Pedersoli 45-70 COAL/Seating question

[RPRNY]

I have a new to me Pedersoli rolling block with the super heavy octagonal 30" barrel proofed in 1996.

Barrel slugs .450 / .4585. I'm patching Buffalo Arms 500 gr slicks to .460 with 2.102" Star Line brass. Using the Lyman black powder taper crimp. 148985I'm getting the ogive and patch into the lands at 3.052" COAL, which seems short, but there it is.

My question is whether folks find better performance with the bullet chambered into the lands or just short of. I haven't done a chamber cast but at .460" the chamber feels and appears full.

I can't say that I've seen a clear difference between just short of and into the lands, but there are other variables that still need nailing down like less patch lube and more consistent lube cookies.

So views on seating depth appreciated. I'm concerned that seating hard into the lands could lead to over-obturation. Is that even a thing? Just concerned about too much stress on the base but not sure if I'm overthinking it.

Thanks for your input.

[country gent]

My Paper Patched bullets are bore riding, .442 dia bullet 2 wraps ( 4 layers) of .002 onion skin paper. seated into case .187-.200 deep. bullet sits lightly snug into rifling and obtrates to seal and engage rifling when fired. Groove dia will need to be seat similar to a grease groove right up to the rifleing or so. You may have more "out of the case due to pedersolis throats.

[oldracer]

If it were me, I would get overall length set and figure accuracy before I added in the paper patching. When I got my first Rolling Block Doug Knoell told me to start testing and try 10 shots of all the possibilities and settle on what worked best. He did mention paper patching was to be done last and to use grease groove bullets during the work up. He noted to set case length after fire forming them, then filling a case with crush type foam, insert the bullet I planned to use, seat it out far enough so it would press on the rifling. Measure the OAL then take several thousands off ( 5 or so) and then move the bullet out/in to set the seating depth. Use a compression die and wad to compress the powder so that the bullet was seated finger tight on the wad. He said a crimp would not be necessary and he was right and the bullets should just press into the case by finger pressure. It took me 6 months of trial and error to come to the best shooting setup so take your time.

[RPRNY]

So I'm doing the things that Doug Knoell told you which is promising affirmation. Only using the taper crimp die to get the bell out of the case mouth.

I'm not new to paper patching so I know it will take a while to get things right, just trying to get any experience on contact vs non-contact with the Pedersoli, especially as mine seems to have a shorter throat albeit a very nice, shallow leade. Sounds like you're advocating just off the rifling?

Nevertheless, all experiences and observations bring something to the table.

[oldracer]

Sounds like you are and since I was NOT experienced with paper patching he said to work on that last. Same thing I am doing now with my muzzle loading slug guns (home made and Pedersoli Gibbs) and it takes a bit. I would suggest not crimping the case as in my experience the crimp made things worse. I talked with several shooters and they all used very slightly belled cases and sized so that the patched/lubed bullet would just slide in with finger pressure.

By the time I got done I had a small spiral note book filled with notes on what worked and what did not and in some cases I forgot and did them over.....

[montana_charlie]

I'm concerned that seating hard into the lands could lead to over-obturation. Is that even a thing? Just concerned about too much stress on the base but not sure if I'm overthinking it.
I also patch to groove diameter, so I am on the same page as you.

No, over-obturation is not a cause for concern.

Your bullet will do all of it's expanding before it even moves, and that is 'not much' since you are patched to groove. Because the throat is already 'full', there is no place for it to over-obturate into ... and no way to distort the base.

Do make sure that your cases is a long as the chamber is deep so there is no 'gap' between the case mouth rim and the end of the chamber. A little 'cubbyhole' like that can scrape off enough of the patch to create the dreaded 'paper ring' found in the chamber after the shot.

As for COAL ...
I have seated to have the patch firmly into the lands, and also just shy of the lands. I can't claim to have seen a real difference in performance.
The fouling might be a little less objectionable on the rounds pressed against the lands, but that's more of a suspicion than a proven result ...

I wipe between shots so I don't use any kind of lube.
Perhaps it's not connected, but I have some difficulty (sometimes) when chambering loads that are long enough to hit the lands. Of course, your rolling block can probably 'cram them in' better than my Sharps.

The cure for that (for me) was to adjust the stack to include a 1/8th-inch dry felt wad.
When seated to allow land contact, the felt has enough 'give' to fully insert the case before closing the block.

Hope something in this 'butters your bread' ...

CM

[RPRNY]

The notebook is a good idea and I'll give the no crimp a try. The attached pic 149017 shows a 45-70 cartridge where there's no real crimp per se, just the mouth returned to round (next to a 35 Krag with a 280 hrs soup can). I'll try that vs the minimum required to chamber a round.

[semtav]

Does your chamber have any Freebore? If so you are doing about the same as I am with my Win 45-90. I cam it in to the rifling about 1/8 inch and it is my most accurate gun to date.

