Fixed or Floating Shell Holder

[survivalshop]

 This is for single stag Presses , but could be for others , including Progressives . If you read the Thread on the new MEC single stage Press I purchased , you will see something that the MEC has that most Single Stage Presses do not have & thats a floating Cartridge Shell Holder , so I had a chance to test its theory & there is some strange aspects of this design that was made apparent with sizing Cartridge Brass . 
 Brass used was once fired various Match & Commercial from my Criterion 20" HB  & LC once fired from probably a belt fed & ranged in years of 2006,2010 & 2011 . 

    In summery , I found that the MEC & my (OLD ) Pacific single stage presses , with the same Sizing die & Shell Holder , set up the same way , with shell Holder Touching the bottom of the Die Body , came up with a  average of 0.003" difference in Case sizing , with the Fixed Shell Holder on the Pacific attaching the brass longer , on average . RE-Sizing the MEC shorter stretched Brass case in the Pacific , stretched the cases that same average of  0.003" .

   Needless to say I found this kinda strange & remembered a thread I posted here a while back from a reloading writer & match shooter , who said if you have a Fixed or locked in shell holder on your Press , to get rid of it & use an O-Ring in place to hold it in its slot in the Ram , because he said it altered the case when sizing , well after my initial testing , he was right about it , I did another test after removing the clip that held the Shell Holder locked into my Pacific Press & the results were eye opening , not only did the cases size or stretch about the same , but re-sizing the cases from the MEC in the Pacific , there was absolutely no change in length , where there was an average of 0.003" with the locked in shell holder in the Pacific .

  I have ordered a Case Concentricity Gage w/ dial indicator to see if any case deformation is going on when sized with a fixed position shell Holder . My testing has just begun & will keep this Thread updated with any info & photo's . 

  I started a dedicated thread because I think this will get a lot of info .

[survivalshop]

A few photo's ,

Clip that secured the Shell Holder in the Ram of my Pacific Press 

lip removed 

I think I can find an O-Ring of the proper size

Ram with O-Ring & with Shell holder in the Ram . All I do is raise the Ram a little & pull down the O-Ring in front & slide the Shell Holder in & let go of the O-Ring .

 The O-ring in this Press sits in a Grove for the Clip that was removed 

 

[sketch]

Nice work SS! 

[survivalshop]

 An interesting issue turned up with the MEC Press & am pretty sure its because of the Floating Shell Holder . I haven't tested it on the Pacific Press yet ,but probably don't need to .

 I started seating 155 gr.SMK Bullets into the Match Brass I have sized on the MEC Press & set the RCBS Seating Die as I always did on the Pacific Press , this consisted of putting a Charged case in the Shell Holder & raising the Ram of the Press all the way up & screwing the Dis down until the Roll Crimp of the Seating Die just touches the Case Rim & backing it off a Turn , then locking it down . 

  Well , my first seating operation of the 155 SMC , felt funny at first , checked the COL & adj. the Seating stem until I got to my desired COL & noticed a scuff on the side of the Bullet , strange , so I Seated another & felt the same strange fell on the seating of this one & a similar scuff mark on the Bullet , now I had to find out what I was feeling & why was there a scuff on the Bullet . I know this is not normal , so I disassemble the Die , all OK there , nice & clean , check the Press Ram stroke with out the Die & nothing strange in the way it feels , so now I have an idea of what it is by looking at the scuff , its not deep , just a rub mark . The only thing it can be is the Roll Crimper in the Die , so I raised the Die in the Press to make sure the Roll Crimp would make no contact the Bullet & Seated another Bullet & no scuff mark , so I did a couple more & no scuff marks on any of them .

  I am convinced it is the free floating Shell Holder that permitted this condition , what I believe was happening was the floating Shell holder was not perfectly aligned with the Die & the Bullet was hitting the Roll Crimper in the Die on the way up into the Seating Stem . No matter how I made sure the Case with Bullet was or looked like it was aligned , it still scuffed the Bullet until I readjusted the Die to keep it from happening.  I'm going to seat some in the Pacific Press with my normal way of setting the Seating Die to see if it does the same in that press , just for curiosity sake .

 How this will effect the anything , I have to wait for my Concentricity Gage to show up .

