Someone else suggested an American 1100. I second that PROVIDED it will fit your case. Depends on the case we're talking about.
Thieves (baggage handlers) that want to get your guns are going to go with a few options. One, they'll cut the hinges off the box. Two, they cut the lock shackle. Three, they shim the padlock. Thieves tend not pick locks but they've probably learned about can shims.
In this case, that lock has a pretty tough shackle, and it's not (easily?) shimmable. So you're forcing them to destroy the case to get your stuff. Which is all you can expect from any lock. Make the lock harder to get past than the container.
That makes no sense - they come in original packaging, and have the serrated key pins, the fully serrated driver pins, and spools. The bitting however is just plain terrible. Not sure how it would be counterfeit.
Edit: American Lock A1106YLW Padlock Keyed, Aluminum, Yellow https://www.amazon.com/dp/B015MG09E8/ref=cm_sw_r_other_apa_qoMQAbGW14XCR here is the link to the Amazon purchase. If they're selling counterfeits, we have a problem.
I picked up a blue 1100 from a guy on Facebook marketplace for $16 (after shipping) and there is loto 410's and a yellow 1100 for $10-15 on Amazon American Lock-A1106YLW Lockout Padlock, KD, Yellow, 1/4 in. Dia. https://www.amazon.com/dp/B015MG09E8/ref=cm_sw_r_apan_i_0B1HJZ1BYZZJ5NR5MKJT
I definitly can say the dollar tree and Dollar General locks are not good. I posted a video of a DG lock that I popped with just a tension wrench.
My first 410 LOTO was a lot easier to pick than my second. My second the last pin in the very back has to go up quite a bit. So you might try another 410. You also might try raking a false set then trying to pick it. That was how I picked my first one the very first time. You also might just move to another lock, I would suggest trying out an American 1100 at some point they are about $11 on Amazon and it is a good lock to move to at some point anyway.
I guess amazon for 10-15 dollar is your best bet if you are in the UK, this one ships to my country for a reasonable price. Browse amazon a bit to find something decent. Other than that a bigger lot on ebay may also be worth the effort, get a better deal on multiple american locks and just pay the 20 dollar shipment.
I dont own any American Locks though, this is how i would buy them.
I paid €17.40 on amazon.com for an American 1100 delivered in France within 5 days. It was something like $10 for the padlock and about the same for freight and taxes.
Edit - Here is the link... https://www.amazon.com/American-Lock-A1106YLW-Padlock-Aluminum/dp/B015MG09E8/ref=mp_s_a_1_15?dchild=1&keywords=american+1100&qid=1596152541&sr=8-15
You can order them directly from Amazon US, they do global shipping to Europe. You can see the shipping and fees details of your country if you click on the link under the price. It should be around 19 euros for this one: https://www.amazon.com/American-Lock-A1106YLW-Padlock-Aluminum/dp/B015MG09E8/ref=mp_s_a_1_1?currency=EUR&dchild=1
If you go to amazon.com (yes the American version of the site), you can get American Locks delivered to Europe at a reasonable price. Normally, amazon stock their own at this link, but things are messed over there, so you may have to wait for things to calm down before they come back. Please check the exchange rate and shipping rate before you buy. Last time I checked, the lock was ~$10.87, which ended up at ~£15 with shipping and exchange.
Running 1/4" shackle. I recommend getting 1" - 1.5" shackle length. Bought American Lock from Amazon: https://www.amazon.com/American-Lock-A1106YLW-Padlock-Aluminum/dp/B015MG09E8/ref=sr_1_1?s=industrial&ie=UTF8&qid=1510819926&sr=1-1&keywords=american+lock
Had them all re-keyed so I just need 1 key so I didn't need to carry multiple keys to open one case.
Pick the American 1100 for a blue belt. Amazon has it in yellow for $9.68. https://www.amazon.com/dp/B015MG09E8/ref=cm_sw_r_cp_apa_evtJzb30VMHB0
American Lock-A1106YLW Lockout Padlock, KD, Yellow, 1/4 in. Dia. https://www.amazon.com/dp/B015MG09E8/ref=cm_sw_r_apan_glt_i_48GE24BN02ANVTAB4488
PACLOCK's 90A-PRO Series Padlock, Buy American Act Compliant, Black Anodized Aluminum, High Security 7-Pin Cylinder with 1 Key per Lock, Keyed Differently, 1-3/16" Tall Hardened Steel Shackle https://www.amazon.com/dp/B088P8L1HH/ref=cm_sw_r_apan_glt_i_3667WZJ6WBYNPETTXZJQ
American Lock A700D, 2-1/2". https://www.amazon.com/dp/B0013G51QS/ref=cm_sw_r_apan_glt_i_52CKCR97DA79Y1QSQWZS
There's a few from Amazon that might keep him busy for a few minutes. 😀 Those are blue belt level.
If you don't mind yellow, you can save a few bucks:
American Lock-A1106YLW Lockout Padlock, KD, Yellow, 1/4 in. Dia. https://www.amazon.com/dp/B015MG09E8/ref=cm_sw_r_apan_glt_fabc_9QF1MR8TB336V2X6BYNH
https://www.amazon.com/dp/B015MG09E8
This is the one I just bought and it came as advertised
Sure. American Lock-A1106YLW Lockout Padlock https://www.amazon.com/dp/B015MG09E8/ref=cm_sw_r_cp_api_glc_fabc_d6O9FbN7JD0A0
I ordered this one and got exactly what I expected. Security pins, hardened shackle and plate, tough as nails.
The American 1100 is available on Amazon. https://smile.amazon.com/American-Lock-A1106YLW-Padlock-Aluminum/dp/B015MG09E8
So is the PACLOCK 90A-PRO. https://smile.amazon.com/PACLOCKs-Compliant-Anodized-Aluminum-Differently/dp/B088P8L1HH
Both are blue belt level.
On Amazon.com I ordered an American 1100 for about 12$ and paid around 14$ for shipping to Italy. I don't know if it's the same for Denmark. Also, you could try Amazon.de.
Here is the link https://www.amazon.com/gp/product/B015MG09E8/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 and it took about 4 days to get it.
Congratulations on the open. I ordered an A1106 on amazon dot com for $10.49 + $6.74 shipping = $17.23. I was charged 15.26€ on my card, I think it is a good deal: my locally purchased 72/40 was more expensive than that )I still need to record its open+disassembly on video). No VAT or customs in my country under 21€, anyway amazon automatically calculates and makes you pre-pay them.
https://www.amazon.com/gp/product/B015MG09E8/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
Not OP but in the US the yellow one us 10.50 on Amazon:
https://www.amazon.com/dp/B015MG09E8/ref=cm_sw_r_apa_i_tQLBEbEX7HKJB
The American 1100 is probably the most popular blue belt lock and isn't too expensive on Amazon. I'm sure some good TOK tension wrenches like the flat bars and/or heavy bars from Sparrows would be appreciated. For advanced picks, his preference may vary a bit based on what brands he likes (if he has a preference). My personal recommendations would be something like either the Tuxedo Royale or SSDeV (also available in 0.025) sets from Sparrows.
If someone really wants to get in, they will. Lockers don’t hold big enough shackles for you to have much physical resistance, and someone could just break the cheap locker door or hinges regardless.
That being said, I agree with u/stab_in_the_eye. American 1100s are light, decently strong, impressively cheap, and will take some time and decent skill to pick (not astroturfing). They can be bought here, and this color (Master Lock Influence, priced by color) is currently on sale for some reason.
EDIT: Also, if you don’t think the longer shackle on the 1106 will fit, this one has a shorter shackle, but is (Master Lock!) priced... higher?