forster benchrest seating die problems, please help

aheppner

aheppner

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I just got a forster benchrest seating die, (loading .223-80gr AMAX-25.3gr varget-lapua cases)

so i set it up in the press with my dummy round.

I start weighing out powder and seating bullets (5 cases), and my seating depth is NOT consistent at all. there is about 15 tho variation from longest to shortest (mesured with a rcbs precision mic) also measured COAL with a caliper.

when i feed the round into the die the cases wont go in the spring loaded sleeve all the way, and after i seat the bullet and try and feed that same round again the case goes in even less, like the case bulged out at the bottom after seating the bullet, this is a compressed load but not by much


could this be because my cases are fire formed and neck sized? this will be the 4th firing

or because of the compressed load? the cases seem to fit into the sleeve fine before i load them


using my old rcbs seater die i was able to get 2-3 tho max variation in seating depth measured with my rcbs precision mic


I am about ready to throw this die out the window

any help would be awesome, thanks Alex
 
I have not used the benchrest seater die but are you measuring from the tip of the bullet? or using a bullet comparator in your mic/calipre to measure from the ogive to get OAL?
 
COAL is not an accurate measurement and you should be using a comparator, but the rest of your issue is boggling.... not sure I understand....

It sounds like your cases need to have the shoulders bumped and it also sounds like they need to be checked for length. Machine gun cartridges are bad for brass flow. If they are not inserting into the die properly, they are not properly sized to the right dimension.


BR seating dies likely don't like generous factory chamber dimensions.

Do ANY of your cases work properly in the die?
 
thanks for replying but ill clarify a few things

yes, im using a comparator to measure. a sinclair one, im also measuring with the rcbs precision mic which if you dont know what it is, it has 2 halfs that you screw together with the round inside, you can measure length to the shoulder (head space) or if there is a bullet in it with the second top piece, you can measure base to base of the ojive

I don't think my shoulder needs to be bumped back but maybe, they still chamber in my gun well, i measured a new unfired lapua case and a 4 times fired and neck sized case and the fired case was .003 longer to the shoulder,
 
good idea ill try that but ill use a dry erase marker instead, putting a flame to a loaded round just seems wrong somehow

i should be able to see if its hitting at the shoulder or if the base of the case is bulging from compressing the powder
 
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If I understand correctly your case is not inserting fully into the bullet seater's springed die chamber the shell holder is not making contact with the die at all. I assuming your dummy round is a FL sized unfired case. Since you're running a slightly hotter compressed load with the 80s I think you have some case head expansion which your mic and comparator will not catch. That is probably why it will not fully insert into the Forster seating die. Body size the case to get it back to nomal specs and watch out for case head seperation that maybe forming.

I assume you setup the die according to the instruction. Make sure the ramp is at its highest point and the springed die chamber is making contact with shell holder, screw the die deeper until you commpress the die chamber spring 0.125" or two full turns. adjust the bullet seating stem up or down until the APPROXIMATE seating depth is obtained slightly short of the lock the die in place and use the micro adjustment to get you to your final desired depth. Then check cartridge for proper length.
 
aheppner said:
good idea ill try that but ill use a dry erase marker instead, putting a flame to a loaded round just seems wrong somehow

i should be able to see if its hitting at the shoulder or if the base of the case is bulging from compressing the powder
Click to expand...



Old school, and not the brightest candle in the chandelier neither .... been putting the Bic to loaded brass for decades, still waiting for 'boom'. G:

As your resized empty brass is entering the die ok, and it's unlikely that even a heavy powder compression would swell the case down low by the web, where it is thicker/stronger .... they tend to bulge at or just below the shoulder, IME. Takes a hefty compression to do that. You'd likely be seeing seating stem marks on the bullet were you to be crunch'n 'em that hard.

Have your necks thickened after 4 stout reloads?.
Have you checked for case stretch/trim length?.

Every once in a while, an inexpensive Redding body die comes in handy.

That wee 3 thou. headspace you have, is not the problem.
 
Check to see if the CASE itself is not too big.

Take a case without bullet and just drop it into the seater while out of the press. A case should fall freely into the die with the extractor groove even with the bottom of the sleeve.

if the case stops with some case exposed, the web area needs to get sized down. Here a FL sizer or small base body die can be helpful.

for comparison, just take a new case and drop it into the seater and you will see clearly.

There is simply no way you can compress powder enough to bulge a case- the sound of cruching powder will likely scare you from squishing anymore ;-)

Jerry
 
Just wondering if you cleaned the die first? Perhaps it's just a bit sticky?
One guy I learned from always kept stressing consistency in the technique of using the press.
Make sure you are always trying to maintain the same movement and pressure with each round.
 
thanks for all the good replies guys, but i figured it out finally.

so the problem was when i raise the ram the bullet was hitting the seating stem before the case was all the way into the sleeve. so i needed to turn the die in more so the case body of the die is almost touching the shell holder (1/16 or so from the shell holder)

in the instructions for die set-up it says turn the die in so the case body touches the shell holder and then back it off at least one turn, well that is too far for these long bullets.



so after loading a bunch and checking length with my comparator, about 1 to 1.5 thou variation, i tried to run a loaded round through the seater die again. After seating the bullet all the way the case will not go into the sleeve.

so the case must be bulging a little somewhere from the compressed load, i can't think of anything else it could be
 
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