backboring

[FullChoke]

This is a description of backboring by Angleport.  It also has info on cone lengthening and other work:

http://www.angleport.com/backboring.asp?C=

You might speak with gobblerguns.com and Ed of Ed's Guns in MS.  664-534-0551.

Ed's Guns telephone number in New Albany, MS is 662-534-0551

FullChoke

[Deputy 14]

Has anyone had a newer 870 done? Just curious if the improvement was worth the extra money?

[ILIKEHEVI-13]

Well I would love to see Remington offer a 870 with a .775 backbored barrel.  Now that would be the gun of guns.  

I'm interested in why a .775 dia. barrel would be at an advantage over something in say .735 or so.  The Mossy's seem to shoot some great patterns, what is the bore diameter of those barrels?   Learn me some lessons on the logic of bore diameter if you would.

Well I own both guns, and I can tell you the 835 is the better shooter consistently.  Most Remington 870 barrels will have a standard bore diameter around .729 or .730.  The 835 and 935 barrels will have a bore of .775.  The larger bore diameter after the shot column exits the forcing cone just means less disruption and less pressure on the shot column thus improving patterns.  

I also owned a Browing Gold 3.5" semi-auto invector plus barrel with a .742 backbored barrel at one time.  I can tell you now it would out shoot the 870 with lead or htl loads.  It would not out shoot the 835.  

[Mike Honcho]

I had an interesting conversation with a gunsmith recently and I mentioned to him I hunt turkeys with a Mossberg 835 turkey special / Star Dot choke etc. and get outstanding 40 yard patterns with Hevi Shot.  His comment piqued my curiosity...he thinks Mossberg "backbores" the 835/935 to relieve pressure in the action so the guns will stand up to heavy loads without destroying themselves....ie gas escapes around the wad.   I am a Mossberg fan and love hunting turkeys with my 835 so I was a little offended.  He commented that you lose velocity with the backbored barrels....has anyone out there chronographed Nitro or Hevi 13 loads from a Mossberg 835 (or lead for that matter).  Or has anyone else ever heard this "theory"?  I can't speak for velocity but my patterns are sure good!

[stinkpickle]

I had an interesting conversation with a gunsmith recently and I mentioned to him I hunt turkeys with a Mossberg 835 turkey special / Star Dot choke etc. and get outstanding 40 yard patterns with Hevi Shot.  His comment piqued my curiosity...he thinks Mossberg "backbores" the 835/935 to relieve pressure in the action so the guns will stand up to heavy loads without destroying themselves....ie gas escapes around the wad.   I am a Mossberg fan and love hunting turkeys with my 835 so I was a little offended.  He commented that you lose velocity with the backbored barrels....has anyone out there chronographed Nitro or Hevi 13 loads from a Mossberg 835 (or lead for that matter).  Or has anyone else ever heard this "theory"?  I can't speak for velocity but my patterns are sure good!

I don't know about the gas escaping around the wad part, but I read somewhere that backbored barrels lowered velocity somewhat.  I imagine it's only a small drop, if any, though.  I doubt that's something that Mossberg did to protect their actions, though. 

[SumToy]

What gun are you looking to have this did to.

rem 11-87

It will cut down on the chamber pressure on the barrel some.  Most auto loader guns don't get into the chamber pressure deal that much. Back bore a barrel works good with the fixed choke barrels.  It will make the gun shoot a better pattern.  Now we have reason to back bore the barrels in target guns but I will tell you to not throw your money away to try to help the hunting gun.  Just have forcing cone work did and let it go. 

[Mike Honcho]

I can't speak for velocity but I've got three extremely dead toms this year so far with the 835...two at 39-40 yds.

[muddyhole]

i have seen remington 870's bored to .745-.750.  when you get the chokes you have to make sure they dont protrude into the bore.  if they do, bad juju.  you would need to open up the rear of the choke