems a few have a really hard time with it. One guy forgot to take the weight out of the BCG so there was that, but a few others said it was really stiff, then night and day easier after firing it, couple others it didn't really get any better. don't know if something is getting hung up on the front edge of the tube, the guiderod doesn't line up with the carrier or something else. I got my other ones in, and they seems fine, one is in a Maxim SBR stock, but the rest are in "enhanced" Aero tubes with the extension around the buffer retainer. Did have to pull the buffer retainer out of the Maxim ala JP SCSS being I couldn't fit the buffer around the trigger. Most of the rest I might have to get the bumper in, then lower the hammer next to the buffer body to have room to slip it in behind it. They are stamping them out as fast as they can, and allegedly have new machines and people, so good chance of QC problems, but they are cool, and should take care of any problems.

 

[John from MD]

Mine is ridiculously hard. I'll take it apart and look at it. Might have to call them....

Maybe you're turning into a wimp.

 

[teratos]

Maybe you're turning into a wimp.

This is definitely a possibility.

 

[outrider58]

I checked mine with a digital fish scale and it seemed to break at around 20 lbs. Once it breaks, the pull went down to around 9 lbs.

If you have a slick sided upper, it will be much easier to charge because the FA wouldn't impinge on your grip on the charging handle.

 

[teratos]

I took it apart. There is some rough machining on the guide rod. 3 lines of it. The buffer does not move smoothly over it. I’m going to throw it on the lathe and run some sand paper over it. I only have 1000 grit in the shop…gotta run to AutoZone.

 

[teratos]

Ok. Sanded the guide rod. Took it to 3000 grit sand paper. Then lapped the parts of the buffer that touch the buffer tube. MUCH better. Still can’t do it with 1 finger like Alucard, but haven’t fired it yet. We’ll see after a range trip.

Might lap anything that moves, just for fun. It should be the pressure that moves the bearings, not the friction.

 

[alucard0822]

Good to know, awesome info T, and should definitely let Maxim know. Had a rainy day off, so grabbed a comp PCC and a suppressed SBR to try out several buffers.

I put a few hundred rounds through them, 2 malfs unrelated to the rifles, one mag was filthy and the follower was sticking. The smoothest recoil in the unsuppressed comp build is the blitzkreig short stroke comp setup on the far right, also feels the fastest cycling with very little dot movement.

The RDB in the same rifle has slightly lighter recoil, but a little more snap to it, not uncomfortable at all, and both allow fast splits. I can't outrun the trigger, but can feel it cycle where the short stroke blitzkreig just feels instant.

Next up was my older 10oz KVP and cushioned wave spring short stroke setup. It's still very smooth, and feels as light as the blitzkreig, but more mass means more dot movement. Also notice that big buffer cycling about as fast as the maxim, not quite as fast as the blitzkreig.

Next was my suppressed SBR, where the 3 buffer setups had small changes in felt recoil, and how smooth it was, there was a much more noticeable difference with the same buffers in the SBR.

The Maxim reduced recoil quite a bit compared to the blowback buffers with a can to increase backpressure. The heavy short stroke setup was still a little smoother, but with more of a noticeable increase in recoil. The Blitzkreig with less overall mass, and most of that mass uncoupled from the BCG did less to control bolt velocity. It was a little heavier recoiling than the others, and had a little more harsh feel than the silky smooth bump when it is installed in the PCC.

All in all, I think the Maxim shines brightest in a suppressed application, it cut gas to the face, reduced recoil, and reduced the effects of the can restricting gas more than the others. Competition builds are a different animal, I tried it on both my sleeved 5.25" lightweight, and older 16" side charger, and in both cases the short stroke hydraulic setup was the smoothest. In both cases the Maxim had perhaps a little less overall recoil, but it felt sharper, amd wasn't quite as fast as the blitzkreig with it's comfortable and fast cycle that barely moves the dot. Even so either would be a good choice in a comp build, both have similar cost, and I had to shoot them back to back a few times to really understand the different feel.

