The Accurate Reloading Forums
Boring bar...
07 August 2009, 05:34
boom stickBoring bar...
quote:
Originally posted by RIP:
Canuck,
Pretty cheeky of me, eh?
Fred Zeglin agrees with me, eh?
Remember when you taught me to spell "eh?", eh?
I like Fred.
He wrote a neat book on wildcats and gave the 470 Mbogo a whole page.
Fred should rebore "Ol'Purple," the most accurate .416 Rigby in the world,

to .510 caliber.
I need a third 500 Mbogo made from a rebored RSM.
Does Fred do the rebores himself? ... Headed for his website now ...
He says he sends out his rebore work but for a few hundred dollars to turn a 416 RSM into a 500 Mbogo with the sights and quarter rib is awesome.
This would make the cheapest 500 in that size since not much work needs to be done.
07 August 2009, 05:49
boom stickFrom Freds site
http://www.z-hat.com/Rebore.htmReboring Barrels
When that old friend has failed you but you can't bear to give it up,
having it rebored to a new caliber is often an affordable option.
Why rebore your Rifle? Most often this is done to save an old gun. It is especially useful when you have an expensive barrel with special sights, original markings, barrel bands, quarter ribs, or full ribs built in. There are many reasons why you might want to keep the original profile of the barrel, reboring allows you to do that with a minimum of expense. If you would rather just rebarrel, click here.
The first step in reboring is to pull the barrel from the action. Next it goes in a machine similar to a lathe where a special boring cutter is used to remove the rifling. This rough boring step leaves the bore 0.006 to 0.008 inch under the final bore diameter. A bore reamer of the desired caliber is then pulled through the bore to give the final bore diameter and a smooth finish. When the reaming is done, a rifling head of the appropriate size is installed, and the rifling is cut into the bore. We use a single point hook cutter for rifling. It takes an average of 75 passes per groove to cut the rifling to depth
There is no guarantee that any barrel will rebore successfully, but in most instances there is no charge for an unsuccessful rebore. Sometimes the barrel can rebored to the next caliber above the one requested if the first rebore doesn't come out. The exception is post WWII European made barrels. Due to various reasons that I won't go into, these barrels stand a higher then normal chance of not reboring well. Most American and postwar Japanese made barrels as used by Browning, Howa, Weatherby, etc are very nice to work with in both stainless and chromoly steel.
The old Winchester nickel steel barrels usually bore and ream well but are tough to get a real nice finish in the bottom of the grooves. The steel is tough and stringy and while the barrels will look a little on the rough side, they usually shoot well. Barrels made before WWI and especially before the turn of the 20th century tend to be non-uniform in their make up. Steel making was more of an art then a science at that time. Normally they will rebore OK. WWII production barrels can run the gamut from very good to work with to horrible. Standards were relaxed in order to hurry production and get weapons into the hands of the troops, and reboring can be an iffy thing on some of these barrels. This is also true of the 1917 Enfield barrels both from WWI and WWII.
Cost to rebore your barrel, $395. A pretty good savings over a new barrel which starts at $675. If your barrel has special sights setup, integral ramps, ribs, or quarter ribs, integral swivels, or if it's octagon, or any other special or unique barrel then reboring really becomes cost effective. One limitation is diameter of the barrel, a rule of thumb is if the muzzle is at least .250" bigger in diameter than the desired caliber a rebore will likely work. Calibers to choose from,
Who does the rebores for Fred?
I sent him a request for a quote.
Also mentioned adding a washer-style recoil lug to action as primary lug,
throw away recoil plate,
or cut off end of it and use front end as a barrel lug at the same place in forearm,
crossbolt behind magazine,
hidden crossbolt in forearm for secondary lug,
glass and pillar bed ...
All of that should be easy enough.
Of course one could just retain the RSM system and reinforce and bed as best you can.
Then, yes, just a rebore and rechamber, and a feed job.
A 500 Mbogo is a lot easier than a .505 Gibbs or 500 Jeffery.
About like reboring and rechambering to 500 A2,
only better.
The barrel on Ol'Purple is black.
Only the action is plum.
A refinish all over might make it match.
07 August 2009, 05:58
boom stickquote:
Then, yes, just a rebore and rechamber, and a feed job.
A 500 Mbogo is a lot easier than a .505 Gibbs or 500 Jeffery.
About like reboring and rechambering to 500 A2,
only better.
Exactly...
Cheaper than a 500 A2 rebarrel job.
I dont know how much feed work would need to be done since you are using the same parent case.
I would shoot it as is till it splits then go synthetic. Does anyone make a drop in synthetic for the RSM?
quote:
Originally posted by boom stick:
Does anyone make a drop in synthetic for the RSM?
I have gone looking for them on the internet and never found one in the past.
Gave up looking.
The "recoil plate in the forearm contraption" is not conducive to bedding in foam filled forearms.
Suckers for RSMs usually like pretty walnut, little demand for innovation.

