Keyholes from my Sharps .45-70

[WildmanJack]

Went to the range today and shot my new Pedersoli Sharps in .45-70. Loadedd cast boolets of .405 gr from ww over 70 gr. Hodgdon 777. Out of 25 rounds I got two keyhols at 100 yds. Any ideas? :-?
Jack

[dubber123]

Whats the bore slug at, and what do the boolits measure?. A friend just bought some cast 405's, at best, they measured .457". Pretty small.

I got a bunch of keyholes out of my Sharps when I first got it. I was using smokeless, and found out I was shooting the plain base boolits WAY too fast. I reduced the load, and it shot great. I dunno if you can get enough vel out of 777 to do this. My bets on an undersize boolit.

[405]

Yep, first impression is that the bullet is too small for the bore/groove. I assume your bullets are plain base. I also assume the Pedersoli is .458 groove?

I'd try a .458 or .459 bullet. Next, with smokeless, I'd go gas-checked (RCBS makes the mold in the bullet style you're shooting) and try 5744.

For BP the plain base should work ok with over-powder wad.

In either powder type and for the velocities/pressures you want in a BPCR type gun... an alloy BHN range of about 7-11 should work. The velocities that work for me in the 45-70 with that bullet style run about 1100-1250 fps. FWIW- That recipe of bullet style/size/hardness, bore twist rate, powders, etc. produces consistently 4"-4.5" @ 300 yd accuracy in my Sharps with zero wobblers :mrgreen:

[August]

I have a couple of buddies that I shoot long range BP with who own Pedersoli Sharps style rifles. Both of them has had this problem along the line. It was cleared up by using heavy, soft bullets, sized close to bore dimensions, which seem to be on the large side of things.

My first reaction to your post, however, was that you are shooting a light bullet over a VERY HEAVY charge. Triple seven is the hottest sub and 70 grains is a lot of powder in the 2.1. So, I'm going to suggest the following:

A. Use real black powder if it's available to you -- 63-65 grains of 2F to be specific.
B. Be sure to use an over-powder wad -- the Walter's .060 is a good starting point.
C. Run some lead through your bore to get an idea of the dimensions (again, P.S. tend to be on the "generous" side of bore dimensions in my experience).
D. Use a 500 grain+ booolit.
E. Try some 30/1 alloy for your booolits -- it will "bump-up" to fill the P.S. bore.

I suspect the hot load, with no over powder wad may have distorted the base of your boolits. This, in conjunction with hard lead, will make accuracy a problem. I am assuming you were wiping the barrel after every few shots to eliminate fouling as an issue.

Hope this helps.

[WildmanJack]

Wow, Well I guess I have a lot of work to do over the next few days. I thank u guys for all the info. I wondered why some of the boolets were dead accurate then I had these two keyholers that were no where near as accurate. I'll slug the bore today, and see what that brings, Measure the Boolets and see if I can get some real black. Now finding a 500 + grain boolet mold might be a bit more of a challenge.
August,
I would guess that 30/1 alloy would be almost pure lead, right ??
Jack

[August]

August,
I would guess that 30/1 alloy would be almost pure lead, right ??
Jack

It seems to be just enough tin to get the mould to fill out consistently. It conserves tin, too. Seems to run well in Pedersoli Sharps, as I make the boolits for my buddy who shoots one. Before we went to the softer boolit, I used to watch his booolits in flight and they wobbled all over the place. Now, they go on a smooth arc to the target.

I make my 30/1 using lead from a radiology lab salvage job and certified 50/50 bar solder. For cowboy shooting, I use whatever lead is at hand. But, for long range, I try to carefully control the alloy at 30/1 lead to tin. Yes, the 30/1 boolits are pretty soft -- I believe that's why they run well in the P.S.

Hope this helps.

[montana_charlie]

Every Pedersoli Sharps I have had contact with will accept a .460" bullet. That is the diameter I would recommend you use.
If the first ones you shot were undersized, you may have leaded the bore. That might even account for the keyholing on two rounds.

Many BPCR shooters like 30-1 alloy.
But it seems that more and more are coming to regard 20-1 as the 'all around alloy' as they get to shooting bullets of the correct size...and depending less on 'bump up' to make a poorly-fitting bullet shoot well.

CM

[405]

WMJ,
For sure slug the bore if you haven't already. With a single shot like the Sharps it's easy to slug both ends. Gives a little better picture of what you are dealing with. Drive a slug in from the breech a couple of inches. Then drive back out the breech using a rod placed into the muzzle. Then do the same thing for the muzzle end. If you have an extra slug say a tapered 46-47 cal then you could also drive a slug into the breech stopping where the slug is about midway between chamber and bore. The idea is to get a slug of the throat. Tap back out thru the breech and you should get a fair idea of what the throat looks like.

Bullet diameter should equal the groove diameter up to about .002 larger. I like to start at groove, test, then try .001 larger than groove, test, then last resort try about .002 larger. Of course at some point the rounds with larger bullets won't chamber. Better to start at groove then work up. Easy to hone out a Lee push thru sizer.... really hard to hone in a Lee push thru :mrgreen:

The 30-1 and 20-1 lead-tin alloys are good places to start. They should test about 9 BHN. If you try some mixture and it jumps to BHN 14 or something then likely there's some antimony in the mix and a little too hard to obturate and not needed for this type low pressure/low velocity shooting.

Reverse of the same coin... if you have alloy that is say BHN 14-18, the bullet is gas-checked and the bullet matches the groove diameter up to +001" then that likely will shoot very well, particularly with the smokeless loads going a little faster.

