Shoulder bumping: a poor man solution (pics)

[Motard]

Having troubles with a very picky 30-30 levergun (10-15 % reloaded cartriges reiected) I come to conclusione that one of the factor coming in play is the shoulder of repetively shooted cases. So I found a bushing that flush pass the collett and seat at the firts third of 30-30 case's shoulder. Then I measured some new factory loads, some ONLY once reloaded and shooted loads (this should be carbon copy of my rifle chamber) and some pluri-fired cases. Only this one differ as much as half a millimetr or more while the other's two had way similar dimensions. Assuming that shoulder of the "difform" cases had "walked-on" by being repeating fired (I full size once a time after three neck sizing) I FSized them and.......you can see a huge diff in thee pics First and after FL. Interesting note: the cheaper LEE RGB FL seems resinzing way more deeper than the RCBS FL die I have. What You all think aboout? Please correct me where I am wrong.159807159808

[aspangler]

I always full length size 30-30 for a levergun. Makes life much easier.

[Greg S]

I've tried neck, partial FL and FL resize chamber -.002. Neck sizing is sometimes good depending on your brass quality but really only works in bolt guns and single shots. Semi and lever need some slop so the breech isn't tryng to lock in a bind. It doesn't take much to bump a shoulder back but, case hardening can cause spring back and what you thought was sized is only partially re-sized. When brass gets like this the only solution is to bump it, turn and bump again and measure to see if it is re-sized or anneal and resize. I run into this alot with 223 and sometimes have to bump the shoulder back 2-4 times. If it doesn't I either have to adjust my sizing die another .001+ or anneal.

[BK7saum]

I full length resize every time, but my dies are set up to bump the should 0.001-0.002" only. There are less than 20% of my full length resize dies that are screwed into the press enough to touch the shell holder.

Now that you have a bushing to give you a shoulder to base dimension, only screw the sizer into the press to push (resize) the shoulder dimension back 0.002-0.003" (for a lever action) and full length resize those cases every time. They will last almost indefinitely if using light cast boolit loads.

[skeettx]

Full length resize a lever gun cartridges every time,
Mike

[Motard]

Great infos here:-)
Greg S: When brass gets like this the only solution is to bump it, turn and bump again and measure to see if it is re-sized or anneal and resize
I actually aneal the brass two or three times, before giving it up and discard it. I know this is a common and cheap caliber in Us, but here in europe is all but common, prices aren't popular and stocking is rare . So I try to keep it as long as possible.
BK7sauM: I full length resize every time, but my dies are set up to bump the should 0.001-0.002" only.
How to set dies so to bump such a little amount? I don't have bushing dies, only the common Lee or RCBS (with seaters and F.C.D.), and the Lee collet.
Probably I have to deserve the collet die to 308 Bolt action rifle (read somewhere it can be done)

[Motard]

need to add that what I am tryng to achieve is not maximizing brass life, I still can find Win, S&B an Hornady empty cases, but minimize the reject loaded round quote. empting, depriming, reforming and re-reloading a round on ten or more rearly bother me.

[BK7saum]

Regardless of trying to maximize case life, cases with shoulders bumped about 0.003" should chamber 100% and usually have better accuracy as well. Of course with a lever gun, you may not even be worried about accuracy. I don't know. Minimal shoulder bump is what I do on all bottleneck calibers to get the utmost accuracy, 100% reliability, and maximum case life.

Brad

[d garfield]

May have to turn the necks.

[blpenn66502]

Great infos here:-)
How to set dies so to bump such a little amount? I don't have bushing dies, only the common Lee or RCBS (with seaters and F.C.D.), and the Lee collet.

The collet you are using to measure is the key. Ideally it should be .375 inches (9.53mm) in diameter to reference on the datum point on the shoulder but your smaller diameter collet may be reliable as well. You can measure how far back you are pushing the shoulder when resizing after you baseline from a fired case from your gun using a collet to get the setback you are seeking.
Alternatively the L.E. Wilson Case Length Headspace Gage for the 30-30 would also allow you to check.

[EDG]

Push the shoulder of a FL sized case back to the same location of the fired case . Your FL sized case in a bolt rifle should be .000 to -.002.
For a lever gun make them -.001 to .-003.

If you cannot get the same result on every case everytime you will have to size the cases multiple times by sizing and rotating and sizing again.

Variations in the speed of the sizing, the dwell at the top of the stroke and the amount of lube used from case to case all combine to make sliight variations that you can see when you measure using the calipers with a datum bushing.

To minimize these variations you should try the following and measure every case after it is sized until you have a technique that results in every case having the same head to shoulder length.

1. Size each case with identical amounts of case lube
2. Size each case slowly and let the ram dwell at the top of the stroke about 3 to 4 seconds. This allows the brass to creep to its final location.
3. Lower each case far enough to spin it 120 degrees and size again per #2 then repeat for a 3rd sizing.

Your sized cases should be exactly the same length if you maintain the same exact technique and give the brass time to creep to the final location.
All you have to do other than this is set the die to the correct depth so the brass will fit your chamber. This length will be about the same length of a fired case. However fired cases vary a little so check a number of fired cases and use the longest one from your rifle for a reference dimension.

