As someone pondering a first building project, I wonder about the pros and cons of reboring a barrel rather than rebarreling.

Are there expected accuracy reductions or advantages? And the rifling is cut rather than 'button', yes?

Does the initial barrel need to be longer than the rebored barrel, and if so how much?

For example, could a 375 Ruger 20" be rebored to a 500 AccRel, or 49/338?

What are the costs of reboring+chambering+fitting versus new-barrel+chamber+fitting?

.510 or .500 barrel will require, from most shops, .150 per side, barrel thickness...

or .810 as the point diameter that dictates max length of barrel

all rebores (might be exceptions, but none i have heard of) are cutt rifling, and is LESS stress than button

www.deltagunshop.com

Clearwater Reboring

http://www.deltagunshop.com/cl..._reboring/index.html

Rebarrel ... Barrels are pretty cheap, even Kriegers.

The only reason to rebore would be to save a non-removable sight system, sight island or to avoid having to re-profile a custom barrel to fit a custom stock. For a .510 you'll need at least a .810 diameter barrel with no screw holes deep enough to compromise the rebore ( check this little tidbit carefully). In theory there should be a significant cost savings associated with a re-bore, but I can also see how this might turn into a horror story in a hurry.
Personally, I've never rebored a barrel and choose to go the re-barrel route, just because in the end I didn't want to deal with the people who advertise their re-boring capabilities.-Rob

Cost is another reason to rebore...I have yet to find a gunsmith who can supply a barrel, fit, chamber, contour to match the original barrel profile, put open sights back on (if needed), and blue to match the rest of the gun for the cost of a rebore, which if safe to be done, is about $450 give or take.

its about 200-250 for rebore and chamber ...
its 200 for a barrel...

ifi the barrel is big enough, go for it...

I would rebarrel every time...almost...I do have a Marlin that Jess Ocumpah rebored/rechambered from 30-30 to 356 Win but that was several years ago when he only charged about $150 to do the job...I couldn't have done a new barrel/rechamber for that price...now the price is about $100 more. It shoots as accurately as the OEM caliber and I'm very happy with it.

The only way to know about the cost is to compare a quote from a gunsmith to the cost of what a reborer charges directly, including ALL work...rechamber/sight mounting/recrown etc.

All barrel makers can contour the barrel to most of the popular shapes and only charge a moderate fee to contour to match or anything you might want...CNC machining is a wonderful thing.

I used a McGowen barrel to do my 510 Makatak,...a slightly longer version of the 500 AccRel...on an older Ruger Tang M77...26", $200...$155 for the barrel - $30 for the contour - $15 for shipping, reamer $147 including shipping and I did all the other work.

Check with McGowen as they will do you a 500 AR for a good price, chambered and installed...just send them your action. Reloading dies are available from CH4D and maybe McGowen has some stocked.

If you really contemplate a 500 AR be sure to use a receiver with at least a 3.60" magazine length. My version has a 14% volume advantage but I can't really use it except by single loading at a COL that won't work through the 3.30" mag box.

When I was working through the cost/thought evaluation for my 50 cal project the 500 AR came out on top over the other 5-6 50 cals I could have done...except I wanted my own named wildcat so that's what I did.

But...don't let the nickel wag the dollar...a rebore MIGHT be cheaper initially but there are no guarantees it will be better(or worse) than a new barrel, but I would bet on a new barrel quicker than on a "re-evaluated" barrel and there are horror and happy stories all over the net concerning rebore vs new barrel.

Luck

other than..
ch4d isn't doing the dies... i am having them made and selling them directly.. shesh.. done to 2 sets in inventory...

you can setup the 500 AccRel for a 3.65 ... but i don't recommend it, as the round does perform at that length, with h335 ... no reason for more/slower powder, for more recoil...

I didn't know you were the only one doing the 500 AR dies Jeffe...I just remember back a couple years ago McGowen had a reamer and was doing the rifles/barreling and CH4D has a lot of 50 cal dies already available plus could do dies from a fired case, reamer or chamber drawing.

Your AR and my Makatak are prime examples of a larger case capacity not necessarily being "better" in many respects. Efficiency is always rearing an "ugly" head no matter WHAT size the caliber.

I have two Savage LA's set up for the 375 H&H magazine that will handle slightly over 3.60" so I might just get a 32-34" McGowen barrel and do some more playing.

This game is always "relative" to something else.

