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Discussion Starter #1
Has anybody out there ever ported their own barrels?  My SBH has a nasty recoil 'flip' when shooting big loads [so what else is new?] and i've been considering checking into barrel porting [or am i just being a whoosie?] .  Is this something that's terribly complicated [i.e. needs to be 'tuned'] or is it just as simple as putting a few holes on the top of barrel's muzzle and something i could do myself w/ a drillpress? I've done a web search and can't find much info about it [except pertaining to paintball guns... a lot of help that is].  Any info on this subject would be appreciated.
 

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Any sort of mechanical process (ie typical drill or milling machine) is going to leave one hideous burr where the bit punches through.  First bullet down the barrel hits this - BIG problem.

Now, if you could drill from the inside-out... problem solved.  BUT... solve that problem in your garage, and I'll sure be impressed.

Some ported guns have a recessed crown, with an expansion chamber as part of the barrel.  That is, for a short distance back from the 'apparent' muzzle, there is a chamber that is larger than the groove diameter of the barrel.  The ports are drilled into the expansion chamber, not the part of the barrel that contains the rifling.

To do this and make it work, the hard part is probably crowning the 'actual' end of the barrel.  Burrs on the inside of the expansion chamber are probably not a huge problem, which is my guess as to why a manufacturer might choose this style of porting.

Another thought would be to make a sleeve that fits over the muzzle, with the part of the sleeve which protrudes past the rifled part of the barrel having the ports drilled in it.  This style of porting is represented by the old Cutts compensator, some of the compensated choke tubes for shotguns, or even IPSC-style race guns with compensators which are attached to the slide of a semi-automatic hangun.

For something like a shotgun barrel, where the inside has to be absolutely perfectly smooth around a port (think about how soft a plastic wad is), things like lasers and EDM (electro-something discharge machining) are used.

As you can see.... probably not a good project for the do-it-yourselfer.
 

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Thanks for the info and advice, MikeG.  I wonder if i put a slug in the barrel where the drilling is to be done to help minimize the burring as much as possible and then hand-lapped?  Oh well... maybe i'll just put up with the recoil...
 

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I've ported several handgun barrels over the years with varying degrees of success.  The technique I've used has been to shove an oval egg sinker down the barrel, further down than where I intend to drill for porting.  Then, I heated the muzzle end of the barrel with a propane torch to pre-heat it (like pre-heating a bullet mold), then poured in molten wheel-weight alloy on top of the egg sinker to fill the remainder of the length of the bore with lead.  Once cool, I used Dykem fluid to lay out my lines for drilling the barrel, a set of wing dividers to evenly space the holes and a very sharp center punch to mark and index those places to drill.

I then employed a brand new cobalt drill bit in each case, and very slowly, using a drill press and a drill press vice (don't hand hold the gun.... not ever!) I drilled the holes in the barrel.  The lead in the barrel GREATLY reduced the amount of burr on the inside of the barrel using this technique.  Once the holes were drilled, I drove the slug out the breach end of the barrel, then fire-lapped the bore once again to smooth up the porting job. (by the way, the barrel should be fire-lapped first to remove any barrel constriction at the forcing cone end of the revolver, or you'll play heck getting that solid, bore diameter poured slug out of the barrel!)

Success was varied in each case, with two guns being very well tamed using this technique to port them.  It seems that port placement is the key, and I found a 60 degree tapered hole to be superior to a straight-walled hole.  It seems the gas escapes quicker, and without a ventouri effect.

However, with the price of guns today, and the very reasonable costs of having a gun properly ported using an EDM, it seems to me, in retrospect to be penny wise and pound foolish to do a shade-tree porting job these days!  Sure, you might get a great job, but then again you might botch the barrel.... it only takes one slip, or one hole walking out of alignment when you are starting to drill the holes to really foul up the works.

Just for reference.... I've ported I think seven different big-bore handguns over the years (the last one about eight years ago), and right now I don't own a single one of them... (I think this figure speaks volumes for my satisfaction with the end product!)

