View Full Version : Upgrade for a p90

07-05-2004, 04:46 PM
I'll be upgrading my p90 soon with the Ver6 systema bushing set, an m120 spring, and a tightbore barrel made for an m4 ( KM 6.04mm TN 363mm). Does this sound like a good place to start?


07-05-2004, 06:05 PM
Yep...thats the basics...pretty much all you need for 400 fps is spring and bushings.

07-05-2004, 06:25 PM
Are you aware of any online guides on doing this work? I imagine that it shouldn't be too difficult, but at the moment I am without a diagram of the p90 gear box. Installing a new barrel should also be pretty straight forward, correct?
Also, what type of supplies will i need assuming i do this myself? Any special lubricants or grease?

Thanks for the help.

07-05-2004, 06:50 PM
The one that most of us learned from: http://www.airsoftplayers.com/guides.asp

07-05-2004, 10:12 PM
What brand barrel would you all recommend in general? I've seen Prometheus, Systema, and KM. Also, when choosing a tightbore barrel is it best to go with a 6.03 or 6.04 diameter barrel?
Is a new cylinder head and piston head also needed?

07-05-2004, 10:47 PM
The reason we encourage people to read the Airsoft FAQ on this site: http://www.austinairsoft.com/modules.php?name=FAQ&myfaq=yes&id_cat=8#33

Although, the info does need to be updated to reflect that the Prometheus barrels are getting slightly better comments from what I've read than previously.....apparently, they take a "breaking in" period, of which basically the coating needs to worn down a bit to get consistent accuracy if I understand some of the comments correctly. In addition, the Prometheus barrels allegedly prefer thinner hop buckings, thus some of the popular ones out there may cause some weird hop-up issues. Again, I have no direct experience with one of these barrels, but have read up on them some.
In the end, save yourself $30 and go with a Systema barrel.

07-05-2004, 11:55 PM
My apologies. I'll read through there again.

Thanks for the info.

07-06-2004, 09:00 AM
my personal opinion is that the systema barrels suck. I have had 2 of them and ended up replacing them with KM barrels. The KM barrels are twice the price but they do not get dirty as fast and I have had far better results with them. I have not used any of the prometheus barrels as of yet.

07-06-2004, 09:26 AM
Need more objective feedback than that. I have both KM and Systema barrels in all of my guns and have not experienced significant difference between the two. Of course, I clean them every couple weeks or so.
The KM's inner surface is definitely slicker, and I agree in that they don't seem to need cleaning as often, but other than that, I've had similar results.

07-06-2004, 09:31 AM
That is objective feedback......I object to using systema barrels in any of my guns.

My opinion of systema parts in general keeps going down. I have seen multiple brand new gear sets strip a gear cleanly. I trashed all the aluminum pistons I had after I used one and it appeared the teeth were not spaced correctly or something to that effect. I dumped all my systema motors due to the heads coming off them non stop. They might have been good in the past but they are just putting out crap these days.

07-06-2004, 09:45 AM
Alright, what I meant was objective data. As in running a test at 30 feet (or whatever distance you want) and see what the groupings are between the same gun with only the barrels swapped out. Saying one sucks isn't really objective. Saying one gets dirtier is objective in that you can see the results (when the barrel is swabbed over the same amount of rounds through it). Without doing the actual test, there are too many other variables that could contribute to what the user perceives as good results. For example, my M249 back in its' working day was an absolute laser, and to me, it was an accurate as my SR16. The M249 has a Systema barrel in it, while the SR16 has a KM. {shrug}

Aluminum pistons suck. I'm not a fan either. They like eating gear sets for lunch.

07-06-2004, 04:30 PM
So, what your opinions on a systema m120 and pdi 170% spring? Those aren't as complex as a gear so I imagine they should both be around the same quality.

What is the recommended method of cleaning the tightbore barrels? A silicone based lubricant and a swab or something else?