As always when doing a wildcat...ALL the costs and availabilities including gunsmith, receiver, barrel, dies and expendable components must be researched and pinned down before cutting loose the dog.

Luck

Foobar

quote:

Your AR and my Makatak are prime examples of a larger case capacity not necessarily being "better" in many respects. Efficiency is always rearing an "ugly" head no matter WHAT size the caliber.

I don't know about that. The short Rigby case (or modified 338Lapua) looks awfully efficient for the .500 and .510 diameters. When the .590" base-x-2.65" case reaches a peak load (6500-7000 ft lbs.) there is not much need for a bigger case. In efficiency it would seem to outdo the Mbogo (full Rigby .590 base-x-3" for 8000ftlbs) or the Gibbs (.635 base-x-3.15"). The Gibbs is almost certainly a cartridge whose potential is almost never used, and I'm not sure that I would want to put my retinas up against a 9000 ftlb charge in an 8lb rifle. It might reach the edge where mistakes happen.

quote:

Originally posted by 416Tanzan:
Foobar

quote:

Your AR and my Makatak are prime examples of a larger case capacity not necessarily being "better" in many respects. Efficiency is always rearing an "ugly" head no matter WHAT size the caliber.

I don't know about that. The short Rigby case (or modified 338Lapua) looks awfully efficient for the .500 and .510 diameters. When the .590" base-x-2.65" case reaches a peak load (6500-7000 ft lbs.) there is not much need for a bigger case. In efficiency it would seem to outdo the Mbogo (full Rigby .590 base-x-3" for 8000ftlbs) or the Gibbs (.635 base-x-3.15"). The Gibbs is almost certainly a cartridge whose potential is almost never used, and I'm not sure that I would want to put my retinas up against a 9000 ftlb charge in an 8lb rifle. It might reach the edge where mistakes happen.

Tan, I have to ask, “Why is 6500 ft-lbs of energy the magic demarcation line?”

Reason I ask is that none of the early 20th century cordite era .500 calibers cartridges reached that demarcation line with their original “stopping loads”:
.500 Nitro Express – 570gr: 2,150 ft/s and 5,860 ft-lbs
.505 Gibbs – 600gr FMJ: 2,100 ft/s and 5,877 ft-lbs
.500 Jeffery – 535gr: 2,350 ft/s and 6,286 ft-lbs
Obviously all of these reach or exceed 6,500 ft-lbs energy when run at modern pressure levels…but all earned their reputations…

Thanks,

"Efficiency", just like ugly and beauty is in the eye or mind of the beholder...highly argumentative and having to do with semantics and each persons definition of the word or whatever you want to call it.

My case measures ~146 gr H2O and is 0.200" longer and I can only feed at ~3.25 - 3.31" COL, no matter WHAT weight bullet in my Tang Ruger, although I can single load those same bullets out much longer for much more performance.

The 500 AR is about 124 gr H20 at a slightly longer COL but would work better in my Tang Ruger I think, even at the shorter COL. My design worked out to where the longer case hit that particular bullet's cannelure at the length I could use in my rifle...to do the same thing with the 475 gr bullet, "hit the cannelure" I need to trim the case to 2.68-69"...the COL is shorter but the NET case volume remains the same. It depends more on HOW the CASE VOLUME is used.

The smaller cases do get more for the dollar up to a certain point, the larger case will almost always do more "something" with "something" else...I didn't want to start up another hoohaw over "what?".

I had the 590 gr cast up to ~2200fs with a lot more to go if I wanted...without pushing it at all...that's ~6200 ftlbs and the 525 gr at 2400 is very close to 6800 ft lbs...with a MB the recoil is not much more than a 10 ga heavy magnum.

I also think anyone that wants this level of slap in an 8 lb rifle isn't one I want to hunt with...WAY too much gonadotropins running through his/her veins.

Your point is taken tho'. All these 50 cal cannons have potentials way beyond most needs.

I think it is human nature and need to catagorize everything and put limits or beginnings or "what?" on all things for "proving" or "defending" some totally incosequential position.

Again...I did my 510 Makatak for specific reasons and had nothing to do with what was already out there or what performance the others provide, other than for informational purposes. I think comparisons for bragging rights are a waste of time...I think ANYTHING that uses powder, bullets and primers and goes bang is a good thing...when used for constructive purposes.

Luck

quote:

Tan, I have to ask, “Why is 6500 ft-lbs of energy the magic demarcation line?”