 

 Three different Bullets ,

 

[mrmackc]

Sorry to say but you may end up with a MEC floating shell holder boat anchor . It won't be the first time MEC  came up with a dud. I bought one of the first MEC Grabber 12 gauge loader. It grabbed more than just a AA hull a lot of times.

[jtallen83]

Wonder if a different style of crimping die would behave the same?

[survivalshop]

 A Forster Die or any of the Match Seater dies , don't have a Crimping ring in them . I have a Forster 300 BLK Die Set & it has a plunger guide for the Cartridge & Bullet thats spring loaded & follows the case & bullet into the Die Body, keeping them in alignment  , but not really needed . The Seating Die works fine now & no issues with the Bullets . 

 This RCBS Die is well over thirty years old . I believe the new RCBS AR Die set comes with a Taper Crimp feature on the Seating Die , so it would not catch the Bullet & make a Mark or scuff .

 My Concentricity Gage should be here soon to see if there is any abnormal case distortion from the different Shell holder attachments . The Floating Shell holder has already proven to be easier on Sizing the Case for longer life & less Trimming .

[survivalshop]

 This is how my 300BLK Die looks & works , might order one in 308 .

 

 

 

 

Edited February 4, 2017 by survivalshop

[survivalshop]

 I just ordered the Forster Die in 308 & some Bullets for my 300BLK .

[survivalshop]

 The Sinclair Concentricity Gage came to day & I went through some loaded ammo & some sized cases , just to see how this thing worked , its really a no brainer on how to use this thing . I first took a reading past the Ogive , to make sure it was not the Bullet , well hoping it wasn't anyway.

 I took some loaded 155 SMK ammo loaded on my Pacific Press with the fixed or locked in Shell holder & probably did a doz. rounds & came up with a reading of 0.004" run out & it wasn't't average , it was almost dead on for each round I tested .

 I then went to the 155SMK loaded on the MEC Press with floating Shell holder & I did about a Doz. also & came up with a run out reading of 0.002" & it also was not an average , all were at that reading , almost exactly . I found this almost unbelievable , but did too many for it not to be .

 

  I then thought , well maybe its the case , not so, the cases , all brands & Match cases , would only show a bump in the needle & I think that was caused by imperfections in the Brass . I took measurements at all places of the Brass case , Base, Neck & in between & there was almost no run out .

 I also took the same measurements of my hand loaded Nosler 175 Match ammo & some 155 Hornady Amax , both of these came in at around 0.0025-0.003" , all of these were loaded on the Pacific Press with the secured Shell Holder , so the Bullet may also have an effect on these measurements .

 The Instructions with the Gage , read , any thing over 0.003-0.004 " is an issue & should be looked into & corrected . Seems the Pacific , locked in Shell Holder loaded ammo is at the max for Run Out .

Nice tool , not for everyone  , but I will be using it more often & since I have a Forster Match Seating Die on the way , I can't wait to see if that makes any difference.

Edited February 6, 2017 by survivalshop

[survivalshop]

 OK , so I got curious & took some 300BLK reloaded ammo made on my Dillon 550B & did some tests with the Concentricity Gage & had some interesting results , Bullets were seated with a Forster Match Seater Die , three different Bullets ,

 From left to right , all 110gr. , Hornady Vmax, Sierra Varmint HP , Barnes TSX

I tried to set the Dial Indicator right at the junction at the Case Mouth ,but on the Bullet . zero'ed the DI at the lowest reading , just to show the max run out .

Hornady Vmax , got any where from 0.005" & a couple at 0.008" , but most were in the 0.005"

The Sierra Varmint was 0.002" consistently 

Now the Barnes TSX , was scary , almost no run out , at all & I did every one I had loaded .

 I'm not sure what to make of this , the instructions read or should I say the Trouble shooting instructions read , it could be , because they are all Flat base Bullets , the chamfering of the case may not be letting the FB Bullets align going into the case , my question is , then why did the Barnes align perfectly , maybe they have a slight BT to them , I'm going to have to pull one now to see .  

   Or is the shape of the Bullet in the Seater Die have an effect on its outcome .

 

 

Edited February 7, 2017 by survivalshop