Considering reboring Pedersoli RMH to .58

[Chris Nolin]

It's a .50 right now, and the bore is perfect. But I already have another .50 BP rifle, and I'd love to hunt elk with a .58 PRB. Bob Hoyt (famous on these forums as a barrel-smith) asked me to send it to him to look it over and see if it's possible. His rate is very reasonable, and I'm sure he'll do a great job. But I was hoping there's some experience with this sort of thing here on this forum. Other than my simple desire to do it, what are the advantages and disadvantages? Any hidden risks? Also, is there a twist rate I should request from Bob, or just let him pick it?

Some details, if it helps: Pedersoli Rocky Mountain Hawken in .50 cal. 32" barrel. 1" across the flats. No corrosion inside or out. I don't know the depth of the sight attachment screw holes.

 

[phoenix511]

My choice would be buy a new 58cal barrel, have a new breech plug made and fit to your tang, keep the old 50cal for another time.

Reboring just gets you another bore diameter with the same barrel. And maybe a pretty good one!

Check prices on new barrels with same external dimensions, like ToTW, etc. I'd wager a rebore will be about the same $$$.

 

[nwtradegun]

I have had bob do 3 barrels for me excellent work and very accuste. you may ask if it can be done in 56 cal, 550 rd ball or to use a 562 rd ball.

 

[galamb]

If it's 1" ATF or even the metric equivalent which is about 24-25 mm then there should be more than enough "meat" in the barrel to bore it out to 58 cal.

It seems a shame to "bore" a sound barrel but if that will get it on the rifle instead of in the back of a closet, that's a positive thing.

Bobby can definitely advise you on a rate of twist. Colerain and Rice would make it 1:66 unless you asked otherwise, and Green Mountain cuts them with a 1:70 twist in that cal - should give you somewhere to start.

 

[nkbj]

My understanding is that Mr. Hoyt will make what you want. Once upon a time I sent Mr. Hoyt two rusty TC's and asked him to rebore them to his best .58 round ball rifling, figuring he'd probably already seen a few more than I ever would. When the barrels came back they had relatively narrow lands, seven grooves cut in a trapezoid sided round bottomed groove configuration. And it's good. Happy I didn't try to tell him what to do.
The bores needed lapping as received because the riding surface of the lands is bored with a rotating reamer head. The cut on that surface was relatively rough with lines running perpendicular to the bore. Those cut lines form little bitty buzz saw teeth at the edge of the lands and I lap those things until I'm shooting to my satisfaction.
That's been a while back and I'm still getting around to breaking in the 28" TC Hawken percussion barrel. This afternoon I was lapping out a hang up point in one groove. Couldn't see it. It's location didn't line up with one of the under rib screws (Oh the horror!). But with a tight patch I could feel it. So I decided to lap it out. The poured lap showed the hang up to be a tiny nub in the center of one groove where the groove cutting head dragged up a little burr.
At this time the bore diameter is about 0.582" and the groove about 0.612".
I think I want to set this rifle up to take a larger ball, probably .575" diameter, and will put a pretty good cone in the muzzle.
By the way, previously I was thinking these had 48" twist. But, I found my note book and discovered (duh) that I had measured the twist at 60".
I have tried the flinter (26" Renegade) barrel with an over sized RCBS minie sized down on the hind end to load it like a maxiball (front end engraving on the rifling). It worked with heavy charges so I'm ready in case a zombie Peterbuilt shows up.
The flinter cuts nice groups at fifty yards. The Hawken will probably do better.
Good luck with your barrel. Please post how it turns out.

 

[BrownBear]

Speaking from the standpoint of end results rather than knowing any details of feasibility with that particular rifle, I gotta say GO FOR IT!!!

I'm kind of a 58 caliber nut, owning five of them right now with barrels ranging from 26" to 36", including a 32". Quite a range of weights from just under 8# to a little over 12# since two of the barrels are tapered and one is an old pre-lawyer model on a 15/16" tube.

Every single one of them is my "favorite" hunting gun, or at least I reach for one or the other when the hunt is on. Which just depends on the terrain and my mood. But 9 times out of ten the 50's, 54's and 62's stay home as one of the 58's goes for a nice walk.

If I had to guess yours is going to come in somewhere between 8.5# and 9#. That's just about perfect for the caliber.

If I was to dump all mine for a single 58 (not likely!) it would read much like yours: Hawken stock, 32" barrel on a 1" tube.

Twist rate? I'm going to be radical here, but I'd have it rifled 1:48 with deep rifling, just like the original Hawkens. What you'll find with that 1:48, it will shoot light charges (40 grains or so of 3f) into a ragged hole at 25 yards. Yet snort it up to 120-130 grains of 2f, and it's likely to be nudging toward ragged holes out at 50 yards.

For reference my 36" barreled version has a 1:72 twist and it's a ragged hole shooter at 50 with 140 grains of 2f, but it's never found a charge under 80 grains that would qualify as a rabbit head muncher at 35 yards. Just won't shoot light charges at all. Yet my assorted 1:48's all qualify as bunny head munchers with light charges while delivering great accuracy with a full load.

