Sudden Loss of Sharps Accuracy

[1874Sharps]

Gentlemen:

I wanted to garner some opinions about what could be the cause of the loss of accuracy in my Pedersoli Sharps 45-70. First some background: I have had this rifle for about twenty years and have shot around two thousand rounds through it ( mostly lead boolits with BP). The rifle has consistently been able to group 1 MOA with a load of 67 grains of Swiss 1 1/2 FG and a Lyman 500 grain RN boolit. In fact, I used that load to harvest an antelope with one shot through the heart at 200 yards two seasons ago. I was very confident with the rifle and that load until recently. There’s nothing going on in the bore that I can see that would explain the accuracy going to about 7 MOA at 100 yards. I also checked the firing pin to see if it was broken and it was good. I can’t think of anything else to check.

If re-barreling the action is necessary, do any of you have recommendations as to brand? I have been looking at a Krieger barrel. They sell one with Henry rifling and one with conventional cut rifling. I have never heard of Henry rifling before, but apparently it has rounded lands and grooves and is claimed to be superior for BPCR. Does anyone have experience with this type of barrel? Will such rifling shoot paper patch boolits, or only conventional grease groove boolits? If I am going to have to re-barrel my Sharps, I want to optimize it for BPCR.

[country gent]

Have you changed anything, Brass, powder, primers, alloy. If this is the same bath of powder it might be age. Even different lot numbers can make a big change.

Have you annealed your brass lately?

I would anneal the brass if you havent been. Then try a test load of +1 grn and minus 1 grain from your load.

[Jeff Michel]

I can scarcely believe that 2K of lead bullets could harm a barrel. You may want to invest in a bore scope, then you'll have information that can help you decide which direction to jump. It would be a shame to replace a barrel that just needs the fouling removed. Good luck on your project.

[BLAHUT]

I would look real hard at your powder ??? Did you ever run a load over a coronagraph ?? Lot to lot on powder has a big area for discrepancy's ? I have had from one lot to the next, going from 38 to 41 grains to hold 1200 FPS, that was just on two lots... I check every lot now for the 1200 FPS threshold ??

[M-Tecs]

Unless the barrel was allowed to corrode or it was damaged from improper cleaning 2K is hardly even broken in.

Last two Krieger barrels that I purchased for BPCR 50/50 had land/groove width. Krieger recommended that over the Henery rifling.

[1874Sharps]

My load did not change, in fact I used ammo from the same lot that I loaded up for the antelope hunt, since the outfitter guide recommended bringing at least fifty rounds to the hunting camp. I tried fresh loads as well with the same bad results.

It does seem reasonable that there should be nothing wrong with the barrel after shooting two thousand lead boolits through it. After all, we are not talking about a 220 Swift or some such thing. Perhaps the gunsmith can bore scope it and see if anything shows up.

I should have addressed this thread to Ladies and Gentlemen, I see. Pardon my assumption that only guys would be out there.

[indian joe]

[QUOTE=M-Tecs;5618565]Unless the barrel was allowed to corrode or it was damaged from improper cleaning 2K is hardly even broken in.

This !!!

the 2000rounds of lead and blackpowder is not the problem

That said - if you are running a grease boolit that doesnt quite carry enough lube (most of em!) it takes only the tiniest corrosion mark near the muzzle to upset things - likely to happen with extended storage in a damp environment - ask how did I learn this ? --bought one ! --after struggling with leading near the muzzle (tantalising accuracy for two or three shots from clean then all gone to hell) I ended up lopping four inches off the end till I got back to 100% clean rifling, sold the molds I had with skinny little grease grooves, problem went away! It took a jewellers loup, a proper bore light and good eyes to see what was wrong with that bore until after I cut it off.

"Consistently one MOA ? " you are a better rifleman than most of us .....................................

Something has changed - could be as simple as how you support the forend when you shoot.

[Don McDowell]

Might run a turpentine patch thru the bore and see if you pull any lead.
Also pull the firing pine and clean the hole in the breech block.
Might also pull the forearm and see if the wood has swollen or shrunk and putting different pressure on the barrel.

[NSB]

Might run a turpentine patch thru the bore and see if you pull any lead.
Also pull the firing pine and clean the hole in the breech block.
Might also pull the forearm and see if the wood has swollen or shrunk and putting different pressure on the barrel.My first thought…..forearm. Doesn’t take much to ruin accuracy if this is or has moved.

[stubshaft]

I'd go with scoping the bore and insuring there is noo leading. A six MOA difference is a heck of a change.

