[IamScotticus]

Hello folks,

I wish to create an open thread regarding the issues with the RDB .223 rifle holding metal "GI" STANAG pattern magazines at any time, while actively shooting or not or at least, even if they did not drop while shooting, were easily accidentally released with a slight bump of the magazine release lever. I measured the pressure required to release a metal magazine around 2 pounds whereas a plastic P-mag required 5-6 pounds.

Although there have been some videos made and put online showing shooters having unintentional metal magazine drops, I will not place links to those here as it is my intention to help the platform and not sabotage it. Please don't post links to negative videos. I wish to provide RDB owners a platform to share information to possibly fix the problem or at least be aware of the problem before they make life or death decisions with their magazine choices.

It should be stated that the manufacturer supplies a plastic Magpul Gen3 magazine with the RDB and this is the best magazine to use. If you are content and able to continue to use Pmags for the entirety of your RDB usage you have no need for concern; your RDB will run perfect.

If you have any experience with this issue, please chime in. I will have more later.

 

[Trunkmonkey]

My RDB will lock in loaded or empty GI mags, fire one round, but then the mag will fall free of the lock. The mag does not fall free of the mag well. Of course this results in a failure to feed the next round from the GI mag.Mine is a brand new RDB serial Z0Zxx

 

[IamScotticus]

Exactly!
I had a closer look at my RDB to try to find the cause of this problem.
I found some good indicators why the mag catch doesn't get good purchase on the GI mags.

If you notice the height of the catch while locked onto a mag tab, you should notice that on a Pmag, the catch falls into the tab hole in the mag and lays flat.
On a GI mag, the catch still has some height, indicating it does not insert into the tab as deep as on a Pmag.
Remove the RDB mag catch and insert magazines to compare the tab holes.
You will notice that GI pattern magazines holes are not equal to Pmags.
GI catch tab holes are the same height but shorter in width. Therefore, the RDB mag catch is not fully inserting into the GI mag because the catch width is greater than that of the tab hole width.

For description sake, I will refer to the left side of the tab hole as (LTH) and right as (RTH), and right/left catch face (LCF/RCF).
I think that taking a file to widen every GI mag RTH I own would get me shooting,
but It wouldn't fix the rifle.
Therefore I must alter the mag catch to work.

I don't see any issue with the LTH/LCF, other than the LCF surface is rather bowed and could be squared off some. If I took enough material off the LCF, equally on both sides of the rifle, the catch would have more forward travel and more of the RCF will fall into the slot. This would place the release lever closer to the shooting hand, but not by much. Take too much off and the catch may rattle in place.

Alternately, If I removed material off the RCF, it would provide more depth into the RTH. My fear of doing this is, too much material may require removal and the integrity of the spring may be compromised.

In either case, allow the catch to insert too far and the catch may contact the spring or rounds and cause a jam. This does not seem to be a problem in the AR so it may not be an issue.

I will try these mods when I get my test mule in from KT and report.

 

[IamScotticus]

A representative in KT customer service stated to me that there was not an improved mag catch (as of June 2017) and they were advising owners to take off the catch and squeeze the arms together to provide more seating pressure.
OK, if that works for you. I don't see it being a solution based on my observations, that GI mags don't hold as well as Pmags because the catch holes are not equal.
Also, bending may change the original temper and weaken the unit. I'm not buying that solution.

 

[IamScotticus]

Fast forward to March 2019.
I have heard some grumbling from a new RDB owner that his mag catch was too stiff.
Play Handel: Halllliluuulia!!
They finally did something about it.
So I sent in the request for a new part#430. It arrived a in few weeks.
I will share my findings.
Firstly, I will mention I had received a replacement 430 a while back, hoping to score an improvement. But close inspection revealed it was identical to the unsatisfactory 430 I have.
So now I will conduct another trigger break scale test with these numbered 1,2&3 in the order I got them. Testing on a 30 round metal USGI pattern mag with ten shells on a closed bolt. Since the GI mags were the most problematic, its with these I need to see the most improvement.
Unit #1: five tests averaged 1.65 lbs
Unit #2: five tests averaged 3.5 lbs
Unit #3: could not be measured. tension exceeded 8 lbs. Actual tension may be closer to 14 lbs.
So, I am very happy now. Thanks KT for this improvement.

