Taming Recoil in a Mossberg 500 TActical Shotgun

[W.R.Buchanan]

If any of you were paying attention you heard that my M500 beat the snot out of me at Front Sight last week.

Pretty serious about correcting this problem, and so far tried various light loads and Recoil Pads.

Neither had any significant effect.

The Federal Low Recoil Slugs had slightly less recoil than regular Winchester #8 Birdshot, as did the Federal Low Recoil Buckshot. Obviously lighter loads are not the answer.

I ended the class with a Limbsaver Slip on Recoil Pad over the Magpul Pad on the stock. didn't make any noticeable difference.

I looked around and remembered Hans Vang who used to be closer to me in Santa Barbara until he moved to AZ a few years ago. His process includes reaming the forcing cone from 1/2" long at 3 degrees to nearly 3" long at a much lower angle, as well as numerous holes (31ea.) drilled on either side of the front sight, (62 total) for porting similar to Magnaporting. I can do the porting on the mill easily, but will probably just let them do it when they ream the forcing cone.

Apparently the vast majority of the Recoil Reduction is in the forcing cone which is pretty abrupt from the factory, and after having a look at my Browning Citori Trap gun which has the same type of Forcing cone and porting and is a joy to shoot, it became obvious that was what is needed to fix this gun.

Anyway more to come on this project.

Randy

[Ginsing]

Have you tried a more traditional stock design?
Does the gun fit you properly?
Adding weight will help as well

[edp2k]

Knoxx (blackhawk) makes several flavors of butt stocks which reduce recoil by having something built in
similar to an automotive shock absorber.
Under recoil the butt stock actually telescopes in/collapses somewhat and compresses a coil spring,
which of course recovers in a fraction of a second, distributing the force over a large fraction of a second
vs. the milliseconds of a solid butt stock.

the have several versions, one of which looks like a traditional shotgun butt stock
and other one or more which have pistol grips and optionally a folding wire type stock.
I believe that they are called the knoxx (blackhawk) comp stock.

here is a cutaway pic.
midway and other outlets sell them.

reviews say they work, although the different recoil impulse may take some getting used to.

http://www.gunmart.net/shooting-accessories/equipment/blackhawk-knoxx-recoil-reducing-stocks

$82
https://www.lapolicegear.com/blkncoshst.html
http://jumpthestack.blogspot.com/2009/12/blackhawk-knoxx-compstock-for-mossberg.html

[Greg S]

Get the barrel backbored by someone. Next item I would look into is how much room you have in that space age stock. I would first add some birdshot in the stock until you get an even balance point in the center between both your hands. If it is in the 10-14 oz area, look at adding a mercury recoil reducer instead of the lead shot. If I recall correctly, I'm running a 14 oz recoil reducer and 2-3 oz of #9 shot in epoxy on my skeet gun with tubes to get it to balance. More weight will change the perceived recoil.

If those two tweeks and the porting don't tame the mule, see if you can try someones Benelli M3. I shot 5 boxes of Rem express slugs and 3 boxes of 00 through one. It was like shooting an auto with dove loads.

[W.R.Buchanan]

The Vang mod is backboring. It changes the forcing cone from an abrupt step to a long taper, they also port the barrel which will help as ell..

I first thought of more weight but there isn't any room inside the Magpul Stock it is nearly solid.
The Mossberg stock the gun came with will swallow nearly 3 lbs of shot. (Tried it yesterday.)

The Space Age Magpul Stock is staying on as it solves several other problems these guns have with ergonomics. The grip portion of the stock allows you to pull the gun into you easier than a conventional stock, also it has adjustable LOP.

I have a Mercury Recoil Reducer in my Marlin 1895 .45-70 and it works a little. It is really nothing to write home about as the effects are minimal. I thought I got more out of the 15 oz of additional weight than the Mercury.

The Blackhawk stock is interesting and isn't too expensive. There is one called a Gra-coil and is used by some Recoil Sensitive Trap Shooters but I have never needed one with my trap gun. They are not cheap.

I will figure this thing out. Thanks for the ideas.

Randy

[mcdaniel.mac]

There's a removable mod for 500s (I believe called the OpSol Mini clip, but I could be misremembering) that allows you to cycle 2" and 2&1/4" shells reliably. Centurion makes the shells, or you could roll your own. I haven't loaded enough shotgun shells to know if you could down-load them effectively yourself. I find the various low-recoil buckshot options to be more than adequate, but I don't shoot more than a couple boxes in a day, max.

[725]

The knoxx stock is very forgiving in terms of recoil. Added weight applies basic physics principles. Mercury recoil or spring mounted recoil dampeners work. Some of those are fitted in the rear stock - some in the magazine tube. I have hunted with the reduced recoil slugs and still got pass through performance which dropped the deer within yards of the shot. Also, I have found the reduced recoil slugs to be more accurate than the shoulder rocking type. Good luck.

[megasupermagnum]

I don't understand, if the reduced recoil loads didn't solve your problem, a long forcing cone wont either. Are you saying the gun kicks up rather than back into your shoulder?

[SteveD]

I don't know what they teach at Front Sight, but look up a class by Rob Haught. He teaches a method that works, regardless of equipment.

[W.R.Buchanan]

This gun was brutal with normal #8 birdshot which are the lightest loads on the market. I reload Shotshells and my normal trap loads still smack me pretty hard in this gun.

The forcing cone on this gun is about 1/2" long it is an abrupt step in the barrel in front of the chamber. Back boring opens this up to a 3" Gradual Transition which smooths out the recoil impulse over a longer period of time.

