Many self proclaimed “experts”, on various PS90 forums, will tell you that the factory PS90 barrel can’t be cut down and threaded as they have chrome bores and the chrome will flake and the accuracy will be poor. That statement is only partially right. They do have chrome bores but I have threaded well over 1000 PS90 SBR barrels and none of them exhibit flaking chrome or poor accuracy. Many of these guns have upwards of 5000 rounds thru them with no accuracy degradation. If proper procedures are followed neither accuracy nor reliability are negatively effected when the barrel is shortened and re-crowned. The only issue with any of these barrels were two that had so much runout between the bore and the outside of the barrel that they could not be threaded and maintain concentricity.
On my SBR conversions I cut the shroud off of the barrel and cut it back to the correct length of 10.4”. I then thread the barrel M12x1 LH, just like the P90 SMG, and install one of my custom thread adapters. ½-28 threads are standard but there are several options depending on what suppressor you will be running. Please e-mail with your specific needs and I will be happy to make a recommendation. The standard adapter is compatible with the factory FN 3 point sling and allows the use of any AR-15 sound or flash suppressor.
There are 3 basic ordering options for the PS90 SBR’s. First, I can sell you a complete gun with the conversion already done. E-mail me at firstname.lastname@example.org for current pricing and availability. I usually have complete guns in stock ready to transfer.
If you already own a PS90 and have an approved Form 1 send me the barrel ONLY, along with a copy of the approved Form 1, and I will cut and crown the barrel, thread it M12x1 LEFT HAND and ship it back to you with a M12x1LH to ½-28 thread adapter for you to install in your receiver. The cost for this conversion is currently $195.00 including return shipping. When you file the F1 you are telling BATFE that you are the one “making” the gun and that means you must install the short barrel, or be there when it is done.
If you already have a PS90 but don’t want your name engraved on it you can send me the barreled receiver and I will log it in and engrave it with my information, perform the SBR conversion and transfer it directly back to you with a form 4. Please note that I can only do this if it is transferring to you as an individual. If it’s transferring to a Trust or LLC it will have to go first to an in state FFL-SOT, who will then transfer to your entity. The cost for this conversion is currently $350 including return shipping.
Again, as long as it’s transferring to an individual, and you can document that you owned the gun prior to conversion, I can ship it directly back to you with no in state FFL/SOT required. A sales receipt or invoice with your name and the guns SN will show proof of ownership was will a copy of the 4473 you filled out when you bought it from your dealer. If you have none of those, or it will be transferring to a Trust or LLC, it will have to transfer to an FFL/SOT in your state, tax free with a form 3, then to your entity with the tax paid form 4.