[RPRNY]

Thanks. The Pedersoli chamber seems to be known for a fairly long freebore. I haven't done a chamber cast of mine but that certainly appears to be the case.

[montana_charlie]

The Pedersoli chamber seems to be known for a fairly long freebore. I haven't done a chamber cast of mine but that certainly appears to be the case.
The Pedersoli Sharps chamber has a substantial freebore (.236").
But, because Pedersoli built rolling blocks for quite a while before they started with the Sharps, your chamber could well be quite different.

[John Boy]

0.109 – Length of throat
0.458 – Diameter of throat
0.202 – Distance to lands at full height (.004)
0.311 – Leade Length (0.109 + 0.202)

[RPRNY]

Charlie, John Boy thanks very much!

[montana_charlie]

Charlie, John Boy thanks very much!
You still need to do that chamber cast ...

[RPRNY]

Any suggestions on getting round the gate and hammer on the RB?

[montana_charlie]

Any suggestions on getting round the gate and hammer on the RB?
Here's a suggestion you probably won't hear anywhere else.

Fire form a case in your chamber.
Drill out the primer pocket as big as you are able to.
Shorten the case by about a half inch.
Make a funnel out of cardboard, coke can metal, or 'whatever' and wedge it into the 'big' primer pocket hole.
Put this arrangement into your chamber, hold it firmly down in the rim recess and fill it with cerrosafe.

The front end of the chamber will be cerrosafe metal, and the rest will be brass that fits the chamber closely.
The 'funnel' can be shaped however needed to wind past the hammer or 'whatever'.
It can even be more of a tube than a funnel, but big enough to pour into.

Flexible plastic tubing will also work, but it's best to have a 'barb' soldered onto the case head to slip the tubing on.
The trouble with the flex tube ... you might need to have more than two hands to manipulate all of the moving parts.

I DO recommend heating the barrel in the chamber area in order to get a good quality casting (just like preheating a mould on a hotplate).
You only need to get the metal hot enough to feel 'hot' ... uncomfortable to hold.
If a propane torch is the only heating tool you have, a short bath in that flame (enough to just reach 'hot') will not affect your metal finish at all.

[Keith]

Any suggestions on getting round the gate and hammer on the RB?

By gate , do you mean the Breechblock?
On Rolling blocks its dead easy to remove the screw holding the "keeper" for the pivot pins for the hammer and breech block.
Cock the hammer first. Remove the BB. Let the hammer down then remove it.
One of the advantages of the Roller.
Much easier to pour in the Cerrosafe. I use a cut down coke tin , squash one side into a spout. Squash the other side enough to hold with vise grips. Heat with propane tourch and pour in.
As was said preheat gives a better cast.
Oh, remove the extractor as well or it may stop the cast coming out.

[RPRNY]

Thanks very much!

[rfd]

rprny, it sounds like you have the 'adobe walls' 30" version, i have the 'bodine' 34" model. a baco 459525m3 bullet engraves for me @ 3.115" and i load fire formed starline brass for a working oal of 3.090", no crimp, gato lube.

[country gent]

I recently sacraficed a split case. I layed it out with a line from mouth to 7/8" back then 3/8" down from case mouth and a 1/2" x 3/8" wide square 3/8" under the case mouth. Then size the case to hold your bullets lightly snug. You can now chamber the bullet in the case and extract it carefully. pinch and measure overall length or with the cut out measure from case mouth to base of bullet to determine compression depth needed. If needed the primer pocket could be drilled and taped to 1/4 X 28 for a long screw to but up to bullet base once chambered so the bullet could be reinserted. Like the hornady or the predecessor chamber all and the modified cases. A chamber cast is still helpfull to know what your working with.

[Lead pot]

It's a lot easier to make a good chamber cast to get enough information what your chamber looks like using a wax cast. Just melt down some old birthday candles or canning wax, what ever you have on hand. a darker wax is easier to see all the fine marks your chamber has.
Wax will shrink on the inside of the cast when it hardens.
Lightly oil your chamber and bore and follow with a patch to remove most of the oil, not all.
Push a patch in about an inch ahead of the chamber to hold the wax. Pour it in let it set till it's set and use a flat tipped patch jag and palm it out. It will take a little hitting the rod end with the palm of your hand to get it moving. Just don't remove to much oil. Put it on like you would wipe the metal down after cleaning your rifle. That is enough to have the cast move.

