I might have had a 330 spring break before but I can't remember one. I beaver trap year around. I am on the coast of NC with some brackish, and Tannic acid water. This past year I have done quite a bit of farm work. Anyway I have had 7 330's break a spring and one MB 12x16 break both springs. All broke in the coil. Duke, MB, and Belisle. My traps are not all that old, I trade them out every 5 or 6 years.
I keep them painted and now I am starting to wax them to see if that will help.
Anyone else have springs break?

No, I run all belisle's and wax them couple times a year. Odd they would all go in one summer. I have very similar conditions as you.

I once purchased some waxed 330's that had 1 in plate welded to kill bar,,,,,,,,,,Man that hurt................more then once..........

Do they break while you are setting them?

No, when I return they are broke. We have a 72 hour check on submerged bodygrips.

I use around 3 dozen 330's for the every day trapping and others if I need them. I am thinking of just replacing the springs on all of them.
Bad Karma I am thinking the waxing will make a difference. Well see.

Sounds like somebody is coitising with you!

It does seem strange.

I am wondering now if it was Muriatic Acid. My ADC traps get worked hard and I wanted to clean them up, no rust, or paint, and start over. Never did that before. I diluted it down 3 to 1. I let them sit for 1 to 2 hours and them pressure washed them.

If you do an acid bath (muriatic or even vinegar) you need to neutralize them afterwards to stop the acid from working. Pressure washing them probably helped but it is likely that that still left some acid in places and the breakage could be the result. A soak in a baking soda solution would neutralize and stop the acid from eating away at the steel.

Can you show pics of the break? Both from the end and side? Maybe they had a problem trying to temper the coil? But I wouldn't expect the issue across brands.

I will try to get some pictures and post.

I’ve had Dukes break before.
They will sometimes replace them if in otherwise good condition.
Sometimes mfgs just get a bad batch of springs

It’s odd you would get several different brands break close to the same time ??

You might have a bigger challenge- IMO, it sounds like Hydrogen Embrittlement, if stress was introduced in the manufacturing process they would typically break when setting. Over prolonged use in water, containing higher levels of tannic acid you technically could be absorbing more hydrogen into the springs and causing a fracture point under the stress of the loaded springs. I think painting and waxing is a good idea to fill in any porosity in the steel.

you stinking liar David!

I think it was the muriatic acid since its happening to several makes

I know that 1:10 ratio takes plating off chain, so I'd keep it around there if it was me.