 

[teratos]

I probably need to see other peoples guide-rods. Particularly the relief for the bearings. I wonder if I need to make the angle less acute.

Any volunteers?

 

[smdub]

I poked Mean Arms since its been a month since they've charged my card for the upper. I have a serial # now and he says it will be finished and ship this week. Doubt it will be in in time for this weekends shoot.

 

[teratos]

I poked Mean Arms since its been a month since they've charged my card for the upper. I have a serial # now and he says it will be finished and ship this week. Doubt it will be in in time for this weekends shoot.

I can’t wait to hear your review.

 

[FrankZ]

I probably need to see other peoples guide-rods. Particularly the relief for the bearings. I wonder if I need to make the angle less acute.

Any volunteers?

Always trying to get other members to show you their guide rods.

 

[teratos]

Always trying to get other members to show you their guide rods.

For science!!

 

[alucard0822]

I probably need to see other peoples guide-rods. Particularly the relief for the bearings. I wonder if I need to make the angle less acute.

Any volunteers?

Just saw this, here are mine. Middle pic is a 1st batch with about 500 rounds through it, last pic is the newest one from last week with maybe 100 rounds. Not sure if the more bronze color is from gas fouling, or if they changes something in the process, doesn't wipe off, don't think it any type of electro coating, probably from the heat treat oil bath, but it does have a finer finish than the new one, and is a little easier to rack, even after putting rounds through both. I have oiled them before, added a little grease in the bearing cage/rod, and feels maybe a little smoother, so I'll keep doing that. I did have to back some tubes out a turn to avoid putting pressure, and partially disengaging the delay mechanism, but caught it while putting the system together, the BCG tail should just make contact with the face of the buffer, not put pressure or rattle, the design requires a relatively tight tolerance to function as designed, and buffer tubes can vary.

 

[teratos]

Just saw this, here are mine. Middle pic is a 1st batch with about 500 rounds through it, last pic is the newest one from last week with maybe 100 rounds. Not sure if the more bronze color is from gas fouling, or if they changes something in the process, doesn't wipe off, don't think it any type of electro coating, probably from the heat treat oil bath, but it does have a finer finish than the new one, and is a little easier to rack, even after putting rounds through both. I have oiled them before, added a little grease in the bearing cage/rod, and feels maybe a little smoother, so I'll keep doing that. I did have to back some tubes out a turn to avoid putting pressure, and partially disengaging the delay mechanism, but caught it while putting the system together, the BCG tail should just make contact with the face of the buffer, not put pressure or rattle, the design requires a relatively tight tolerance to function as designed, and buffer tubes can vary.



View attachment 432725 View attachment 432726 View attachment 432727

Thanks, I'll compare!!!

 

[outrider58]

The milling on the grooves looks kind of schitty, or is that just the picture?

 

[alucard0822]

The milling on the grooves looks kind of schitty, or is that just the picture?

Mine isn't bad, pretty smooth , but definite streaks that I normally see when a bit is worn.

Thanks, I'll compare!!!

LOL, my theory that with great intelligence comes a messy workbench holds true.

 

[outrider58]

Mine isn't bad, pretty smooth , but definite streaks that I normally see when a bit is worn.


LOL, my theory that with great intelligence comes a messy workbench holds true.

Put it this way, an this may be apples to oranges, but if you received a gun barrel with such tool marks, you'd send it back, right?

(You should see my work bench. Lol)

 

[teratos]

LOL, my theory that with great intelligence comes a messy workbench holds true.

 

[alucard0822]

Put it this way, an this may be apples to oranges, but if you received a gun barrel with such tool marks, you'd send it back, right?

(You should see my work bench. Lol)

Not sure if I was getting a shadow or seeing dirt or something, cleaned them off, the machining is good, better than most barrels in fact. just a little streaking, but nothing like Doc T's posted above, he might have just

got a bad one.