[WildmanJack]

CM,
I thought about the leading issuee and looked right quick at the bore. It didn't appear that it was leaded and it cleaned up nice and shiney when I got home. Now the thing that gets me is that the two keyholed shots were about 7 or 8 shots apart. Ya know I think I'll just slug the bore, the throat and see what the heck the thing measures out to. That will be the beginning of solving my problem. I also need to seriously decide if I am going to shoot Black or smokeless. I really dont' know yet. I know that smokeless is a lot easier to load.. No wads, no grease plugs, etc. but I was seriously thinking of getting into paperpatching and trying to keep it as origional as possible.
405
I didn't size the boolets I used, I water dropped them from wheel weights and then lubed them by hand. I forced the lube into the grooves with my fingers. I don't want to do that again!!! Tthey miced at .45825 So maybe I need to go to a bigger boolet. Tomorrow will tell..

August,
When I figure out the boolet size, I'll tryr some 30-1 and some 20-1 and we'll see what happens.

Thanks to the three of you for your input.. I'll post my slugging numbers soon as I get it done...

With MANY Thanks,
Jack

[405]

Yes, each one is a whole new experience. Sometimes you just throw a bullet in a case on top of some powder and bingo! Other times just have to start at ground zero and work up. Keep at it. 99.9% of the time it will all work out then there is nothing like the feeling of punching out, shot after shot, a one inch round hole in the target at 100!

In my load data log I'm now at load #115 for just the 45-70! That is 115 different load combinations in that one caliber! That does include several different guns... from trapdoors to levers to Sharps. But possible combinations are near endless. Some guns took only a couple of tries to get a good one. Some guns have taken 30+ tries! But, with patience the magic combo is usually found.

[boommer]

wildman I would say the problem is in water droping w/w and would use SPG lube to start with and.459 soft bullet 1-30 to 1-20 even with smokeless up to 1450 fps. This is my ground zero combo and never seen a keyhole in any 45-70 I've owned , including a old trapdoor.Where your bases on your bullets good and sharp? If you had no leading then the bullet was not stripping but I have had lube that has not let the bullet bite in to the rifling but wouldn't leave leading because the pressures of the load.This lube that I mixed up is great for the nastist mag loads but sucks for med to low pressure loads so look at your lube.

[cajun shooter]

Jack, I will agree with Boommer. I think you need to stay away from the water drop. You don't need that hard of a bullit for your rifle and a too hard bullit can cause a pot full of problems.

[August]

Actually, black powder enhances the accuracy potential of this cartridge greatly over smokeless! You will be shooting M.O.A. groups much sooner if you stick with Holy Black in my experience.

[WildmanJack]

Finally got some dowling to slug my barrel. So here's the results. Barrel slugged from the muzzel slugged at .4557 x .4511 Slugged from the breach it was the same. Now my cast boolets drop at .460 unsized. So what do u think? Maybe it was the powder load? Should I beagle the mold and try a bit bigger boolet? I wwill stop water dropping them from now on...Let me hear what you think....
Jack

[405]

Well, I assume you mean the groove is .457 not .4557 :mrgreen:
Your mold is dropping .460 bullets- that's the good news.

You'll get as many opinions as there are guns, bullets and shooters.

My list of gadgetry/techniques that may help if you are serious about getting the gun to shoot to it's potential would include:

Lee push thru bullet sizer- .457 try, lap to .458 try, lap to .459 try, etc.
The sizer can be used to size all bullets same and can be used to size and seat gas checks if you decide to go that route.

BHN tester, Lee is about least expensive. Work with bullets of known hardness. Try soft bullets, medium bullets, hard bullets etc.

Try black powder with .030 card, bullet seated to lands
Try black powder with .060 card, bullet seated to lands
Try black powder with .030 card+ grease cookie+ .030 card, bullet seated to lands
Try cleaning between shots with the black powder loads
Try different lube like SPG or a soft Felix type, etc. (can be used with the smokeless also)
Try a gas checked bullet over something like 5744 (same trial and error on the sizing as with the plain base bullets)
Shoot for 1150-1250 fps velocity- these type guns/calibers seem to work best in that range.
Have fun!

[WildmanJack]

Nope the groove is .4557, measured it 10 times to be sure..
Jack

[405]

Yeow that be tight!
Not necessarily bad though. Never had a 45 cal rifle that tight so into unkown territory here.

Couple of thoughts .0002 cents plus grain o salt each :-D

Given your first tests with the odd bullet going unstable it could be either.... bullets too big or full powder charge (777?) blowing the base or otherwise destroying the integrity of the bullet as it passes from chamber to bore or a combination of all those.

Can only theorize here. At ignition the .460? bullet is rammed into a very tight hole. Pressure builds quicker and beyond what one would expect given the load data for the 777 charge. Something may give and in this case if it gives too much once in a while- might account for the once in a while wild one.

Still, I'd get the .457 Lee push thru and try it. They're only 15.00 plus change.
Another cheap thing to try with smokeless would be to get a hand full of .457-458 gas checked bullets like the RCBS 400 FN GC in a softer alloy about 8-9 BHN. Size them to .457 in the Lee push thru and load over a light charge of 5744 (1150 fps) and see what happens.

[chuebner]

Finally got some dowling to slug my barrel. So here's the results. Barrel slugged from the muzzel slugged at .4557 x .4511 Slugged from the breach it was the same.
Jack

Wow and I thought my Numrich barreled rolling block was tight at .450 X .456. You only have .0023 rifling and my guess is that you are stripping the bullet with that 777 load. I think I would try 60-63 gr. of 2F black and see how they perform. FWIW my Pedersoli Sharps slugs at .450 X .458.

Just my .02 cents.

charlie