07 August 2009, 06:51
boom stickIt would be quite something to pick up a used RSM for say 1k and come out with a 500 Mbogo for under $1,500 with the purchase cost included to have a CRF with sights and a quarter rib. Boring out will make it lighter too

Yep, the 2nd generation 24"-fat-barreled .416 Rigby is 10.75 pounds.
Might be 10 pounds when the barrel is rebored and rechambered to 500 Mbogo.
Feed job might be "not much ado", since mine already feeds GSC FNs in .416 Rigby.
Since I am the only 500 Mbogo Maniac in the world ... No. 3 coming up.

07 August 2009, 07:09
boom stickWould not a 2.9" (416 rigby case length) version of the 500 Mbogo or 500-416 be less work to feed?
Because of the smaller casehead would not a rebore for a 500 A2 be out of the question?
07 August 2009, 07:59
MacifejAre any of you lunatics actually gonna do the math and post it or is someone gonna send me a bottle of booze for doing it and posting what you actually need and not what your third cousins dog used to do when he owned a .437 Jethro Express when you were in grade school. Nothing ever changes here. Personally, I think you guys are bunch of lazy assed hound dogs ...

Some thoughts:
1) do the math
2) 65,000 psi chamber pressure is NEVER 65,000 psi at the muzzle.
3) barrels bannana from obstructions not unobstructed over pressure.
4) Rich is trying to save 50 bucks again by burning 30 hours of his life - been hangin' out in the pub with Boomstick too long. (why do I never get an invite?)
5) I have found I enjoy the company of intelligent single women more than you guys. Do any of you wonder why?
6) Oh well ... whatever ...
07 August 2009, 08:13
boom stickquote:
been hangin' out in the pub with Boomstick too long. (why do I never get an invite?)
Next time I go to LA let's go

07 August 2009, 08:16
boom stickquote:
Personally, I think you guys are bunch of lazy assed hound dogs

Boom stick,
Yes rechambering to 500A2 after the rebore would require chopping the barrel threads off and setting back.
More complicated but do-able.
Thanks for pointing out how the 500 Mbogo shines here also.
Now I must tell you that I am no way going to change the 500 Mbogo ... it would simply not be a 500 Mbogo anymore.
You do it, and call it the "500 Boom All."

07 August 2009, 08:32
Macifejquote:
Originally posted by boom stick:
quote:
been hangin' out in the pub with Boomstick too long. (why do I never get an invite?)
Next time I go to LA let's go
I thought you WERE in LA ...?? You git my info - let me know .... I'm always game for some amusement.
07 August 2009, 20:56
RobgunbuilderHeck that sounds pretty good to me for a .308! Most of my .308's have barrels 1 inch in diameter. I always try to go .200 on my barrels as a rule of thumb. I like barrel heavy guns and have never had a barrel unzip from the muzzel. It really depends on the muzzel pressure of the cartridge. On a low pressure 12GaFH I've seen Nef and TC Encore barrels as thin as .135 per side and no issues. Do I like it ,no, does it work yes! Would I go that thin on a .378 Wby for example? No!-Rob
Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012
Nothing Up my sleeves but never without a plan and never ever without a surprise!
08 August 2009, 05:59
JBrownquote:
Originally posted by Robgunbuilder:
Heck that sounds pretty good to me for a .308! Most of my .308's have barrels 1 inch in diameter. I always try to go .200 on my barrels as a rule of thumb. I like barrel heavy guns and have never had a barrel unzip from the muzzel. It really depends on the muzzel pressure of the cartridge. On a low pressure 12GaFH I've seen Nef and TC Encore barrels as thin as .135 per side and no issues. Do I like it ,no, does it work yes! Would I go that thin on a .378 Wby for example? No!-Rob
Dang that seems heavy. My 375 has .100 on either side and I have had no problems after about 1000 rounds.
I think your rule of .200 is over the top because nearly all sporter weight rifles are well below this.
I am sure you rule works, but it seems like over kill.
Jason
"You're not hard-core, unless you live hard-core."
_______________________
Hunting in Africa is an adventure. The number of variables involved preclude the possibility of a perfect hunt. Some problems will arise. How you decide to handle them will determine how much you enjoy your hunt.
Just tell yourself, "it's all part of the adventure." Remember, if Robert Ruark had gotten upset every time problems with Harry
Selby's flat bed truck delayed the safari, Horn of the Hunter would have read like an indictment of Selby. But Ruark rolled with the punches, poured some gin, and enjoyed the adventure.
-Jason Brown
08 August 2009, 09:39
RobgunbuilderI've got a nice collection of burst barrel pics that start at the muzzel.I'm sure the owners all thought their guns were perfectly ok too. Sorry but .100 is way too thin in my opinion. A .375 should have way more barrel than that to be well balanced and not butt heavy! To each his own! But then I like the whole concept of Overkill!

