Neck tension issues in Cat Sneeze/Mouse Fart loads

[anhurset]

I had my first experience working with ultra light loads yesterday, I've got a FR-8 which I love, but which also beats the **** out of me when I shoot it, so I decided it would be a prime candidate for light loads. I had a handfull of 7.62 NATO brass which I had fired through this gun so, following the info I could find on this forum, I drilled the flash holes out with a #30 bit, neck sized with a Lee Collet sizer and loaded a 112gr 32-20 boolit sized to .309 in front of 3.2 gr of Bullseye.

All rounds fired and were fairly accurate at 50 yards, the problem arose when I attempted to reload those rounds. I again neck sized with the Lee Collet die, but when I got to the bullet seating stage I had three cases where the boolit just dropped into the case. I resized the necks on those three cases, marked them, finished loading them, fired and began reloading them again at which point I found the same issue with two other cases. I'm not sure what's going on here, I don't know if it's an oversized throat on the FR-8 (not unusual from what I understand) or if it's my technique with the Lee Collet sizer. Anyone had neck tension issues like this with Cat Sneeze/Mouse Fart loads?

[mehavey]

Don't think it has anything to do with the weapon/throat.
Rather it is under-adjustment of the die to fully reduce the neck to the internal mandrel diameter

See:
https://www.youtube.com/watch?featur...R43TN5Zk#t=182

Out of curiosity, are you sure all the cases have the same neck thickness ? (req'd if the collet is to work to a consistent result)_

[popper]

I never could get it to work for the 243 or 30/30. I polished everything and use a classic cast press, still didn't work. I found partial neck sizing with the FL die worked ok but ended up with a lot of split necks when shooting the hornady 110.

[Calamity Jake]

It's time to anneal.

[anhurset]

Don't think it has anything to do with the weapon/throat.
Rather it is under-adjustment of the die to fully reduce the neck to the internal mandrel diameter

See:
https://www.youtube.com/watch?featur...R43TN5Zk#t=182

Out of curiosity, are you sure all the cases have the same neck thickness ? (req'd if the collet is to work to a consistent result)_

All the cases were LC 94 headstamp, I don't have the proper tools to accurately check neck wall thickness, but I can't believe there would be to drastic a difference. This was my first time seriously using the Lee Collet die, I'll get it set up again later today and try it fiddling with it, I'm thinking you're right and that it needs to be screwed in another 1/4-1/2 turn.

[Artful]

Did you check the case length on all the cases you are using, and are they uniform?

[anhurset]

Did you check the case length on all the cases you are using, and are they uniform?

Yes, all cases were trimmed and double checked.

[gloob]

Oh, there is definitely neck thickness differences in same lot of brass. Work hardening will also cause variation, with the more hardened cases opening back up more after the collet sizing. Collet sizing is a little finicky unless you track your brass.

If you have continued issues with that batch of brass after making adjustments, you can screen your collet-sized cases by putting in your sizing die with the expander ball set long. Work the ram just enough to get the expander ball thru the neck. The ones where the expander ball doesn't drag, set those aside. Likewise any that seem to drag too hard. This is a way of cheaply uniforming your brass without turning equipment.

Disregard what the headstamp says. Expecting cases to be the same just because of what's stamped on the bottom is folly. The expander ball will tell you which of your cases are not like the others.

[MikeBitzenburger]

It's time to anneal.

and switch to a MAGNUM primer. I shoot a lot of MOUSE FART loads in several different guns. Both the annealing and mag primer operations seem to help most of the time.

[MT Chambers]

I would first check to see if your sizing die is doing it's job or if it is out of spec., it should size it down and the expander should open the mouth to be a proper fit of the bullet. I use Redding dies and have never had this problem, my Redding bushing dies allow me to fine tune that bullet fit with dif. sized bushings.

[gloob]

I would first check to see if your sizing die is doing it's job or if it is out of spec., it should size it down and the expander should open the mouth to be a proper fit of the bullet.

I thought the point of collet sizing was to size just the neck of unsized or body-only sized cases. Could the sizing die be part of the problem if he's not using it?

[MT Chambers]

The OP needs to use a proper sizing die and see what that does to case neck tension, a proper expanding die would include an expander button, unless using proper bushing style dies that don't expand. By "proper" I mean not any collet die.

[Yodogsandman]

How about trying a boolit sized bigger like, .310",.311" or .312"?

[Hannibal]

How about trying a boolit sized bigger like, .310",.311" or .312"?

Wouldn't that be fitting the bullet to the case, rather than fitting the bullet to the barrel ?

[Cowboy_Dan]

Wouldn't that be fitting the bullet to the case, rather than fitting the bullet to the barrel ?

If the larger boolit chambers freely, then he is approaching fitting it to the throat. From what I hear, that is the way to go.

[Hannibal]

If the larger boolit chambers freely, then he is approaching fitting it to the throat. From what I hear, that is the way to go.

I presume the OP sized to .309" for a "fit" reason. He even mentions the performance on target was "fairly accurate". The only issue raised was with neck diameter after sizing. I agree with the position of previous posters that there is either a die set-up issue or the case necks are in need of annealing. I stand by my position that sizing the boolits larger to fit the irregular case neck diameters is sizing the boolits to fit the cases and not the rifle given the information we have at hand thus far.

[Yodogsandman]

I presume the OP sized to .309" for a "fit" reason. He even mentions the performance on target was "fairly accurate". The only issue raised was with neck diameter after sizing. I agree with the position of previous posters that there is either a die set-up issue or the case necks are in need of annealing. I stand by my position that sizing the boolits larger to fit the irregular case neck diameters is sizing the boolits to fit the cases and not the rifle given the information we have at hand thus far.

The OP has stated that he doesn't know if he has an oversized throat. We can presume that he did not do a pound slug of his chamber. Cowboy Dan is correct about fitting the boolit to the throat.

My FR-8 needs a boolit sized to .311".

[1johnlb]

Hardened case necks spring back to different sizes after collet sizing with lee dies. With varying cases and thicknesses some harden faster and some slower, that creats a varying amount of spring back. The collet die presses each case to the same size mandrel, thus creating the varied inside neck diameter.

In short as already stated, anneal the cases.

[anhurset]

Hardened case necks spring back to different sizes after collet sizing with lee dies. With varying cases and thicknesses some harden faster and some slower, that creats a varying amount of spring back. The collet die presses each case to the same size mandrel, thus creating the varied inside neck diameter.

In short as already stated, anneal the cases.

I got the Collet die set up again yesterday and fiddled with it a bit, I believe those of you who are suggesting anealing may be right. Regardless of how deep I had the die threaded (within reason) I was getting enough spring back that there was still a noticeable difference in neck tension between cases, with one case being open enough that the boolit just fell through again.
I've never anealed cases before, so this is going to be a learning experience.

[mehavey]

I've never anealed cases before, so this is going to be a learning experience.

It can be very easy, but you will get as many opinions on how to do it as there are people on this board.
My way is best though.
See: http://thefiringline.com/forums/show...34&postcount=8