Maxim Defense Roller-Delayed Blowback Buffer?

[zzt]

First takes.  I will do an apples-to-apples comparison next week.  Today I shot three loads.  First up was my steel challenge load.  Leadstar Prime PCC with A5 tube.  The Blitzkrieg standard buffer, with their 2.5 oz. slug and a JP carbine spring was slightly softer than the maxim.  The 3 oz. bolt weight was in the bolt.  I think it was a tad softer because of the extra 3/4" length of the A5 tube.  I'll try it again later with a 3/4" spacer in the rear to essentially make it a carbine length tube.

 

The Maxim was run just as it came from the factory.  All four bearings were installed.  It had a sharper impulse than the Blitz and recoil was slightly more.  The 3 oz. weight had to be removed from the bolt.

 

My steel load is 2.8gr Clay Dot under a 124 plated.  I next shot a 4gr. Sport Pistol load under a 124 plated.  Sharper recoil and a little dot movement.  I was able to keep fast double taps in a 9" circle at 100 yards.

 

Next, I tried my steel Open loads.  Very noticeable recoil.

 

The roller delay very definitely kept the bolt closed longer than the Blitz.  After five quick shots with the Blitz, I'd have smoke coming out of the holes in my skeletonized receiver.  None at all with the Maxim and the first two loads.  Just a whisp with the hot load.

 

The maxim definitely deserves more evaluation and maybe some load development.  A very real plus is it keeps the gun cleaner than the Blitz does.  Maxim definitely must come up with additional recoil springs.  With a heavier spring it would have been dynamite with my Open load.

 

 

[Texaspaul]

So I have their system and I do not feel it is any better than other systems I have used.  I am concerned about the load it is sending to the buffer tube and rear of receiver.t

[rishii]

I finally received mine and installed it in a QC10 colt lower, after reading all the comments on AR15 on how hard it is to rack, I picked up a Techwell tac latch L which allows me to grip it with 4 fingers.

https://techwellusa.com/advanced-ambi-arc-l-charging-handle-for-ar-platform-223.html

my initial install I simply pushed it in and used the buffer detent to hold it and I couldn’t close the upper, it would almost close and I ended up forcing it shut.

Racking it was easy and I realized I had bypassed the rollers by forcing it shut

i removed the detent and back the tube out 1 turn and closed the upper without any issues

racking it went from easy to omg, the unit was shipped bone dry and I put slideglide lite on the roller lock area which made it easier to rack

testing was done at 10 yards on a NRA B-8c repair center with my 115 gn, 135 PF PCC loads which are subminor out of a pistol, the 1 st mag was loaded with 4 rounds to test function and to see if it would lock back, the gun functioned and locked back and the saw the dot never left the black on the target. Next loaded a 42 round mag and did a series 2 shot as fast as I could pull the trigger and not waiting for the dot to settle, again the dot didn’t leave the black and except for a few flyers all the shots were in the black and the majority were within the 10 ring

i also tested with my regular production/SS/co ammo doing the same drill and noticed a bit more dot movement with the dot moving the the outer edge of the black

So far I’m liking it 

 

[erwos]

My Maxim Defense RDB came on Friday last week, but I haven't had a chance to take it out for a spin yet yet. I didn't find it super hard to rack out with a BCM Gunfighter CH, and switching to a Springfield Armory LevAR made it pretty easy (when used in leverage mode). I like how it lightens up the gun.

[zzt]

I did a side-by-side evaluation today.   Load was 4.3gr Sport Pistol under a 124 plated.  This makes 131-132 out a 5" 1911.  No idea of PF in a 16.1" carbine barrel.

 

I shot the Maxim and was pleasantly surprised.  This is a max load of SP. I had previously tried a magnetically delayed buffer and got whacked by the recoil.

 

Next, I tried my Blitz Standard with the 2.5 oz. slug in front of the buffer and a JP 308 spring.  Recoil was about the same as the Maxim.  Next, I tried the Blitz with the 3 oz. weight in the bolt and another 2.5 oz. slug in front to short stroke.  I can't say it was much softer.  It was just different. 

 

I'm going to use the Maxim for a while, instead of the Blitz setup.  It handles both my sub-minor and minor load nicely.  If Maxim comes out with additional recoil springs, I'll add a heavier one and drop my sub-minor load.  I'm down to three 9mm loads at the moment (down from six).  It would be nice to load just two, 9mm major for USPSA and 9 minor for everything else.

[dmshozer1]

How hard was it to rack?

I tried one and it was way to hard for me.

I liked the way it felt but living in a 10 rd state I could not rack it as easy as I need it to be.

I ask because I know you are older as I am.