Reason I ask is that none of the early 20th century cordite era .500 calibers cartridges reached that demarcation line with their original “stopping loads”:
.500 Nitro Express – 570gr: 2,150 ft/s and 5,860 ft-lbs
.505 Gibbs – 600gr FMJ: 2,100 ft/s and 5,877 ft-lbs
.500 Jeffery – 535gr: 2,350 ft/s and 6,286 ft-lbs
Obviously all of these reach or exceed 6,500 ft-lbs energy when run at modern pressure levels…but all earned their reputations…

Thanks,

Jim

Why 6500? Because I currently use a 416 Rigby loaded to 6100 ftlb. If I put together another rifle I would want a little more punch.
With the 416 Rigby, if I want traditional energy transfer we have 340 grain Woodleighs that will unfold themselves like popcorn, expanding to well-over double diameter. If I want guaranteed penetration, and I do, then an expanding 'X' mono-copper is fantastic at 350 grain, and we now have the exploding tip non-cons. The Rigby remains a classic, one-rifle army. But there is nothing that forbids a second rifle in one's battery.

Foobar said

quote:

...

My case measures ~146 gr H2O ...

I would choose such a cartridge if I wanted an 8000 ftlb load, and then I would need a heavy rifle.

quote:

I also think anyone that wants this level of slap in an 8 lb rifle isn't one I want to hunt with...WAY too much gonadotropins running through his/her veins. Eeker

Your point is taken tho'. All these 50 cal cannons have potentials way beyond most needs.

Well, I would want a scope on an 8-lb rifle, which means 9-lbs. And I hear that these light Rugers are pretty comfortable because of the flex in the stock, though I might want to spring for the full-length aluminum-bedding-block Hogue. The whole purpose of limiting oneself to the 500AccRel would be the anticipation that I would not want any more powerful loads in such a light rifle. I'm thinking that a GSCustom 450 at 2600 fps with 6750 ftlbs and 9" drop at 300 yards would be fine ballisstically and about as much shaking as I could handle with a crooked smile. The recoil calculates at 100 ftlbs with a 27 ft/s velocity. If I wanted more and flatter, then I would need a bigger cartridge and a heavier rifle. But following the 'terminals' thread leads me to try out a light rifle, with "limited" ballistics.

Do I know what I'm doing? No. But I will get at least one more hunt with a flat-loaded Rigby before having a chance to finish a 500 project. Flat-loaded means 350 grain at 2807fps (6120 ftlbs) and is +1.8" at 200 yards, -4.8" at 300yards, -18" yards, something worthy of O'Connor's 270 elk loads though my son and I plan on impala, eland and buffalo.

I see nothing wrong in what you are doing or the way you are doing it. Part and parcel of developing something new and different is all the number crunching, deciding, exploring etc...and you have to bring together ALL the different parameters into a specific "thing"...including but not limited to bullet weight, velocity, barrel length, receiver, cartridge case, load components, etc., to achieve a SPECIFIC set of functions...understanding that by changing ANY ONE or more of those parameters will change the end result.

If you are looking at muzzle energy as the binding parameter then you need to understand the physics involved. VELOCITY is the overriding parametere when it comes to energy as energy increases at the SQUARE of the velocity and only directly proportional to bullet weight. You probably already know this. That means increasing the velocity even by 100fs with a 600 gr bullet increases the striking energy a whole lot more than increasing the bullet weight by 50 gr...all you have to do is study ballistics tables. In the old days I reduced the energy formula to a simple plug in the numbers so I could calculate energy relatively quickly...and boy am I glad of todays software

So by picking a specific ME, then working backwards, you pick out a bullet that will give you the required killing results within a range of distances, calculate the velocity that will give you your required ME and what size case will do it and put it in a package you can live with.

"Efficiencey" in this case means picking a case size that will achieve you goal without being TOO big.

There is always a point of diminishing returns in case size vs velocity...the bigger the case the more powder required to get to a certain velocity...each incremental additional powder amount gives an incremental additional velocity, but the diminishing returns thingy means it takes more powder and the resulting velocity curve falls off quicker.

With todays powders you can achieve higher velocities at lower pressures than in "olden" times, therefore you can use a smaller case and less powder to get where you want to go.

You can buy QL which will give you a way to do the math quickly and also design your cartridge if you want...I used Load from a Disk to design my Makatak...but I've been at this game for 50 years and was lucky to work with several early wildcatters and be involved(to a greater or lesser extent) in the development of many strange and beautiful felines...mostly as a gopher/grunt work/recoil absorber/flunky so I learned and paid for what little I know.

