I am a fairly serious sporting shooter and have been happily shooting a European model Browning B325 with the lighter 32″ barrels. Problem is, I have 9 Rhino chokes for the Invector threaded barrels, but I find that the heavy Rhinos really alter the delightful balance of the lighter barrels. I’m loathe to back bore since that will render all those Rhino$ useless, but I do shoot better with the standard factory chokes because of the improved balance. I’ve been toying with the idea of getting the largest area porting job I can find (angle porting?) and maybe even seeing if the mid rib could be ventilated– to further lighten the barrel without resorting to backboring. What do you think? How about having the barrel shortened an inch and rethreaded? Stock has a Kickeez and a thin sheet of lead under it; gun now balances just a hair in front of the hinge (with the factory chokes), and I’d hate to make the gun any heavier. The forcing cones have been lengthened by the Rhino folks (who did a fairly mediocre polishing job) but that wouldn’t change the balance much in any event.
So…would you recommend…
A) Bite the bullet: chuck the Rhinos, backbore and get new chokes or…
B) Look for weight/balance improvement by removing metal via porting/? mill mid rib or…
C) Chuck the Rhinos and just shoot factory or Briley flush chokes or…
D) Shorten and rethread the barrels keeping the Rhinos or…
E) Leave the bloody thing alone, use the Rhinos, and (as Jack Mitchell says) “You can get used to anything.”
Answer C- Chuck the Rhinos and just shoot factory chokes.
There are a lot of ways to pull weight out of barrels. They all work, but none of them work for everyone.
You can make barrels SEEM lighter by adding weight to the stock. While this can shift your balance point rearward, it really screws up the gun’s moment of inertia (the effort required to start and stop movement of the gun). Imagine a broomstick which balances in the center. Now imagine that broomstick with a brick on each end. It still balances in the center, but its moment of inertia has changed drastically. You have already added some weight to the rear, so it does not sound as though adding more would help, but you might try it just to see.
Backboring probably will not solve your problem. First of all, backboring (from Briley) costs about $300 for two barrels. Second, Briley says that they will not backbore a factory screw choked barrel because they are concerned about exposing the rear edge of the screw choke. Others, like Ken Eyster, might do this work. Finally, backboring removes weight all along the barrel. Your weight problem is located in one lump right at the muzzle. Again, it is a moment of inertia problem.
Same with ventilating the side ribs. That will be fairly expensive (requires rebluing) and not very weight reduction efficient. I have seen and shot several Belgian Brownings which had the side ribs removed (a la Remington 32/Krieghof) with just a portion of rib left at the muzzle to join the barrels. This works well, but really is more involved than you need. Point of impact often changes when side ribs are removed.
Shortening and rethreading the barrel: not such a good idea on a factory screw choke gun. I have shortened and screw choked several solid choke barrels, but not ones with factory chokes. Note that your barrels have some slight entasis (swelling) at the chokes. This permits thicker metal in the threaded part of the barrel. Cutting half of this away forces the replacement screw choke to fit half in the swollen part of the barrel and half in the standard part. Not impossible, but complicated.
Porting to reduce barrel weight: you cannot punch enough holes in your barrel to significantly reduce barrel weight.
There is really nothing wrong with the standard Browning Invector chokes. Have you spent some time patterning them? Have you had them measured? I have original Invectors on a B-80 and found them all to be about one choke more open than marked, but the patterns were perfectly adequate once this was taken into account.
Rhino chokes look neat, but all that porting does absolutely nothing to affect patterns or recoil. Any difference in recoil which a shooter thinks that he feels is caused by the extra muzzle weight. Rhinos use a plain straight taper choke with no parallel section and no muzzle flare section. This is just the same as the old invectors. The Rhino chokes are longer (no one has ever shown that long chokes work better than short ones- in spite of what you read in the magazines) and the taper continues right through the ported area up to the muzzle. This constriction in the ported area provides anything but a smooth transition through the choke.
Nigel Teague, the screw choking Rolls Royce engineer wiz in England, has installed, up until recently, exclusively short chokes and the best Brits line up to get them. Nigel recently went to long chokes, not because they were better, but because the public seemed to want them.
Browning invector chokes are cheap. If what you have does not suit you, buy a bunch a full choke tubes and have your local gunsmith grind them out until you get what you want. Or you can just order custom ground flush chokes from Briley. You can go through life quite happily with pairs of .005″, .015″ and .030″. Pitch the Rhinos or sell them to someone with a 28″ barrel.
Shotgun Report’s Technoid