The gun kicks both up and back. The porting will stop the up part. The back boring will reduce the back part.

I can't really see any reason for full house slugs. There is nothing that will live thru a low recoil 1 oz slug at 1300 fps. That is a .45-70 with a larger frontal area.

For the purposes of this gun low recoil slugs and Buckshot will be the norm. I will load them myself to make sure they are as light as they can be.

For 3 gun shooting you don't need anything stronger than enough to break clay targets at 10-15 yards which doesn't take much. Anymore is just a waste.

You could shoot a 1 oz ball at steel targets with a slingshot and score points. Nobody is looking at the force of the hit on steel

Randy

[Lagamor]

Really interested in hearing how the back boring will affect recoil. I know the porting will make it much louder, but I'm not sure if it will affect perceived recoil. I'm not knowledgeable enough to Know for sure, but it seems to me that the payload has moved almost the entire length of the barrel, so it doesn't make sense to me that it would reduce recoil much. But what do I know, I'm just a dumb hick.

[megasupermagnum]

I don't think a lengthened forcing cone will affect the recoil too much. The porting will reduce muzzle rise, meaning it wont slap you in the face as much. I really don't see how this thing could kick that bad. This gun should be in the ballpark of 7 pounds. I've shot plenty of single shot guns that are 5-6 pounds, and a target load is still pleasant to shoot. I have a mossberg 500 with a 18.5" barrel, and standard hogue stock. Even 1 1/4 oz field loads are not what I would call brutal. I don't shoot 3 gun (or any competition), but after a couple rounds of trap with said field loads, I feel just fine. I'd swap out that magpul before anything. The standard stock fits me just fine, and I'm not sure what you mean by pulling the gun into you. I'd hazard a guess you shoot in a more "combative" style, while I am entirely a wingshooter.

[Cap'n Morgan]

Back boring and lengthening the cone will only reduce recoil by reducing velocity - Newton's second law cannot be circumvented.

Often when a shotgun "smacks" you, the stock is too short and have too much drop, causing the gun to jump upwards, and banging the back of one's thump against one's nose and upper lip - this gets tedious really fast!

I notice the gun has slug sights. If the sights are too low, and you must force your cheek into the stock to get the correct sight picture, the gun will hurt you! That's why an aimed shot often seems to kick harder than a snapshot at a fast flying duck; when aiming a shotgun most people will try to look straight along the rib instead of looking slightly above it as when wingshooting.

[W.R.Buchanan]

Mega: the difference in shooting is the number of shots fired in a short amount of time.

In Trap you are on the line with 4 others and each shoots his target in a round robin type order, one shot about every 2-3 minutes.

In a tactical class or 3 gun shoot you are shooting 25-30 rounds as fast as you can run the gun. Then you won't shoot again for a while.

The target I put up on the other thread had three shots in the head at 50 yards in 10 seconds off hand. Obviously mounting the gun the same way everytime is critical to recoil control, but when shooting multiple rounds in short order that gets overlooked more and more as the string progresses.

If I was only shooting this gun once or twice and then resting it would be a different story. On the first iteration of this class I shot a whole box in less than 10 minutes. That's what I am up against.

Randy

[rking22]

Biggest contributor to recoil difficulties is gun fit, you may like that stock but it doesn't fit you like it should. Thats assuming a typical weight shotgun. Now I'm a wing shooter but also compete and coach. When we run clinics a box in 10 minutes is off pace and we will run 10 to 15 boxes in a short day and 25 is not unknow. If the gun fits the shooter there is no issue and these are 7.5 lb 12 ga over unders. Note we also do not teach pulling the gun into the shoulder, rather the shoulder to the gun held firmly balanced in both hands. This lets the muscles handle recoil not the bones and tendons. Most targets are fast true pairs, so control and fluid motion is a must. Just my experience, but I would try a factory 870 or gas auto, I never shot a Mossberg that didn't kick harder than it should!

[W.R.Buchanan]

Here's and article that explains the barrels mods and shows what they do.

https://rifleshooter.com/2012/07/tactical-shotgun-barrel-improved-back-boring-a-barrel-and-lengthening-a-forcing-cone-to-increase-performance/

Randy

[Hogtamer]

Is a 20 ga out of the question?

[Ginsing]

To tell you the truth I havnt noticed any difference in recoil between my back bored winchester and my other shotguns of similar weight. If there is any reduction it isn't enough to notice. I havnt noticed any increase in performance with it either. Though I don't spend much time patterning birdshot. I did notice it gives slightly more uniform patterns with buckshot but only buck loaded without a shotcup. 9 pellet 00 buck loaded in stacks of 3 was more uniform with less pellets clustering in groups.
I'm not sure if it really will give you the recoil reduction you are looking for.
Might I suggest you trade for a different shotgun before spending extra money on something that may have a negligible difference in recoil.

[edp2k]

Myself I stay far, far away from porting in rifles, pistols, and shotguns.

It definitely makes the gun louder and increases the concussion your body and head are exposed to.
After a few shots I find that I have a headache growing, which decreases my fun factor and shooting performance.

Ports spit out particles and very high pressure gas.
In the event you are not wearing shooting glasses (or even if you are)
the particles from the ports or particles blasted off a close tree/bush in the field or plywood/2x4 in a competition stage
can get in your eyes and around your glasses (either directly or by ricochet) and blind you or at least disturb your vision
and your performance.

