Shooting shells with any rifled airgun? 😦
Printed From: Kiwi Airgunners
Category: Technical
Forum Name: Pauly's Technical Area
Forum Description: Technical information, Modifications and DIY projects are all in here
URL: www.kiwiairgunners.co.nz/forum_posts.asp?TID=703
Printed Date: 23 Nov 2024 at 2:00pm
Software Version: Web Wiz Forums 10.14 - http://www.webwizforums.com
Topic: Shooting shells with any rifled airgun? 😦
Posted By: paulo.baronceli
Subject: Shooting shells with any rifled airgun? 😦
Date Posted: 04 Nov 2022 at 7:33pm
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You will think I'm crazy, but after I bought a Gamo Shadow DX Express I've been a bit obsessed with the concept of an air shotgun, and in my adventures I have read and learned a lot about the shot shells, why they are designed the way they are, and have decided I wanted to try something different... Well, I've kinda designed and 3D printed .177 shells to be used on a rifled barrel instead... So I designed, printed, and filled it with no. 9 shots - between 7 to 12 pellets per shell - and to my utmost surprise, it worked!! Definitely not hunting material, but it never jammed, and it's so freaking fun. After a few tests I figured that allowing the shell to be propelled forwards help a lot on neutralising the rifling, as the shots seem to spread only after - or just before - leaving the barrel, and it adds an extra punch and kinetic energy when it connects to the target. I tested it with a youth 6FPE and after a few different designs, the one I found worked the best was the one below:  The cartridge spins some times, but when I tried a more aerodynamic model I didn't really get too good patterning:  Still working my way through it, but it has been so fun that I decided to share it here. Maybe once I get a more final design I can send some to some forum members to test it out.    |
Replies:
Posted By: kruzaroad
Date Posted: 04 Nov 2022 at 8:11pm
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Sweet. Good on you for experimenting. You say the cartridge spins some times, is the whole thing being fired? Wonder what it would do through a pcp. What is your end for grouping pattern over how far. Keep us updated it's definitely pipped my curiousity |
Posted By: kruzaroad
Date Posted: 04 Nov 2022 at 8:32pm
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Have you got a chronohraph? Your welcome to borrow mine for while and see what sort of fps your getting. I'm due to head into town in the next week. |
Posted By: paulo.baronceli
Date Posted: 04 Nov 2022 at 9:00pm
Yes, I even tried shells with larger skirts to hold the shell in place, but I guess the fact it breaks the tightness of the breach seal reduces the power output by a lot, so allowing the entire cartridge to be propelled forwards with its content has got me better and more consistent results, and despite being made of PLA, the shells pack quite a punch when they don't spin. It's just for fun, so I'm trying not to have too many rules around it, and if anyone has any ideas, just let me know and I can give it go. On the chrony thing, I don't really have one. I think right now the numbers will be quite inconsistent though, but happy to try. Maybe you can even have some shells to give it a go at your end too. I wanted to test it with a .22 too, but all my 22s have mags on and I didn't really wanted to take them out to test it. ------------- |
kruzaroad wrote:Posted By: kruzaroad
Date Posted: 04 Nov 2022 at 10:46pm
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pm me to sort out a day for chrono to be dropped off. Have you tried printing the cartridge in 2 pieces length ways? One side with the end plug attached, so the compressed air has something to push against. It will allow the cartridge to separate from around the pellets earlier. Basically a 2 piece sabo for an undersized projectile in a shot gun. Have you seen, taofledermaus? Basically they load and test home made shotgun projectiles and various wierd shot loads. A lot of them he alters the way the cartridge is packed for the particular load. Could be some good ideas there. https://youtube.com/c/taofledermaus I wouldn't mind a letting you run a few shots through gamo, it's listed for experimenting. |
Posted By: xyon
Date Posted: 05 Nov 2022 at 8:17pm
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Not too crazy! sounds like it's a fun project. ------------- --- My favourites springer - Diana 52 PCP - FX Wildcat III |
Posted By: kruzaroad
Date Posted: 06 Nov 2022 at 9:22am
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What about a 2 piece shot case pushed by a pellet? End of case printed to pellet nose shape. I can see potential problems such as lost volicity, uneven case separation aftecting pellet flight, pellet over taking shot. But could be worth a try. Biggest problem with steel shot is the bore damage to rifling, so firing the whole unit is an advantage. If you got a smooth bore you could try muzzle loading a wad then pour down some lead shot, then wad the front. Slow but give you a preety good spread pattern and basically no extra weight. I've got some of cotton shoot through swabs I never used you can try. 
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