[Motard]

1. Size each case with identical amounts of case lube
2. Size each case slowly and let the ram dwell at the top of the stroke about 3 to 4 seconds. This allows the brass to creep to its final location.
3. Lower each case far enough to spin it 120 degrees and size again per #2 then repeat for a 3rd sizing.
.
Tnakyou for tips. I had been budgered by not thinking to metal springness and had some variation unitill I resized all as per Your's tips. Tested them on rifle's chamber before priming, filling and seating bullet and all' where fitting perfect. Unfortunately I have yet ended my 308 CB reserve so I need to cast some before loading and testing again. This rifle (MY 2015 Win-Miroku '94 model) has a so tight chamber that any variation (coal, collet flare, shoulder, crimp, minimal protrudring primer) results in a not chambering round. Have been struggling with it since day one (also because id dedicated to CB) but cause factory loads seems per5fectly axcepted seems I need to total refine my reloading skills. Is a good school anywhay, lerned more from this rifle (and Your'all great help obviously) than from all the other rifles and guns I have and reload for :)

[Motard]

159877
Job done. As soon as they harden I will test them and write
Thankyou again

[W.R.Buchanan]

You asked in a post above how to size less than Full Length?

You run the die down on a fired case until it touches the shoulder and then turn it in a little farther.

This is known as "Bumping the Shoulder Back."

You do this instead of running the die down until it contacts the shell holder, which will Fully Size the case.

Reloading dies are threaded 7/8-14 English. That means each revolution of the die moves it down .071 or 1.8mm. So in order to move the die down only a few thousandths you will have to "interpolate" what portion of a turn results in the desired movement.

This is easier done by trial and error.

Randy.

[EDG]

Giving the brass time to creep helps, multiple sizing with rotation helps, multiple sizing without rotation (just pull the brass back 5 mm or so and size again) helps though it might not help an out of square condition. I forgot to mention that annealing the brass also helps if you have problems with it springing back. Just don't over anneal.


Tnakyou for tips. I had been budgered by not thinking to metal springness and had some variation unitill I resized all as per Your's tips. Tested them on rifle's chamber before priming, filling and seating bullet and all' where fitting perfect. Unfortunately I have yet ended my 308 CB reserve so I need to cast some before loading and testing again. This rifle (MY 2015 Win-Miroku '94 model) has a so tight chamber that any variation (coal, collet flare, shoulder, crimp, minimal protrudring primer) results in a not chambering round. Have been struggling with it since day one (also because id dedicated to CB) but cause factory loads seems per5fectly axcepted seems I need to total refine my reloading skills. Is a good school anywhay, lerned more from this rifle (and Your'all great help obviously) than from all the other rifles and guns I have and reload for :)

[Motard]

:smile: thankyou

[Greg S]

Turning necks in a factory chamber is unessessary and a waste or time and will only produce more slop unless seating bullets into the lands/freebore. Generally, chambers are generous enough for +.006-.010 clearance with factory brass. High end (Lapua/Norma ect.) brass generally has a slightly thicker neck but is is way more consistant in thickness therefore not requiring turning unless used in tight neck applications. It is cheaper to buy quality brass than turn necks to 50% clean-up.

Measuring shoulder bump: Hornady, RCBS, Sinclair ect all have tools to measure cases. I Have several styles and prefer caliper mounted for ease and speed of measurement while resizing each case if needed (work hardened brass). I generally don't anneal cheap brass 223/308 because the primer pockets don't last but 4-5 loadings. I need to get an annealing machine though and its on the list.

Some fine advise above concerning uniform and sufficient case lube application perticulary with work hardend brass for consistant results and screwing in sizing die in clock face increments in the absence of shoulder datum measuring tools.

[castalott]

Motard...Is English your first language? If it is not, I must commend your mastery of it. Most people can do very simple things in another language but to be able to discuss such technical things in a second ( learned) is impressive. Well Done!

[Motard]

Not sir, I am italian. I seldom I come to Us and greatly enjoy my time Overseas. But most of my ability to be undestood doesen't come by speaking but from reading alot in Your's language. Thankyou for appreciating my efforts :)

[Motor]

Motard. Nice comparator. I use aluminum blocks that were left overs from machining operations. For as often as I "need" to compare case length in that way which was once, I couldn't see buying the Hornady tool.

I used it when lapping out an undersized Lee full length size die for 7.5x54MAS to make sure that I was not removing metal from the shoulder of the die.

If I still had access to a lathe and vertical mill I would probably make a nicer one. :)

Motor

[Motard]

Need sayng thousand thanks to everyone for great infos and help on shoulder bumping. Reloaded about 30 30-30 cartriges and tested them on rifle chamber: not one rejected. As said in previous post this may seems ordinary for most folks and to mee too untill I bought that absolutely picky rifle.
Never happened to me since now not having two dismantle 5 or 6 rounds at the least for every rolading session.
I foresigh I am goings (sadly) to say good bye to my collet sizer and just full-lenght size all' rounds within the new tight specs.