Paintball

[russc]

Well, first of all, here's the two "shotguns" in my life.

I just received my first RAP68 tonight. As a long time (and dedicated) pump player, there are some mods that I could see helping the shotgun in basic functionality.


Barrel lip check



Ball breakage seems to be a problem with some of these Shotguns. The first thing to do is to unscrew your barrel and check the lip for any dents or deformities. Reshape and polish it so the ball can smoothly transition from the breech into the bore. Small defects here can magnify and turn your shot into soup, because the ball is not held inside the bore when the gun is cocked. It is almost a quarter inch back. As it is blown forcefully into the barrel, any edge can catch and cause breakage. By simply beveling the barrel lip slightly, these breaks can be avoided.

Starfire bolt

Another thing I noticed is that the stock bolt cups the ball right in front of a very concentrated gas blast. A "starfire" pattern in the bolt may help distribute pressure as the ball is first impacted.



As you can see, the "cup" of the RAP68 bolt can be preserved while diffusing the gas jet slightly.

Nail polish detents.

I have found that the bolt lock mechanism can be fairly annoying. I love the idea that it stops rollouts, but its effectiveness seems to be sporadic. Some ball breakage may also be attributed to the retention finger. The ball is not held in the barrel bore. It is set almost a quarter inch back. Remember this, as attempts at putting nailpolish in the bore will result in breakage and inconsistent velocities.

To stop rollouts while also leaving bolt lock off, simply paint some nail polish into the breech where the ball sits while the gun is cocked. (See photo, place polish in circled areas)



To see where the polish should be painted, degas the gun, remove the barrel and load one ball into the breech. Put the polish just where the ball sits, so it is pinched in. Now the RAP68 will function more like a normal pump, and dry firing will be possible without jams.

Once your polish detents are in place and dried, a ball should sit on top of them like this. You should be able to easily push the ball back behind the polish without much effort.



Once your gun's rollout problems are solved, turn bolt lock off forever. Switch bolt release to on.





Besides these issues, I've been very pleasantly surprised by the RAM68. The first thing I did was tear off the stock rear sight. I'll be hacksawing the remainder of it away tomorrow so that I can properly use my AR carry handle, which is of much better quality and allows for easy use of a riser. The rain cover is a lovely addition to any home, and the 1" OD TASO unit I use fits nicely with a little electrical tape to make it a good solid friction fit.

Interesting note: The grip is mounted with an AR style lug, however the body is quite a bit wider than the usual that you'd see on a Phantom or VM. I believe that almost any grip, including .45 frames can be used if some material is taken off around the mounting lug.

Squeegeeing shouldn't be done with a pull-thru, unless you feel like unscrewing the barrel. The feed spring makes it very hard. I suggest using a straight shot.

More intensive mods may also be able to help the RAM68. It wouldn't be a stretch to lathe the very overbored barrel for inserts, and I think that the feed port would make a great candidate for a mag-fed mod. Faster reloading may also be possible with some hacking, possibly by removing the spring system and placing a CCI feed gate at the end of the magazine tip.

I haven't torn it down to the internals yet and I don't think I will until I see problems. Overall I'm impressed with the RAM68, and I think with the slight modifications many MCB members are capable of, it can become a very effective pump gun. I look forward to spending some play time with what may very well be a collector's gun in the future.

Here's hoping it doesn't fall apart in the meantime.

[kidneythief]

Any chance at getting some pics of it torn all the way down? Internals and such.

-Jake

[Walker]

How many rounds does it hold? How fast to reload under fire?


Walker

[sloonan]

I still prefer the Tippmann SL68II.

[russc]

Kidney - here's an exploded diagram. I may end up disassembling it. We'll see.

http://www.rap4.com/operation/RAP68_diagram.jpg

Walker - it holds 15 rounds under the barrel. Reloading is done much like a real shotgun, as in you push single balls in at a time. I haven't found any way to speed this up, and I think the best way to hold balls in a game situation would be loose in a dump pouch of sorts.

[edit]

I've shot my gun around today and it's working great. Chronoing strong, shooting straight. No problems, no nothing. It was eating balls for breakfast last night, but with the transition polish at the barrel lip and those nail polish detents, it's shooting just like any other pump.

[idkfa]

I have heard/read that adjusting the velocity can be a chore. Any thoughts?

[russc]

Compared to most guns, yes. When you take off the tank you see a brass cap. You have to take it off with needle nose pliers. There will be a spring behind it, which you have to sort of unscrew to get it around the gas ready indicator. Once those are out, you just screw a brass nut in or out to adjust the valve spring tension. Directions of adjustment are opposite that of a Sniper II.

[Azzy]

Anything that is Quian Wei is a chore to adjust, or even get working right.

Ive heald one of these, and it seemed pretty sturdy, but had the feel of every other RAP4 gun I checked out.... I suppose they are getting better, btu remmber, these are the same people who brought us the S4.

[russc]

I'd honestly love to have an S-4. I don't like semi autos to begin with, so recocking problems be damned.

[russc]

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I just cut off the rear sight to move the AR carry handle back. Much better with some real steel iron sights.