Do you double pump?

Memnok · December 29, 2009, 05:30 PM

So I'm sitting here resizing/de-priming 40 S&W on my single stage press. I noticed that I "pump" the handle twice, fully inserting/removing each case two times. Does anyone else do this? Anyone out there a triple pumper?

Progressive/turret folks need not reply I guess.

Creeper · December 29, 2009, 06:08 PM

No. A cartridge case, run thru a sizing die, will compress and "spring back" a small amount, rendering it, a median size suitable for most all modern firearms that cartridge case would be used in.
If you "hit it again" you may compress it an additional amount, which then would reduce it's dimensions to a lesser value... not much less, but a thousandth or two, perhaps. In extreme, it would be akin to running a case (needlessly) thru a small base die.

This can cause several things... all relative to the individual circumstances.
A tighter bullet fit... on some cartridges, perhaps shaving of bullet material.
A looser chamber fit. Perhaps more critical in a bottleneck rifle cartridge than a pistol round.
A shifting of the cartridge axially in the chamber, (if it chambers on the case mouth or bottleneck) causing, potentially a light primer strike and possible misfire.

All perhapses and maybes and what ifs... but sizing dies are not designed to be used in that fashion.

Chances are if you've been doing this for a long time with no ill effects, you aren't hurting anything (except maybe the life of your brass)... but you might find that single stroked cases are (slightly) more accurate due to a slightly better alignment/concentricity in the chamber.

In a purely practical sense, you are wasting 50% of your time and energy.

C

FrankenMauser · December 29, 2009, 07:34 PM

Quote:

Does anyone else do this? Anyone out there a triple pumper?

...Only when forming certain cases...
(Such as .35 Whelen, from .30-06. Without an intermediate step, I've found it best to expand the neck in small increments.)

Normal reloading sees single throws of the handle; anything else is a waste of precious energy.

Ozzieman · December 29, 2009, 08:52 PM

Why do you run it through twice?
I also think that you might be shortening your case life by work hardening.

Memnok · December 29, 2009, 09:37 PM

Quote:

Why do you run it through twice?

No reason in particular. I just started reloading again after about 15 years. I just wanted to ask before I kept going.

Pathfinder45 · December 29, 2009, 09:38 PM

......obsessive compulsive disorder. Some people are born with it. Some people aquire it usually due to a very high fever in their past. No big deal; ya just waste some time double and triple checking yourself to make sure everything is right. Some people have it worse than others. The opposite is much worse: People that are boldly over-confident in themselves leaving a wake of accidents that wouldn't have happened to someone more carefull. Anybody could total a car but some people do it habitually.

RidgwayCO · December 29, 2009, 11:10 PM

Yep, sounds like the ol' OCD. I'm sure glad I don't suffer from that because it could get... LOOK!! A SQUIRREL!!

**Unclenick** · December 30, 2009, 12:09 AM

I have found multiple stroke sizing useful when dealing with rifle cases once-fired in other weapons than my own. It is common to find a few among such cses that come out of the sizing die a little longer than others. If you re-resize these, counting to 5 at the top of the stroke to let the stress relax a little, you can sometimes set the shoulder back another two or three thousandths to get them closer to the size of others. Once fired in your own chamber, they should all resize usefully with one sizing die stroke.

40 S&W may be an exception here, in that some guns produce highly "pregnant" cases. These should probably be sent through the Reddiing G-Rx die, first, before resizing. (G-Rx is no doubt Glock Prescription, since Glock's are known offenders in creating those pregnancies).

Jim243 · December 30, 2009, 12:30 AM

Sorry Memnok, this turret press operator double pumps. In sizing the 40 S&W case I will often size decap and turn the case 1/2 turn and resize it. Often when the cases appear to be stepped on or a little out of shape. When Seating the bullet I always run the case through a Lee FCD to insure that the outer size is to factory specks after the bullet has been seated. No crimp just a case resizing again. Often I will find that Bullets themselves with bow the case because they are not uniform even in the same bag or lot. This insures that I will not have any FTF when I need to use the round. Is it absolutly necessary - no, does it make me feel better about my ammo - yes.

Do what makes you happy.

Jim

FrankenMauser · December 30, 2009, 01:39 AM

Jim reminded me that my first post was incorrect.

When sizing pistol brass, fired in a semi-supported chamber; I'll do the same thing: Stroke it. Turn it. Stroke it. (With the possibility of one additional turn and stroke.)

It works fairly well for removing fish bellies from Glunked cases.

tsigmon · December 30, 2009, 08:21 AM

"In extreme, it would be akin to running a case (needlessly) thru a small base die."

I guess this statement is a depends on the gun situation.....

