Maxim Defense Roller-Delayed Blowback Buffer?

[LowSpeedHighDrag]

On 12/4/2023 at 7:17 PM, LowSpeedHighDrag said:

Yes, the charging is a bit stronger, but I have a Devil Dog Concepts side charging handle installed - makes charging easier whatever you're using.  Even with a normal AR-15 charging handle I can't see any real issue.

 

Okay, perhaps more than a bit stronger.

 

Shot it at the range today and found myself needing to pull fairly hard to charge the gun.  No crisis, but not exactly smooth either.

 

The interesting thing was when I went to put the gun away this evening I had real trouble charging it, but once I got it moving it went back to the way it ran earlier.  No idea what’s behind this behavior.

 

Still, definitely worth dealing with the hassle to get the superior recoil control.

 

[WxGuy]

Did they provide any instructions on greasing or what grease to use for the bearings?  It's an interesting system.

[LowSpeedHighDrag]

2 hours ago, WxGuy said:

Did they provide any instructions on greasing or what grease to use for the bearings?  It's an interesting system.

Not that I remember, although I'm not that religious about reading instructions.

 

Nothing on their website...

 

I'll try lubing it today to see if it makes a difference.

Edited December 8, 2023 by LowSpeedHighDrag

[zzt]

4 hours ago, WxGuy said:

Did they provide any instructions on greasing or what grease to use for the bearings?  It's an interesting system.

 

Lubing the buffer partially defeats the purpose.   You want to retard rearward movement as long as possible.

[LowSpeedHighDrag]

12 hours ago, LowSpeedHighDrag said:

Okay, perhaps more than a bit stronger.

 

Shot it at the range today and found myself needing to pull fairly hard to charge the gun.  No crisis, but not exactly smooth either.

 

The interesting thing was when I went to put the gun away this evening I had real trouble charging it, but once I got it moving it went back to the way it ran earlier.  No idea what’s behind this behavior.

 

Still, definitely worth dealing with the hassle to get the superior recoil control.

 

Okay, at least found where the problem was.  When I switched to the other upper the charging ran smoothly.  There's something about the setup of the first upper that doesn't fit well with the buffer and makes charging next to impossible, and I assume the fault is with the upper.

 

Now, to use the buffer in a match tomorrow...

[LowSpeedHighDrag]

Ran the PCC with the old upper on Saturday, and had no issues.  Recoil was well controlled.

 

Rebuilt the new upper and took it to the range today.  Again, worked great.

 

Okay, charging the action is a bit stiffer, but no big deal even when on the clock.

 

Well worth the purchase.

[WxGuy]

Thank you!!

[MedicineMan]

I was initially very pleased with the effectiveness of the maxim defense rdb buffer and could manage to charge the pcc with my support hand only, hard but doable. After about 400 rounds it required both hands to charge my pcc. I started using some 30-weight oil to lube and that didn't seem to have any effect either way. It still works as it should but is much more difficult to charge the weapon.

 

Has anyone else had a similar issue?  Does anyone have any insight into this issue?

[Dirty_J]

19 minutes ago, MedicineMan said:

I was initially very pleased with the effectiveness of the maxim defense rdb buffer and could manage to charge the pcc with my support hand only, hard but doable. After about 400 rounds it required both hands to charge my pcc. I started using some 30-weight oil to lube and that didn't seem to have any effect either way. It still works as it should but is much more difficult to charge the weapon.

 

Has anyone else had a similar issue?  Does anyone have any insight into this issue?

If it’s gotten MORE DIFFICULT to charge with use… it’s either gotten fouled… OR the bearings and their respective holes have become deformed. Yikes. 

[WxGuy]

Thanks for the update.  Sorry it is not working out.

[LowSpeedHighDrag]

8 hours ago, MedicineMan said:

I was initially very pleased with the effectiveness of the maxim defense rdb buffer and could manage to charge the pcc with my support hand only, hard but doable. After about 400 rounds it required both hands to charge my pcc. I started using some 30-weight oil to lube and that didn't seem to have any effect either way. It still works as it should but is much more difficult to charge the weapon.

 

Has anyone else had a similar issue?  Does anyone have any insight into this issue?

Yes, although I don't know what caused it.  It happened with the original second upper.  When I rebuilt it with a new upper receiver the problem went away.  Didn't do anything to the buffer itself so I don't have any advice as to how to fix it.

[MedicineMan]

I discovered why charging the Maxim RDB became much more difficult over time. The forward tip of the charging handle had bent slightly and was significantly increasing drag. I was using a War Hammer and changed it out for a BCM. Works as it should now. You need a really strong charging handle for this buffer.

[LowSpeedHighDrag]

1 hour ago, MedicineMan said:

I discovered why charging the Maxim RDB became much more difficult over time. The forward tip of the charging handle had bent slightly and was significantly increasing drag. I was using a War Hammer and changed it out for a BCM. Works as it should now. You need a really strong charging handle for this buffer.

Thanks for the tip...

[Joedirt199]

Wondering if anybody has modified their delayed buffer with a short stroke kit? I was looking into it and it would benifit from it greatly as the bolt leaves a lot of empty space behind the bolt stop for brass to accidently end up. When looking at the buffer setup, the bumper is built into the rear of the recoil rod so a spacer would need to be fitted over the spring between the rear bumper and roller buffer. Anyone tackle this yet? I have an email into Maxim and JP to see if they have any ideas or have considered it. One person said he made one out of delrin on reddit.

Edited February 12 by Joedirt199