Maybe they have found a way to make charging the gun easier, I hope.

[zzt]

Nope.  It is hard.  It bothers my arthritic fingers.  I'll have to rack with my left hard.  Anything done to lighten the racking partially defeats the purpose.

[dmshozer1]

4 hours ago, zzt said:

Nope.  It is hard.  It bothers my arthritic fingers.  I'll have to rack with my left hard.  Anything done to lighten the racking partially defeats the purpose.

DAM,

[Mad Doc]

I tried mine and there is a significant decrease in felt recoil with no malfunctions. I greased the ball bearings wells and now racks a lot easier.

[bigdawgbeav]

14 hours ago, Mad Doc said:

I tried mine and there is a significant decrease in felt recoil with no malfunctions. I greased the ball bearings wells and now racks a lot easier.

did you take it apart to do that greasing, or just worked it in?

[zzt]

1 hour ago, bigdawgbeav said:

did you take it apart to do that greasing, or just worked it in?

 

You don't have to take it apart to lube it.  Just pull the top down a little and you expose the tops of the bearings.  If you pull it all the way down to the bottom, the bearings will fall out.

 

My thinking is if you lube it to make it easier to rack, it will open sooner when fired.  I don't want that.  I want it closed for as long as possible, so the gun, bolt and firing pin channel stay cleaner.

 

If you do lube it and later decide against it, just shoot some Remington Action Cleaner in there to blow the lube out.  I may try some lube just to see what @Mad Doc is talking about.  I'm also curious to know how much sooner the bolt opens.  Then I'll blow the lube out and go back to normal.

[Mad Doc]

8 hours ago, zzt said:

 

You don't have to take it apart to lube it.  Just pull the top down a little and you expose the tops of the bearings.  If you pull it all the way down to the bottom, the bearings will fall out.

 

My thinking is if you lube it to make it easier to rack, it will open sooner when fired.  I don't want that.  I want it closed for as long as possible, so the gun, bolt and firing pin channel stay cleaner.

 

If you do lube it and later decide against it, just shoot some Remington Action Cleaner in there to blow the lube out.  I may try some lube just to see what @Mad Doc is talking about.  I'm also curious to know how much sooner the bolt opens.  Then I'll blow the lube out and go back to normal.

I use aeroshell 22 which is a total overkill, my guess is that any grease will work. I agree with zzt be careful opening it because the bearings will fall off, they are easy to put back in place but you don’t want to lose them. I no longer use oil on my handguns, rifles or shotguns I only use aeroshell 22 and never looked back. That’s another controversial topic

[erwos]

I finally had a chance to take mine out for a spin, and I was really quite impressed. About a hundred rounds of ammo, no failures, and a noticeable recoil reduction. There was still a bit of dot bounce, but I found super-fast doubles to be pretty easy at 15yds on an 8" target, with very minimal side-to-side dispersion (which is really the bigger problem for action shooting). The use of the LevAR made it reasonably easy to open the gun up for administrative loading/unloading. Some of the ammo I used was from my "suspiciously overcrimped" pile and it ran very well despite what I assume are higher pressures. There was no early unlocking like I experienced with the magnetic TACCOM buffer.

Verdict's still out on reliability, but at least for 124gr 9mm backed by 4.0gr Titegroup, it runs great so far. I would certainly recommend it based on my current experiences.

[Ner]

tested it yesterday with my 5020ss.. Pretty damn solid. Hard to load but faster splits. Same recoil about same dispersion. 100% ok if it wont cause any malfunctions in a long run

[bigdawgbeav]

So I finally got to test mine.  I actually had to test twice.  The first test was marred with feeding issues and I wasn't sure if it was the Maxim or the mags.  Turned out it was the brand new ETS 40-round CZ mags.  Ok then... 

Today's test was as close to apples to apples as I could get.  I ran my normal buffer setup (Taccom air buffer w. bolt weight),  then the Taccom with no bolt weight and finally the Maxim.  This was done with my 100gr (100PF) SCSA sanctioned match rounds, my 124gr SCSA club match rounds (110PF) and then finally some Blazer Brass factory.

 

I did not notice much of a difference with the Taccom system and bolt weight vs. no bolt weight.  I noticed a HUGE difference with the Maxim and my SC loads.  I have it all on video and it's kinda hard to tell just looking at the muzzle rise.  But it certainly felt different.  It appeard to me that the dot hardly moved.  I did not run any speed tests.

