Hand pumping small vs large air reservoir

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hokieben

hokieben

Member
Feb 11, 2017
21
1
Virginia
I've heard a lot of people say that guns with smaller air capacity are better for hand pumpers. I understand that from the standpoint that it takes less pumps to fill the gun from the bottom of the shot curve to the top, but it seems to me that there are two big advantages of larger air reservoirs that don't get mentioned.

For the sake of argument, let's assume you have two identical guns, except gun "A" has a 150cc air tube and gun "B" has a 480cc bottle. The usable pressure range for both guns is 1k - 3k PSI. Filling gun "A" from the bottom to the top of that range takes 60 pumps and delivers 30 shots. Gun "B" would also get 30 shots after 60 pumps, but the pressure would ramp up much more slowly, thus making the pumping effort easier for the same number of shots. If the guns are unregulated, Gun "B" should also have a lower extreme spread since the tank pressure is changing less across the string.

The other obvious advantage of the larger tank is that you can get more shots per fill. Most of my shooting sessions are in the 40 - 60 shot range (I can only sneak away from the family for so long). With gun "A", I would almost always have to top off once during a shooting session. Alternatively, I can fill gun "B" to 3k psi ahead of time with a few 5 minute pumping sessions and then not have to worry about jacking up my heart rate and spending any of my limited range time topping off.

If you haven't figured it out already, I'm looking at the Brocock Compatto vs the Bantam for my next gun and I'm leaning toward the Bantam for the reasons stated above. Does my logic make sense? Am I missing something?

 
Only thing I can tell you is with a larger capacity when the strokes get harder it takes a LOT more to top one back up . Pump up an Air Force gun just once ....And your pump will be on classifieds next day :)
There's a really good chance I'm older than you but I'm a big guy , and at least above average strong . And believe me hand pumping is something I wouldn't wish on anyone . Unless they simply can't get access to compressed air to fill a tank . The only other thing would be when pressure really gets past say 2500psi it is a struggle , and bigger tank would probably wear pump seals faster
 
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even my brocock concept .22 at 11 foot pounds will do 70 shot with out having to do a refill.it has a very small air tube. it only takes about 4o to 45 pumps.i fill it from 165 bar and shoot down to 100

​my day state air wolf wolf is rated to 230 bar but I fill to 180 bar and shot down to 80 bar. I get 220 shots at 15 foot pounds .177
and it has a 500 cc bottle.

​a bigger bottle will always take longer to pump. it takes more are volume and more pumping to fill a bigger bottle.
a smaller bottle is much quicker to fill up to needed pressure.
​if you pump during a shooting sessions you air pressure will spike if you do it quickly and give u false readings as it cools down.
always good to wait a few mins at least half way through to start pumping again.

if you go with a gun like the air wolf you can go many sessions with out having to pump at all!
trust me not having to pump during a session is the best way to go
 
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the air wolf is very effecent. much more so than most air rifles. so you get many more shots for the same effort in pumping.
​if you want to pump less your going to need to be taking a look at the effecent guns out there. so that means a day sate air wolf or fx royal.
​
​with my daystate air wolf I can easly get 500 shots with out repumping.
​my hill pump have got about 20 000 shot through it wiith out a hitch.
​
if yr pumping you will need a hill pump. don't look further
 
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My personal experience: Handpumping is not bad at all, the bad part is the pump overheats, and you have to wait for it to cool down. That comes from a lightweight person out of shape. I don't know how people can complain about handpumping, but that wait between pump sessions is a massive pain in the ass, and with a 480cc tank, there will likely be more than one rest for the pump. 

Another option is a small compressor
 
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I already have a Hill pump, which I use to fill my prod. I'm 33, 5'11", weigh 195lbs, and I'm in decent shape. I don't find it difficult at all to fill the prod since it has such a small air cylinder. I'm just thinking for my next pcp it would be nice to have something that can go through a modest shooting session without needing a refill, but I don't need hundreds of shots per fill, so I wouldn't have to fill a large bottle all the way up to 3k... and if my logic is correct, it would actually be easier with the big bottle since I am using the lower end of the pressure curve.