[RPRNY]

So I got out to shoot yesterday with mixed results. I had a lot of chronograph trouble. I had it at about 10 ft from the muzzle and was utterly perplexed when the first three shots grouped at about 4" @ 1552 - 1534 fps !!!! (500 grs, over 69 grs OE 1.5 f) Impossible, then I was getting readings in the 712 - 730 fps range and closing up the group's and then it just kept giving error readings. Later I shot smokeless 35 Krag rounds over it and got good consistent readings, so there's nothing wrong with the chronograph (newish comp electronics prochrono)

I assume that the gas and residue ejecta were sufficiently solid for the chronograph to register (and 1550 fps seems reasonable). There's no way I was getting 1550 fps for the bullet).But can the @720 fps have been right? It seems extraordinarily slow.

Anyway, still many variables to eliminate. My second batch that had extremely little patch lube got consistently better confetti at the muzzle and tightened up to about 3" - 3.5" with no flyers. Damp patch (water and a little Ballistol) followed by two dry ones seemed to work well.

Sights are another issue....

[Don McDowell]

It's pretty tough to get good chrono readings if the thing is much closer than 20 ft from the muzzle with bpcr.

[Gunlaker]

I'd definitely move the chronograph further away. I go as far away as the wires will allow. Both your high and low numbers are really off. I'd guess you are somewhere close to 1250 fps, maybe a little less.

Chris.

[RPRNY]

Shot again today. Left the damned Chrony on last time out so had no battery!!!! Only got about 25 shots in after sporting clays.

But got two solid groups of 10 @4" 100 yards, and once in tightened up to about 2.5", wiping one wet two dry between shots. I have a cheap Track of the Wolf Vernier sight on there that is canted too far right and is far too small diameter. The new Lyman 17A globe works well. Feel good about load, patching, and cleaning. I want a Hadley eye piece and need to shim it more vertical.

[Don McDowell]

You can probably save yourself a lot of headache by spending the money on a good rear sight. Baldwin,Hoke, Kelly, MVA all well worth the money.

[Gunlaker]

I would also consider trying two wet patches and one dry. I find that the cleaner the bore the better my rifles will shoot. Sometimes I even need three wets and a dry.

Chris.

[RPRNY]

Don - I'm reminded of a line from what I think was a Sheryl Crow song: "It's the good advice that you just didn't take". This time I think I will Thanks for the recommendation.

Chris,

I'll give it a shot. Always try to listen to the voice of experience. I think a better sight is going to make a difference.

[Don McDowell]

Keep us posted on how things progress.

[RPRNY]

Much work-life imbalance created a hiatus. However, I ordered a Lee Shaver Long Range Soule type sight with Hadley eye piece and was able to chronograph some loads this weekend. Closed groups to about 2.5" wiping two wet one dry.

500 grs patched .460" 69 grs OE 1.5F at avg 1734 Fps with 18 fps SD.

400 grs patched .460" 72 grs OE 1.5F at avg 1758 and 11 fps SD.

500 grs were tighter groups but shot them first. I think the longer COL of the 500 grs helped. Had a couple of fliers with the 400 grs. I feel like I patch the 500 grs better. Have to see if I can tighten things up with the new sight. God forbid it's the shooter rather than the sights!

[Chill Wills]

Much work-life imbalance created a hiatus. However, I ordered a Lee Shaver Long Range Soule type sight with Hadley eye piece and was able to chronograph some loads this weekend. Closed groups to about 2.5" wiping two wet one dry.

500 grs patched .460" 69 grs OE 1.5F at avg 1734 Fps with 18 fps SD.

400 grs patched .460" 72 grs OE 1.5F at avg 1758 and 11 fps SD.

500 grs were tighter groups but shot them first. I think the longer COL of the 500 grs helped. Had a couple of fliers with the 400 grs. I feel like I patch the 500 grs better. Have to see if I can tighten things up with the new sight. God forbid it's the shooter rather than the sights!

RPRNY - Somethings up with your Chronograph. The velocity is very much too high for the load you show above. In fact it is not likely that any amount of black powder in the longest 3.25" case could top 1500 fps with a 500 grain bullet.
Not trying to be a kill joy but if you have a chronograph that needs to be set for spacing between screens and you have them set up for the wrong space; this might be the trouble. Or.... if it is the all in one box chrono it may be something that needs the maker to repair.
Shoot a 22 lr over the screens Standard velocity 1080fps or HV 1250fps (about) if they show 1600-1800fps it was an easy check.

[RPRNY]

Seems unrealistically fast. Newish chrono, Comp Electronics ProChrono Digital. Has been accurate with other rifles but 1700s does seem too fast. Moved it a good 20 ft from the muzzle. Hard to believe it's still picking up gasses and residue but will check it out.

[RPRNY]

Finally got accurate chronograph readings today with the 500grs and 69grs OE 1.5. : 1236 fps with 19 fps SD. It was fairly chilly, 38-41F, so this seems right. Was getting very nice muzzle confetti.

My Lee Shaver Long Range Soule sight finally arrived. And they sent me the wrong one....

[Don McDowell]

Those chronograph numbers sound about right.
Sucks about the sight..