Even particles impacting on my face/head/neck would cause me to lose focus on the next shot or several.
That could mean life or death or at least missed game or a lower score.

A body part exposed to the ports while firing is going to cause huge trouble.
If the gun is being used for defensive purposes you never know what kind of wrestling you will have to do
or what position you are in when the gun goes off.

All this and my experience has shown that it doesn't really mitigate the recoil impulse much.
The added concussion may actually increase the perceived recoil.

Of course you can make your own decision on porting, however mine was definitely made long ago,
and its downside does not outweigh any possible upside for me.

[edp2k]

http://www.kick-killer-recoil-pads.com/
$35 lace up or velcro

HP White test results
http://www.akton.com/documents/HP_White_Shock_Absorbing_Test.pdf

[W.R.Buchanan]

rking: My Citori XT doesn't bother me to shoot 200-250 rounds in a day with only a tee shirt on. It is back bored and ported from the factory and the vast majority of Trap and Skeet guns are as well and have been for the last 25-30 years. Most Factory made O/U's are as well as it is just the way they make the barrels now.

It costs more to do the extra Machining to the barrels so those guns cost more. mY XT was $2000. A M500 is an inexpensive Shotgun, and the vast majority are sold in some kind of Tactical Configuration. There is even on Combo where you get a 28" Sporting barrel and a 18"short barrel so you can have both worlds covered. I think that gun sells for about $350 ish.

My Father in law gave me this gun about 25 years ago. It was unfired and he bought it at Big 5 for $205. I bought the 20" barrel and Magazine tube from Brownell's for $116 and the Magpul furniture came a few years ago for @$100. So I've got about $250 in this gun.

I have used this gun a lot in local 3 gun shoots which might have 10 Shotgun targets in a string so I never experienced the same recoil issues I did in the Tac Shotgun Class where I fired 20 shots in a few minutes every time we came to the line. The cumulative effect of that much shooting in a short period of time is what has gotten to me. The gun fits OK and I will refine that as I go along. I have also reworked the inside of the action so the gun cycles like it has had 1000's of rounds thru it. It runs pretty nice.

There is a lot of back and forth as to the effects of Back Boring but the general consensus is that it makes the guns recoil impulse much smoother as opposed to the abrupt hit without the treatment. It also dramatically improves patterns. My gun shoots 00 buck at about 12-15" at 15 yards. Hans Vang Guarantees 7" at 25 yards and all the tests I have read over the last few days have confirmed that. He also has done thousands of these mods and people wouldn't pay for it if it didn't work.

AS far as porting I have lived with it on my Citori for 10 years and the only problem is cleaning the plastic from the wads out of the holes. the holes tend to work like a cheese grater. A Bronze Brush on an Electric drill solved that problem. The more you shoot the gun the less that occurs as the holes get chamfered on the inside more and more as the gun is shot.

The reason why I want to fix this gun is because Mossberg's are the Defensive Pump Gun. They are easier to run and don't malfunction as much. I'm sure the Rem 870 crowd with object, but all I saw in my class was people fumbling with their 870's. I had no problems adapting to the drills quickly because I was not fighting the gun.

One main issue is that the ejection port is smaller than the Mberg. This slows down the Port Loading of single rounds, and also complicates unloading and clearing of stove pipes and type 3's. The lifter on an 870 has a fence on the right side which gets in the way when trying to unload the gun or clear a type 3 (failure to extract) malfunction. The Mbergs don't have this problem.

I have some more work to do on this gun to get it where I want it. When done I will be able to shoot it like I need to. I have an old Browning A5 I want to "Tacticalize" as well. That will be easier now that I know what I am going to be doing with it

Under 100 yards Shotguns are devastating weapons. They have the ability to launch many different payloads from Non Lethal little Missiles to Slugs that are powerful enough to take down anything in N/A. It is fun to play with them, and I enjoy it.

More guns not less! :Fire:

And NO 20ga. is not an option!

Randy

[fecmech]

I think your A5 would be the better option. The long recoil of the gun can be tuned to the loads shot so that the recoil is spread out over the cycling of the action. Most people think A5's are hard kickers but they are not when the friction rings are correctly set and the amount of lube on the mag tube is just enough for proper function. I've shot an A5 20 ga for 50 yrs in skeet and sporting clays and there is not a more reliable or softer shooting auto when set up correctly. I recently picked up a Remington Model 11 (A5) in 12 ga that mimics my 20 for soft (12 ga) recoil and reliability. Beretta 390's are super reliable and fairly soft shooting. I kept track of the first 50k rounds through mine and found it would run trouble free (no FTE or FTF) for 2K+ rounds between cleanings.

[W.R.Buchanan]

I actually have 2 A5's. My cherished 1964 Light 12 that my uncle gave me which has been kept in it's case for it's entire life with Full and Modified barrels. It is in 99% condition with only a few belt buckle marks on the stock from him walking around in the weeds with it. He fired exactly 22 rounds thru it in the 30 years he owned it, and gave me the 3 remaining rounds of Remington #6's with the gun.. I fired 4 boxes thru it the first day I shot it at a Dove shoot in Santa Paula CA.

If you shoot with both eyes open, seeing the barrel coming back at you on the first few shots is a truly enlightening experience. Whoa!

The other gun is a 1950 model I got at the local Hardware store with the sole intent of making a Fighting Gun out of it. It has some problems that need to be fixed like it doesn't hold the bolt open after the last shot which is annoying. I have the replacement parts just never got around to fixing it.

