Trimming when loading on a Dillon 550

[Scarface26]

Gents,

All of my previous reloading - 308, 30-06, 300WM, and .357 has been done on a single stage. I've recently taken the plunge on a 550 thanks to the advice on this site and others, and was wondering where in the process those of you who load 223 on a 550 are trimming your brass. Do you trim before resizing? I've always trimmed after resizing and that would create another step on the 550, if required. Trimming before resizing doesn't seem like the best plan.

Thanks in Advance

 

[pmclaine]

If you use Dillon dies note they size really tight. I think Dillon had full auto in mind when in design.

I use a Dillon Rapid Trim on my rifle prep tool head.

I love how fast it makes case prep.

My first position is a Dillon size die that I have size to about 80%, just a guess, a thou or so bigger than I want it to be.

I load on a S1050.

After the initial size I swage, next is the Rapid Trim and I final size to desired bump. The RT cuts really clean.

After final sizing I neck size with a 21st century mandrel.

You could do similar except for the swage set up on a dedicated 550 case prep toolhead.

I like the presize because the Trim die is so tight I don't like the force needed if it was the only size die.

Hopefully I made sense.

If you don't use the RT.......Trim after sizing because sizing will/can push brass into the necks.

 

[SalomonQST99]

Trim after full length resizing.

 

[1moaoff]

I rarely trim.

 

[Scarface26]

If you use Dillon dies note they size really tight. I think Dillon had full auto in mind when in design.

I use a Dillon Rapid Trim on my rifle prep tool head.

I love how fast it makes case prep.

My first position is a Dillon size die that I have size to about 80%, just a guess, a thou or so bigger than I want it to be.

I load on a S1050.

After the initial size I swage, next is the Rapid Trim and I final size to desired bump. The RT cuts really clean.

After final sizing I neck size with a 21st century mandrel.

You could do similar except for the swage set up on a dedicated 550 case prep toolhead.

I like the presize because the Trim die is so tight I don't like the force needed if it was the only size die.

Hopefully I made sense.

If you don't use the RT.......Trim after sizing because sizing will/can push brass into the necks.

You live in the wrong state - wrong part of the country.

 

[jet_lagged]

I use the Dillon Rapid Trim for .223 and .308 for the AR's. Trim/size then tumble the lub off. I normally trim to or even a little shorter than min length. Then don't have to trim again, so on future relaods, I can just size with a regular die.

 

[Franko]

I trim after sizing. I also trim off the press using a Giraud.

 

[Scarface26]

Thanks, all. I was hoping for a handgun-esque answer, but common sense will dictate that I handle the brass again. Still better than a single stage.

 

[DocTLE]

always after sizing, but I'm also in the 'i rarely trim' camp.

 

[clcustom1911]

Gents,

All of my previous reloading - 308, 30-06, 300WM, and .357 has been done on a single stage. I've recently taken the plunge on a 550 thanks to the advice on this site and others, and was wondering where in the process those of you who load 223 on a 550 are trimming your brass. Do you trim before resizing? I've always trimmed after resizing and that would create another step on the 550, if required. Trimming before resizing doesn't seem like the best plan.

Thanks in Advance

The rifle brass flowing/lengthening within the sizing die as the brass is squeezed is what necessitates the trimming.

If you trim prior to the sizing, it will still "grow" after full length sizing.

Now, if you have a die that happens to almost perfectly match your chamber, then very little "growth" will occur and trimming will be less.

Example. One of my AR 5.56 chambers is tight and even fired brass still slides into a chamber check gauge easily. When I full length size it, the brass grows maybe 0.002". Even after 3 sizing cycles, that brass is still under max length. Win.

 

[mtrmn]

I size on my single-stage, trim, and then go to the dillon for the loading stages.