The earlier guns, up thru the 303, were simpler & easier to clean because they don't have the gas pressure relief system like the 390's & 391's. The hammer braces, the bolt connecting rod & occasionally the locking block are the parts that tend to brake & I don't know if one model is anymore durable than another since they're basically the same design. The 390 seems to be a little heavier than the others but any of them should be good if the price is right. John
My friend and I both started shooting Beretta 303s at the same time and shot on the same squad for over ten years. I loaded up on extra 303 parts because I remembered shooting a Rem 1100 and how often IT needed parts replacement. Anyway, neither of us ever had to replace a part or have the 303s repaired during that time. Unbelievable for an automatic. I don't shoot much anymore but still have two 303s and a bunch of extra parts.
If you're having custom wood made, any of the series AL-2, A301, A302 or A303 is a good choice. Parts for these are inter-changeable, though sometimes you have to change more than one part with the bolt/carrier/connector. I've had a 390 and a 391, but am not as familiar with them. My favorite is the A303.
If you are going to shoot doubles, a 390 or 391 would be the best. The reason is that the older models dont cycle well. The gas ports in the the 390 or 391 fix that problem. I know someone will write back saying they will, but it is a fact that the new ones cycle light shells better. If you are shooting hunting shells with a lot of recoil, any gun will work fine. Handicap shells will work better in the older models than light ones, but to avoid the hassle, a 390 or 391 is the way to go for trap.
The 303 Beretta is no easier to clean than a 390 Beretta. Once the barrel is removed from the receiver, the only difference between the two is the 390 gas cylinder has 4 holes in it that the 303 doesn't have. The 391 is an entirely different story with the relief spring attached to the gas cylinder.
Many of the parts interchange-e. g. firing pins, firing pin springs, hammers, hammer braces, hammer springs, sears, links, extractors, ejectors.
There is one significant difference between a 303 and a 390. The recoil spring tube for the 303 is much longer than the 390. As a result the stock length on a 303 cannot be as short as one for a 390. This is not a problem as long as you have a length of pull over about 13 3/4".
I own 303's and 390's. I think the 390 is a better gun because of the gas spring which can be changed to adjust bolt speed. The only way to slow down a 303 is either to use a longer recoil spring (and perhaps adjust its length) or use a stiff grease on the bolt slide grooves in receiver.
You dont know what you are talking about, I shoot my 682 Gold for doubles and my A303 Special trap 32" for singles. OU may be used for singles but I rather use my semiauto or a single barreled gun for singles.
Bill, It seems to me that I see guys having less trouble overall with the 303's then with the 390's and the 391's. If it were me I would keep my eyes open for a clean 303. I have owned all the above as I suspect you have as well and my opinion is that the 303 was a simple gun to keep going. The 391's have issues that when they crop up can be a real bugger to figiure out. I suspect you know that my answer to it all is to shoot a SX-1 but that wasn't your question. Jeff