Pedersoli Rolling Block chamber cast results

[JKR]

Best take off that sight if you’re gonna shoot that outfit with the scope that’s on it!

[Gunlaker]

I have a C. Sharps rifle in 38-55 that I ordered without a chamber. I sent it to a local gunsmith who had done good work for me in the past to be chambered with a custom reamer I ordered. When I got it back it was crooked like yours, maybe even worse. The first loads I tried ( grease grooved bullets ) it shot poorly. Later I decided to try bore diameter PP bullets and seated them ahead of most of the freebore. It shoots great this way. Surprisingly, the best targets it's shot have also been breech seated but with a BACO Creedmoor tapered bullet. I guess that the imbalance it gives to the bullet is consistent enough that it shoots well. This is only at 100m & 200m as it's a short range gun. No idea if it would hold up at further distances.

Chris.

[piwo]

Best take off that sight if you’re gonna shoot that outfit with the scope that’s on it!

It’s off… that was taken the day I added the mount and just took a quick pic

[piwo]

I have a C. Sharps rifle in 38-55 that I ordered without a chamber. I sent it to a local gunsmith who had done good work for me in the past to be chambered with a custom reamer I ordered. When I got it back it was crooked like yours, maybe even worse. The first loads I tried ( grease grooved bullets ) it shot poorly. Later I decided to try bore diameter PP bullets and seated them ahead of most of the freebore. It shoots great this way. Surprisingly, the best targets it's shot have also been breech seated but with a BACO Creedmoor tapered bullet. I guess that the imbalance it gives to the bullet is consistent enough that it shoots well. This is only at 100m & 200m as it's a short range gun. No idea if it would hold up at further distances.

Chris.

Thanks Chris… I’ve been thinking about trying something in the interim (before having it looked at and discussing options). I only have the ability to shoot a couple hundred yards, so maybe that will work out..

[piwo]

Any updates? I wouldn't mind seeing a pic of the rifle and maybe a story of how it came to you.

Here’s a few pics… not great presentation: still working on that. Top pic shows some of the rust that I worked on removing. Rifle had been sitting in a basement behind an open door and was overlooked for some time. Scope is a 2-7X scout scope for deer hunting in a few weeks. Using 325gr Hornady Leverelution bullets I shot a .616 MOA group at 100 yards, and a 1.18 MOA group at 200 yards this morning at STL Benchrest Club. The 200 yard group was shot using the confluence of the thick crosshair and thin “hair”, and compensated for the 6” drop at 200. I think the group would have been even better if I actually used the crosshairs, but I was trying to see if I could compensate for drop without dialing clicks or guessing. Pretty dang pleased!

[Fitz]

I have a pedersoli sharps that Lee Shaver refined the barrel with a Crome moly sleave the rechamberd to 45-70 and set it up for shooting pp bullet, it is a tack driver

[Unclenick]

I remember reading some years back in Precision Shooting about a gun with a chamber that was 0.007" off the bore axis at the breech end. Nonetheless, if the case headstamps were oriented the same way each time they were fired, it drove tacks. It's no good for a magazine-fed gun, but for a single-shot, no problem. IIRC, this was reported by Merrill Martin, and he would likely have been loading on an arbor press. If you load on a press with a conventional shell holder, it would be advisable to put the cases into the shell holder with the same headstamp orientation each time so any tilt fire-formed into the case head has the same pressure angle applied to every case by the holder, too.

If you intend to avoid the ammo handling complexity and try to straighten things by going the 45-90 route, I would have a gunsmith mount the barrel in a lathe and then center the bore with the lathe spindle axis. Then, he should use a dial indicator to see how far off-axis the back of the current chamber is. If it is not so far that truing it would take the back end of the larger chamber out of diameter spec, then he can use a boring bar with the cross slide set to cut a 0.36° angle to gradually true the sides of the current chamber with the bore axis before running the new reamer in. Otherwise, despite using a correct pilot, the back end of the reamer can be pulled off the bore axis at the floating reamer holder by having to cut into the existing error. If the truing results in the breech end being too wide to rechamber, you will be looking at cutting the barrel back or replacing it to get it put right. All this bother makes minding the ammo orientation look more appealing.

[piwo]

All this bother makes minding the ammo orientation look more appealing.

Thanks for your thorough observations. I am not interested in the 45-90 option, so the ammo orientation angle is appealing. I’d be fine if a gunsmith proficient w rolling blocks could shorten the barrel a few inches(it’s an 30” barrel) and recut the chamber “square”. I guess time will tell. After hunting season I am going to reach out and see what options make the most sense. Appreciate your thoughtful insights.

