More Pedersoli Sharps, curious situation

[chuebner]

This past Sunday I shot a series of loads to experiment with 5744. I loaded 5 rounds each of 24gr. 5744, Lyman 457193 sized to .459 and each group of five had a different primer. WLP, WLR, WLRM and CCI #34. I was attempting to see if primers made any difference in the amount of unburned powder left behind. I also loaded 5 rounds each of the same charge with the Lee 459-405HB sized to .459 and WLRM and CCI #34 primers. I would shoot one 5 round batch, observe unburnt powder in the bore then wipe bore before next batch. At 100 yd. all rounds are impacting within the 10 ring of the SR1 target. The curious situation occurred when shooting the Lee loaded rounds. Bullets are impacting 2-3 inches to the left of point of aim yet the groups are tight. This is a WTH for me. Both Lyman and Lee bullets weigh around 400gr and both sized to .459. The only difference between the two is the lube used. The Lyman bullet is lubed with Rooster Red and the Lee bullet is lubed with Emmerts BPCR lube. Could the difference in lube have caused the difference in POI? Any ideas?

BTW, the WLRM and CCI #34 primered loads left the least amount of unburnt powder. Makes sense, hotter primer more complete burn.

charlie

[cast405]

Just a thought but could the bullet be leaving the barrel at a different spot on the harmonic of the barrel..due possibly to the different lube, velocities ect?

[dubber123]

You have learned a valuable lesson! It's particularly useful with fixed sight handguns. I took out one of my S&W .38's that hadn't been shot in years. All I had was 148 gr. wadcutters. They shot low, (expected that), but 3" to the right. (I didn't remember that.)

Most fixed sight .38's are regulated for 158's, so I loaded some, and the zero came back to perfectly centered. I have had this happen with rifles also. The thought about harmonics makes sense. I have seen windage change as velocity is increased/decreased also.

This can be annoying, but also sometimes useful.

[northmn]

The Federal 215 Mag rifle primer has been a very common primer for BP use in cartridge guns. Matthews used to recommend seperating the BP cases and drilling out and very slightly enlarging the primer holes. However you are using 5744 so I question if that would be wise. Lee bullets have very shallow lube grooves and are often undersized for a 45 cal rifle. I had one that cast 456 with 1-20 lead alloy and barely made 457 with WW. Might explain impact difference.

Northmn

[montana_charlie]

When shooting your Sharps, do you rest it in the forearm...or on the barrel's sweet spot?
CM

[chuebner]

When shooting your Sharps, do you rest it in the forearm...or on the barrel's sweet spot?
CM

My Sharps has the schnabel forearm and I rest it with the curved part of the forearm just forward of the front rest. I haven't yet determined where the sweet spot is on this rifle. Everytime I go to the range it is either too windy or I have forgotten the baby powder on the bench.

[chuebner]

Lee bullets have very shallow lube grooves and are often undersized for a 45 cal rifle. I had one that cast 456 with 1-20 lead alloy and barely made 457 with WW. Might explain impact difference.

Northmn

You must be thinking of the Lee 457-405-F which does have shallow grooves for smokeless loads. The bullet I'm using is the Lee 459-405-HB which is for black powder and has substantial lube grooves. I lapped this one out to .462 for my trapdoor and size it to .459 for my Sharps and rolling block.

charlie

[NickSS]

I have noticed changes in impact point with bullets of similar weight in numerous calibers over the years. Some calibers are more sensitive than others. Weather, temperature and wind also make a difference. I think the lee bullet you were using has a hollow base and the other is a flat base bullet. That alone can make the difference. That is why you always take a sighter shot or two before you shoot a match. You will probably have to tweak the sights. I had one match several years ago where I shot at 600 yards a 10 shot string and got a 98 4X. So I just knew the rifle was zeroed for the next string. I took a quick look through my spotting scope and the conditions looked the same. So I decided to not take the two sighters allowed. Afterall the rifle and load was right on only a half hour before. Well I fired my first shot and what do you know? The bullet instead of hitting dead center like I called it hit way out in the 6 ring thee moa left of where I called it. The wind conditions had changed and I did not catch it. So after cranking on three minuted right I was back in the x ring for my next shot.

[montana_charlie]

I haven't yet determined where the sweet spot is on this rifle. Everytime I go to the range it is either too windy or I have forgotten the baby powder on the bench.
First, make sure you relieve the contact between the forearm and the front of the receiver. You should be able to see a sliver of light between them. This keeps changes in the wood from changing the vibration in the barrel.

