Basic Dremel Question: Proper bit for removing material?

[badpennny]

I have a very basic modding question: I just picked up the Tippmann mag adapter for my old Model 98. I'd like to be able to use first strike rounds with it, but I'll need to remove some material around the breach in order to get the first strike rounds to feed properly. I have a Dremel, but I'm not sure which bit or attachment to use for removing the excess material. Any suggestions would be appreciated. Thanks!

[Cyco-Dude]

i would probably use the course sanding drum, followed by the fine sanding drum, and then hand-sanding with sandpaper to smooth everything out. i guess it depends on what you're removing and how much, though.

[maniacmechanic]

The thing to remember here is once the material is removed it is Very hard to put back ,, take your time

[Grelvire]

I normally use the conical grinding bit and then use a fine file to finish when im doing mods by hand

[bowcycle]

I like using the small, screw-attached cut-off wheels. I usually double stack those when working in tight places. The EZ wheels are HUGE and pretty much only useful for making flat cuts.

After that, go with the sanding wheels to smooth everything out and take out that last bit of stuff. and then go with a hand file to get the corners smoothed out where the fins of the FS fit. I use a chainsaw round file for that part, but I have plenty of those around.

remember that the back of the current hole is where the flat, back part of the FS feed hole is going to be. Don't let the feed wander backward as you're removing material.

[Spider-TW]

I like using the small, screw-attached cut-off wheels. I usually double stack those when working in tight places. The EZ wheels are HUGE and pretty much only useful for making flat cuts.

After that, go with the sanding wheels to smooth everything out and take out that last bit of stuff. and then go with a hand file to get the corners smoothed out where the fins of the FS fit. I use a chainsaw round file for that part, but I have plenty of those around.

remember that the back of the current hole is where the flat, back part of the FS feed hole is going to be. Don't let the feed wander backward as you're removing material.

The fiber reinforced abrasive wheels are nice too. I keep worn ones around for their smaller diameter.

I have one of these single cut tree burrs that I have used to carve a lot of aluminum and other stuff. It does a lot better than the standard dremel burrs.

http://www.mcmaster.com/#dremel-comp...e-burs/=ucjb7k

[badpennny]

Thanks everyone for such great advice. I'm prepared to do this slowly and the right way. Bowcycle, I was just playing with the FS rounds and my modded mags yesterday and started thinking about how they will feed into breach once modified. I was wondering about whether I should be more focused on the front or back of the breach as far as what to remove, and you pretty much answered that with your comment. I somewhat suspected the back part wouldn't warrant much removal because the front of the bolt rests pretty close to it. That said, have you (or anyone else here) actually done this mod before? I'm curious as to whether the FS rounds will "tumble" while feeding into the breach, causing the bolt to smash into the fins at an angle, and whether or not this is a function of spring tension in the mag or too much room in the breach (or maybe it's not a problem at all and I'm just over-thinking). Just some thoughts I had before cutting into the gun. Thanks again.

[bowcycle]

a big part of how the FS rounds feed into the breech is how close the mag opening sits to the breech.
XMT did a mag-fed mod to one of his warp mag bodies. He did this by fabricating a FS-shaped feedneck welded to the body so that there was no space between the opening of the mag and the breech in which the rounds could "tumble."

I have only done a similar mod to hand load FS rounds, but even then, sometimes feeding straight was challenging.
I would definitely recommend having your mag and breech mate up as closely as possible which may mean doing some basic fabrication to create a FS-shaped spacer to make sure stuff doesn't tumble.

I'm about to start work on a bottom-mag fed automag, but will be coming up through the rail. So the receiver will be right against the rail which should prevent misfeeds.

[badpennny]

I found a youtube video of some guy who basically did the same thing to his Project Salvo. He shakes the gun a bit to demonstrate that the round stays put in the breech, but then at 2:31 you can see him instinctively adjust it after he opens the feedneck to check: https://www.youtube.com/watch?v=WCgxOY5NTy0

I think I'm going to hold off on this mod, as I'm not confident the FS round will consistently stay put enough and avoid breakage for me to enjoy a day going FS-only with it. I'm glad I was able to bounce some ideas around before I started cutting though!

[bowcycle]

I think the guy in the video cut his breech too much. The tighter you have it to the actual size of the round, the less likely it will be to bounce around.

However, I see no down side to doing a simple mod similar to the guy in the video. Making the marker mag-fed is definitely going to be more of a challenge, but if you just want to feed the occasional FS, go for it.

If you really want a dedicated FS marker, there are many out there that are not super expensive. Perhaps you could just sell your marker and buy one that is already FS capable.