I've got nothing to base it on other than experience with the guns, but I'm betting those cagey old guys buying Hawkens when the brothers were building them carried a powder measure dumping 40-50 grains. Then they'd use one scoop for small game maybe including deer, two scoops when they needed more range, and three scoops for long range and things that bite back. That's how I run mine, and it sure works slick.

 

[Kapow]

Do it! .58 is an awesome calibre! Wish I could turn my .54 into a .58. You might find the rifle a little lighter to carry as a bonus. I would be inclined for a 1:56 twist if you are only going to shoot roundballs although it might handle maxi's as well. 1:48 seems a little quick for the calibre. If I could only own one rifle it would be a .58 Hawken.

 

[varsity07840]

I think he'll find that a replacement barrel from TOW, if he can find one, will cost more. The barrel alone will run around $175.00. Add the cost
of a custom breech plug to match the tang and fit it to your barrel. Dennis McCandless used to do them(he did one for me) but I believe he's out of business.I believe the plug on the Pedersoli is color case hrdened. And if he's going to get the barrel from TOW, he might as well have them cut the sight dovetails, install a new barrel rib and thimbles and underlugs for the barrel keys. If he can't find the correct barrel length in stock, then he'll have to buy a longer one and have it cut and recrowned.

Bob freshed out a .54 to .58 for me to my spec.
The entire job was less than $175.00.

Duane

 

[StewartLeach]

La Poudre: several years ago I bought a 50 cal garage sale TC Renegade. Bore was in poor condition, had it redone to 58 cal with slow twist to hunt with round ball and shoot in Big Bore Match. Took a while to break in- 100 rounds or so, but now I love it. Not at all fussy about loading or cleaning.

You should come and shoot the Colorado Squirrel Rifle Championships at the Buckhorn Skinners April 26-27. Range is in your neighborhood, a couple miles north of the Big Thompson School. There will be an any caliber Hunter Class. Lots of fun, lots of shooters, a few traders, potluck dinner Saturday night, everybody wins a prize. Go to www.csmla.net and mouse around to find the flyer.

White Fox, in the People's Republic of Boulder

 

[azmntman]

potluck dinner Saturday night

Don't eat the brownies :shocked2: ! :rotf: ff

 

[Chris Nolin]

I've been quietly reading the advice and opinions since posting the question, and I want to thank you all. I'm definitely going to do this, and I'll let you know how it turns out. Also...bonus! I'm so happy to hear there's a Mountain Man club in my neck of the woods! Thanks White Fox for the suggestion to attend the shoot. I'll try to make it!

 

[nkbj]

potluck dinner Saturday night

Don't eat the brownies :shocked2: ! :rotf: ff

OMG Reminds me of all the happy little old ladies the time cousin Mike brought desert to the family reunion. They actually got along for a change. OK, off topic but I couldn't help myself! :rotf:

 

[George T.]

Just for conversation have you thought about a 54? I let several posts talk me into a 58 and the darned thing just loves 110 grains of 2F. It is a hand full but my 54 will shoot light and heavy loads well.

I might add that the tables show that the 54 holds up better past 75 yards,

Geop. T.

 

[BrownBear]

I'm curious about the twist rates in your 54 and 58.

Not questioning your points or your choice, but in my own rifles the 54 cals in both 1:66 and 1:48 love small charges as well as large, while in the 58 cals the 1:48's get the nod for small charges as well as large, while the 1:72 barrel hates small charges. It just doesn't seem like that much difference between 1:66 in the 54 and 1:72 in the 58, so I've always wondered if it's something unique to my slow 58 that makes it cranky about the smalls.

 

[Loyalist Dave]

The only thoughts for you that I'd ad are what sort of loads do you envision for this elk rifle. Are you planning on stout powder loads as well as the larger caliber?

I ask as Pedersoli are mostly machine made, and as such they can have some gaps in wood to metal contact, both in the tang area and they have been known to be scant of wood inside the lock mortise. Your removal of weight, plus the added force of the recoil on a now lighter rifle might just over stress the stock in some points beyond what Pedersoli expected when manufacturing the rifle.

So when you get the barrel done you might want to consider bedding the area of the tang and where the barrel lugs where the barrel key(s) go, plus check the tang screw fit through the stock. Thus when you start launching that .570 round ball with a stout load you won't run the risk of a cracked stock.

Granted, possibly not even a factor, but a little prevention is worth a pound of cure, eh?

LD

 

[BrownBear]

Granted, possibly not even a factor, but a little prevention is worth a pound of cure, eh?

You raise some good points. I doubt anyone would notice the difference in recoil between a 54 and 58 with charges less than 100 grains, but when you nudge past that boundary as is typical with 58's and not 54's, things start to move back with enthusiasm. I never consider 120-140 grain loads with the 224 grain balls in a 54, yet that's not an unreasonable charge range with the 58 and its 279 grain balls.

If a stock is going to develop problems with repeated recoil, it could happen lots sooner with the 58.