 

https://rumble.com/v3pbhpt-maxim-defense-roller-delayed-buffer-test.html

 

I think I'm going to leave this in for a little bit, give it some real world runs.  I am not a huge fan of the racking difficulty.  I'm running the Devil Dog Side Charger and it seems rather difficult.  I have not tested with a different charging handle yet.  I'm probably jinxing myself, but I have had very few issues with feeding in my AR-V so needing to fast rack has not been much of a concern.  Besides, being an SCSA shooter I only really need 5 rounds to feed in a row.

 

I was really worried about my sub-minor loads but it has handled them like a champ.  True test comes in a falling steel match in a few weeks.  Interested to see if it makes a big difference.

[zzt]

For the same ammo. the Maxim had the least muzzle rise.  Muzzle rise with the Taccom, no weight, was 'sharper' then with the weight, and appeared to rise less.

[erwos]

Alright, I shot it at a match.

I have mostly good things to report. Reliability was good - only one failure to feed, and my squadmates felt that it was bad (reloaded) ammo upon inspection. Recoil reduction was stellar, IMHO - I was able to run the gun very hard in terms of moving and shooting, and I was able to keep to A/C hits without a lot of drama.

Where I kinda got bit was on unloaded starts (there were 2). The LevAR is great for loaded starts, but slow and awkward for unloaded starts. I honestly think I would have been better off with a Radian Raptor CH and just pulling through as hard as I could. It's just not THAT hard to pull through on if you're really going for it.

Basically, I think in a situation like Falling Steel at AGC, where you're generally assured of having a loaded gun in your hands, the MD RDB is pretty sweet. If unloaded starts are a thing, it hurts a bit.

[dmshozer1]

17 minutes ago, erwos said:

Alright, I shot it at a match.

I have mostly good things to report. Reliability was good - only one failure to feed, and my squadmates felt that it was bad (reloaded) ammo upon inspection. Recoil reduction was stellar, IMHO - I was able to run the gun very hard in terms of moving and shooting, and I was able to keep to A/C hits without a lot of drama.

Where I kinda got bit was on unloaded starts (there were 2). The LevAR is great for loaded starts, but slow and awkward for unloaded starts. I honestly think I would have been better off with a Radian Raptor CH and just pulling through as hard as I could. It's just not THAT hard to pull through on if you're really going for it.

Basically, I think in a situation like Falling Steel at AGC, where you're generally assured of having a loaded gun in your hands, the MD RDB is pretty sweet. If unloaded starts are a thing, it hurts a bit.

Try using it in a 10 rd state where doing two  to three reloads per stage,

I tried one. I liked everything about it except the very hard to charge problem.

[erwos]

1 hour ago, dmshozer1 said:

Try using it in a 10 rd state where doing two  to three reloads per stage,

I tried one. I liked everything about it except the very hard to charge problem.

Yeah, I can imagine that would be unpleasant.

[bigdawgbeav]

I ran a real world test this weekend at a 5-stage falling steel match with 35 targets per stage.  The system ran great and felt great.  Had one bad round which caused me to have to rack it out.  It was not as bad as I thought.  It was harder than a normal buffer system, but when you are in the zone you tend to do manual processes faster and harder.  Probably cost me an extra second or so over my normal setup.

 

The rest of the day was fine and it ran great.  I'm not the fastest by far, but I did manage to finish 26th out of 95 PCC shooter for the match.  Were it not for the one bad round I might have made top 20.  Either way, it ran great and looking forward to running it in a SCSA match this weekend.

[zzt]

I shot a 6-stage SCSA match today with 100 PF PCC loads.  It ran flawlessly.  Loved the recoil feel.  The dot stayed put.  It is staying in.  I'm using it in an A5 buffer tube.  I dropped a Blitz 3/4" slug down first, so the carbine length Maxim would work.

 

Two things I noticed today.  The first is it is easier to rack with a mag inserted.  A little harder than normal, but quite doable.  When dropping the mag and racking to show clear, it felt much harder.  That may be because I had the chamber indicator in one hand and racked with the butt against my stomach.  At the start, I had my hand on the grip, so there was something solid to pull against.

 

I recommend the Maxim.  Don't let the slightly harder racking deter you from buying if you are interested.  It is a minor price to pay for all the benefits.

[MedicineMan]

During a stage run you don't even notice the harder racking with the maxim rdb. The improved control offsets the initial  difficult racking and a charging handle with a longer lever makes charging much easier.

[Joedirt199]

I use the PRI gas buster with the large latches on mine and it makes it easier to charge with more fingers on the levers. Keep the stock in your shoulder so the gun has a something hard to press against while charging.

[LowSpeedHighDrag]

Just got my Maxim Defense buffer.  Works great.  Softer recoil with no other obvious downsides.  Can't comment on any changes in accuracy.

 

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.

 

[Ner]

Does anyone know where to buy a Maxim in Europe?