Possum Hollow - readjust for each headstamp?

[Mike in CT]

So I bought the Possum Hollow power set up to start processing some range brass in .223 What I am finding out is that since it sizes from the neck there is a large variance in the trimmed cases depending on headstamp. If I run 50 LC brass they all come out +/= .005 but if I run some FC or other headstamps things can be all over the board. Some headstamps will size (cut down) in the trimmer but then end up short at like 1.740.

Do I have to readjust the PH for each headstamp? That sounds like a pain in the @$$...

Would I just be better off with a Lathe type trimmer and set it at 1.750 and trim as needed?

rhetorical question, but is there a fast way to reload .223?

Mike

[Chills1994]

are you resizing/decapping the brass first?

a quick way to reload .223....HA! buy the imported ammo by the case at the next gunshow.

[Mike in CT]

Yes I am resizing first.

I am using a Hornady full length sizer.

In sorting my brass it looks like I have mostly several LC variations, FC headstamp and then a small mix of random others.

Mike

[Chills1994]

are you using a headspace gauge kit to see how far you are bumping the cases back?

[Nuke8401]

I use the Possum Hollow to process range brss for my 55gr bulk/blaster reloads.

I trim a little short so all cases will be at or under max.

I don't expect match load precision with the possum hollow, but in reality the case length always falls withing the canular and the loads are at least as accuarate as cheap factory ammo.

For match quality loads I trim each case with a hand case trimmer.

My process:

1hr tumble (gets off the big dirt)

lube, (inside the necks q-tip=TV time, then into a ziplock bag with some one-shot)

full length size/deprime

1hr tumble/polish

trim (Possum Hollow in a drill press)

swage primer pockets (RCBS, if not my cases)

Hand prime (TV time)

charge and load on progressive

As you know the Possum Hollow is not easy to adjust, I have only adjusted mine once.

David E.

Edited March 3, 2012 by Nuke8401

[Mike in CT]

I am not using a head space gauge, was not even sure what one was until I looked it up.

Maybe I am keeping all the brass within spec, I will load some dummy rounds and see where the bullets line up after seating/crimping,

Mike

[groovinpickle]

An RCBS Precision Mic is almost as essential to my bench as my 0-6" calipers. Without measuring you're just guessing or going by "feel," but that doesn't work too well in a semi-auto. A drop-in case gage like the Wilson works well, but I like the micrometer-style.

I suspect you'll see that your base-to-shoulder ("headspace") length is varying, and when that happens to me it means I'm not lubricating the cases evenly. Also check to be sure that your expander button (if you're using one) is not stretching the case.

[Mike in CT]

Thanks for the suggestions.

I feel like I just do not have everything set up just right yet so I am holding back on any reloading.

Am I just being to exact and can I just move forward with a variance of OAL of 1.745 ~ 1.755?

I can buy a head space gauge or even Mic my chamber but I want to be able to reload for more than one rifle.

Kinda feel lost out here, appreciate any help from someone that is reloading similar to me, ranger brass, Possum Hollow, etc.

Mike

[Religious Shooter]

Well it's common knowledge that different makers have different case volumes. I'd guess it is because the thickness of the brass and the actual alloy is different from maker to maker.

If I have my dies set and I run different headstamps through it I find that the average headspace with each headstamp differs. Which makes sense given the case volumes of each headstamp is different. When the brass is sized and it springs back, the amount it springs back will depend on the thickness of the brass, etc.

If you really want to control the headspace and the trim length you will have to sort the brass.

For close range ammo, as long as it's safe I don't bother.

These are two different batches that I measured using the RCBS mic. The AVG is in thousands. With RCBS, zero represents SAAMI minimum.

Looking at the first batch the PMC is -1.58 * .001= -.00158 from SAAMI minimum. Etc. PMC varied about 2.15 thousands from AP and only .94 from LC.

HEADSTAMP AVG COUNT

PMC, -1.58,12

AP (ARMSCOR), 0.57, 15

LC, -0.64, 25

WCC, -1.00, 4

TAA, -0.10,10

AVERAGE COUNT

WCC -0.68 36

FIOCCHI -1.89 22

LC -5.00 2

[Mike in CT]

Thanks for all the input.

I actually talked with Eric at Possum Hollow and he was able to provide some good information. He is a second generation reloader and has solid information.

The one factor that I think I was overlooking was that in addition to different headstamps these rounds have also been fired through different chambers, thus stretching out to different lengths with firing.