I agree on the points of efficiency... if I get a Compatto or Bantam, most of my shooting would be done on the low power setting in order to increase my shot/pump ratio. An Air Wolf would be nice, but I don't think it is in the cards for me financially. I understand that the Bantam would be harder to fill to max pressure... what I'm saying is that I think there are benefits that a large air reservoir can offer us hand pumpers that get overlooked because most people only focus on the daunting task of trying to squeeze every last cc of air into that big ole bottle.
 
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I have a Compatto and I had a Marauder, which I left on the factory tune. 

The Marauder wasn't bad to fill from 1900 to 2500 psi. 60 pumps or so.

The Compatto is about the same. It's got a smaller tube, but it needs 3100-3200 psi. 65 pumps or so, and the last ones are pretty stiff. I'm 5'8" tall, 170 lbs. I do that in two pumping sessions; as I need a break after 30-40. I'm in OK shape. I'm not an athlete, but not a fatass either.

The Bantam is going to be NOTABLY harder to pump. Whether you're going from empty to full or partly discharged to top off, it's a lot more pumping. After about 60 pumps, the pump gets hot, so even if you're in excellent shape, the PUMP will need breaks to stay cool, so you don't damage it.

Also, the Bantam is ugly, whereas the Compatto is more .... neutral. I don't exactly call it great looking, but the way it fits the body is unrivaled, in my opinion.

I get about 80 shots to a fill on low power, at 12.5 FPE on my .177, and that's enough power for pests up to squirrel size out to probably 30 yards. Oh, my pump is a Hill also, Mk. III, I think, from about 5 years ago, so it should be apples to apples with yours.
 
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I hand pump both my FX gladiator (680cc from 120b to 220b) and my FX Boss (500c from 150b to 250b) and it is not so hard. I am far away from a strong guy.

I made this choice because I only shoot during week end so it is the optimal solution for me. If I had the opportunity to shoot more often I would clearly invest in a small compressor or altaros booster unit.
 
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Hand pumping is as much about technique as it is mass. Yes, a larger person will have an easier time, but knowing the right technique is helpful, not only in the ease department, but also in keeping the pump from heating up. I've pumped up an FX Boss to 250 without needing to stop and let the pump cool down. That's because I paused at the top and bottom of every stroke. Also, this reduces the number of strokes you need to have to fill a particular volume because it gives the air the time it needs to get into the tank. 

If you guys that are pumping aren't pausing at the top and bottom of each stroke, check it out, you'll be pleasantly surprised. 

+ 1 for the Hill Pump
 
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I'm not sure you guys are getting the point of the comparison. (No offence intended)
I don't have a pump but I do have a Drager Carbon Fiber and a guppy carbon fiber.
When I want to shoot some long streams with my bulldog or air thirsty Texan I will fill the guppy to 3000 psi and leave it tethered to the gun and open giving the gun an extra large tank to pull from. The big Drager is filled to 4500 and I will use it to top the guppy back to 3000 psi as needed.
The result is I can set up and even with the Texan get a lot of shots down range without stopping for a refill I get to shoot within my power curve peaks more and learn more about that power curve.
Yes the larger tank would take longer to refill but if you are shooting only on the weekend then you can break the fill times into manageable sections throughout the weekday and not overheat the pump. The result would be that when he has the time to get away to shoot he would be shooting and not spending time with refilling a tank in the middle of the shooting time. Furthermore he would be getting more shots out of his peak power curve.
Sounds like a win win to me.
 
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I think a lot depends of the way you use your air gun. For someone who uses it for a weekly hunting trip and only ever fires two or three shots at a time, pumping is no big deal. It's just a few pumps to top it off here and there if it's a 22 cal (or smaller). 

If you like to shoot a lot like me, or use 25 cal guns and above, then pumping is a real PITA. I doubt I'd want to stop shooting at the range to pump for 20 minutes after every 3-5 mags again. 

I stopped pumping because I found a place that sold used 4500 psi SCBA tanks with fresh hydros and my first fill included for less than I paid for my hand pump. That included me pricing in the fill adapters fittings too. 

If I had to pump again for some reason, I would choose something that gave me a lot of shots from a small air reservoir. Something like a Marauder is relatively quick to pump but it doesn't get that many shots per fill, so you have to pump too often for my liking. 

I would probably choose my Mutant Shorty out of all my air guns. I'm getting 48 shots from a tiny reservoir. My Ataman gets 15-20 shots from a similar size air supply for less than a 4fpe difference in power. I would probably want to turn the power down more to get even more shots. 
 
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