Metric or Standard?
 

What is the threading for the front end of an armalite receiver/back end of a RIS/RAS? Its just that I was told PTW's have a standard threading because they can fit real steel front ends out of the states which are, of course, standard. But just the other day I was helping two guys assemble PTW's and the G&P RIS fit perfectly onto the PTW, meaning its standard. Back when I had a G&P SR-25 I put a KA RIS on it and it fit fine, so is KA standard as well? I recently bought a Madbull dragonfire RIS and it was metric threading, didn't fit the PTW receiver at all (neglected to test it on the G&P receiver.) Just that there was a thread in the accessory sale section about someone selling a metric RIS because their very old ICS armalite had standard threading. Was it just a fluke that he got a metric RIS or whats going on?

The metric thread is 1.50 t/mm and the Imperial thread is 15 t/inch. I have a MetalTech RAS that is metric, and it doesn't fit a PTW. I reworked the threads on the PTW with a metric thread file for about an hour until it did fit. The PTW is Imperial threads, and so is the real gun.

But are most airsoft RIS/RAS's metric or standard? If the threads are totally different then why does a G&P RIS fit on a PTW? I've put a King Arms RIS on a G&P body, thats why I'm wondering.

Not all airsoft guns are made the same. Remember old CA guns that you couldn't find rails for years ago? The Metal Tech RAS fit those no problem, so I guess they were metric.

Heres a kicker.....

Madbull RIS, does not fit my PTW, does fit a stock TM receiver = metric
G&P RIS, does fit PTW, unknown if it fits TM but fits G&P = standard
King Arms RIS, does fit PTW, DOES fit a stock TM receiver = !?!?

I know the PTW is standard threading and I know the Madbull RIS is metric thus the incompatibility. But the KA one fits standard and metric threading....is it just a loose thread thats compatible to both? When I tightened the KA barrel nut with a barrel wrench it was just as solid as the stock PTW barrel nut so I figured its not too loose of a thread or it wouldn't be able to be cranked on that tight.

A heads up for PTW owners at least, both G&P and King Arms threading will fit PTW's, Madbull will not.

I noticed that when I used a metric thread file to fit rework the threads to fit the MetalTech RAS on the M16, I could still re-install the factory PTW barrel nut. I think what I ended up doing doing was taking the threads down enough so that either would fit, but not perhaps as good of a thread "mesh" as if I used an Imperial barrel nut on a receiver with Imperial threads. But either one holds up solid.

That sucks about the Madbull, but at least I've already altered the threads so I could fit it anyways.

I've spoken to Mad Bull about about offering a separate barrel nut with imperial threads. They plan to release one for each of their Dragon Fire CNC Handguards and JP Rifle kits.

Didn't Hong Kong used to be a British colony? Would explain why theres standard products coming out of asia...

Except all of Asia and Europe are metric. There are only three countries in the world that are still standard, the United States and two third world countries that are too poor to change. Take the PTW for example, everything threaded on the real AR is threaded standard on the PTW but parts that aren't on the real AR (mechbox, motor plate, etc.) are threaded metric.

Most of those other parts have no upgrade potential from real steel parts manufacturers though. Imagine how Systema's PTW sales would be if it was threaded metric, and was not compatible with real accessories? For many guys, this is a huge selling point.

Would be a nice idea though if they did sell a Metric threaded upper.

Or just don't buy Madbull products for PTW's......

Well im glad you did it first.. then again that was a nice RAS

Maybe G&P wanted people to be able to use real steel parts on their guns? Or they realized not many other people had a standard RAS so they made one just for the PTW's sake?

I doubt G&P made their products both just for the PTW. It was said on a sale thread a little while ago that a guy was selling a RAS because it was metric and his old ICS was standard. Its probably because there are differences in manufacturers and G&P and KA wanted their products to be universal.