 

[babue]

I have only had my RDB for a couple of months but it has worked equally well with P-Mags and most of my metal mags. The only problem I had was trying to use the Elander metal mags that I used to use exclusively with my FS2000. The Elander mags lock in so tight they were a problem to even get out. I have just put them away to use in AR's. My other GI type mags worked in both guns.

 

[Eddie Adamson]

Fast forward to March 2019.
I have heard some grumbling from a new RDB owner that his mag catch was too stiff.
Play Handel: Halllliluuulia!!
They finally did something about it.
So I sent in the request for a new part#430. It arrived a in few weeks.
I will share my findings.
Firstly, I will mention I had received a replacement 430 a while back, hoping to score an improvement. But close inspection revealed it was identical to the unsatisfactory 430 I have.
So now I will conduct another trigger break scale test with these numbered 1,2&3 in the order I got them. Testing on a 30 round metal USGI pattern mag with ten shells on a closed bolt. Since the GI mags were the most problematic, it with these I need to see the most improvement.
Unit #1: five tests averaged 1.65 lbs
Unit #2: five tests averaged 3.5 lbs
Unit #3: could not be measured. tension exceeded 8 lbs. Actual tension may be closer to 14 lbs.
So, I am very happy now. Thanks KT for this improvement.
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So do they offer different magazine release tension weights now?

 

[RogueIV]

They offer only 1 type, the newest, heaviest one.

 

[Eddie Adamson]

Thank you. That is the only real issue I have faced with mine. I really wish they offered a push button release rather than the style they have opted for even though it is ambidextrous.

 

[IamScotticus]

it was available in the RDB parts page

 

[A_Brutal_Potato]

it was available in the RDB parts page

Glad to see my complaining shed some light on the issue lol! For those who are receiving new ones and find them to be a tad too stiff, I found that (gently) bending the clamp in an open direction with minimal finger strength, just enough to flex it a centimeter or so at max tension does the trick to loosen it up. Someone pointed out how they are heat treated steel and thus would be more likely to snap than bend if overly stressed on a fulcum/axis). I also sanded the inside edges of the clamp and lubed the hell out of it, but while this made it feel less "crunchy" to engage, the real tension problem is in the clamp being a little too narrowly U shaped.

 

[Percevel]

My rdb-s does not seem to like GI magazines.

It will take the first but then come unseated and then drops out for the second.

It works fine with Magpul.

 

[IamScotticus]

Im just starting to read reports of this. Han't help much since I don't have one. Stiffer spring?

 

[LG45]

I have only 200 rounds through my RDB. All but a few rounds using aluminum mags. I have had no problems with the mags dropping out. I picked up mine in January 2019.

 

[IamScotticus]

Assuming you refer to the pistol grip RDB,
The mag catch/release is stiffer in later production

 

[Eddie Adamson]

Thank you. That is the only real issue I have faced with mine. I really wish they offered a push button release rather than the style they have opted for even though it is ambidextrous.

I contacted KT about my issue and they sent me a new Magazine Release Spring... after 500 rounds and multiple magazine (PMAGS & Steel) everything worked as it was supposed to. The spring is stronger and prevented me from accidentally releasing the magazine during some weird position shooting that I did. Previously when I did them I would bump the mag release and lose the mag but with this new spring it is riding in my patrol car with me daily.

 

[John Munley]

Just a comment regarding the mag catch on my RDB. My gun is about 1.5 years old but only a couple dozen rounds as it has been back to KT for double tap issues. Just got it back the second time a week ago. Everything seems to work fine but the GI mags will drop out with any contact with the catch. I found that I could improve this a good bit with a piece of stuff foam rubber glued under the mag catch so it compresses a little when the catch is pressed. If you take care to trim this well and glue it place it hardly shows and can make the mag catch on early model units more reliable. Worked well for me.

 

[IamScotticus]

I found that I could improve this a good bit with a piece of stuff foam rubber glued under the mag catch

Yea, I used some door seal weather strip. KT will send you a new MR for the asking is you tell them you have a dropper.

 

[MNBushmaster]

OK complete newb to the RDB - just picked up one a few weeks ago (Jan 2020). I have the drop issue with the GI Mags - PMags work fine. From what I read here, I just have to contact Kel Tec and they will send me a new spring? One of the reasons I went with the RDB is the mag compatibility - I have a decent supply of GI mags for my ARs and I'd like to swap without worrying about it.

I guess I'll check out the KT website and see if I can get help... Hope I don't have to send it in!

 

[IamScotticus]

naw, you shouldn't have to send it in.
Does your release trigger have two holes in front?