I just bought a beretta 3901 off gun broker. Does anyone have one of these or familiar with them? I got it to use for sporting clays. Anyone know which choke system it uses, i found it says mobilchoke's. But it seems there are several different mobilechokes. Any advice or info on this shotgun would be nice too.

There is Mobil-Choke and Optima-Choke. Mobil-Choke uses standard barrel internal dimensions respective for its gauge. Optima-Choke tubes are a bit longer in length and are designed for over-bored barrels. There are also different styles of Optima-Choke tubes. Both M & O can be had in flush fitting or extended length tubes. 3901's I'm certain were Mobil-Choke only. 

 

The differences:

http://berettausa.custhelp.com/app/answers/detail/a_id/41

 

thank you for that info. Yea i think its mobilchoke only. I have never used a choke tube shotgun. I have an 1100 which doesnt have chokes. Do i get the flush mount, extended, ported ect? Also i plan on shooting cheap federal 12ga 2 3/4 #7.5 or 8. I think that ammo is lead based but not sure. Do i need one that is steel shot compatible? Or anything specific. Also do i need any special tool to screw the choke in?

thank you for that info. Yea i think its mobilchoke only. I have never used a choke tube shotgun. I have an 1100 which doesnt have chokes. Do i get the flush mount, extended, ported ect? Also i plan on shooting cheap federal 12ga 2 3/4 #7.5 or 8. I think that ammo is lead based but not sure. Do i need one that is steel shot compatible? Or anything specific. Also do i need any special tool to screw the choke in?

Mobil-Chokes are all steel compatible. Beretta sells a choke tube wrench that works well. Years ago they sold a choke tube removal tool that also had a thread chaser on the other end so you could clean the threads in the barrel. I don't see style that sold anymore. You might find one used on eBay.

 

You should be fine with flush-mounted tubes. Skeet, IC or MOD would be a good start for a skeet/clays course. MOD or IMOD or FULL for trap. After-market makers also make Mobil-Choke compatible tubes. 

 

Best choke removal tool I've used from Precision Reloading:

http://www.precisionreloading.com/mm5/merchant.mvc?Screen=PROD&Store_Code=PRE&Product_Code=RY12B&Category_Code=BCA_WRENCH

thanks that helps alot, now i can order some stuff for it, so i can take it out once i get it after the 2 week wait for nics.