I'm far from an expert and try to do things by the books especially on things I know little about and am trying to learn. I have started reloading .308 Win.
for a Winchester model 88 lever action and was advised ,and read, that small base dies should be used for rounds used in automatics, pumps and lever guns. Did I search invane until I found the SB dies.? Part of the reasoning for searching was the variery of brass I had that was not fired in this gun and I wanted to make sure It fed correctly.

jdscholer · December 30, 2009, 10:07 AM

I'm crazy and excessive about too many things already to start this one. I do however "double clink" my Uniflow powder measure at the top stroke when using it. jd

jmorris · December 30, 2009, 11:03 AM

Sounds like a bad habit to form if you ever have aspirations to load on a progressive.

troy_mclure · December 30, 2009, 12:24 PM

not during sizing, but when seating bullets ill run it in then rotate, then hit it again.

Tex S · December 30, 2009, 01:15 PM

I have found that some case necks can be straightened out if I run them into my Forster Bushing Die, then turn 1/4 turn and size again, turn 1/4 turn and size again, etc. Using this method the case actually gets sized 4 times, and sometimes it dramatically reduces bad concentricity readings.

Other than that I am a one pump chump.

Nate1778 · December 30, 2009, 02:04 PM

Quote:

Yep, sounds like the ol' OCD. I'm sure glad I don't suffer from that because it could get... LOOK!! A SQUIRREL!!

That would be ADD, OCD would be Squirrel, Squirrel, Squirrel.

I only know this because I have ADD and have a hard time,,,,,,,,,,,what was I talking about.

Mark whiz · December 30, 2009, 08:47 PM

I don't double pump with straightwall cases, but sometimes I do when resizing for my .308 - especially when sizing mil-spec brass. But even then i don't just do it autromatically..................if it didn't "feel" right the first time I hit it again and I usually sample my cases headspace too and i usually have to hit one or 2 again to get them where I want them.

Hey_Allen · December 30, 2009, 09:46 PM

I don't know that I do this on my single stage press, but I've found myself double pumping to seat primers on my progressive that I just got!

I'm still getting used to it, and how it behaves, so it's taking me a little bit, and more than a couple of cases acting as powder funnels rather than holding the powder from the powder drop. (Wolf primers being slightly oversize compared to others doesn't help, either!)

For me, it wasn't "ooh look, a squirrel" or the "squirrel, squirrel, squirrel", but rather "Never mind what happened to the daylight, what happened to half the night as well?!"

Stargazer · December 31, 2009, 05:57 AM

Don't feel pregnant there: I double and or triple bump my powder measure the same times in my up and down motion with the handle so each load has the same amount of bumps. I rotate my cases three times during bullet seating too. Might be useless but in my mind it makes for a more concentric load.

F. Guffey · December 31, 2009, 10:11 AM

Only when forming cases with a forming/trim die, raise the ram, if resistance to raising the ram causes too much resistance, I will stop, lower the ram and start again, after forming the case and before lowering the ram the case is trimmed with a hack saw and finished with a file, then the ram is lowered and raised again, it is believed the case recovers a small portion of what it once was, I believe that sounds nice, I raise the ram again before removing the case and remove the brass that rolls over the top of the die with a file, normally lowering the case shears the roll-over off, but not all of it, so I finish file the mouth of the case before lowering the ram for the last time.

I have used air craft counter sinks to trim the cases when forming, lowering the ram shears the neck, meaning the counter sink does not always cut the brass, sometimes it bells the neck to be trimmed above the die, the belled neck shears off when the case is lowered.

F. Guffey

furtaker · December 31, 2009, 02:17 PM

My Lee collet dies (rifle) say to turn the brass 180* then press again. Thats there neck sizing die.

abber · January 1, 2010, 01:10 AM

One stroke per round for me!

Hook686 · January 1, 2010, 02:29 AM

In your double pumping, have you ever double charged a case ?

December 29, 2009, 05:30 PM	#1
Memnok Member Join Date: November 27, 2009 Posts: 33	Do you double pump? So I'm sitting here resizing/de-priming 40 S&W on my single stage press. I noticed that I "pump" the handle twice, fully inserting/removing each case two times. Does anyone else do this? Anyone out there a triple pumper? Progressive/turret folks need not reply I guess. __________________ Clint ---------------------------------- Good government is no substitute for self-government. Mahatma Gandhi That government is best which governs least, because its people discipline themselves. - Thomas Jefferson