[MichaelR]

Your rifle is shooting more than good enough with jacketed bullets to get through this season. Then order some either .441 or .444 pp bullets from Buffalo Arms and some paper and try some black powder to see if the lead bullets do okay in that chamber. If they shoot 2 MOA then just ignore the bad chamber. Since Lee Shaver is close, see if he can reline the barrel for a reasonable price. A PP bullet may have a good chance to get through that throat without leading that I would give it a try if you have any interest in shooting black powder.

[piwo]

Your rifle is shooting more than good enough with jacketed bullets to get through this season. Then order some either .441 or .444 pp bullets from Buffalo Arms and some paper and try some black powder to see if the lead bullets do okay in that chamber. If they shoot 2 MOA then just ignore the bad chamber. Since Lee Shaver is close, see if he can reline the barrel for a reasonable price. A PP bullet may have a good chance to get through that throat without leading that I would give it a try if you have any interest in shooting black powder.

Indeed Michael! Very pleased w the factory results. I am going to order some .441’s and after I assemble the appropriate dies and shell plates for my press I’m going to PP some and at least give it a whack. My intention has always been to shoot BP: I make it in my basement for my flintlocks and intend to shoot the rolling block w the powder it was designed for. Not to say I’ll never try smokeless, but that’s not where my interest lays.

[K43]

An easy way to keep the shell alignment is file a little notch in the rim at the same point in relation one of the letters/numerals on the headstamp. Makes it easy to align in the dies and also in the chamber.

[piwo]

An easy way to keep the shell alignment is file a little notch in the rim at the same point in relation one of the letters/numerals on the headstamp. Makes it easy to align in the dies and also in the chamber.

[Huvius]

"Using 325gr Hornady Leverelution bullets I shot a .616 MOA group at 100 yards, and a 1.18 MOA group at 200 yards this morning at STL Benchrest Club."

If that is the case, I'd ignore the chamber and try the PP boolits.

[piwo]

"Using 325gr Hornady Leverelution bullets I shot a .616 MOA group at 100 yards, and a 1.18 MOA group at 200 yards this morning at STL Benchrest Club."

If that is the case, I'd ignore the chamber and try the PP boolits.

I ordered some BACO .441 slicks today for paper patching. Of course I don’t have the dies I need or the correct S Jaw for my Forster Co-ax press so may take a bit to assemble all the correct components.

[Delkal]

Updated cast: more of the same. A much cleaner cast but exactly as previous. 3 lands start at the case mouth, one about .05 up, two about .15+” above case mouth. What crap!

I suppose I can buy some .444 paper patch slicks from BACO and patch them to @.450, though I think .451 or.452 is probably more in line with bore dimension. I wish they sold some of those.446 slicks and not just the mould!

How can you chamber a round with the lands going all the way to the case mouth? All rifles need some freebore so the bullet will fit without jamming into the rifling. Your second pic where the rifling stops before the case mouth and the lands taper to full thickness looks normal to me. A good gunsmith should be able to separately throat your chamber and have it even all around.

[Bent Ramrod]

A well-set-up blackpowder paper patched boolit should be land or bore diameter; ie, you should be able to push it through your barrel with your cleaning rod, leaving rifling marks on the patch but not tearing it.

Depending on brass thickness and chamber dimensions, the patched boolit should slide into the case mouth by hand seating and only need a slight mouth reduction (like a light taper crimp, not a roll crimp) to keep it from falling out again. If you use one of those newfangled dual-diameter paper patched boolits, you might not need the case mouth reduction at all, and should be able to avoid the use of reloading dies altogether. The slightly enlarged base should push into the case mouth by hand, and stay there with reasonably careful handling.

The boolit base should sit maybe 1/8” to 1/4” into the case mouth, with the rest projecting up past the leade into the bore. (And looking really Cool as it does it.) You should feel a “press-fit” when you thumb the cartridge into the chamber. There is no engraving of the boolit, just rifling marks on the paper.

When a blackpowder cartridge is fired, some 55% of the blackpowder products of combustion are solids: potassium sulfides, oxides, carbonates and the like. They form an aerosol of tiny solid particles moving at the speed of the expansion of the gaseous products.

They slow down quickly when out of the barrel, making that satisfying, roiling cloud of white smoke. But inside the barrel, at full velocity behind the boolit, they act like a hammer, slugging or riveting the boolit up until its diameter increase is stopped by the bottom of the grooves before the boolit starts moving. (Frank Mayer, the buffalo hunter, called this “the miracle of interior ballistics,” IIRC.) It then spins up the rifling, protected by the paper, until it clears the barrel. The paper comes off in shreds and pieces and the naked boolit is off to the target.

[MichaelR]

That’s a good description for a target load, but the OP is a hunter and the loading requirements are quite different.