[Castaway]

All good suggestions, but something else to check is your rear sight for any wobble and your front sight to see if it’s sliding back and forth in the dove tail

[Shawlerbrook]

The fact that the accuracy loss was sudden rather that gradual makes me think one of the above suggestions are the case rather than a shot out barrel.

[Teddy (punchie)]

Well that sinks .....

Okay if not the shooter then something changed.

Something loose, moving.

Dirt or something around barrel.

Was gun dropped, barrel bent? Something else bent.

Powder, bullet, casing, and primmer the same.

Over cleaned ?? I have a gun if I clean it shoots 5-7 inch groups at hundred.
Lightly cleaned 3-5 inch groups. That barrel needs replaced but first shot tests
are about 2 inch group and 150 gr. pill is moving at 3250 or so. A hunting gun
for white tails and hard to get over a 200 yard shot.

Best of luck !!

Teddy

[HWooldridge]

How old is the lube on the bullets? I had a batch of Buffalo Bore .54 ML slugs that previously shot well then they sat for about ten years. I fished them out for some guests to shoot and the lube had dried out enough that accuracy went out the window. Are you working from an old batch?

[freakonaleash]

Make sure your stock screws are tight.

[1874Sharps]

The shooter, in this case, is always of dubious quality- lol. The cartridges were both freshly loaded and 1 1/2 years old, with no discernible difference in function.

[indian joe]

[QUOTE=1874Sharps;5618986]The shooter, in this case, is always of dubious quality- lol.

like most of us! so go shoot something else that you know is on the money - eliminate one variable at the time?

[ATCDoktor]

I'm not sure if who it was (Mike Venturino i belive) spoke to a sudden loss of accuracy in a Sharps of his that sounds eerily like yours.

He rendered the issue down to a broken firing pin.

I have no idea how a broken firing pin in a Sharps would affect accuracy but once it was replaced his issue was resolved.

[ascast]

Had your eyes checked lately? I would go with crown buggered, screws loose, forearm loose or warped. Your bullits are the same?

[Woodtroll]

A broken firing pin was my first thought too, but you said you've already checked that. I'm not sure if the transfer bars can break in a way that will let the rifle still fire at all, but I assume if you've checked the pin you've taken the dovetail plate off the back of the block? A broken transfer bar would have been obvious then, I would think.

Any chance the barrel has gotten a ring in it?

I hope you'll let us know once you figure it out! Good luck!

[M-Tecs]

I'm not sure if who it was (Mike Venturino i belive) spoke to a sudden loss of accuracy in a Sharps of his that sounds eerily like yours.

He rendered the issue down to a broken firing pin.

I have no idea how a broken firing pin in a Sharps would affect accuracy but once it was replaced his issue was resolved.

Weak firing pin springs will give inconsistent ignition. I have seen sub 1/2 MOA match rifles turn into 2 MOA rifles with weak firing pin springs than back to sub 1/2 MOA when the springs are replaced. Going for 1 MOA to 7 MOA is a bit of a head scratcher?

https://bulletin.accurateshooter.com/2016/03/vertical-fliers-poor-ignition-may-be-the-cause/

[Woodtroll]

^^^In the 1874, the main/hammer spring would provide the power to strike the firing pin, but that could also be weak or broken.

Another thought, does the firing pin move freely in its hole (is the hole battered, peened, or burred)?

Do you have access to a chronograph? I'm still thinking inconsistent ignition due to a mechanical change would be the cause of such a sudden change, ruling out leading or traumatic bore or crown damage.

[Woodtroll]

Just curious - did you ever make any progress on this?

[1874Sharps]