However, I've done the same with shotguns, and finished polishing with a brake-hone (used for automotive brake wheel cylinders), and had perfect satisfation.... still own all of the shotguns I've ported!

Weigh the options, then enjoy!

God Bless,

Marshall
 

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A neighbor did mine with a home made EDM. I think he got the plans from Mechanics Illustrated or Popular Mechanics. It was a real simple and low cost set up. This machining did not produce a bur.
Dave
 

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Get someone to EDM it, It will not produce a burr. That is the process Magnaport uses, and it will not add stress to the steel. Drilling fractures the steel on a microscopic level. It won't be unsafe, but accuracy, especially when the barrel is hot can suffer. GregS
 

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Why not just let the pro's do it? Leading Edge Tool uses the EDM method, and it doesn't cost much. Or there's always the originator, Mag-Na-Port.
www.edmport.com
www.magnaport.com

Given the possible consequences of screwing it up, I think I'd rather leave it to the experts, myself.

PJ
 

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You can build a EDM machine (Electrical Discharge Machining) with plans available from Village Press Publications, POBox 629, Traverse City, MI 49685-0629. Its in a book called "Build an EDM" by Robert Langlosis and costs $18.00 plus S&H. Was featured in one of there magazines either "The Home Shop Machinist" or "Machinist's Workshop" in the middle 1990's so your public library may also have in there archives.

Unless your going to do a lot of them your better off having the professionals do it for what the cost amounts to these days. I had my S&W629 44 Mag done in the 1980's and it only cost $40 at the time on a $325 gun. You do the math -- I would never attempt this myself and I'm handy with tools and have the necessary equipment to do it the way it should be done but would never attempt it. It's not worth the risks!
 

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Slamhound -

Someday you may want to sell that handgun, and the value wil be diminished considerably with a poor vent job. Better to spend a few bucks and get a proper job done with an EDM machine. Or trade the gun for one that is already ported. Or shoot a different load.

My .44 Mag SRH kicks butt with 240g bullets and 24.0g H110, but put a 300g bullet over a max charge of H110 (20.0g) and its much milder in the recoil department.
 

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Slamhound, Coyote Hunter's right, if you goof it up your going to have a .44 Mag paperweight on your hands! I've had Mag-Na-Port do two of my rifles and the results were excellent. You'll probably come out ahead of the game in the long run. Good luck! CEJ...
 

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To make as small a bur as possible use a drill slightly smaller by about a few thousands then the hole you want ! Then start the drill size you want into the drilled hole and stop 3/4's of the way ! Then take the same size drill and recut the point flat square and very sharp and finish drilling the hole at high speed but very slowly with very little pressure the rest of the way ! Driving a jacketed bullet into the barrel under where the holes will go first will help some ! JAGG
 

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They do make small reamers and the finish cut from a reamer usually takes the burr out. I would think pouring lead down the bbl first would make it that much cleaner of a cut. If you have a large cal handgun it should be possible to use a reverse spot facer to remove the burrs also.
 

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You could let me put one of my brakes on it for you that would cut the recoil down to that of a target loaded 38 spl. The cost would be $80.00 plus return shipping....

I can make the brake length whatever you wanted, up to 4" and port it all the way around for maximum recoil reduction or just the top and sides for near "0" muzzle rise....

God Bless,

DAVID
 

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i AGREE WITH THE OTHERS, LET THE PRO'S DO IT. i JUST SAW A 38-44 HD AT A GUN SHOW RECENTLY, THAT THE OWNER DRILLED AND TAPPED THE TOP STRAP FOR SCOPE MOUNTS. HE SURE WAS PROUD!!!!
3 HOLES DRILLED TO GET TWO THAT LINED UP. SO MUCH FOR THE 90% COLLECTABLE HANDGUN......OH WELL, ITS HIS GUN.
 
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