FN Herstal Firearms banner
1 - 2 of 2 Posts

15,575 Posts
Discussion Starter · #1 ·
I had an opportunity to try out one of these aluminum buttstock extensions last week. The aluminum extension is sold by Critical Dimensions, and I believe he charges $89 for it.

I hit the range with my PS90 last Friday morning, and I used the extension during some of my range time. I also attached it to my PS90 earlier in the week, to see how it balanced on the weapon.

At home, I found the extension very easy to install. It basically replaces the polymer buttstock end-piece. If you remove the polymer end-piece first, you would then slide this aluminum buttstock on the very end of the rifle. Afterwards, you would slide your polymer end-piece onto the end of the aluminum extension. This increases the length of the rifle a few inches (2.5 inches, according to Critical Dimensions).

The extension is made of aluminum, and it had a textured feel identical to the metal protective cage on my Eotech. I have found that any scratches on the Eotech hood always rub off when you use your fingers. I assume the surface of this metal extension would work the same (should one bump it into something and get a mark on it). In addition, there is also a small storage area located inside of the extension. I suppose one could store extra batteries for an optic, or something else if needed.

When I purchased my PS90 back in early December '06, I immediately installed my Eotech and put a laser and a flashlight onto the side rails. So, I've sort of forgotten how the stock PS90 balances (I've added at least 2 lbs to it, if not more). But, I will admit that my PS90 is a bit front heavy with all the stuff I have attached. This aluminum buttstock balances my rifle out a bit. I immediately noticed this change when shouldering my PS90.

We all obviously know that the PS90 was originally designed as the P90 - a fully automatic personal defense weapon. The PS90 has a longer barrel and is instead a semi-auto design. Because of this, the longer length of the weapon is not that big of a deal, and the PS90 is still shorter than any other legal length rifle. But, the design does put the optic rather close to one's face.

It is my understanding that the purpose of the buttstock extension is to put a little more distance between you and the optic - making it a bit more like a traditional rifle when aiming. It does do this. Also, as the manufacturer points out, you could now use the back of the rifle as a weapon should you get into a hand to hand situation (fighting over the gun).

Out at the shooting range, the buttstock extension was comfortable to use. Some people like to put their Eotechs further away from their faces when mounted on AR15's - this extension sort of simulates this effect on the PS90 by lengthening the rifle a short amount.

The black color of the extension looks good on my black PS90 (things are slightly different in the pic due to the white flash). Obviously, there is some color variation, as the weapon's stock is polymer, and the extension is aluminum. But, it does look nice.

It is also my understanding that Critical Dimensions will eventually release a polymer version of this extension that is supposed to match the finish of the PS90 closer. Some of you may prefer this, but as I discussed above, there is some benefit of having the heavier aluminum version.

If this is a product that interests you, then I think it is very well made, and would work as advertised. If the weight at the end is an issue, then the polymer version that will be released later would alleviate that issue. But, be aware that the added weight can serve a purpose if you have all sorts of extras strapped onto your gun's rails now.

Critical Dimensions has information to buy this item located here:

1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.