Interestingly enough, I found the problem. It turned out to be the same thing that happened to Indian Joe as he posted earlier in this thread. Let me give a little background: A year or so back I was having trouble with my Lyman 500 grain mold. It would not close properly and I wrongly figured that after several thousand castings maybe it just needed replacement. That bullet had always worked well for me, so I figured on buying a new one. I could not find one available so I bought a new 500 grain mold from Accurate Molds. The one I settled on was a little different than the Lyman. It was a bit longer in the nose and a bit shorter in the shank with one less grease groove. The idea of this new mold was to allow bullet seating a bit farther into the leade. I shot a number of loads with this boolit and did not have as good accuracy with it, so I picked up the old Lyman mold again to see if I could get it casting again. Turns out it was just carboned up and a good cleaning fixed it. Amazing what a little magnification will reveal. More on that in a second. As Indian Joe experienced, it appeared that the new boolit from the Accurate Molds did not carry enough SPG lube for the last couple of inches of the Sharps’ 32 inch barrel. I had undetected leading with BP fouling underneath it and that set up the conditions for pitting. I will be 65 this month and amazingly both of my eyes are better than 20/20 at distance. However my ability to focus up close started diminishing in my 40s. Like the flight surgeon humorously told me when I was a young aviator in the navy, “When you hit your 40s your arms are going to get short.” If I had only looked down the bore with magnification (maybe it’s time to get a bore scope), perhaps I would have seen the leading and avoided the pitting problem. Well, that’s water under the bridge. I decided to buy a Krieger barrel blank with Henry rifling and sent the blank and Sharps to Lee Shaver to have it made into a 12.1 pound silhouette rifle with an octagon to round profile with Hartford collar. (I always liked the looks of that style.) Krieger no longer makes the blanks with Henry rifling, but Buffalo Arms had some in stock. They are not supposed to be any more accurate than conventional rifling, but the Henry rifling is supposed to hold up to repeated shots without cleaning between shots a bit better without losing accuracy. You see, I figure if I am ever up against Marston’s bad guys in Australia that will give me an edge (a reference to Quigley Down Under, in case you have not seen the movie). The turn around time will be a good year because Lee Shaver is in great demand and a bit backed up, but he is a famous single shot expert and competitive BPCR shooter as well, so I don’t mind the wait.

[indian joe]

Interesting!!
I freebored mine about 1.5 inches first, got the worst rust mark out but still didnt fix it --ended up sawed four inches off it, recut the front dovetail, back in business !

[1874Sharps]

Some of us are born with carbines and need every inch we can get!

[indian joe]

Some of us are born with carbines and need every inch we can get!

thought we were talkin about gun barrels?? I was.........................

[Woodtroll]

Interestingly enough, I found the problem. It turned out to be the same thing that happened to Indian Joe as he posted earlier in this thread. Let me give a little background: A year or so back I was having trouble with my Lyman 500 grain mold. It would not close properly and I wrongly figured that after several thousand castings maybe it just needed replacement. That bullet had always worked well for me, so I figured on buying a new one. I could not find one available so I bought a new 500 grain mold from Accurate Molds. The one I settled on was a little different than the Lyman. It was a bit longer in the nose and a bit shorter in the shank with one less grease groove. The idea of this new mold was to allow bullet seating a bit farther into the leade. I shot a number of loads with this boolit and did not have as good accuracy with it, so I picked up the old Lyman mold again to see if I could get it casting again. Turns out it was just carboned up and a good cleaning fixed it. Amazing what a little magnification will reveal. More on that in a second. As Indian Joe experienced, it appeared that the new boolit from the Accurate Molds did not carry enough SPG lube for the last couple of inches of the Sharps’ 32 inch barrel. I had undetected leading with BP fouling underneath it and that set up the conditions for pitting. I will be 65 this month and amazingly both of my eyes are better than 20/20 at distance. However my ability to focus up close started diminishing in my 40s. Like the flight surgeon humorously told me when I was a young aviator in the navy, “When you hit your 40s your arms are going to get short.” If I had only looked down the bore with magnification (maybe it’s time to get a bore scope), perhaps I would have seen the leading and avoided the pitting problem. Well, that’s water under the bridge. I decided to buy a Krieger barrel blank with Henry rifling and sent the blank and Sharps to Lee Shaver to have it made into a 12.1 pound silhouette rifle with an octagon to round profile with Hartford collar. (I always liked the looks of that style.) Krieger no longer makes the blanks with Henry rifling, but Buffalo Arms had some in stock. They are not supposed to be any more accurate than conventional rifling, but the Henry rifling is supposed to hold up to repeated shots without cleaning between shots a bit better without losing accuracy. You see, I figure if I am ever up against Marston’s bad guys in Australia that will give me an edge (a reference to Quigley Down Under, in case you have not seen the movie). The turn around time will be a good year because Lee Shaver is in great demand and a bit backed up, but he is a famous single shot expert and competitive BPCR shooter as well, so I don’t mind the wait.

Thanks for the update! Please post photos once the rifle returns!

[1874Sharps]

Lee Shaver is in high demand and told me upfront that it’s going to take about a year to get to my rifle, so it will be a while before I get it back, but I will be happy to post photos as soon as I can.

[John in PA]

Damage to sight(s)? Broken solder joint , loose screw, dovetail loose, I had a joint come loose during a 1000 yard artillery match on time with my 10-pounder Parrott rifle. Couldn't figure out how it could have suddenly opened up groups so much, having shot winning scores for several years prior. Found the loose solder joint in the rear sight at the end of the match. Stabilized with a hose clamp (only option on hand) and won the match the next day.
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