December 29, 2009, 06:08 PM	#2
Creeper Senior Member Join Date: September 9, 2008 Location: Woooooshington Posts: 1,797	No. A cartridge case, run thru a sizing die, will compress and "spring back" a small amount, rendering it, a median size suitable for most all modern firearms that cartridge case would be used in. If you "hit it again" you may compress it an additional amount, which then would reduce it's dimensions to a lesser value... not much less, but a thousandth or two, perhaps. In extreme, it would be akin to running a case (needlessly) thru a small base die. This can cause several things... all relative to the individual circumstances. A tighter bullet fit... on some cartridges, perhaps shaving of bullet material. A looser chamber fit. Perhaps more critical in a bottleneck rifle cartridge than a pistol round. A shifting of the cartridge axially in the chamber, (if it chambers on the case mouth or bottleneck) causing, potentially a light primer strike and possible misfire. All perhapses and maybes and what ifs... but sizing dies are not designed to be used in that fashion. Chances are if you've been doing this for a long time with no ill effects, you aren't hurting anything (except maybe the life of your brass)... but you might find that single stroked cases are (slightly) more accurate due to a slightly better alignment/concentricity in the chamber. In a purely practical sense, you are wasting 50% of your time and energy. C __________________ Shoulder Drive Nicholson Club

December 29, 2009, 09:38 PM	#6
Pathfinder45 Senior Member Join Date: January 7, 2008 Posts: 3,224	It's called...... ......obsessive compulsive disorder. Some people are born with it. Some people aquire it usually due to a very high fever in their past. No big deal; ya just waste some time double and triple checking yourself to make sure everything is right. Some people have it worse than others. The opposite is much worse: People that are boldly over-confident in themselves leaving a wake of accidents that wouldn't have happened to someone more carefull. Anybody could total a car but some people do it habitually.

December 29, 2009, 11:10 PM	#7
RidgwayCO Senior Member Join Date: March 22, 2008 Location: Western Colorado Posts: 244	Yep, sounds like the ol' OCD. I'm sure glad I don't suffer from that because it could get... LOOK!! A SQUIRREL!! __________________ "A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed." Nope, not a single word about hunting...

December 30, 2009, 12:09 AM	#8
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	I have found multiple stroke sizing useful when dealing with rifle cases once-fired in other weapons than my own. It is common to find a few among such cses that come out of the sizing die a little longer than others. If you re-resize these, counting to 5 at the top of the stroke to let the stress relax a little, you can sometimes set the shoulder back another two or three thousandths to get them closer to the size of others. Once fired in your own chamber, they should all resize usefully with one sizing die stroke. 40 S&W may be an exception here, in that some guns produce highly "pregnant" cases. These should probably be sent through the Reddiing G-Rx die, first, before resizing. (G-Rx is no doubt Glock Prescription, since Glock's are known offenders in creating those pregnancies). __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; December 30, 2009 at 12:14 AM.

December 29, 2009, 08:52 PM	#4
Ozzieman Senior Member Join Date: December 14, 2004 Location: Northern Indiana Posts: 6,117	Why do you run it through twice? I also think that you might be shortening your case life by work hardening.

December 30, 2009, 12:30 AM	#9
Jim243 Senior Member Join Date: January 5, 2009 Location: Just off Route 66 Posts: 5,067	Sorry Memnok, this turret press operator double pumps. In sizing the 40 S&W case I will often size decap and turn the case 1/2 turn and resize it. Often when the cases appear to be stepped on or a little out of shape. When Seating the bullet I always run the case through a Lee FCD to insure that the outer size is to factory specks after the bullet has been seated. No crimp just a case resizing again. Often I will find that Bullets themselves with bow the case because they are not uniform even in the same bag or lot. This insures that I will not have any FTF when I need to use the round. Is it absolutly necessary - no, does it make me feel better about my ammo - yes. Do what makes you happy. Jim

December 30, 2009, 01:39 AM	#10
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	Jim reminded me that my first post was incorrect. When sizing pistol brass, fired in a semi-supported chamber; I'll do the same thing: Stroke it. Turn it. Stroke it. (With the possibility of one additional turn and stroke.) It works fairly well for removing fish bellies from Glunked cases. __________________ Don't even try it. It's even worse than the internet would lead you to believe.

December 30, 2009, 08:21 AM	#11
tsigmon Junior Member Join Date: November 30, 2008 Location: sc Posts: 12	"In extreme, it would be akin to running a case (needlessly) thru a small base die." I guess this statement is a depends on the gun situation..... I'm far from an expert and try to do things by the books especially on things I know little about and am trying to learn. I have started reloading .308 Win. for a Winchester model 88 lever action and was advised ,and read, that small base dies should be used for rounds used in automatics, pumps and lever guns. Did I search invane until I found the SB dies.? Part of the reasoning for searching was the variery of brass I had that was not fired in this gun and I wanted to make sure It fed correctly.