To find the sweet spot...

Hold the rifle by the receiver with the muzzle hanging straight down.
Tap on the upper barrel flat with your knuckle...hard enough to hear the barrel 'ring'. (A plastic mallet is more comfortable to use, but it doesn't take a hard hit.)

Start tapping a few inches back from the muzzle, and work upward.
The sound will be like 'thumm'...'thumm'...'thumm'...'thup'

When you get 'thup', put some masking tape on the spot.

I used to wonder if finding the sweet spot that way would agree with the talcum powder method. It was always too windy for me to find out, myself, but some other shooters tried it and said the two methods agree...

CM

[StrawHat]

I haven't yet determined where the sweet spot is on this rifle. Everytime I go to the range it is either too windy or I have forgotten the baby powder on the bench.


How does one use talcum powder to find the sweet spot? I must have been talking during calss on that day and missed it.

Thanks.

[montana_charlie]

On a day when the wind will cooperate by being absent...
Apply a generous dusting of talcum powder to the top flat of a dry (not oily) barrel.
You may rest the barrel on the forearm while shooting from a bench, but it is better to shoot offhand.
Fire one or a few shots, disturbing the rifle as little as possible between shots.
You should find that the talcum powder has been vibrated off of the barrel...except for any spot which vibrated less, or not at all. The presence of talc indicates a 'node' and it's possible for there to be more than one. But the one nearest the muzzle is the 'sweet spot'.

CM

[chuebner]

On a day when the wind will cooperate by being absent...
Apply a generous dusting of talcum powder to the top flat of a dry (not oily) barrel.
You may rest the barrel on the forearm while shooting from a bench, but it is better to shoot offhand.
Fire one or a few shots, disturbing the rifle as little as possible between shots.
You should find that the talcum powder has been vibrated off of the barrel...except for any spot which vibrated less, or not at all. The presence of talc indicates a 'node' and it's possible for there to be more than one. But the one nearest the muzzle is the 'sweet spot'.

CM

Definitely works bets with octagonal barrels. I tried the powder trick on a friends H&R BC and had a dickens of a time with keeping powder on the round barrel. We fired a dozen shots and never did find a "sweet spot".

charlie

[JSnover]

The only difference between the two is the lube used. The Lyman bullet is lubed with Rooster Red and the Lee bullet is lubed with Emmerts BPCR lube. Could the difference in lube have caused the difference in POI? Any ideas?

charlie

I've had it happen with both lyman and lee boolits. Group size didn't change much at 100 yds but when I tried different lubes the group centers would shift 3-4 inches.

[twotrees]

Try this and see if you get the same spot, as the talc.

Take a piece of 12-14 gage copper wire about 1 ft long. roll it flat (straight) then bend it at 90 deg in the center. Place this on the barrel and tap the barrel with a plastic mallet. With the gun supported buy the forearm and the butt, and level, the wire should stop moving at at least 2 places between the fore-end and the muzzle.

That is the sweet spot/spots. I have used this method on muzzle loaders and BPCR rifles and when held on crossed sticks or off sandbags, the rifle shoots quite well.

Good Shooting.

[montana_charlie]

Take a piece of 12-14 gage copper wire about 1 ft long. roll it flat (straight) then bend it at 90 deg in the center..
You had me worried, twotrees.
I thought you would have us holding two bent copper rods...and dousing for sweet spots!
CM

[chuebner]

I've had it happen with both lyman and lee boolits. Group size didn't change much at 100 yds but when I tried different lubes the group centers would shift 3-4 inches.

I guess I'll just have to try these bullets again but lubed the same to see what happens. Thanks for the input gentlemen.

charlie

[twotrees]

That some "black magic" is involved in getting these things to work right.

Also, on a couple, I was ready to call for an Exorcist to get the Demons out of them.

So Dowsing isn't too far off. LOL:-D

[montana_charlie]

I don't know how you feel about black magic and demons. Heck, I'm not sure how I feel about them, myself. But I AM a believer in dousing.

I was a skeptic when I heard about it...and still a skeptic when I watched it.
But the day I tried it myself...and felt that branch bob down while I tried to hold it up...I came to believe.
CM

[chuebner]

I was a skeptic when I heard about it...and still a skeptic when I watched it.
But the day I tried it myself...and felt that branch bob down while I tried to hold it up...I came to believe.
CM

Many strange things out there that defy logical scientific explanations.

Shooting black powder is only one of them.

charlie