Teach me about Automag Pump Kits

[Chuck E Ducky]

Pictures would be helpful.

What kits were made over the years?

Who seemed to have the best design and why?

Are there permanent mods needed other than the rail slot?

Looking for design ideas, apparently some of these things sell for $500. What makes a $500 pump kit? (Is it just rare)

[Magageddon]

I can think of about 4 pump kits that weren't home brew.

The original agd Pump kit. I has an oval shaped guide rod to reduce slop in the pump stroke, all aluminum construction, now a days pretty rare

Cerberus had a couple designs, similar to the agd pump kits, but some of the handles were delrin, The pump kit on my stockclass mag is one of the delrin ones.

Rainman made a couple generations of pump mag kits, I used to have a gen 3, they use a dual guide rod similar to a ccm pump kit. I never really liked them, the pump handle tends to sag forward a little bit.

XM15: you don't really see to many of these, its just an aluminum block with a single guide rod/delrin handle

The only readily available pump kit that I know of is a guy on facebook that 3 d prints/assembles a kit, its pretty solid, I've owned 3 of them now and at the price point of 47 bucks shipped, its the best kit for the price

The other kits I've mentioned range in the 200-500 range, mostly due to scarcity. Of those, either Cerberus or AGD would be the better ones of the bunch in my opinion

As far as a parts list for a pump mag you need:
Pump milled rail
Pump milled body, a lot of stainless bodies were factory pump milled, but ule bodies were not
Wave spring/cut down bolt bumper
Cut down bolt spring
Pump kit

The cheapest I built a pump mag for was around 250 with the 3d printed pump kit about a year ago. Depending on what you want parts wise, your looking at about 300-1000 for a complete build

[Chuck E Ducky]

Oh so the body would need to be modified as well. I don’t think I want to get into that. Especially with mine being Carbon Fiber. I just thought I might be a cool option to have but it doesn’t sound like an easy swap. I would probably be better off building a dedicated pump mag. This just gives me another excuse to buy more stuff as if I needed one. lol

Thanks for the detailed info.

[Trbo323]

Yes the way the mag pumps work is a little different.

The marker basically functions as semi auto but that wave spring prevents the bolt from coming all the way back. The pump arm goes into the rail and the body cut is needed so the pump arm can bump the bolt back into it's fully rearward position where it will catch the sear

Sent from my motorola edge 5G UW (2021) using Tapatalk

[Chuck E Ducky]

Ahh I see, So the rod slots through the rail onto the body pushing on the fat part of the bolt to reset it? Any adverse effects from modifying a body? I think I was offered the ability for a pump mod when Keith put these together but I didn’t think about it. I will probably look for a detacated pump mag I think. Riot has a nice fancy one I’m sure he will get tired of eventually.

[superman]

AGD made 2 kits. gen 1 and 2. Gen 1 was able to twist.
Cerberus made gen2 copies in delrin and aluminum.
XM15 made kits
Rainmain made about 4 different kits overall. gen 1 had issues with the pump handle pulling off during play. gen 2 and 3 were better. gen 4 looked like they were drilled at an angle and sagged.
The 3d printed one is the easiest to get, but definitely feels cheap.

[Chuck E Ducky]

I definitely don’t want a 3D printed one. There is one on Facebook apparently that uses a brass and or Aluminum mount and just the handle is printed. He sold all the ones he made but has plans to make more. I want to see if I can fit an early T2 pump handle that I have on that kit. The pump plate looks pretty sturdy, and the 1st Gen T2 handle would fit perfectly under the mag it’s narrow and don’t use a secondary lower guide rod. It would just need a custom pump arm bent to work with the pump slot. I got some brass pump arms that might be up to the task. It’s such a simple design I’m surprised with the cost of them nobody has offered a nice kit for them. I guess it’s a pretty niche option.

[superman]

It is on the list of things i'd like to offer, but further down the list.

[Chuck E Ducky]

I even thought about modifying a CCI Dual rod plate to key into the mag rail slot but I think the material would be to thin at the dual rod area after it was machined down to make it key in. Might be just as easy to machine an aluminum block into an L shape and tap the end so that it excepts a 2k+ guide rod and use off the shelf parts to complete most of it.

[Spider!]

Aside from tuning, try to keep the wave spring free of sand/grit. It chews a spot on the contact points of the waves, which then breaks the spring right there. My son went through a few wave springs pretty quick like that until I told him to keep it clean.

[maggot]

Speaking of, anyone happen to have a couple of wave springs handy? I have been too lazy to search but am happy to pay for them.

[maggot]

Love to support AGD any chance I get, but those are out of stock

[superman]

I would shoot sandman an email. I’m sure he would consider ordering more. I want to say he had to order a bunch before, so maybe it just shows out of stock on the website.

[maggot]

That's a good lead, will try him. Thanks!

[Riot]

Nick answered pretty much entirely in the first post.

My .02 is I’ve had a rainman, AGD, and Cerberus kit…

The rainman felt janky- in a bad way. Lot of slop.
The AGD was fine.
The Cerberus is what I kept. Hands down the best feeling.

