|February 10, 2013, 07:52 AM||#1|
Join Date: January 24, 2009
Location: Anchorage Alaska
Rounds per hour: Sustained vs Cyclical rate
Rounds per hour: Sustained vs Cyclical rate
Just for curiosity's sake and for another thread I discussed the production rate achievable and commented on the claims of some loaders of excess of 250 rounds an hour on Lee's Turret Presses. That's doable. But can you keep it up indefinitely?
If a loader can drop one finished round every 15 seconds, that is 240 RPH (Rounds Per Hour) cyclical rate (3600 seconds divided by 15 seconds = 240). But you can't do that forever without interruptions. You have to stop every once in a while.
So, I knocked out a spreadsheet to allow comparing the two rates depending on the factors that separate the cyclical and sustained rates, namely; Interruptions for checking the powder drop, refilling powder hopper and primer feeder and to stretch your legs and bathroom breaks.
The first set of figures below, I believe, are reasonable for a smooth-running auto-indexing turret press with an automatic powder drop. For progressive presses, the figures are much higher but the principles are the same.
If the process is interrupted once
every 25 rounds for 45 seconds to check the powder drop and
every 100 rounds for 60 seconds to replenish the primer dispenser,
every 50 rounds for 10 seconds to replenish the powder hopper,
every hour for 5 minutes break to stretch your legs
A smooth-running turret press with an automatic powder drop
then 240 RPH cyclic/188 RPH sustained (205 RPH without a break).
Without an automatic powder drop, one round every 30 seconds.
120 RPH/102 RPH/110 RPH
if 20 seconds per,
180 RPH/146 RPH/159 RPH)
A 500 RPH cyclical progressive pencils out at
500 RPH/337 RPH/367 RPH
On a progressive press with a case and bullet feeder), these figures are similarly reasonable by my reckoning
720 RPH/434 RPH/474 RPH
So, when you read anyone's report (boast or complaint) of their throughput, ask yourself how they measured it, what they included and what they left out.
Obviously, I've been bored. Off work sick for a few days. Getting better now, though.
edit: My formulas don't work well for batch processing, as done on a single stage.
Last edited by Lost Sheep; February 10, 2013 at 09:00 AM.
|February 10, 2013, 10:22 AM||#2|
Join Date: June 16, 2008
I use an old Dillion RL 1000 which has a cyclical rate of 1800 rounds pre hour.
It don't. Sure if you're talking about just pulling the handle you can exceed that. But every now and then I have to stop and reload the powder reservoir and primer tube.
Then some cased slow you down in the sizing department. Its much easier to size a 38 case with a carbide sizer die then, lets say a 30-06 round which takes a bit more work sizing.
Even 357s and 9mms slow you down a bit, because of the pressures of those rounds being fired, they require a bit more sizing pressure, that slows you down. Low pressure shells like 38s and 45 ACPs don't expand the cases as much so they are faster to load.
I count my rounds per hour or sustained rate by primer count or how many 100 pack of primers I go through in an hour. That's the bottle neck, filling the primer tube.
With 38s, I can get an easy 800 round per hour. Faster if I push it and pay attention. With something along the '06, I'm lucky if I can get 200 per hour.
To be honest you have to add your prep time. The time it takes to get your bullets, cases, primers, powder, etc lined up to start reloading.
And of course jams do happen.
Also when loading you have to take into account the bullet casting, bullet cooling, lube and sizing.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071
|February 10, 2013, 11:35 AM||#3|
Join Date: November 22, 2006
Yep if you count everything the numbers add up. Picking up the brass, sorting it, running the tumbler for a few hours, casting ingots to later cast bullets from, taking out the trash and vacuuming up when you need to. Not to mention the hours spent just figuring out what load your going to stick with.
|February 10, 2013, 02:50 PM||#4|
Join Date: December 4, 1999
Location: WA, the ever blue state
In the book "Waldon 2" by B.F. Skinner, there is a commune that gives labor credits for time worked. The more unpleasant the task, the more labor credits per hour.
Handloading gets unpleasant when the tasks feel repetitive.
I combine watching TV on my computer with high volume handloading.
If I have to size 1,000 cases, I am going to be watching TV while I do it.
But if I am doing 10 cartridges with incremental powder charges, I do that in the reloading room.
What does it all mean?
Rounds per hour does not matter if it is pleasant and combined with something you were going to do anyway.
The word 'forum" does not mean "not criticizing books."
"Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist.
Are we a nation of competing ideas, or a nation of forced conformity of thought?
|February 10, 2013, 03:56 PM||#5|
Join Date: February 17, 2012
Location: Las Vegas
My sustained throughput on my progressive (RCBS Pro 2000, auto indexing) is approximately 275 RPH. That includes replenishing primers, powder, breaks, going to the garage to get more brass if needed, etc. It assumes I have set the press up for that caliber and everything is "ready to go" (i.e. brass prepped if necessary). I don't have a bullet or case feeder. 4 hours is about the max I'll go in one session.
My sustained throughput on my single stage is about 80 RPH, loading in 50 round batches, assuming I'm dropping straight from the hopper. If I'm trickling, it's about 40 - 50 RPH.