-Rob
Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012
Nothing Up my sleeves but never without a plan and never ever without a surprise!
08 August 2009, 10:19
ScottSRob,
Better tell that to all the double rifle makers!!!
All one needs is 0.135" wall thickness for the VAST majority of hunting cartridges.
Boomstick,
I have rebored two older RSM to 500 A2. The action needs a lot of work to make feed the 500 A2 though! The 500Jeffery, contrary to AR BS is much easier to make feed in an RSM, but will only hold 2 down in stock magazine configuration. As RIP has reminded you, although I believe I was the first to say is about 5 or 6 years ago, the 500 A2 will not clean up the 416 Rigby chamber. However if loads are kept below 55 ksi the uncleaned up 416 Rigby chamber in a 500 A2 will provide good service as I learned from my first conversion. Having said that I recommend taking the barrel back one thread and cleaning up the 416 Rigby chamber (or start with a 375 or 458 and adjust the bolt face).
08 August 2009, 10:36
boom stickI am sure part of the 500 a2 feeding issue is the rebated rim. Going from a Rigby to a Rigby has to be easier. If you started with a wby I am sure feeding the 500 A2 would be easier.
08 August 2009, 18:42
ScottSBoomstick,
The feeding issues have NOTHING to do with the rebated rim! They have to do with the magazine geometry and the Ruger feed ramp. A 500 Jeffery requires NO work to feed (if two down is all you want that is, more down requires a new drop box) the 500 A2 requires MASSIVE amounts of grinding to reconfigure the feed ramp.
08 August 2009, 23:47
boom stickquote:
Originally posted by ScottS:
Boomstick,
The feeding issues have NOTHING to do with the rebated rim! They have to do with the magazine geometry and the Ruger feed ramp. A 500 Jeffery requires NO work to feed (if two down is all you want that is, more down requires a new drop box) the 500 A2 requires MASSIVE amounts of grinding to reconfigure the feed ramp.
Why would magazine geometry be so different going rfom a 416 rigby to a slightly blown out 416 rigby? I can see the argiment for say going from a 458 Lott to 500 A2
09 August 2009, 05:05
JBrownquote:
Originally posted by Robgunbuilder:
I've got a nice collection of burst barrel pics that start at the muzzel.I'm sure the owners all thought their guns were perfectly ok too. Sorry but .100 is way too thin in my opinion. A .375 should have way more barrel than that to be well balanced and not butt heavy! To each his own! But then I like the whole concept of Overkill!

-Rob
Not to beat a dead horse, but how many of those barrels burst due to the thin barrel, and how many burst due to the bore being blocked or fouled with ice/water/oil/etc?
I just have a hard time believing that relatively few problems encountered with the millions(billions?) of rifles of produced with less than .200 barrel wall thickness at the muzzle doesn't disprove the need for such a thick muzzle.
I would guess that 95% of rifles sold have less than .200 muzzle wall thickness. Most are closer to .125. It is rare to hear of a problem.
Jason
"You're not hard-core, unless you live hard-core."
_______________________
Hunting in Africa is an adventure. The number of variables involved preclude the possibility of a perfect hunt. Some problems will arise. How you decide to handle them will determine how much you enjoy your hunt.
Just tell yourself, "it's all part of the adventure." Remember, if Robert Ruark had gotten upset every time problems with Harry
Selby's flat bed truck delayed the safari, Horn of the Hunter would have read like an indictment of Selby. But Ruark rolled with the punches, poured some gin, and enjoyed the adventure.
-Jason Brown
09 August 2009, 09:21
ScottSBoomstick,
I am not going to explain it, as it would take far more typing than I feel like doing. I could post pictures showing the problem areas, etc, etc, but why? You don't have to believe me, afterall Rob and Jeffe have already stated what a trolling assclown I am. Like Rob's statement that one must have a muzzle thickness of 0.2" or barrels will explode.
