Minimag double-feeding paint...

[Justus]

So I put on an event this past weekend and my dad was playing with the Minimag I built for him (not the same one I had to grind to fit on the RT Pro rail). It's normally set up with a Q-loader, and I really haven't had many problems with it. Recently I replaced the DYE Boomstick barrel he was using with the new J&J aluminum that I got a couple weeks back. I've only got some wire detents, and a wire detent is all that was on the Boomstick anyway, so I thought I was good to go.

But, no dice. For some reason this thing was double and triple feeding into the breech. I first suspected the detent, so I tried another, and another. Still no results. So I took off the Q-loader and put on a 45* elbow with a V-Force Eye-Force loader. I was still getting double feeds. I had left the old Boomstick barrel at home, so I didn't have the option to go back to that. In the end, the gun was dead for the day and we just used a different marker.

Would switching up to the new plastic detents have a chance to solve the issue? On my other Minimag build, which my father-in-law was using, I had put on the same kind of barrel with wire detent, and it didn't double feed at all (Ricochet Apache agitated hopper). I'd really like to go back to the Q-loader, but if it continues to double- and triple-feed that can't happen without going back to the Boomstick too. How best to resolve this?

[athomas]

What was the size of the barrel id, and what was the outer diameter of the balls that you used? small ball diameter can cause your issues.

What is the outer diameter of the barrel. How snug is it in the body? A loose fitting barrel will allow the detent to be loose in the barrel (ie; won't hold with as much force). Sometimes with wire detents, it helps to bend the end so that it protrudes a bit farther into the barrel.

[sjrtk]

The problem is most likely the current smaller paint and the barrel. I have an aluminum J&J as well it will double feed with a revi. I measured the bore it came out at .695. So this might be the same problem. My boomstick is .689.

[Justus]

I use Nelson paint, which is actually pretty large compared to some of the complaints I've heard online of the average size of paint shrinking. Using my FLASC kit a .684 is an underbore on this stuff.

I'll check the ID of the barrel when I get a chance. I had to give my calipers back to my friend, since they're actually his.

But the barrel fits very snugly in the body. Which brings me to another issue... ever have a problem removing a barrel from a Minimag body? The barrel o-rings seem to get caught in the front slots from time to time. It's not a make-or-break issue, but it can get annoying since the whole point of a twist-lock is to have a barrel that comes out quickly.

[sjrtk]

Which brings me to another issue... ever have a problem removing a barrel from a Minimag body? The barrel o-rings seem to get caught in the front slots from time to time. It's not a make-or-break issue, but it can get annoying since the whole point of a twist-lock is to have a barrel that comes out quickly.

All of mine do that. More so with the plastic nubbin. But they really work better. IMHO

[athomas]

What do you mean "get caught in the front slot"? Do you mean the orings are coming out of the slots they are supposed to be in? If that is the case, perhaps the orings are weak or the barrel slots are not deep enough. Even if they come out, the barrel should still slide out fairly easily. One problem that comes up from time to time is if the twist lock slot is too shallow. The twist lock pin can come out of the slot and get in the wrong place. This can cause the barrel to get caught and be hard to get out.

A bit of oil on the orings can make them slide a bit easier so they will be less prone to being pushed out of their slots.

[Justus]

What do you mean "get caught in the front slot"? Do you mean the orings are coming out of the slots they are supposed to be in? If that is the case, perhaps the orings are weak or the barrel slots are not deep enough. Even if they come out, the barrel should still slide out fairly easily. One problem that comes up from time to time is if the twist lock slot is too shallow. The twist lock pin can come out of the slot and get in the wrong place. This can cause the barrel to get caught and be hard to get out.

A bit of oil on the orings can make them slide a bit easier so they will be less prone to being pushed out of their slots.

Yeah, right where the barrel o-ring fits over the wire detent there's a noticeable bump. Sometimes this gets caught one one of the Minimag shroud cut-outs as I pull the barrel out, and it causes the o-ring to slip out of its slot a little bit. If I stop for a second, twist slightly and then pull again it usually comes right out of the body without catching on the shroud a second time. Ultimately, the barrel is new and the o-rings are brand new, so it's probably a matter of breaking everything in.

I was hesitant about putting oil on the barrel o-rings because of the close proximity to the inside of the barrel, and I didn't want oil getting into the breech and the barrel to screw with shot accuracy. But I'll try a few drops of Triflow on them to see if that doesn't help too.

The Boomstick I was using previously I acquired used, and everything was already fit together and broke in.

[athomas]

The orings don't have to be dripping in oil, just not dry. It will help quite a bit.

I understand your problem much better now. It appears that your nubbin slots aren't milled deep enough.

Solutions:

1) You can find couple of orings that have the same ring size, but smaller cross section. That will reduce the amount of oring that sticks up.

2) You can put some tape in the slots under the oring where the nubbin is not located. That will even out the amount of oring sticking up, so that there is no definate bump to get caught.

3) The next option is to mill out a short section of nubbin groove to make the nubbin sit lower. That is a bit difficult and may not be practical for most users. If you have a small mill, drill press with a movable axis, or dremel and a very steady hand you can probably pull it off.

[Justus]

I do have a dremel and a steady hand, and that sounds like a more permanent solution so I might end up going that route. Of course, I'd definitely still get some help on it and a proper work area, with a vice to clamp and hold the barrel steady. My workshop is still a work in progress (new home) so I don't have a proper workbench yet.

I've also got to find the correct sized bit to do the milling. Looks like I'll need to purchase some calipers (been meaning to do that anyway).

[athomas]

You might be able to use a thin flat wheel. Use the dremel as a "saw" to cut a groove for the metal nubbin to sit into. If you are going to use a plastic nubbin, then a bit is the way to go. A square nose is needed to allow the nubbin to sit flat on the bottom of the groove. A rasp bit will work on aluminum but you will have to clean it regularly. The best bit would be a square nose carbide mill bit. A small one that size would be fairly inexpensive. It will last a long time so you can use it for many projects in the future.