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New to pneumatic gun

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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New Member
Jan 30, 2022
Hi everyone,
I'm new to pneumatic gun, recently got a new Seac Asso Up 75. I read that its all in technique on loading it but seems like the piston jam up on the muzzle after every shot. I have to really over come initial push then its was a lot easier. Wonder if this normal for the break in period and once it break in, the piston won't jam up as much??

Also I'm running a shooting line bungee and seems like the mono sometime get tangle up with it when i shoot it. Should just remove the bungee and run mono all the way? And does it matter which way I wrap the shooting line, from the shaft/slide first or from the gun first).

I been practicing loading and shooting it in the bay, getting better each time but its still really hard. I load it horizontal to the water but feel like my body is twisting. Do people load it horizontal or vertical to the water line?

Hi, i have a seac asso 115 so hopefully i have something useful for you. Firstly ill mention the shooting line, i run dyneema only with no mono, and i dont run a bungie because i use a reel so the reel acts like a shock absorber. The reason i don't use mono is because i found its a pain and it just holds memory, and honestly i found it pointless. Ive dragged my line through rocks with no problem and never had an issue. As for the piston getting stuck, i have found that sometimes sand gets stuck on the line slider on the shaft and gives the illusion that the piston is jammed, so next time try and give the line slider a little wiggle to get the sand out, if that doesnt work id say make sure youre at 20 bar of pressure, salvimar sells a pressure guage that lets you check and it fits our gun. If that still doesnt work is say check to make sure you have oil in the gun, to insert oil just put oil into the pump and pump it into the gun, id suggest YouTubing it, just dont over pressure
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Also as for loading, i put my gun between my feet and push up with my foot while down on the loader, making sure to direct the shaft straight so as not to bend it, i like to load the shaft first and then adjust the slack with my reel, so shaft first, then 3 wraps and on the third i fix any slack by rotating my reel, with no reel i would say to do the same though because any slack would be taken up by the bungie and it would keep everything nice and tight to wrap first so you can adjust that last bit with the slack of the bungie, how many wraps is kinda up to you, i do 3 on clear days and 1 or 2 on dirty days, i hope this helped and good luck!
P.s. i highly suggest the salvimar pressure gauge that fits the seac guns, i bought mine from spearfishingworld.com
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One last thing, cover the nozzle of the gun while on the beach, and while touching the sea floor, I've used a plastic bag and rubber band before while walking on the beach so any way the does the job, same with the handle of the gun watchout not to get sand in the mechanisms because it damages the o rings, ive had to take mine apart when thats happened and its just not necessary with a little care, if you do have to take it apart its verry easy, just buy the o ring kit from spearfishing world or amazon and do it yourself, again YouTube is your friend, and if you have any questions on that ill be glad to help with what i can
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i don't think its sand, it just seems everytime right after I shot it it take a lot more effort to loosen the piston. Once I can get piston to move, and if I try to reload it again it will be easy. Don't know if its normal or something is wrong with muzzle bumper or piston itself? I just spray some silicone lube in the muzzle and see if it help.

Thanks for the advise on covering the muzzle. I only shore dive so that is a good idea. I will def will order some o-ring kit and piston. Pneumatic gun looks super easy to rebuild.

I read somewhere that the 75 range is not quite long enough for feet loading and short enough for hip loading. I guess I just need to practice more but I seems to get better every time.

I will look into getting dyneema and remove the shooting line bungee.
Hope it helps, popgun pete has a wealth of knowledge you can try messaging him if you need more help, those are the things i do since i also primarily shore dive, sometimes i have to walk a few miles on the beach so sand can get tricky
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The initial resistance to loading is normal if a gun has not been fired for some time as the piston seals can stick on the inner barrel surface, but after the first shot of the day this should disappear. However getting started on a gun with good pressure in it always needs a quick jerk on the loading bar to push the piston back. Guns are easier to load wet as the front piston seal is not that well lubricated and the barrel needs some water in it to provide this. Before setting off for the day's diving after a few weeks of not diving it is worth putting a few drops of oil down the muzzle and working the piston back and forth for the first few centimeters of barrel travel.

It does not really matter which end you wind on the gun's wrapping hooks first for the muzzle anchored shooting lines, however for guns with a rubber loop bungee tied in the shooting line it has been suggested that this section be strung last for the final stretch to the line release hook. Unless you need high shaft speed I would not bother with mono, plus it will be susceptible to damage around rocks as a bad nick and the mono just pops under any strong jerk as your victim tries to escape.

One way to assess the muzzle effort is to fire a shot on low power and then reload. The effort to get the piston moving is much lower as air under cocked loading pressure is locked up in the front tank, the low power shot only using what is in the gun’s inner barrel and prechamber in the rear end of the gun.
Muzzle loading pneumatic guns.jpg
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Thanks for confirming its normal. Unfortunately my gun doesn't have power regulator. I just need to practice more on loading. Still haven't hunt with it yet since my friends and I were using pole spear and speargun is pretty new to us and we are very cautious using around each other.
You can always let a bit of air out to check, just a brief push so as not to let too much air out using a wooden toothpick or something that will not scratch the inox ball of the inlet valve. Keep the gun with muzzle down for an hour or so to send oil to the nose end of the gun before doing it. You always get a puff of oil droplets when doing this, but nothing to worry about as the amount of oil lost is very small. Replace lost air with pump strokes until you can barely load it, then let a small puff out and it should be about right. Too much pressure and near the end of the dive you may not be able to load the gun as your energy runs down, say after four hours in the water!
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Although guns should not be loaded on land you can do it by pressing the spear tip against a wooden block and leaning down on the gun with your body weight pull the trigger and then control the gun coming up as it pushes against the shaft. To get the spear out which will be jammed in the piston you can stand on the floppers and pull the gun up and off the shaft, a quick jerk is all that is required. A hole in a flat piece of of wood with the floppers spread on the other side works well to trap the spear tip stuck in the dirt. Don't do this indoors and never fire the gun in air as you will likely bust the piston and possibly the shock absorber.
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if it came with a cheap galvanized shaft, the resistance could be due to some rust on the metal ring slider on the shaft, if not stainless/inox steel. It happened.
Sand that gets inside the can also make loading impossible.
It happened to me once after 5 years of use.
Are you sure that what is jammed is the piston? It looks like the slide ring is jamming with the shaft end to me. When that happens, you better get a new ring and shaft end.
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