Upgrading P90 Inner Barrel
 

I have a King Arms FN P90. I am looking to upgrade and possibly lengthen the inner barrel from stock. Stock inner barrel length is 255 mm. Would increasing my inner barrel length to 300 mm or a 363 mm require a different cylinder or an internal change to increase the volume of air? Also, what brands of inner barrels would be best?

360+ is cutting it close to where you need to move to the next size cylinder. If you sorbo the cylinder head, you will need to move to the next size up on cylinder to make up for the volume lost with the sorbo.

I swear by prometheus eg barrels. A properly set up compression system doesn't really see huge benefits from a longer barrel.

Ok. I think I'll go with a 300 mm length barrel. What about Madbull 6.03 barrels? They are less than half the price of prometheus.

madbulls are complete garbage. They are disposable inner barrels and suffer from scratches frequently.
Also, nothing wrong with a 255mm inner barrel. Just run an Rhop or firefly, perfect compresion, 400fps and .30s, you'll be shooting just as good as DMRs

Guess why they are half the price.

Just like my car is half the price of a Porche...

they work... but they don't work as nicely as prommy

Madbull barrels are fine...sometimes. I'm running one in a build up I did with fantastic results as well as in a p90 I used to have, while my groups tech has tried them twice with bad results. I think for some reason they are either hit and miss quality wise or just picky with the rest of your setup. For this reason I would stay away from them unless you already have one to try or know someone who'll let you test it out b4 you commit to buying off them.

^ This

I run this exact setup with a Prommy Barrel that is 247mm. Even when my gun shot at 360-380 I could still outrange most people.

I had a Madbull Barrel before I got a Prometheus, 2 years later I am still running the same Prommy barrel, probably will last forever. I found my Madbull barrel did warp after a couple months of usage though.

Buy Prometheus. Not Madbull, not a Miracle Barrel, not Army Action, not Angry Gun, not some cheap unknown china brand, PROMETHEUS BUY PROMETHEUS.

OR just stick with the stock King Arms barrel, I'd say you would get equivalent if not better performance and results out of it then a Madbull or anything I listed above. It's not a bad barrel even though it is stock.

I have a madbull python 247mm in my p90.... people like to think I can reach out and touch them... till they get hit square in the chest from farther than their fancy tacticooled out m4 can reach me.

Recently got a Prommy barrel, and sincerely wish I got one sooner.
After going through few madbulls, to a modify, finally bit the bullet and went Prommy.

Buy quality, buy once, and be done.

for sure. This madbull is the only one I have left that is waiting for replacement. Once I get my new/old feeding issue fixed again, I have a prommy waiting to go in.

I run a stock TM P90 with a m16 length TK twist inner barrel.

Works wonders, it is a nail driver and has excellent range.

Hi Short Round. I do have a King arms P90 and i am about to get a 247mm prometheus inner barrel and i would like to know what kind of hop unit are you using or which one you recommend. I am willing to improve the accuracy of my gun. Right now with the stock parts it is lacking accuracy a lot.

What weight of BB's are you using? The P90's hopup chamber is a good design. As long as you're using a good rubber it should have great accuracy.

I use a TM Hop Up Unit