Question: Inner Barrel Upgrade for KP-05
 

I'm trying to decide on an upgrade barrel for my stock KJW KP-05. I only use it for IPSC practice, no skirmishing. I do get 1.5" groups at 5-6m with a stock barrel, but wouldn't mind tightening these a bit.

Would a Mad Bull 6.03 be OK, or should I go for PDI 6.01? Both accuracy and group size are important to me. I did search, and it seems that a 6.03 is preferred to 6.01?

Please tell me if there's a better alternative, I picked Mad Bull and PDI because they can be sourced locally.

TIA.

P.S. I'm also looking for recoil/shock buffers, does anyone know a Canadian supplier that may have these in stock?

Don't know much about inner barrels, so will subscribe to this thread as well.

I know PDI has a huge reputation, and is known as the top of top. They are also pretty pricey.

Did you consider hop up rubber bucking?

Not really, I run with minimal hop-up because of short distances, and didn't pay much attention to what's available in this area - which may be wrong.

You should consider looking into them, I think Maple Leaf EVO, and A+ are good buckings.

By getting a better hop-up bucking/nub, you'll likely see an increase in range and accuracy. This also means you'll get better groupings that you want, and a longer effective range.

Bucking + Inner Barrel combo is ideal, but if your limited to budget, I would start with a bucking/rubber first, then inner barrel.

I've heard very good things about the nineball purple bucking and have good results with mine.

As for barrels, again heard that 6.01 increase the power more than accuracy and that 6.03 might be a better bet for accuracy since you dont need to up the power. I have a 6.01 in most of my pistols, and my brother runs stock marui barrel and his gun is a laser, it may be attributed to his shooting .. but a bit difficult to compare cuz his gun is obviously set up how he likes it and for me to pick it up and shoot as well as he does isn't that easy.

At that range, it's more user-related than barrel or hopup rubber related.

6.01 with .32g bbs and an A+ rubber.
But at that range its mostly just you

I disagree.

At that distance I can shoot 10mm groups all day long with my RS Production pistol. The fundamentals are the same.

If you want to be sure, hook it up to a gun vice.

Real firearms are always going to be magnitudes more accurate than airsoft.

I'll admit I'm being a tad bias, my comment is based on you using heavy ammo.
Are you using at least .32g BBs in it? Because it really does make a huge difference.

I'm running a KSC USP compact (pre-system 7, so it's OLD), before and after Rhop I was hitting torso's at 140ft on .32g BBs

At 20ft, unless you're running something really light like .20s, I wouldn't expect there to be more than an inch of deviation. 1.5" at 20ft means you're probably getting REALLY horrible accuracy out at 100ft.

There's some common misunderstanding on barrels in airsoft. If the barrel is of good quality, that is the only feature that actually matters.
If you notice an improvement between the stock barrel and a PDI 6.01, it's the quality of the barrel that made the improvement. It legitimately has nothing to do with the bore.

However, the hop rubber is going to make the biggest difference, it's similar to the rifling effect. Without a good hop rubber, you're basically shooting a musket with an oversize barrel.

I used .28g for a while, now using .30g (Red Devil? don't like it, gives me occasional flyers), and have a bottle of .32g to try next.

I did another test last night, reasonably slow fire, 10 rounds at 6m. With two flyers, the group size is 25mm. Discarding those two, the group is 10mm wide & 20mm high. This is from stock KP-05.

Is it an OK assumption that a good hop up rubber may improve the vertical spread?

I am quite happy with the pistol, just wanted to get a slight improvement, not to build a race gun. Not having flyers would mean a lot to me. When shooting a 4in plate rack from 5-7m, I would know that a miss was because I did something wrong, not the gun.

I may as well try a Mad Bull 6.03 with an A+ hop up rubber, it's under $40 anyway.

The madbulls are aluminum and can scratch easily. Id try the hop rubber first. You can always change barrels later. Accuracy problems are most often hop related.

Just upgraded to a 6.01 PDI stainless barrel and an A+ hop up. The group size is tighter - not by much, it's about 10-15mm. But the most important thing: flyers are gone. I shot about 20 rounds in slow fire - not one flyer. Shooting the plate rack, the shot is placed exactly where I put it, so now shot calling becomes a reality, just as if I was shooting real steel. Needless to say, I'm extremely happy.

.32g BBs are right on the money, .30gr is about 5mm high, but I can live with that.

The only negative so far: I have the hop up turned completely off, and when I tip the gun down, the chambered BB falls out after the slide goes into battery. I might have to give it just a bit of a hop for the BB to stay put.

If you want IPSC grade performance then you should go with only the best.

The PDI 6.01 stainless barrel is okay. It doesn't perform as good as my NineBall 6.03.
If you want the best inner barrel for a handgun that money can buy, you are looking at a Nine ball 6.00.

Regarding hop-up bucking, A+ is alright. I would say its a "next best" rubber.

If you want something even better then grab yourself a Nine Ball Hop-up. The purple one has proven one of the best hop-ups for handguns, time after time. It's been around for almost 10 years and still one of the best on the market.

+1

PDI and Nine Ball are almost the same quality. But I'll have to say, after using so many of these types of barrels, the Nine Ball one comes out on top being most accurate.

Because it's the hop rubber that actually prevents the BB from rolling out the barrel after the air nozzle pushes it into the barrel.

Also, nineball is laylax/prometheus, so I'm not surprised if they're slightly better than PDI. PDI and laylax are back and forth at being the best.
I totally forgot nineball made hop rubbers -_-

Turned off, its supposed to roll out. Sometimes the pressure or force from he loading nozzle is just enough to slightly push the bb out of the rubber and down the barrel. If you are having issues with the hop-up on and still having bb's roll out that is an issue with the adjustment arm.

Laylax FTW.

Thank you all for advise. I'm not looking to build an airsoft IPSC gun, the goal is to have a training tool that approximates my RS production pistol and allows me to have a meaningful practice.

I sourced whatever was available locally, and am perfectly happy with the upgrade I got for under $60, just need to sort out a few small things.

Thanks again.