View Full Version : Custom bbl work...

Dave McC
September 27, 2002, 06:31 AM
Recently I shot a round of trap with a genial soul who was trying out a new unsingle bbl that had been made by Stan Baker, whose name is spoken of in hushed tones amongst the cogniscienti. It was on a Model 32 Remington receiver, had the usual trestle rib,a few choke tubes and cost about what a decent used P/U truck does.He broke about the same number of targets as I did. He was quite happy with his new toy, and I wish him well.

Baker's Big Bore (TM) barrels are used by top trap, sporting clay and skeet shooters. Brister mentions him in his masterwork, and documents some earlier explorations by him into bbl dimensions, chokes,and loads. He also does bbl work for hunting shotguns, but few can afford the work.

Besides Baker, a lot of ink is spent on Vang, Eyster and other bbl mavens who overbore, recut, rechoke,lengthen cones and so on. None work cheap, most have great reputations and lots of highly satisfied customers. But it costs....

Baker will sell you a reworked factory bbl for your 870, 1100, Beretta auto, etc for $600-700. A Big Bore bbl made from scratch for same runs at least $1100. A new unsingle runs a coupla grand. After that,say for new bbls for your Superposed, it gets quite costly.

So how necessary is all this?

Not at all,most modern shotguns go boom on demand,throw some kind of pattern, and are capable of better results than the person manning them.

Most folks who own a shotgun with choke tubes can find an acceptably performing load for any mission by patterning with different tubes and ammo.

Let's go down the list,starting from the chamber, and show the various mods that gunsmiths offer.

Forcing Cone:

This is the funnel at the front of the chamber that directs the charge into the bore. Most of these on older shotguns run less than an inch, so do some modern ones. A popular mod is to lengthen this to as long as 5 inches to give a more gradual introduction to the bore proper.

5" is overkill, according to the two best smiths I know. One advocates less than 2", the other says that 1 3/8" is optimum with modern ammo, that way the wad enters the bore as or before it leaves the hull, thus eliminating wiggle. The benefits of lengthening the cone include SLIGHTLY lessened kick and better patterns from rounder pellets.

I doubt anyone can tell the difference in kick, but some swear by it. Price, $50 up.

A longer cone mimics a tighter choke by keeping more pellets in the pattern and not becoming flyers. When I had the cone done in Frankenstein, a few before and after patterns seemed to show the after ones had a choke one increment tighter. IOW, Skeet before gave IC patterns afterwards.

Actually,density was improved, not choke per se.


AKA Backboring, this is making the bore larger than the nominal .729 inch of American 12 gauges, or as tight as .722 for Euro guns. Supposedly, this also deforms less shot at launch and improves patterns while reducing kick.It's nothing new, about a century ago Uncle Dan Lefevre and Burt Becker were testing new chokes, bore and cones for Nash Buckingham, possibly the greatest wing shot since Fred Kimble. The Fox Heavy 12, the first 3" mag 12 gauge, was a result of this. Patterns for these Fox doubles are a revelation to those who regard new as best.

Prices on overboring seem fantastic. $150 a bbl, including polishing afterwards, is cheap.

Overboring is a bit controversial, but the few I've tried have been soft shooting. However, they have all been heavy guns, light trap loads, and I'm recoil tolerant. One less so may gain more from this mod.

Overboring also removes weight from the bbls, so the shotgun will be lighter after and also less weight forward,maybe becoming a trifle faster handling. This can be good or bad,so consider yourself forewarned.

Custom chokes:

With companies like Briley offering up to ten constrictions for every bore,one would think we could find the optimum choke for any game, range and mission. We can, but we still have to FIND the right combo.That takes patterning, and some shotgunners would seemingly rather pull out their fingernails with pliers than do this. Odd, but entirely human to want a material thing to substitute for work. Most folks "Need" only two or three constrictions for general work,but we should try out different ones with varied loads to find say,the best dove load,the best pheasant load,etc.

This means not only patterning but also keeping (GASP!)records.

It's important to know how your gun/load/choke combo does, and trying a few chokes and loads can increase your harvest,score and enjoyment.


This consists of cutting sundry holes in the bbl near the muzzle so gases can vent out.

Supposedly,this reduces recoil. This is arguable, the idea works well on high velocity magnum rifles,but its utility at shotgun velocities is questionable.

What isn't questionable is that porting makes the shot louder,since more sound is coming back to the shooter's ears.More than gases leave those ports, and some of us have been stung by ejecta from ported guns.Eye/ear protection is always mandatory when shooting, even more so when porting is involved.


Some of the most vocal advocates of custom bbl work own and use 410s in either whole guns or as tubed sets. NONE of these seem to have a long cone, overbore,or custom choke work. The discrepancy seems lost on these folks.

If any shotgun needs improved performance, it's the pipsqueak 410. A cone of proper length, a mild overbore,tested and patterned choke and trap grade hard shot in the shells would vastly improve the little rat gun for better work in the field and on the range.

Se, here are some facts,opinions,heresies, and educated guesses. Feel free to disagree, agree and discuss....

September 27, 2002, 07:54 AM
I certainly won't argue, Dave. About 15 years ago I wanted to make up a shotgun to start my son on. I bought a 20 gauge single shot NEF gun, and I shortened the stock and added a recoil pad. On the other end I was looking at a full choke. I ordered Brownell's set of adjustable reamers and a choke hone, and I used the kit to open that choke up to 0.006 constriction or about a "skeet" choke. Coupled with 3/4 oz handloads, that little gun became my son's "starter" gun. He was happy, his friends were jealous, and I had learned a new gun-tinkering skill. Since then I have opened up several fixed chokes, and I have reamed at least one choke tube to open it up. That exercise taught me that it is VERY difficult to hold a choke tube for reaming and that RemChokes are made of tough metal. The purpose of this rambling is to say that it is feasible to do at least some of your own shotgun barrel work if you want to avoid the exhorbitant prices for custom work. Be prepared to buy a barrel if you do a whole bunch, however. Sooner or later you will mess one up. I haven't yet, but I am realistic about my chances.:D


September 27, 2002, 12:34 PM
Nice compilation Dave.

Some folks can bust most (or all) of the birds most of the time with just about any gun that comes to hand.

Others have to work their tails off and use the best equipment available to get into the upper percentages.

And some would rather spend money than work on their shooting.

No magic gun. But a good gun is a must.


Dave McC
September 28, 2002, 09:56 AM
Thanks, guys....

Great project,Clem.I'm not a smith, and even having the right tools wouldn't make me comfortable with doing much bbl work. Many gun shops have on display blown bbls from someone who thought they knew what they were doing. Most of the stuff I do does not involve removing bbl metal.

Sam, we're in agreement here.

IMO,there's two groups that can benefit more than the rest of us from lower recoil and better patterns.

The first are tyros,whose form and fit isn't down yet.To make a shotgunner,the tyro has to be hitting some to build confidence, especially kids, and they have to be comfortable and not in pain.

The second are the Local Legends,the folks to whom 99X100 is simply not acceptable.

Their technique and tackle are so polished only an equipment upgrade can give them that last bird or two.

Every shotgunner can benefit from less kick and better patterns, of course.Us folks in between those extremes can be helped by some of the stuff mentioned here, but nothing can rescue a gunner from the morass of Bad Technique.