I also saw a Rem 1100 yesterday that had a 14" barrel, and the gun was the handiest shotgun I have ever handled. It belongs to a Cop friend and it was registered as a Short Barreled Shotgun. The barrel on that gun had the Hans Vang Treatment 20 years ago before Hans moved to AZ from Santa Barbara CA.. It was his Patrol Gun for many years before he retired.

Lots of things to look at with these guns.

Randy

[edp2k]

If the "gun was brutal with normal #8 birdshot which are the lightest loads on the market",
I think gun fit is a huge contributor here.

I had a rifle which kicked and, after I thought about it, a large component was cheek slap.
Brownells sells an adhesive backed sorbathane pad in various thicknesses that you peel and stick
to the cheekpiece on the stock. It eliminated the cheek slap for me.

Possibly the fit, angle, and height of the magpul stock is an un-optimal fit for you and makes you
contort your body is such a way as to make the recoil be harder.

I am not an avid shotgunner, however I have read a few very good articles on stock fit and its
impact on felt recoil and shotgunning performance, and its clear to me that it makes a significant difference.

[DougGuy]

I have the same Mossy 500A combat shotgun with a 20" pro ported cylinder bore barrel. I have never looked at the forcing cone so it's whatever they did at the factory.

The pro porting will allow me and others who shoot this gun rapid fire, to keep the muzzle flip to below 1" and it basically stays on target as fast as you can fire it. The heavier the loads, the more reduction in muzzle flip from the ports so it is more or less self compensating from load to load. Police officers who fired it on the range with department reloads of #4 buck were very impressed and very pleased with the acquisition of the target on follow up shots.


If the "gun was brutal with normal #8 birdshot which are the lightest loads on the market",
I think gun fit is a huge contributor here.

I should mention also that the butt stock has been shortened 3/4" and the factory rubber recoil pad is retained, although considerably rounded at the top to facilitate rapid mounting in cases where a jacket or other heavy clothing might hinder the upward movement of the butt toward the shoulder. The officers who fired this gun very much liked that butt stock modification as well.

That said, I would NOT recommend porting for a home defense shotgun because the shooter is not safe carrying the gun at hip level with the stock hanging past his/her backside in an effort to shorten the amount of barrel that protrudes from the front, (which gives the bad guy a convenient handle to grab in the disarmament move). The blast from the port would put powder particles and other debris in a stream directed at the shooter's face and eyes. Porting is ONLY beneficial when the shotgun is mounted and fired from the shoulder or full length forward fired from the hip.

Several full power strings of fire with a full 8rd magazine would not be too much of an issue with high brass loads. 200 rounds, yes probably so. I don't intend on firing for very long inside my house, one or more of us is going down before the mag is empty, so for my purposes I will just live with what I have and hope nobody ever causes the worst case scenario.

[Bigslug]

While having Hans do your barrel is well worth it for the patterning, I'm thinking that it might not help you out so much with recoil. . .Maybe. . .

The low-recoil tactical loads are well inside my personal tolerance level, so consider where this is coming from, but I can't really tell any difference with the Vang Comp ports shooting those. For me, the "shoot it all day" load is still a shoot it all day load.

Now when you start loading the magnum, 1600 fps stuff, I start to notice the change, and I think it's largely because the more gas you put through the ports, the more effect they have. . .but you're still dealing with a magnum load, and it's still not something you'll want to burn a case of per sitting.

I think fiddling with stock geometry, mercury capsules, and more onboard weight will give you better mileage. Some folks like 'em, but I personally can't abide the Knoxx stocks - too many years of shooting guns without bouncy parts; they extra motion they bring is distracting. . .REALLY distracting.

[W.R.Buchanan]

Doug: thanks for the input. I have been playing with the stock fit on this gun and EDP: thanks for the heads up on the stick on Sorbothane from Brownell's. I was wondering where that stuff came from. I will get some. Might have to get another check piece for the stock at the same time. They are cheap.

Watched a video on Youtube from the Magpul Shooting School that was given by Chris Costas and Travis Haley. Most all of the shotguns in that class had Vang Comp Barrels, and most were LEO Rem 870's.

Lots of good info on gun handling in that video but somehow Youtube screwed it up and it ends at 18:56. It is over an hour long. The Magpul Videos on Carbines and Pistols are also excellent instructional videos on Dynamic force application and really give you some things you can practice that will make your shooting better.

Youtube is free! so go find them, and there is plenty of info there on this subject.

Going to shoot the gun again tomorrow and then send my barrel off to Hans later this week. Will let you know how much difference it makes to this gun.

Randy

[W.R.Buchanan]

Shot the gun again yesterday and it was better. Might be getting used to it a little more. Had no problem with my Trap Loads or my Pumpkin Balls as both are the same Velocity @1100 fps. was able to hit Silhouette Chickens at 50M easily off hand and Pigs at 100M about 2/5. once again offhand.

Ran into some more issues that are being corrected today.
1. Pic rail on bottom of Fore End to mount Light/Laser has to go somewhere else. It was punishing my support hand index finger shot after shot.

2. My sling arraignment is not going to work as done. The rear mounting for it doesn't allow for me to get the buttstock under my arm so I can have the muzzle up for reloading. Thus the muzzle is down which complicates the process.

Tonight I will be fiddling with it more and I got the Magpul Sling mount that places the loop between the front of the stock and the receiver. Then the rear of the sling will move there and I will have the option of moving the front of the sling to that place also or removing the sling quickly if desired. Even in the sling there is plenty of room to get the butt under my armpit, so I can load with the muzzle up which is much easier.