I tried some testing with 10 shells and found that the the before sizing and after sizing lengths varied by .010 and in general every case stretched during sizing, on average .050. I ran LC, FC, PMC and FNM (?) brass through both a Hornady sizer and another test with an RCBS sizer. note - the RCBS sizer required much less effort.

Then I trimmed cases, this is where more variation came into play. Cases came off the sizer between 1.746 and 1.766 and then sized down to between 1.737 to 1.746. I think I can adjust the PH to size a bit longer thus avoiding any really short cases.

What Eric said is after I shoot these reloads through my rifle, I can measure and trim *before* sizing and he feels I will likely see less than .002 variations.

What I have learned is that there are variations in brass, and likely variations in the measurements from base to neck and neck to mouth. Even if I sized with something like a Wilson trimmer, I could end up with brass all withing a few thousandths but there would still be 'internal' variations between base and neck, and neck and mouth.

From all that I have heard, my cases are withing tolerances and should be safe to shoot (depending on powder, etc) so I feel my next step is to load up some rounds and take out the chrono and see how the ammo, and cases perform.

Overall I feel that sometimes reloading is more art than science. Each of us finds our way to create safe rounds with a variety of presses, dies, trimmers, powders and bullets.

Thanks for all the information, now back to the press.

Mike

[goat68]

You will want to make your process consistant in case you end up picking up someone else's brass by mistake. Also, try some reloads in you chamber/rifle with just the bullet loaded so you know they chamber and don't have to worry about a live round stuck in the chamber if things still need tweeking. I've found that small base dies work better that full length dies for my reloading.

[Shadowrider]

Thanks for all the input.

I actually talked with Eric at Possum Hollow and he was able to provide some good information. He is a second generation reloader and has solid information.

The one factor that I think I was overlooking was that in addition to different headstamps these rounds have also been fired through different chambers, thus stretching out to different lengths with firing.

I tried some testing with 10 shells and found that the the before sizing and after sizing lengths varied by .010 and in general every case stretched during sizing, on average .050. I ran LC, FC, PMC and FNM (?) brass through both a Hornady sizer and another test with an RCBS sizer. note - the RCBS sizer required much less effort.

Then I trimmed cases, this is where more variation came into play. Cases came off the sizer between 1.746 and 1.766 and then sized down to between 1.737 to 1.746. I think I can adjust the PH to size a bit longer thus avoiding any really short cases.

What Eric said is after I shoot these reloads through my rifle, I can measure and trim *before* sizing and he feels I will likely see less than .002 variations.

What I have learned is that there are variations in brass, and likely variations in the measurements from base to neck and neck to mouth. Even if I sized with something like a Wilson trimmer, I could end up with brass all withing a few thousandths but there would still be 'internal' variations between base and neck, and neck and mouth.

From all that I have heard, my cases are withing tolerances and should be safe to shoot (depending on powder, etc) so I feel my next step is to load up some rounds and take out the chrono and see how the ammo, and cases perform.

Overall I feel that sometimes reloading is more art than science. Each of us finds our way to create safe rounds with a variety of presses, dies, trimmers, powders and bullets.

Thanks for all the information, now back to the press.

Mike

With the above in RED in mind, the variation you are seeing with your calipers in coming from the behind the datum. The PH trimmer uses the shoulder datum as a "stop" just like the fabled Giraud trimmer does. If you could measure from the datum to the trimmed face you would see almost no variation at all as long as your method was consistent from case to case.

And I seriously doubt that even up to .005" difference in neck length is going to have enough effect on bullet tension to bother accuracy much anyway, but I'm sure you are way under that. As long as they fit a case gage you should be fine.

[technetium-99m]

I'm confused about what you're actually doing here. I can take random range brass and when sized the head to shoulder measurement is within 4-5 thousandths for all cases. When trimming with the possum hollow tool the case lengths all fall within the same +/- 4-5 thousandths range. If you're cases are coming out of the size die with +/- 0.01 variance at the shoulder something is very wrong. That means that sooner or later you are not going to get enough shoulder setback and your ammo will not fit your chamber.

Edited March 9, 2012 by technetium-99m

[Mike in CT]

Chills,

I do not have a way to measure from base to shoulder or datum, except with the Wilson case gauge which they all fit in.

I have used both the Hornday and RCBS full length sizer, and have adjusted them down to the point that I cam over, and that the brass actually fits the wilson gauge.

I made up some rounds to test fire with and my guess is after they are shot out of my rifle the tolerances will tighten up a bunch.

Mike