Improving Browning Invector Plus Shotgun Performance
I've owned, appreciated, and professionally evaluated Browning shotguns for quite some time. By now, that means countless A-5's, B-25s, B-2000's, Double Autos, BPS's Citori's, B-80s, Golds, Silvers and now a couple Maxus models. Added to that, there has been a couple of A-Bolt slug guns and even a 500G or two thrown in the mix, along with the Browning Recoiless. It is either countless because it is quite a pile of shotguns, or perhaps because I just can't count very well.
Invector Plus overbore style barrels have been with us for some twenty years by now. My 425s had them, and even some of my more recently purchased A-5's came with "Invector Plus" barrels and along with them, the Invector Plus choke tubes. At the time of their introduction, they were heralded as a significant improvement upon the shorter, stubbier "Winchoke" barrels and tubes that preceded them. Perception beats reality on a regular basis, but I hadn't focused on the Invector Plus choke array specifically in any detail until recently. All of my personal guns tend to wear aftermarket chokes; I've always been able to find what I'm looking for by patterning different shells and switching to aftermarket chokes tubes one way or another.
I peppered the turkey target shown above with #5 shot at a laser verified 40 yards out of a vintage Browning Gold 12 gauge with a Trulock Precision Hunter Extended choke tube. I'll happily admit that this is excessively dense to be a good wingshooting pattern and that no standard factory OEM type tube is remotely capable of such performance-- nor should it be expected. However, I believe it is reasonable to expect factory tubes to approach their own stated performance levels with extremely high quality ammunition. When factory "Full" tubes can produce no better than Improved Cylinder or Modified performance levels, even then with splotchy, uneven patterns-- it is time to quickly move on.
For a recent magazine assignment, I decided upon a simple question and an equally simple test. In the "battle" between over-bored and hard-chromed and Crio, what factory "full" choke could produce more effective, higher percentage patterns with a quality (the B & P MB Long Range) nickel-plated #5 shotshell? The answer, in this extremely focused and limited test was that a Benelli SBE-II "full" choke beat the pants off of a Maxus Invector Plus "full" choke. It answered no questions on a full or complete basis, certainly not having a sample size large enough to begin to form a conclusion, but it was interesting nevertheless. Though the thrill of spewing pellets at paper and counting the holes has long ago left me, I decided it was time for a closer, bit more extensive look.
Two Browning Golds, a Browning Cynergy, and two Browning Maxus shotguns all went to the test field for two days, along with an ample supply of posterboard. All of these guns, to Browning's credit, had been previously shown to shoot to point of aim. To say that this is not always the case these days is an understatement. The barrels were all measured with a "Precision Skeets Gun Shop" bore gauge from Brownells, an indispensable tool for this type of testing.
The Browning barrels, called ".742 in." bore diameter were surprisingly consistent, running about .741 in. as measured. The Browning Invector Plus "Full" chokes ran about .707 inch exit diameter for an actual constriction of .034 inch. Trulock Precision Hunter "Improved Modified" extended tubes that were used in all 12 gauge shotguns were .715 in. on the money for a constriction of .026 inch. All the shooting was done off of bag and cradle at 44 yards.
The results were overwhelmingly clear and pronounced. Despite having far less constriction to work with, the Trulock tubes placed 10% or more pellets on the 18 x 22 in. posterboard at 44 yards. Perhaps more importantly, the Trulock patterns universally more uniform distribution, and placed an average of 30 percent (or more) pellets into the potential kill zone of a pheasant, based on thirty-three square inches in this series of tests. This is roughly the area of a six and one half inch circle, but based on the situation the exposed area of a pheasant often varies. Head down and wings pumping, the hot zone you experience may be dramatically smaller.
This is one of the reasons that the old pattern percentage in a 30 inch circle at 40 yards can be both confusing and misleading. Cracking clays with 1 ounce of #9 shot around the skeet field hardly requires radical choking. Shots are no longer than 22 yards or so, and that 1 oz. load gives you around 579 pellets out of the muzzle. In fact, a friend of mine wasn't breaking clays particularly well in a recent session; he asked me to give his gun a try. I suggested he might have a little better luck if he screwed a choke tube into his gun's completely empty threads. True story: stranger things have happened. Pattern thinning due to range does not happen with piles of tiny pellets in a skeet situation. But, our 1-1/4 oz. load of nickel-plated #5 shot is a different animal, with 190 or so pellets to work with, and the goal was a reasonable load for pheasants to 40 yards and and a bit beyond, as a pheasant's altitude adds a little bit to the purely horizontal range.
If anyone believes at this stage of the game that the marking on a factory choke tube actually means something, they couldn't be more wrong. All the advice about "Oh, just use a modified, or just use a full choke" is absurd. Even the advice about using a specific constriction choke is of little help. The piles of posterboard here show that patterns do not at all have to be "constriction-related." Again and again, a 26 thousandths constriction Trulock Precision Hunter chokes out patterned and out-performed 34 thousandths constriction factory chokes pattern after pattern, gun after gun after gun, without a single exception.
After all this shooting, I'm inclined to suggest that Invector Plus choke tubes should be disposed of properly just as soon as possible if pattern quality at any range is of any importance to you at all. Browning Invector Plus "Full" chokes are simply not capable of true full choke performance that I have been able to produce in this series of testing.
After wading through all this, you might have the impression that this is some sort of Browning bash article. I can assure you it is not. I've bagged more birds with Browning shotguns than any other brand, though I've never segmented bird count by brand. In fact, certain Browning models have proved to be best of breed-- if you happen to read my review of the new Browning Maxus, you can see how fabulously well it fared.
There is a weak link in Browning shotguns, though, and it is with little question the Invector Plus choke tubes. To be fair, Browning is no better or worse than many other manufacturers in this regard. Firearm manufacturers long ago realized that scant few wingshooters ever pattern their guns and fewer still would pay an extra $200 a gun for high quality choke tubes. So, apparently Browning is forced to do what many other manufacturers have done: job out their choke tube work. To no great surprise, the lowest bidder gets the order. At the end of the business year, taking forty bucks out of the cost of every shotgun can really add up, meaning the difference between profit and loss or being competitive or not. All businesses go through this cycle, whether it is lawnmower blades or bolts and nuts in a home appliance, it is hard to put in additional cost and quality that no one will pay you for. The firearms industry is hardly immune from the pressure to get cost out of the box.
Nevertheless, the interaction between wingshooter and game is the pattern you place. Patterning your individual gun with the shells you intend to use at the ranges you intend to shoot at is the best thing you can do to get more birds in the bag, avoid lost game, use less shells, and to wring the best performance out of your shotgun.
I don't sell choke tubes and the Trulock tubes I choose are the Trulocks tubes I use. In this case, though, I'll make an exception. Does anybody want to buy some genuine factory Browning Invector Plus tubes? I think I can help you out in that regard.
Copyright 2009, 2012 by Randy Wakeman. All rights reserved.