View Full Version : Forcing Cone Work?

02-20-2006, 1:11 PM
Anybody had their forcing cone enlongated on thier guns? This is part of the Vang comp system(he does this and the chamber and porting) and I've seen other websites talk about it tightening up your groups. Anybody with real world experience? I've got a smooth bore 20inch barrel on my 500 so no chokes. I've found a couple gunsmiths that will do it for 60-80 bucks.



02-21-2006, 8:15 AM
Lengthening the forcing cone on a 500 is about the most dramatic mod you can do. Wholly noticeable reduction in felt recoil and in patterning. My 500 has been vang-comped and I love it.

Make sure whoever does it uses a long enough reamer. 1 3/4" taper is about right, meaning the new cone will be 1 3/4" long. Anything shorter isn't worth it.

02-21-2006, 12:23 PM
Vang is the top name in backboring and compensating. Before that it was Scattergun Technologies.

It will absolutely make your shotgun pattern better, and reduce the recoil slightly. On a tactical shotgun that you're going to use for self defense, I think it is an absolute necessity.

02-21-2006, 2:23 PM
As I noted on another forum…

“The ultimate assessment would be to test a barrel before and after being Vanged [or any other type of mod], under identical conditions, load lot, etc, ie, a very controlled comparison. The reality is that all the comparisons are with different guns shot side by side. With that being said, I’ve shot multiple shotguns Vanged and non-Vanged, side by side in various patterning sessions and drills at Gunsite. The 18.5 inch Vangs patterned much tighter than guns equipped with longer barrels/tighter chokes that intuitively should have patterned comparably, if not better. Obviously, there’s a point (shot distance) of diminishing returns, which will vary by load, etc. I was convinced enough by my first hand experience to buy a Vang 870P. No regrets. Hans is a pleasure to do business with as well.”

If you decide to have the mods done, please, please, please conduct a controlled patterning exercise before and after the mods for comparison, and post the pictures.

02-24-2006, 9:38 AM
Vang Comp's backboring is one of the best things you can do for your shotgun if you intend to use it for self defense. Highly recommended. Porting is a matter of personal preference, but definitely do the backboring.

02-24-2006, 1:46 PM
got two remmy 870 express's on the same day (father and son), identical 18". Both got specops knoxx, and only one went to vang for full bbl treatment. At the range, the vang patterns better and kicks less, and on skeet, has a much greater % of hits, side by side testing... thats my experience and im sticking to it

02-24-2006, 6:03 PM
All my shotguns have had the forcing cones lengthened. Definate improvement in pellet patterns.

02-24-2006, 6:13 PM
what do they do when they force the cone? what is it, as well as "vang"..?

02-24-2006, 6:27 PM
The forcing cones are the conical transition areas between the front of the chamber and the barrel bore. Typically they are fairly abrupt (think "countersink" angle) and cause the shot coming out of the opening shell to bunch up, raise pressure and deform. This also adds to the amount of recoil that a shooter feels. When you lengthen the forcing cones you change the angle to a much longer (about 4-5X) and much more gentle. The biggest benefit to a shotgunner is that the shot pellets deform less and thus fly truer. This translates to better patterns and also less felt recoil. The Vang patented process also backbores the barrel (increases the inner bore diameter from the end of the forcing cone until a point before the muzzle or choke if present) and ports the barrel about 5 inches back from the muzzle and extending rearward about 6 inches. The backboring further diminishes pellet deformation and reduces felt recoil. The porting reduces muzzle rise (which most shooters perceive as recoil to the cheek) by directing gasses upward and perpendicular to the bore.

02-24-2006, 6:37 PM
well i guess u learn something new everyday:). id never heard of this before, thanks!

02-24-2006, 8:34 PM
I have 3 Vang comped guns. They are worth every dime. 25 yd head shots with Fed Tactical 00 Buck are not a problem at all. The whole crew down at Vang's are great to learn from. I have lengthened forcing cones in shotguns and can tell you that the Vang product is superior to just a long cone.