There is a lot to getting a gun like this sussed out, and the reasons are not fully understanding how the gun was to be used. I can do a Carbine or a Glock in an hour. Once I get the Shotgun figured out, the setup on other guns will go faster as well.

Having a good time getting this sussed out. 3 gun shoot in Santa Barbara this weekend.

Randy

[RMc]

Low recoil Federal Flite-Control buckshot loads like these have put cylinder bore and tight patterns in the same sentence!

https://www.gtdist.com/products/guns-firearms/federal-12ga-5-bx-00-buck-8-plts-2-3-4.html

https://www.gtdist.com/products/guns-firearms/federal-12ga-5-bx-tac-1-buck-15-plts-2-3-4.html

[W.R.Buchanan]

Set up the sling with the Magpul Piece parts and it works great. I can have single point, or two point attachment, or get rid of the sling all together in seconds.

Still need a sheet of 3/16" 30 Duro Sorbothane with adhesive backing to cover the comb of the stock. Nobody is giving that stuff away!

After that am looking at buying the Forcing Cone Reamer from Brownell's as it appears I have several other guns to do this to also. I can do that in my shop.

The porting is no problem and can be done on the mill easily.

Here's some pics of the slings mods.

1. Sling in two point
2. Sling in single point
3. Front sling mount
4. Brown Coat Tactical Velcro Side Saddle and for $15 these are definitely the ship! I got 3 of them and all you do is rip the empty one off the side of the gun and slap a full one on. Works great! Adhesive Backed Velcro stuck to the receiver, no permanent mod to the gun. You carry the full ones in a regular carbine mag pouch.

It's these little additions and tweaks that make the gun work right. All you have to do is practice with it enough to find the weak points.

Randy

[W.R.Buchanan]

Managed to pick up another older Mossberg 500A today at the Local Hardware store. Nice "lightly used" condition. $160! Needs to be taken apart and cleaned!

It is a Field Gun that spent most of it's life in a closet. It has Wooden Furniture and a 30" Vent Ribbed Barrel, I don't know what the choke is, and don't really care as the barrel will get cut off to 18" or possibly shorter if I can find a way to legally do it.

Another quick project and this gun will be the stay at home SD Gun.

Took me exactly 4 days to find this gun, started looking for one last Wednesday!

Needless to say they are laying around everywhere just waiting for a new owner to come along and put them to use.

Randy

[dverna]

Hate to say this....but lengthening the forcing cone does nothing to reduce recoil. Just a great way for a gunsmith to make money. BTW, this does not imply those offering the service are crooks...most believe it to be a fact.

If you think about the physics of it, it becomes apparent.

Lengthening the forcing cone will usually improve patterns and that is why it has a place in reworking shotgun barrels

There was an excellent thread about this on Trapshooters.com many years ago. It got heated. So I am not going to debate it here.

BTW I had tge forcing cones on my CAS ported before I became educated. Wasted a bunch of money.

Reducing recoil can be accomplished by adding weight, adding cushioning, lowering payload, lowering velocity, adjusting pitch, and making the stock fit you.

[centershot]

Reducing recoil can be accomplished by adding weight, adding cushioning, lowering payload, lowering velocity, adjusting pitch, and making the stock fit you.

THIS! Exactly! As in the use of cast boolits, fit is king!

[W.R.Buchanan]

Don: the physics are fixed and I realize that, and you have more experience behind a shotgun that most people here at this site.

The point of the Forcing Cone Extension is to lessen the abruptness of the Recoil Impulse as it will be spread out over a longer period of time, so the "Perceived Recoil" will be less. How much this shows up is to be determined.

Also the muzzle rise on this gun is excessive and the Porting will reduce that. That is what is causing the gun to smack me in the cheek.

I have a pretty good idea of how this gun acts right now. The only thing left to do to the fit is to refine it a little more,(ie: play with length of pull) and I am waiting for Limbsaver Recoil Pads that directly fit the Rem 870 plastic stock to become available again, as nobody has them in stock including Limbsaver..

My Citori XT is a cream puff to shoot and I can run 250 rounds thru it in one day with no adverse effects whatsoever. It has a long forcing cone and porting so there must be something to be gained by it or Browning wouldn't do it.

I am experimenting with this gun as it is cheap to work on. I can do both the porting and forcing cone in my shop and only need the reamer to do it.

I will post all my findings here for everyone to read and they can make their own decisions based on how much of my BS they believe.

Randy

[fecmech]

Randy--The porting will buy you a small amount of recoil reduction, not very much. I proved it to myself years ago with my A5 20 ga. I set it up A5's so the just function reliably by use of the friction ring placement and amount of lube on the magazine tube. I want the gun to absorb as much recoil and function reliably as it can. Before sending my barrel off to Proport some years ago I fired a number of shots behind my house and noted where the shells ejected to. I set the remaining shells in the box aside for when the barrel returned. Upon receipt of the barrel I took the gun out and tried the ported barrel. The gun would not recoil far enough to eject the shells with the ported barrel and required I change the friction ring setting to light loads. As you know the A5's are strictly recoil operated so AFAIC porting does do some reduction of recoil but not a lot. I would not pay to have it done on another gun. In your case with your abilities it will help a bit. Forcing cones IMO are strictly a pattern thing and questionable at that. Good luck in your quest.

