Case trimming question

[problemchild]

I wanted to get some input from those who know. I see there are two ways to trim a 308 cartridge. The first being off the shoulder and the second being COL. If I am reloading once fired military brass for general use from an AR-10 Based rifle and also reloading match brass for more precise shooting which trimming method is best? My two choice for trimmers are the Dillon's Rapid Trim 1200B Case Trimmer and the The Giraud Trimmer. I have a 650 so I can use the dillon to trim and then I switch to a Redding single stage to load the match ammo. I would continue on with the 650 for the general plinking ammo.

So I guess my questions are this. Would the dillon trimmer do a good enough for both match and plinking ammo? Im not sure it even matters when shooting from a semi-auto?
Second question can I back the dillon sizer die off in the trimmer so that it does no sizing? I size all my brass in a redding carbide die.

[rksimple]

Get the Giraud. You'll use it for your precision stuff too. Its fast, easy, and accurate.

[RaymondMillbrae]

Problemchild,

CLICK HERE to check out a current video tutorial I recently did for yall. (Or you can click on the RELOADING .223 link below my signature).

When there, look at video #4. I have the Dillon trimmer, and I backed the trimmer die/sizer "out" so it does not size the case. (Like you enquired about).

Yes...it can be done on a .223 - but I am not sure about a .308.

In Christ: Raymond

[Religious Shooter]

... Second question can I back the dillon sizer die off in the trimmer so that it does no sizing? I size all my brass in a redding carbide die.

I asked a similar question about this:

http://www.brianenos.com/forums/index.php?showtopic=49421&st=0&p=565103&hl=trim&fromsearch=1&#entry565103

The "dillon" poster is a Dillon employee.

With the Dillon you will have to resize the entire case (one way or another). You can't just neck size the case.

But with a semi-auto you need to resize the entire case anyways. You are asking for trouble if you don't.

It's hard to say if the Dillon will be OK for "precision" loads. Some rifles will show significant improvement if you vary and dial in the neck tension. Something (varying the neck tension) you can't do with the Dillon.

But for some rifles either it won't matter much or the results with the Dillon set-up is "good enough".

With my .308 bolt I was able to do a five shot group under MOA at 100 yards by just using the Dillon. No chamfer or debur.

That's about the same size groups I got with sizing the neck only and chamfering, deburring and trimming by hand.

[problemchild]

Very nice video set, thanks. Wow that floating die cnc toolhead is the cats meow huh? And Holy Cow that bearing on the shell plate is the answer to my 500 smith flinging H110 powder all over as it SNAPS to the next position. Dillons answer was to drag my finger on the shell plate as it moves.

Question for you. Since you are not using the dillon sizer die under the trimmer can you just use an old seater die or a steel sizer die backed to mount the trimmer? I have a ton of die tubes I am not using. One more question. The M die at the end for de-burring/flaring, can I just tumble the brass after I am done to debur? I do not have the M die.

Problemchild,

CLICK HERE to check out a current video tutorial I recently did for yall. (Or you can click on the RELOADING .223 link below my signature).

When there, look at video #4. I have the Dillon trimmer, and I backed the trimmer die/sizer "out" so it does not size the case. (Like you enquired about).

Yes...it can be done on a .223 - but I am not sure about a .308.

In Christ: Raymond

[problemchild]

OK thanks. My question about the sizer dies is because I have a high end redding carbide sizer with the carbide floating neck expander inside. I do not want to resize twice as it stretches the brass.

I asked a similar question about this:

http://www.brianenos.com/forums/index.php?showtopic=49421&st=0&p=565103&hl=trim&fromsearch=1&#entry565103

The "dillon" poster is a Dillon employee.

With the Dillon you will have to resize the entire case (one way or another). You can't just neck size the case.

But with a semi-auto you need to resize the entire case anyways. You are asking for trouble if you don't.

It's hard to say if the Dillon will be OK for "precision" loads. Some rifles will show significant improvement if you vary and dial in the neck tension. Something (varying the neck tension) you can't do with the Dillon.

But for some rifles either it won't matter much or the results with the Dillon set-up is "good enough".

With my .308 bolt I was able to do a five shot group under MOA at 100 yards by just using the Dillon. No chamfer or debur.

That's about the same size groups I got with sizing the neck only and chamfering, deburring and trimming by hand.

[RaymondMillbrae]

Problemchild,

I am not 100% sure, but I believe the trimmer die is SPECIFIC to the trimmer, but don't quote me on that. (CLICK HERE to check it out).




And just for thought: You want to size the brass BEFORE you trim it, as sizing the brass will expand/stretch it. Once sized, you can now trim it.

