Trimming and deburring

[fariagaurd]

New to reloading using a Redding T7 Turret Press. Will be reloading pistol and rifle brass.

Just ordered the Sinclair / L.E.Wilson Stainless Ultimate trimmer w/ micometer to trim brass. Not the cheapest but it makes the most sense for my OCD relationship with repeatable accuracy.

As a newbie my question is this. As the case is trimmed does this trimmer also de-burr the outside of the case mouth? I would rather hear from my peers than get an answer from customer service trying to sell a part however I must say Sinclair has been awesome so far. Sinclair does sell a separate handle for this trimmer that will de-burr (chamfer? not sure on terminology the inside of the case mouth).

When do I need to trim my brass. When using the resizing die does it not re-size the case to the proper length?

I'm just now reading about full length, shoulder and neck resizing so I'm guessing it will have something to do with this.

I also just ordered the reloading DVD from Redding so my questions may be premature.

Thanks as always!

 

[Fire_Moose]

The wilson trimmer does not deburr or chamfer. Not sure if the capabilities of the deburr handle, never used it, but seems like it would be a pain to swap out if it doesn't deburr and chamfer.

You have to trim because the sizing process stretches the brass. Neck sizing makes it stretch slower.

 

[X-Ring]

The word chamfer is a machining term that means cutting the inside diameter (ID) at an angle other than 90 degrees. For example the cut made to accommodate a flat headed bolt or screw. As reloaders we are actually deburring the ID and the OD (outside diameter) of the case mouth. We use the term to differentiate ID from OD.

 

[Renton83]

Some like myself trim every time to make sure each case is the same length for best accuracy. Find out what the maximum case length is for your caliber and you could just trim when it exceeds that.

 

[sage5907]

Case trimming is what works best for a particular individual. I load large rifle cases like a 30-06 and I full length resize and trim every time I reload a case so every case is the same length and each loaded cartridge is identical. Find out what the trim length is for the cartridge you are reloading. For example, SAAMI case length for a 30-06 is 2.494 inches in length. Trim length is 2.484 which is .010 shorter. After the case is trimmed there will be a burr on the inside and outside. I knock off the outside burr with an RCBS chamfer tool and I knock off the inside burr with a Dremel tool tapered stone chucked up in a variable speed electric drill. I don't use a Dremel tool because it spins too fast. I just hit the case enough to remove the burr so the bullet slides in easily.

 

[Schwing]

You always trim brass AFTER resizing. As far as how often, that varies from person to person. I never have and never plan on sizing any semi-auto pistol brass. I have never been able to tell a difference in reliability or accuracy.

For revolver brass, especially if using any kind of crimp groove or cannelure, I trim. It matters more because you usually use a heavy roll crimp that really needs to be in the same place on each cartridge.

Even then I usually trim all of my brass one time and then measure every few reloads. If it doesn't wander more than a couple of thousandths, I don't bother. I usually make it 4 or 5 reloads before it needs to be done again.

Rifle brass is a whole different animal. Personally, I would trim after every load for bottle necked rifle cartridges and use the same criteria I use for revolver brass on non-bottle-necked.

You really do need to de-burr both inside and out every time you trim. If you don't do it on the outside, the cases can hang up chambering. If you don't do it on the inside, your bullets have a hard time seating.

 

[rskent]

X-ring

The word chamfer is a machining term that means cutting the inside diameter (ID) at an angle other than 90 degrees. For example the cut made to accommodate a flat headed bolt or screw. As reloaders we are actually deburring the ID and the OD (outside diameter) of the case mouth. We use the term to differentiate ID from OD.

I can't say what other people do, but reloading rifle rounds where I am not flaring the case to seat the bullet I most certainly do chamfer the case. It makes the bullet seat easier without damaging the jacket.