The "tongue in cheek" crack about too much gonadothropins was just that...8# won't kill you for a few hunting shots and there are ways to mitigate load developement on the bench, but 10-12# is much more managable for a second or third shot, and adding a MB to a lighter rifle will also help reduce the recoil 30-50% depending on a lot of factors.

I'm 70 years old and totally wrecked...my Makatak weighs 12# and is fairly comfortable shooting offhand...you can calculate the difference between 10# and 12# online for a 2200fs, 100 gr powder load, 600 gr bullet easy enought and multiply by 0.30 to get a rough estimate for the MB.

By the same token most of my "walkaround" varminters weigh 10-15# and even as destroyed as my legs are I can still do a couple of miles here in Oregon, up and down the mountains carrying them...anyone half that age shouldn't have ANY problem carting a large bore the same weight chasing some narly badboy down.

By the same token...you DON'T need to load to a cartridge cases maximum limits all the time...I used to have 454 CID engines in all my Chebbytrucks...I only needed to use what the engine was capable of a few times, the rest of the time it just loafed along...but the tire shredding potential was there when I wanted it.

Michael458 has some very nice wildcats that seem to do all that is required and are much more "efficient" than my shooter for certain...it take me more powder in my case to equal his loads than his cases use.

I'm not even certain that all this "extra" energy is doing anything other than taking out something on the far side of what we are poking at.

I'm guessing you already know most if not all and more of what I posted. Physics is Physics...somewhere along the line you have to PAY for everything you get.

Luck

This is my rebored RSM 375 H&H to 500 Jeffery. I agree that rebarreling is cheaper but when I costed out the quarter rib barrel and sights reboring made much more sense (cents also).

Brad

Very OK and nice to boot...GOOD looking wood...

Ain't those 50 cal boreholes GARGANTUAN...I mean a guy better be holding on tight to something solid when he goes to lookin' down that hole.

Any reason for going with the Jeffery over others...nostalgia??

Luck

I know a number of folks that have gone to rebores and they all really like them..Dennis Olson has had a bunch of them rebored and claims excellent accuracy with every one of them. They are cut rifleing so I don't see any reason for them not to shoot well..

Also a rebore is half the cost of a rebarrel with todays gunsmiths prices..

I am going with my first rebore from Dennis and at exactly half the cost of a new barrel installed etc.

I'll let you know how the old .404 shoots, it was a 25-06 Rem 30-S with a fairly heavy barrel and cut off from 24 or 26 inches???, it has close to a .700 crown, if my mic was right..

Oh Geez, Ray. You're having a gun rebored to .404? Good for you!
I just realized that a rebore might be the least expensive route to turning a Ruger No. 1 into a .333 Jeffery Flanged!

Bill,
My Rem mod 30-S customized stocked, 404 Jefferys will be a rebore and it cost me about $250 including the chamber and installation. Of course I had a quarter rib installed and all the other bling so that ran the investment up a good bit. But still I can sell it for much less than any other 404 Jefferys I have seen, even less than a CZ I think, and its much nicer than a CZ and its a good looking trim rifle on a great action..So the rebore keeps the price down to where a frugal person, or a hunter can afford one and still have a real nice looking big bore at half the going price.

A new barrel installed was $650 using a Lothar Walthar barrel. After talking to lots of folks, and got high reviews on all their rebores, I decided to give it a try..I have shot a few rebores and all were accurate. If, by chance it won't shoot, then I will re-barrel it and be so much the wiser, but I'm betting it will be a tack driver, after all it is a cut rifled barrel!

If the 404 Jefferys works out then I have a 30-06 FN with a laminated custom stock with a rather heavy barrel and the stock is slim and trim but still a tad heavy as are all laminate stocks so it will weigh out just right for a super nice .375 or 416 Ruger. It is a pretty gun and functional and will make someone a super nice working gun for Alaska or Africa at a reasonable price.

I think such rifles are in demand due to our economic times. So I think the rebore may be a good way to go, at least a viable option to consider. If I'm wrong then I will sure have a couple of nice rifles for myself, and that ain't all bad.

It could be said the 416 Ruger is the poor mans 404 Jeffery
Part of the appeal to the 404-375 wildcat is a re bore is almost all it takes to another version of a poor mans 404 Jeffery. The new 9,3x62 by CZ has great sights so a rebore and rechamber to 425 WR would make a great project. Only problem would be feeding.