And like Problemchild stated, the brass has already been sized BEFORE it gets to the trimmer. So I don't think the trimmer/sizing die will effect the sides of the brass much.

For myself, since both my sizing die, and the trimmer/sizing die, are from the same manufacturer - I figured they are close to the same dimensions. So I am not worried about the walls getting re-resized again. (Did that make sense)? I adjusted my trimmer die so it would not effect THE SHOULDER of the brass, which was my main concern.

In Christ: Raymond

PS: From what I have read, many folks just tumble the brass to clean out any burrs which "may" appear on the case openings. But the "M" expander die is cheap, helps to balance-out the Dillon toolhead, and places that teeny, tiny, bell that helps my reloading. (Although some will scream "BLASPHEMY" for belling my case opening).

[rksimple]

When it comes to precision, as long as your not crimping, the only dimension that matters when trimming is from the shoulder to the case mouth. This is why we trim. Think of whats happening in the chamber of the rifle. The shoulder determines headspace. Having the chamfer and debur all done in one step is icing on the cake.

[problemchild]

Ahh the threads are different on the top and bottom of that die. Are the holes in the side for sucking out the trim shavings?

Problemchild,

I am not 100% sure, but I believe the trimmer die is SPECIFIC to the trimmer, but don't quote me on that. (CLICK HERE to check it out).




And just for thought: You want to size the brass BEFORE you trim it, as sizing the brass will expand/stretch it. Once sized, you can now trim it.

And like Problemchild stated, the brass has already been sized BEFORE it gets to the trimmer. So I don't think the trimmer/sizing die will effect the sides of the brass much.

For myself, since both my sizing die, and the trimmer/sizing die, are from the same manufacturer - I figured they are close to the same dimensions. So I am not worried about the walls getting re-resized again. (Did that make sense)? I adjusted my trimmer die so it would not effect THE SHOULDER of the brass, which was my main concern.

In Christ: Raymond

PS: From what I have read, many folks just tumble the brass to clean out any burrs which "may" appear on the case openings. But the "M" expander die is cheap, helps to balance-out the Dillon toolhead, and places that teeny, tiny, bell that helps my reloading. (Although some will scream "BLASPHEMY" for belling my case opening).

[RaymondMillbrae]

Ahh the threads are different on the top and bottom of that die. Are the holes in the side for sucking out the trim shavings?

Yes...and for seeing your adjustment of the blade depth as well.

There is actually a very little opening in the die for just the tip of the brass to stick through. This is where it gets trimmed.

If you initially install the triimmer in the die, and the blade is too low, it will hit this "opening" and shatter your blade.

In Christ: Raymond

[Religious Shooter]

And just for thought: You want to size the brass BEFORE you trim it, as sizing the brass will expand/stretch it. Once sized, you can now trim it.

I don't quite follow your reasoning.

If the brass goes through the Dillon trimmer die... it has been (re)sized before it's trimmed.

It's not trimming... and then sizing it.

[problemchild]

I don't quite follow your reasoning.

If the brass goes through the Dillon trimmer die... it has been (re)sized before it's trimmed.

It's not trimming... and then sizing it.

Actually its 1/2 sized as it stretches on the way down pulling out of the sizer.

[Religious Shooter]

Is see what you are saying.

But if it's stretching when you are pulling it out... you don't have enough lube.

You have to take into consideration that the Dillon trim die needs to "grab" the case in order for it to work. If it doesn't have enough grip on the case, the case will spin in the die when trimming. That required grip can cause a secondary stretching of the case if you FL resize before the trim die.

Right now I have a decapper and sizer on #1 that's backed up.

Next time I trim cases I'll see if the variance is reduced by doing a full resize on the first station and backing out the trim die.

[RaymondMillbrae]

The reason I mentioned that was because I have seen folks place a full-length sizer AFTER the trimmer.

But if the brass is already full-length sized, then the dillon trimmer die will not really be sizing it.

In Christ: Raymond

[problemchild]

The dillon die is steel correct? Im using a carbide redding for sizing. The press arm throw pressure is much less. I tried steel but you needed to use about 500lbs force to size and it always felt like it was going to get stuck. Carbide or titanium nitride are sooooo much smoother and less effort.

How is the dillon trim-size die for pressure?

Is see what you are saying.

But if it's stretching when you are pulling it out... you don't have enough lube.

You have to take into consideration that the Dillon trim die needs to "grab" the case in order for it to work. If it doesn't have enough grip on the case, the case will spin in the die when trimming. That required grip can cause a secondary stretching of the case if you FL resize before the trim die.

Right now I have a decapper and sizer on #1 that's backed up.

Next time I trim cases I'll see if the variance is reduced by doing a full resize on the first station and backing out the trim die.