IANAL, but just a fan of Title II items, and my understanding of this is ...
My question is that I am interested in getting an attachment for my rifle that I can use a filter with. I have seen them for sale cheap and I know they work as I have seen people use them.
An unregistered, unserialized adapter with a oil filter on it attached to your rifle is very much illegal. However, you may be referring to the
Econo Can. It is an adapter that is serialized and is on the NFA registry as a silencer. It uses commercial automotive oil filters. While the cost is $75 + $10 S&H + $200 NFA Tax, there are some issues you should consider:
- The oil filter obscures the sights. You'd have to work around this somehow.
- It is not nearly as quiet as purpose built suppressors.
- I haven't shot one, but I'd have to believe accuracy is going to suffer some. That might be fine whilst blasting away at soda cans, but I have my doubts for a hunting application.
- As an NFA item, you're still going to have to pay $200, take care of all the paperwork associated with said, and wait the 3—9 months for approval.
- Contrary to popular belief, you cannot legally replace the oil filter yourself once it is shot out. It must be returned to the original manufacturer. Your looking at $25 per replacement, plus postage.
Personally, I wouldn't waste my time on one, but to each their own.
I can't afford a commercially made suppressor.
You didn't say what you are suppressing, but you did mention deer, so I am assuming a centerfire rifle. I've seen .30 / 7.62mm cans as low as in the $500-ish range. If you let us know the exact rifle and caliber, we might be able to narrow it down some as to what you're looking at for an adapter, suppressor, etc.
Beyond that, .22 cans can be had as low as in the $150-300 range.
Does the $200 tax stamp cover an individual suppressor or the person that applies for the suppressor?
It is a one time transfer tax of the item to you. It only covers that one suppressor transferring to you.
Also, if it only covers the suppressor , does the suppressor have to be commercially made with a serial number engraved on it or can you use an attachment for a filter.
NFA-regulated items must have a serial number. One already built can transfer to you on a Form 4. Or you can build your own with an approved Form 1. Both, however, require a serial number on the item.
Hope that helps.