As for the body being milled, it looks like a pretty simple task, but I have no idea how CF cuts- im under the impression it’s fairly fragile though. Point is, if you know someone who can do it, I wouldn’t think the cut itself is that difficult.


Please stay away from the 3d printed ones. They’re cool in a pinch, but I can’t imagine they feel great. Plus, they’ll kill the market on real ones and im sitting on a really nice Cerberus. ;p

[Chuck E Ducky]

You should probably just sell or trade me your pump mag. But Uncle Sam stomped my Cubes so hard this year. Might be eating PB & J a week or so till that OT check clears. When the play money recovers I definitely want to look into a nice pump mag.

[$L!mBo]

vindicate and bmc are able to mill your rail/body. theyve both posted a few examples recently

[cougar20th]

Chuck Ill get my red stockclass pumpmag shooting again. (probably is just been a few years so I want to look it over.) Ill bring it to Slims. Feel free to take it for a try. If you want I can also bring my purple pumpmag as well. But thats open class.

[Db1060]

Did someone say purple???? Lets me get that lol

[cougar20th]

That gun is going nowhere. First gun I built from parts. And second gun I ever owned. It used to see alot more use.

[Pyrate Jim]

I have two, a Sydarm and a build of a Lukes SC Mag bodies.
The old Sydarm came with the opened body underneath and milled rail, so that was easy. I didn't like it, though. The pump handle stuck out farther than the barrel and I kept shooting my fingertip.
Plus with the pump, it wouldn't fit in the holster.
The one with the Lukes' body (possibly, ~ he wanted a closer look at the welds to be sure it was one of his) did not come with the pump slot. I put it on a rail already milled, I but had to cut the slot myself using a cross slide vise on a drill press with a router bit. That left more meat on the body since the factory opening is huge by comparison. Added a Line SI lever changer island style to make it fully stock class. It's my #1 choice.

Two things, first the wave spring that keeps the bolt from resetting would not allow the bolt to seal (powertube spacer issue) and I would have to pump it immediately or the air would seep out. Shoot and pump is backwards to my normal pump and shoot.
The other thing was Magageddon mentioned cutting the bolt spring, which I've never done. Never had an issue and don't understand why it should be cut?

Good luck! Shooting a pump mag is an experience equaled only by shooting somebody with a pump mag.
And a stock class mag? Restrict the paint supply, the air supply and the semi-auto ~ you cut 3 legs off a race horse and can still win.

[alpha_q_up]

Pic heavy post incoming, these are all pictures from my collection, if you have any pm me, been meaning to make an pumpmag guide thread at some point

[alpha_q_up]

AGD Pump Kits aka the gold standard of pump kits these prolly fetch a pretty penny prolly not close to the 500$ but up there somewhere)







3D Printed kits

Grin and Grind Designs(Clint Quinney) I think I seen these for 47$

CFDesigns(Cody Forsythe) i belive these are 120$

More Pictures Here

Cerebus Kits these are the ones that fetch the 500$ price point(allegedly)









More Pictures Here

Rainman 229 Pump Kits(these somewhere in between depending on working condition, last one I seen of these sell publicly was for 300$ for the kit, I'm still mind blown about that)

Gen 2 maybe a better kit of Gen 3


Gen 3 with Slouch


Gen 3 with fixed Plate and 3d printed handle


Gen 3 with a Check It Pump Handle modified to fit



More Pictures Here

Misc Mods

These I can't really tell where to put a price point, but I figure north of the 3d printed prices for sure depending on the mod/kit

CCM Modded Handle


ID Genisis Kit
The first cocker based kit I modded for my mag fed pump mag


A Slice Kit I Modified(currently have 3 of these prototypes, 1 out for anodize, and currently working on modifying an ID Genisis Kit in this style)


An all aluminum kit I made(this is currently at anodize, if you're in the mcb discord I've posted the prototype modded Cocker handles and this guy there with a shooting video)



More Pictures Here

Not pictured is the xm15, but think of the CFDesigns kit with he threaded pump arm like the rainman kits and idk where to price those I haven't seen them sell lately

[Chuck E Ducky]

So something mentioned to me was there is no stop for the handle. The actuating stroke is very short like pneumatic pump assist. But the handle needs some sort of stop otherwise the handle will not stay on during the forward stroke. What’s the most effective solution for that?

What kit you think has the best solution for that?

[superman]

from the end, but the rainman kits have a pump plate so you can remove the pump plate and slide the handle on so no hole on the front.

[Chuck E Ducky]

That’s probably a cleaner solution. Bolt holding a small washer. Then the handle slides over it all and bolts from the back to the handle. Might need a thicker then average pump plate with a fairly tight tolerance so the handle don’t sag. I suspect that’s why some of his do that.

Or a bolt on liner barring bolted to the end that acts as a stop at the same time. Oh fancy

I wonder if you could hide a return spring in there as well.

[superman]

yep the return spring fits as well.