[Cap'n Morgan]

Don't want to come across as an all-knowing, lecturing jerk, but...:

If lengthening the forcing cone (and back-boring) reduces recoil, it's because it reduces muzzle velocity as well. If anything, increased friction between the payload and the forcing cone could actually recuce recoil as it would "pull" the barrel in a forward direction.

Porting the barrel will work, but only to a small extent in a shotgun as porting works by redirecting the high pressure gasses behind the payload - payload being the weight of both powder and bullet(or shot, wad and powder).

In a typical rifle cartridge the weight of powder can be anywhere from ten to fifty percent of the bullet weight. Combined with the high pressure/velocity it makes up for a substantial part of the recoil. In a typical shotgun load of 550 grain, the powder weight is only about three to four percent of the payload, and the working pressure is only a fifth of the rifle's. By porting the top side of the barrel you no doubt will reduce muzzle flip, but the actual recoil reducing is to small to be felt in any meaningful way.

I'm going to keep my big trap shut now...;)

[edp2k]

A Remington SuperCell recoil pad is much more effective than a Limbsaver.
Do a little googling.
It also happens to be much cheaper, ~$18 vs. ~$35 :)

Since you have the magpull stock on your mossberg, a Remington SuperCell for a plastic stocked 870 should fit.

The Cheek-Ezz Sorbothane 3/16" thick stick on cheekpad (by Kick-Ezz) did wonders for eliminating
the cheek slap on a favorite, hard kicking rifle I had.
As I mentioned before, Brownells :)

[rking22]

Sometime late 90s early2000, Ballistic Specialities built a Beretta 391 to be the softest shooting gun possiable. There was an article in ,probably, Shotgun Sports documenting the build and effects of the various changes.
In 1995 I spend 300$ to back bore,port and extend forcing cones on a 26 inch 870 barrel for sporting clays. I did the work for better patterns not recoil. As far as I can tell there was negotiable effect to the patterning or recoil reduction. I shoot an 870 all the time by preference and have settled on a 28 fixed mod for sporting and trap. I use a 26 fixed skeet for both skeet games. The fancied barrel vs the skeet barrel show no difference in recoil with AA super handicap loads or 7/8 international loadd, I just can't tell any difference, side by side on the same gun. I did this last week due to discussions on this thread. Any patterning difference is on detectable on target breaks, I ain't counting holes in paper. The fixed barrels are from 1966 and 1970, un altered in any way. Gun is the 1966 Skeet C with the original factory pad.
The fancy barrel goes turkey hunting, it's my only 3 inch barrel.
There have been some ought right fights over this issue , I stay out of it generally.
Randy, I know you can do your own work and want to see for yourself. Totally understand that. It is the only way for you to be sure. I posted the above for anyone reading this thread. Also test was a blind as possiable, five stand with my son swapping the barrels randomly and I tried not to know. 50 birds with 2 extremes in ammo. Subjective but best I could think of without instrumentation. I'm an engineer, so I know the test is not difinitive, but we're looking for noticeable to a human.

[dverna]

Don: the physics are fixed and I realize that, and you have more experience behind a shotgun that most people here at this site.

The point of the Forcing Cone Extension is to lessen the abruptness of the Recoil Impulse as it will be spread out over a longer period of time, so the "Perceived Recoil" will be less. How much this shows up is to be determined.


Randy

Randy,

Look at Capt's post.

Think about this way. Say you had a really severely abrupt forcing cone than significantly constricted the bore. All those pellets are forced together and jammed up trying to get out. Now we know the gun would likely blow up. But the Impact of those pellets reaching the constriction will force the gun forward, reducing recoil.

As to your other comment about why Browning does it. First, it may improve patterns with some wads. Most importantly it is marketing. People think it is something that works, and most will never know any different. The placebo effect is a proven fact. If someone thinks it is better...it is better.

[W.R.Buchanan]

Does anyone have a method, other than "seat of the pants," whereby I can produce a meaningful test to show what the before and after results are in this experiment ???

With some empirical numbers it would put this to rest once and for all.

"If anything, increased friction between the payload and the forcing cone could actually reduce recoil as it would "pull" the barrel in a forward direction."

I have to disagree with this.

If the payload had any significant momentum when it hit the forcing cone, and was moving on its own without being pushed forward by a charge that is producing an opposite reaction, I could understand how this might be happening. However since the forcing cone is directly in front of the chamber, and is a rather abrupt step, the actual effect would be that of simply shoving the payload into a smaller hole which would increase movement in the opposite direction (ie: to the rear).

In this case also I could see the longer forcing cone actually working like the Captain suggests. The pressure required to introduce the payload into the longer forcing cone with a more gradual constriction would be less, thus less recoil, as well as pushing forward on the barrel at the same time. Also the time from ignition to full pressure would be longer and thus a longer smoother recoil pulse would be generated,, as opposed to a shorter sharper pulse.

In the end the amount of recoil generated would be the same overall however the amount of time that it took to accomplish it would be longer and thus "Perceived Recoil" would be lower.

I cite the difference in recoil impulses of a 300 WM versus a .45-70. the 300 is short and really fast. the .45-70 is a longer slower push. Compare a 150 gr bullet at 3000 fps to a 300 gr boolit at 1500 fps. the amount of work being done is the same however the time it takes to happen is considerably quicker with the 300WM thus the recoil impulse is quicker and more abrupt. Also why I don't own one! However I do own a .45-70 and routinely shoot 325 gr boolits at 15-1600fps with no adverse effects. A considerable difference in "perceived recoil" between the two.

