Indeed, what is your 5.1 shooting at?

Sorry should have added that bit of information, at the time the gun was shooting 330ish with 0.2g BBs.

Your fps is always a concearning factor.....the higher the fps, the heavier BB you should be using. If over 330 fps, try using .25 weight BBs. However, another thing to consider is the barrel length verses fps. A a higher fps out of a shorter barrel will create what someof us call "blow by", and this causes the BB to be less stable and therefore will result in less consistant in groupings. There is a finite line of solutions;
-you could go with a tighter inner barrel, but this could result in jamming issues,
-you could go with a longer barrel, though not usually an option with pistols.

This is why the GGB techs that do the IPSIC (think thats the correct spelling) pistols in Japan make sick money (around $185 US an hour) to build and tune these pupies.

SHA DO

Sha Do, yes I am aware of that I'm usually running 0.28g BBs in my pistols. I didn't want to use a longer barrel because I wanted to keep the stock look of the Hi Capa 5.1 at the time (similar configuration in my TM 1911A1 right now which is my current side arm of choice).

Here's an example, with the Nineball 6.03mm and PDI 6.01mm (both of which already outshoot moderately upgraded AEGs), I can hit a static man sized object at 120' easily. With the TK I could barely shoot across the floor at TTAC3 (length wise).

In any case it's interesting to hear other people's experiences with TK barrels in their pistols.

that is an excellent point, but Illusion said that even over 330, the barrel was acceptable and performed similar to a tightbore. this is of course disputed by colin.

I'm at my second TK pistol barrel. The first was in a WE1911, and it shot straight for the most part. I got the rare shot that'd spiral off somewhere, but I suspect that was because of the abnormally high rate and size of nipplage of the KSC .30g BBs I was using.

The second and current is in my KJW P226/9 hybrid, and it shoots very straight and consistent.

I don't see how that should be an issue...

No, they're actually worse.

No minimum length that I am aware of. I am effectively using these Twist inner barrels in two of my four GBBs, both of them are using the Hi-Capa 5.1 length inner barrel.
One thing I've noticed in both of these guns, is that the hop up dial has to be turned to the MAXIMUM to get the shots to go straight. Otherwise, they dropped earlier than expected.

Sorry, whenever I refer to "330fps with 0.20g as the limit", I am using that as terminology that is easily understood by a greater audience.

The absolute truth of the fact is, that these barrels are only effective at 1 JOULE or less. This calculates to 330fps with 0.20g BBs. If you are shooting 350fps with 0.20g BBs, putting in a 0.25g BB may drop your velocity, but it WILL NOT lower the work output. Work output remains the same in constant source systems such as AEGs, but in a variable/expanding output systems such as gas powered guns, your work output will actually increase if you put in a heavier projectile, thus, making the performance that much worse.

Buh? What, a 229 slide on a 226 frame?

My appologies. I did not realize what weight of BB you were using as it was not indicated in any of your previous postings.

LOL........ and thank you bro for clarifying the 330 limit....I was assuming that this was the limit for the functional benifit of this design of barrel. I have read so much about these things and nothing is really clear, just a whole bunch of speculation, with possible grounds, but no solid test results.......for higher fps BAs.

Thanks again;
SHA DO

I've observed that as well, but passed it off as being due to my H hopup sleeve.

226 slide on a 229 frame.

Pictures? You can PM them to me, lol.

Ahh alright, that makes a lot of sense. I stopped using the TK barrel after about 10 games at TTAC3 (hopup is not necessary there) and only played two games with it outdoors. Too bad I got rid of it, would like to test it in my 1911.

No worries I guess I wasn't clear but thanks for trying anyway. :)

Thought: If we have to crank the hopup to maximum, wouldn't we be losing more fps compared to someone using the exact same gun except with a tightbore?

Not done yet. Needs 2 more weeks. Here's an unartist's rendition.

Not so, on a gas gun.

The hop up may apply more pressure on the BB, but that also gives the gas more time to expand. By the time enough pressure is placed on the BB to dislodge it from the hold of the hop up bucking, the pressure will be higher than normal, resulting in HIGHER fps.

Not sure why, but all of the AEGs I've tried these barrels in do not require the hop up to be adjusted to maximum, and if you attempt it, the BB will fly upwards, like a normally operating hop up system would do.

Thanks Illusion for clearing up the hopup issue I was having with my 5.1 and the TK barrel. I just could not understand why I needed it at full after installing this barrel, now seeing as you have the same issue I feel much better.