View Full Version : installing a adams arms piston kit

05-30-2016, 01:44 PM
ok I checked the adams arms carrier out comparing the bolt fit and the only difference I can see is the aa carrier is a bit heavier and the bottom will need to be changed to like where the psa carrier fits down in the ak mag. I think the aa carrier will be ok with the adj gas block and the ability to change the buffer stuff if need be with the bottom sides cut to fit the ak mag. I have at least two of the hydraulic type buffers in other guns with the heavier calibers in the ar type guns. I like the psa 7.62x39 marking on the carrier but the ak mag should be enough till I get a 6.5 ak mag ar type around, then I will need to be careful. I have a ar with the ak barrel, and a 6.5 grendel ar but they use the ar mags so it is obvious what they are sorta. I always check the barrel when I pick them up to go shoot because they are all so similar. The ar types have the aa piston kits and I use them with the phantom 308 suppressor.

annnnyway the thing I found out after tapping the bushing in the upper reciever is the channel for the piston rod is offset from the bushing bore and the rod won't go in the bushing straight. Now I gotta get the bushing back out to open the right side of the channel up a little to get the clearance needed for the piston. I have all the left over installation rods from the other kits so I think I can put a flat on one side to get a straight shot at the bushing to get it out. I haven't got a idea other than a small jewelers file to get the clearance. It is probably only a few thousandths. I wish I had a stepped boring tool to just put in the bushing to clearance the notch while the bushing is still in the receiver. I may just try a drill the right size and try to hand turn it till it gets straight depending on how hard the bushing seems to be. I don't want to open the bushing up. I will come back after this little minor deal is done.

There will be the part about notching the upper part of the hand guard to get access to the gas block adjustment. I have done this on a couple utg super slim pros and each one gets better but aren't the best solution to me. I need to make a long tool to go in the front under the hand guard to do the adjustment. I use long allen wrenches on some di adj gas blocks on some of the other ar's. This handguard is nice and small but the aa gas block won't fit so the notch deal seems to be the only solution but I will think about it before I start cutting on anything. I know it seems like a lot of trouble but a adj gas system is the only way I will go with the suppressor. Also it makes the gun so much nicer to shoot with different loads and I can shoot in the back yard and sometimes when I forget the muffs it's not so bad. It looks like maybe I can sand the sides of the gas block a little to get the clearance but that will screw up the finish on the gb. On the one utg super slim pro that I cut the top rail out for the gas block I have to also remove the gb to take the rail off. Really once these guns are converted to pistons they don't need to come apart it seems to me but I don't shoot 400 rounds in a day either. Actually I will be trying a adj gas block piston on some aks after getting the m+m ind m10x and seeing how it works, maybe m+m will make a kit for the ak if adams arms doesn't at some time. I have used homemade adj gas blocks on my mini 14 and a sks and I like the adjust ability on them also with the suppressor.

This is added after the below posts. I know this is a long post but the fix on the bushing was simple I just found a drill the fit the bushing smoothly and welded a 12 inch long 3/16 piece of keystock to it and reamed the upper out to fit the bushing bore with out enlarging the bushing. Thats all I'm gonna add to this endeavor as I think this mod might be too much and I don't want to recommend this to anyone that is not a trained gunsmith on the ar.

Oh what the heck.

It is the XLP carbine aa version. The box says CPS-D-ADA-XLP. I like them so well I ordered two. The hand guard will need the upper inside channel opened up about 2 inches long for the piston and more if you leave the rail to cover the block. This might look the best but covering the opened up bottom wth that long of opening might be hard to do with a single rail. Of course the adj part will need to be opened on the top for adjustment. I went in from the bottom of the hand guard through the keymod rail with a 1/2 end mill to get to the upper inside of the hand guard. you gotta have a 2.0 inch deep endmill. The shortest opening in the bottom means a larger opening in the top for the gas block. the total length for the groove will be about 5.0 inches including the adj knob part and the travel room for the piston. The shorter opening in the bottom can be covered with a pic rail. This is the way I went with a larger opening on top exposing the entire gas block and leaving enough rail for a front sight. This hand guard is nice and stiff. I have used utg pros on other ars with the aa piston kit, but the wider upper on this gun meant the ks guard fit the receiver better. I tried the utg pro but didn't remove the barrel nut to see if it is the same as a regular ar on the threads also it would require the utg guard to be cut on to fit the wider receiver. Oh yeah I forgot the ak mag to carrier fit. The psa hybrid carrier is cut to fit the lips of the ak mag on the sides so either get a aa gas key that is made for the piston kit at brownells ( another 50 bucks) or modify the aa carrier on the sides to match the psa carrier so the carrier will fit down in the mag lips. I added this part at the top so folks would not get the idea the carriers were a easy swap. The sks folks that do the ak mag mod understand this part.

05-30-2016, 05:54 PM
Yup keep the updates comin! Are you using the Xlp system or the original? If you need to adj the gas wont you need access to the gas block and with the 13" keymod rail sitting on top of it would that be possible? What length system you using carbine, mid?

05-30-2016, 06:02 PM
OP, what does this have to do with Palmetto State Armory?

Palmetto State Armory
05-31-2016, 09:07 AM
Thank you for your enthusiasm for our product.

We would like to note that while we are honored that our rifle was used as a base for this adventure, we worry that its placement here might lead people to believe this was a PSA approved modification. This would be an incorrect assumption.

Please be aware that any permanent modifications to the KS47, or use of non-standard or modified parts, is undertaken at the owners own risk, and is not sanctioned by PSA. Serious injury and death may result if the components are compromised.

While the folks at Adams Arms make a fine product, it is being modified from its original purpose. I'm sure they have reservations as well.

Needless to say the factory warranty would be void, and the person who undertakes the modifications assumes all liability for the firearm.

06-01-2016, 06:10 PM
I appreciate the legal stuff. I wish you would make a piston ak/ar upper. Orrr a adj gas block ks upper so I can use a suppressor and adjust the pressure to make the gun as smooth as possible. Piston guns are much cleaner especially with a suppressor. You do make a nice product with a nice heavy stiff barrel but a adj gas system will be the thing for any gas gun in the future as folks find out how nice they operate especially with suppressors. I would buy a 6.5 grendel ks 47 piston upper if you ever decide there is a market for one. Someone will do this I am sure. I realize a long buffer tube and spring doesn't need a adj gas block but the extra distance the carrier travels and the over pressure a suppressor creates is something that can be adjusted out easily. I probably shouldn't list the things I did to get the piston and block to fit because that would encourage folks to try it and I really don't want to cause problems.

Also I am sure your warranty is great. I realize the warranty is out on this gun but after receiving it I'm sure I won't be needing it. I actually have never used a warranty on any of the many guns I have. I don't abuse any of them. I don't have 1000 rounds even on the guns I bought in the 60's. I have lots of favorites but still haven't found the perfect all around gun. For all around I have decided a 125 grn bullet about 3000fps/1000fps suppressed in a ar type gun with a double stack ak magazine, adjustable gas system weighing about 7-7.5 lbs with a light suppressor might be it.

I finished the description of the mods in a added part to the top post. Do this stuff at your own risk and understand the ar carrier and bolt lock up operation real good. Make sure there is clearance between the piston rod and the carrier when the bolt is locked up.

I think it makes this gun better in my opinion for my uses with a suppressor.