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Big Ern · Veteran Member

Beautiful 2240 Al, love the breech, do you still have it?

Alstone · Moderator & Site Supporter

ZipSnipe · Veteran Member

aah so your eliminating the radius and just doing a angled cut.

What about that lil transfer port do you think having a flat surface up against the o-rings will effect the seal?

Alstone · Moderator & Site Supporter

ZipSnipe · Veteran Member

Dammit Al !! I should have done it your way, I even gave a second thought right before I commenced to cutting with my homemade paddle bit with its horrible rake. Now one of the two breeches I was making has been gouged out by about .050 as the paddle bit started sinking into the breech to my horrified surprise.

Usually when a cutter gets sucked into the part, the cutter actually has a good rake and is sharp but was not tightened enough. Mine horrible rake somewhat sharp and I thought I had it tight.

Now I am debating on shelling $23 for a ball nose endmill so it can be done right.

The whole kicker was I was done with the radius on both breeches and decided to touch it a little with the paddle bit. :-(

Alstone · Moderator & Site Supporter

Cutting a radius in to s square block using a lathe can be tricky, especially the setting up of the block. Using a milling machine with a ball end cutter would be better and easier, or even using the ball end in a lathe, the only reason I didn’t go down that route was because of cost, over here ball nose cutters are expensive and unless you are more than one breech not cost effective.

The slot method is easy to do and any size peg cutter will do, I use a counter sink bit for the bevel.

I was just looking at the link for the guy making a 2240 breech, and a good idea which he uses and I do the same is to make the breech longer, so you can use two grub screws to hold the barrel in, it makes for a better job.

Just to make you feel better Zip I destroyed the first breach with it running off center, so your not alone. Smile

Al

ZipSnipe · Veteran Member

Yeah what I did on the milling machine at first was use a fly cutter with the breech standing vertical , this would have been fine if I could have done the full length in one shot but I had to flip the breech. The problem with doing it this way is now the direction of cut goes one way halfway down the breech and makes it off center.

But anyway I was able to copy your method on the milling machine and both breeches have been saved but not exactly pretty on bottom but make all the important contact with the co2 tube.

My next problem is I realized now that to sweeten the sale of my cnc machine awhile back I threw in my center/edge finder. This makes using the milling machine to find center extremely difficult.

I believe there is a way to find the center of a block using my dial indicator but I need to go research how to do it again. I have to do it on the mill to be able to drill the 7/16 barrel hole and it has to be exact dead on.