Does any of this make sense?

Randy

.

[dverna]

Randy,

It may be helpful if you reached out to Neil Winston on trapshooters.com. Neil has done a lot of testing to dispel may of the old wives tales surrounding shotgun loads and shooting. Another resource would be Dr A C Jones, who also used to post on the same forum. Not sure if they are still regulars there but they are great resources and very strong technically.

Good luck!

[W.R.Buchanan]

got the other gun yesterday and tore it apart and cleaned everything up so it runs real smooth now. I also installed the 18" bbl and Mag tube and plastic furniture I had from my previous gun.

The gun came with a 28" removable choke barrel with a vent rib. Unfortunately it has a lot of rust under the rib which is not going to be easy to remove without destroying the bluing. The wood furniture is all stained Birch or Beech wood, and has been relegated to the parts box.

I still have to change out the safety and mount some decent sights on the gun. But it is my HD gun now and it won't really be going anywhere away from home. Might just put a green dot bead on the front and be done with it.

[W.R.Buchanan]

After playing with the newer gun for a while I ordered a XS Big Dot Tritium Front Sight and the same Aftermarket Safety with the raised center for the gun that I have on the other gun.

The Stock Safety on the Mossberg's is pretty hard to disengage until you've ran it a thousand or so times. I deburr everything when installing the new ones and they run real nice after. They are also much easier to get onto with the raised center rib. well worth the $17.

The XS Front Sight actually Glues over the top of the bead. They even give you a new bead that fits the sight exactly so it isn't cockeyed when the glue dries. Since the Glue of choice is JB Weld it is a good idea to have the thing where you want it before the glue goes off.

Still waiting for the Sight to come but I will post pics of it installed when it gets here.

Randy

[pashiner]

i had the same issue in a stevens 320 with a hollow plastic stock. the gun was way too light, and the balance much too far foreward. i made a cheap modification that involved stuffing a half dozen 1" steel balls into the stock packed into a wad of rubber bands. I know the weight and balance helped a lot, but the recoil reduction was drastic! my thinking is that the rubber bands allowed the steel balls to shift forward on recoil, and slam back against the butt plate a millisecond later, effectively lengthening the recoil impulse. it cost me nothing, because i had the stuff lying around in the shop, so needless to say i'm tickled pink with the results. If you can rig up something similar, give it a try. I have no doubt that the spring loaded weight style aftermarket stocks work on the same principle.

[W.R.Buchanan]

Got all the parts and installed them last night.

The Sight went on very nicely, and the Safety was a bit of a PITB to get back together but not too hard. I deburred all the parts on a felt wheel and the safety runs real smooth now.

Also installed a Brown Coat Tactical Velcro Side Saddle. The gun is done except for mounting a light and patterning/sighting in.

All in all it went pretty good now that I know what I want. As stated before this is a strictly HD gun so it is likely done.

Randy

[W.R.Buchanan]

Sent my 20" barrel to Hans Vang for the back boring and porting work last week. Should be back in a few days and then we'll know if there is any difference in the recoil impulse.

My Bro in Law sent his also and we got a bang up deal on two at a time.

Randy

[AllanD]

a 30" vent-ribbed barrel is most likely a "full" choke.

As a Mossberg 500 was my first shotgun I found that the best way to manage recoil was first a "slip on recoil" pad and second switching to a Remington 870.

But my Mossberg and I eventually came to terms it was partially a matter of stock fit and partially a matter of how I held it.

My Remington wears a (high comb) "trap" butt-stock with an adjustable Morgan Butt plate, so the Remington was more a case of modifying it to fit me rather than fitting myself to the shotgun.

But in either case the worst shotgun I ever fired was a Winchester model 1300 About the third time I fired it I wanted to wrap it around a fence pole, the stock shape was such that on recoil the backside of your thumb was driven back into the tip of your
nose. the third time this happens you want to smash it. AND that was with commercially loaded light "trap loads"

My friend (who owned it) never developed the insanity to try firing a slug from that shotgun and neither did I.



Managed to pick up another older Mossberg 500A today at the Local Hardware store. Nice "lightly used" condition. $160! Needs to be taken apart and cleaned!

It is a Field Gun that spent most of it's life in a closet. It has Wooden Furniture and a 30" Vent Ribbed Barrel, I don't know what the choke is, and don't really care as the barrel will get cut off to 18" or possibly shorter if I can find a way to legally do it.

Another quick project and this gun will be the stay at home SD Gun.

Took me exactly 4 days to find this gun, started looking for one last Wednesday!

Needless to say they are laying around everywhere just waiting for a new owner to come along and put them to use.

Randy

My advise to you vis-a-vie cutting the barrel? don't. INSTEAD buy another shorter one. you may eventually find a need for a long "waterfowl barrel" and should that day come you'll find that the long barrels are somewhat more expensive. And as a general rule it is a lot easier to cut off barrel than it is to add onto one..

Or you can buy a rifled slug barrel for it.

[W.R.Buchanan]

Allen: did you see the pics in post #45? That is how the gun looks now. It got the 18" barrel and mag tube off my other gun and is now my HD gun.

The vent ribbed barrel turned out to be 28" with Choke tubes.

The 20" barrel for my other gun is in Prescott AZ getting back bored. Should be back this week.