December 30, 2009, 10:07 AM	#12
jdscholer Senior Member Join Date: March 23, 2008 Location: Jefferson State Posts: 1,197	I'm crazy and excessive about too many things already to start this one. I do however "double clink" my Uniflow powder measure at the top stroke when using it. jd __________________ "We're all dummies, just in different ways." Old Okie Philosopher

December 30, 2009, 11:03 AM	#13
jmorris Senior Member Join Date: November 22, 2006 Posts: 3,077	Sounds like a bad habit to form if you ever have aspirations to load on a progressive.

December 30, 2009, 12:24 PM	#14
troy_mclure Senior Member Join Date: November 17, 2008 Location: gulf of mexico Posts: 2,716	not during sizing, but when seating bullets ill run it in then rotate, then hit it again. __________________ There is only one tactical principle which is not subject to change. It is to use the means at hand to inflict the maximum amount of wound, death, and destruction on the enemy in the minimum amount of time."

December 30, 2009, 01:15 PM	#15
Tex S Senior Member Join Date: November 12, 2008 Location: Fort Worth, TEXAS Posts: 909	I have found that some case necks can be straightened out if I run them into my Forster Bushing Die, then turn 1/4 turn and size again, turn 1/4 turn and size again, etc. Using this method the case actually gets sized 4 times, and sometimes it dramatically reduces bad concentricity readings. Other than that I am a one pump chump.

December 30, 2009, 08:47 PM	#17
Mark whiz Senior Member Join Date: May 19, 2004 Location: Wabash, IN Posts: 227	I don't double pump with straightwall cases, but sometimes I do when resizing for my .308 - especially when sizing mil-spec brass. But even then i don't just do it autromatically..................if it didn't "feel" right the first time I hit it again and I usually sample my cases headspace too and i usually have to hit one or 2 again to get them where I want them. __________________ "Every moving thing that liveth, I give unto you as meat" (Gen 9:3) Aim small.........miss small. Trust God..........but keep your powder dry!

December 30, 2009, 09:46 PM	#18
Hey_Allen Member Join Date: October 14, 2008 Location: NW Washington Posts: 39	I don't know that I do this on my single stage press, but I've found myself double pumping to seat primers on my progressive that I just got! I'm still getting used to it, and how it behaves, so it's taking me a little bit, and more than a couple of cases acting as powder funnels rather than holding the powder from the powder drop. (Wolf primers being slightly oversize compared to others doesn't help, either!) For me, it wasn't "ooh look, a squirrel" or the "squirrel, squirrel, squirrel", but rather "Never mind what happened to the daylight, what happened to half the night as well?!"

December 31, 2009, 05:57 AM	#19
Stargazer Senior Member Join Date: August 6, 2006 Location: Republic of Texas Posts: 506	Don't feel pregnant there: I double and or triple bump my powder measure the same times in my up and down motion with the handle so each load has the same amount of bumps. I rotate my cases three times during bullet seating too. Might be useless but in my mind it makes for a more concentric load. __________________ 5.56mm, reach out and touch something. .458 SOCOM,reach out and knock something down. M70 Web Page

December 31, 2009, 10:11 AM	#20
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Only when forming cases with a forming/trim die, raise the ram, if resistance to raising the ram causes too much resistance, I will stop, lower the ram and start again, after forming the case and before lowering the ram the case is trimmed with a hack saw and finished with a file, then the ram is lowered and raised again, it is believed the case recovers a small portion of what it once was, I believe that sounds nice, I raise the ram again before removing the case and remove the brass that rolls over the top of the die with a file, normally lowering the case shears the roll-over off, but not all of it, so I finish file the mouth of the case before lowering the ram for the last time. I have used air craft counter sinks to trim the cases when forming, lowering the ram shears the neck, meaning the counter sink does not always cut the brass, sometimes it bells the neck to be trimmed above the die, the belled neck shears off when the case is lowered. F. Guffey

December 31, 2009, 02:17 PM	#21
furtaker Senior Member Join Date: February 27, 2009 Posts: 119	My Lee collet dies (rifle) say to turn the brass 180* then press again. Thats there neck sizing die.

January 1, 2010, 01:10 AM	#22
abber Senior Member Join Date: January 15, 2008 Location: PRK Posts: 735	One stroke per round for me! __________________ I ain't got no safe queens. I shoots em all...

January 1, 2010, 02:29 AM	#23
Hook686 Senior Member Join Date: May 22, 2005 Location: USA The Great State of California Posts: 2,090	In your double pumping, have you ever double charged a case ? __________________ Hook686 When the number of people in institutions reaches 51%, we change sides.