Unfortunately both fo my gun clubs are closed due to the fires and flooding. Our fire created a big mess that will take along time to clean up. The floods you saw on TV in Santa Barbara have the 101 north and south shut down for weeks. No way to get into Santa Barbara other than driving to Bakersfield then to Santa Maria and then to SB 5 Hours instead of the usual 35 minutes.

To top it off,,, it's 85F here today and dry as punk. It rained 7" here last Tuesday! Nothing more on the horizon?

Randy

[Bzcraig]

Interesting thread! The only thing I can contribute is; using the same gun and not enjoying the recoil of full power slug/buck loads, I purchased a Knoxx stock, really bad design. The first round I fired, I shouldered as usual, pulled the trigger and the as the two pieces of the stock closed under recoil it grabbed a piece of my cheek and cut me. Sent the whole gun down the road.

[RED BEAR]

Must say no expert but this sounds like snake oil to me. Own 2 mossburg 500s and both are pleasure to shoot. Both have wooden stocks, one came with plastic stock picked up used wood one really cheap. Knew a fellow who thought it would be good idea to port most of barrel. Must admit it was a pleasure to shoot would not penetrate partical board at 25 yards but was a pleasure to shoot. Would like to know what backboreing does to vel. As I said I am by no means any kind of expert. Please let us know how it goes.

[W.R.Buchanan]

Bear: Back Boring reduces the friction on the outside of the wad by increasing the bore diameter. The back end of the wad still seals the charge just as well as before so velocity increases slightly.

Also as far as your wood stocked ones being a joy to shoot? How many times have you fired a whole box of shells in less than 5 minutes? That's where all this beating shows up. It is very hard to maintain your form when firing shot after shot as fast as you can work the action and get back on target.

The porting helps with muzzle rise by virtually eliminating it. Also the recoil becomes a strait line push instead of a muzzle rising punch which loosens your cheek weld and makes the gun slap you in the cheek. This gets old real fast.

The other big benefit is in the patterning. My gun shot 00 buck into a 12-15" pattern at 15 yards. Vang guarantees 7" at 25 yards, and all reviews (literally hundreds) confirm this.

I am waiting right now for the mailman to get here with my barrel so I can put the gun back together. I won't get to shoot it for some time as our ranges are all closed due to the Fires and Mudslides you saw on TV. I will report back with my impressions after I get to shoot it.

Randy

[W.R.Buchanan]

Mailman came and dropped off our barrels. The machine work looks good.

You can easily see the forcing cone extended and the whole interior of the barrel has been polished.

Here's some pics of the finished gun. Still has to be sighted in, and I need a new Front Sight Insert.

One thing I noticed between my two guns is that the one with the Magpul Furniture runs a lot smoother than the one without. Come to find out that the Magpul Fore End has a guide built into it that prevents the fore end from racking side to side which binds up the action bars in the receiver. No matter how I tried I still twisted the fore end a little when racking the slide and that is all the difference in the world as to how smooth the gun runs.

Randy

[RED BEAR]

Mr Buchanan can't say for sure if I shot a box in 5 min. But have shot 400 to 500 per outing. Now as far as it increasing vel. Is this just antidotal or has any one actually checked the vel. And if this is such a wonder treatment then why don't manufactures doing it . would be no problem to make bore larger during manufacture. I will agree that porting does help with perceived recoil but does nothing for actual recoil . that is physics x bullet weight and y vel weight of gun = recoil! Just as adjusting the stock can make recoil feel less even though it is the same. I do own a few guns that will mule kick you the moss 500 just ain't one of them. If .015 over bore does such a great job why not .030 over the gas seal part of the wad would surely still seal the bore.
As I said originally I am not an expert but still sounds like snake oil to me. If there is any testing to prove the increased vel I would be more than happy to admit I am wrong. And I don't mean they said I mean actual ballistic data. Preferably not from the ones doing the back boring. I will admit I am not always right but I prefer proof to a lot of these claims.

[W.R.Buchanan]

And if this is such a wonder treatment then why don't manufactures doing it . would be no problem to make bore larger during manufacture. I will agree that porting does help with perceived recoil but does nothing for actual recoil .

As I said originally I am not an expert but still sounds like snake oil to me. If there is any testing to prove the increased vel I would be more than happy to admit I am wrong. And I don't mean they said I mean actual ballistic data. Preferably not from the ones doing the back boring. I will admit I am not always right but I prefer proof to a lot of these claims.

Bear: to answer your question of why manufacturers don't do it,,, They do. It's just that the shotguns they do it to cost $2000 to start. Pretty much all Trap guns are back bored and ported. My Browning XT has both barrels ported and backbored. We even checked it with a bore gauge. The reason why it isn't done on cheaper guns is the cost.

My Mossberg 500 cost my FnL $205 when he bought it at Big 5 Sporting Goods. I just spent $215 to get the machine work done.

When I get to shoot this gun in a few weeks I will know instantly if it had any effect on the recoil, real or perceived. However that will be anecdotal and I doubt it will convince you, or would you just take my word for it?

In any event it's done and I'm pretty sure I will get my monies worth out of the mod as Hans Vang has only done about 20,000 of these conversions in his 40 year career as a Shotgun Smith. This is what he is known for and people wouldn't do it if it had no effect.

Go have a look at their website and watch the first video it explains what is happening with the barrel modification better than I can.

https://vangcomp.com/latest-works/

Randy

[RED BEAR]

If it feels better to you then it was money well spent. The work looks to be first rate. You are right with out crony data I will not be convinced but I am not the one shooting it you are and if you are happy that's pretty much all that matters. Good luck and happy shooting.