Ok I'm stumped!!

[WildmanJack]

Shooting a 550 Gr Hoch nose pour in pure lead, 63 Gr. of Goex 2Fby volume, a .03 card above the powder, compressed .10", All cases annealed, Large rifle primers.
Shooting from a Pedersoli 30" Creedmore Sharps.
Chrony velocities ...
#1 1071.23
#2 841.32
#3 1009.84
#4 1055.26
#6 1053.61
#7 1052.88
#8 1077.81
#9 1059.88
#10 1026.28
#11 806.62
#12 1040.12
#13 799.18
#14 1051.50
#151068.77
#16 1034.26
#17 1062.30
#18 1082.92
#19 1071.23
#20 1066.80
Accuracy at 200 yds was pretty amazing. Most shots were either 10's or x's with a few fliers. But then maybe I was just lucky...

I realize that when it comes to BPCR I am a complete novice but, man I thought I was really being consistent. ANY hel would be very greatly appreciated..

Jack
:cbpour:

[Lead pot]

I don't think the load has much to do with your readings.
I think it's more with the chronograph. You might have the screens or box set to close to the muzzle and the tripod is not solid enough, to much movement.
I use two chronograph and one is very sensitive to concussion with the brain box to close to the muzzle. I have to set it off behind and off to the side of place a cardboard between the unit (not the screens) and muzzle.

[WildmanJack]

Well to be honest, I shot my last Chrony, and upgraded to the best one they had with the printer and remote reader. I set the Chronograph atleast 12 feet ahead of the muzzle, and have it set on a really heavy tripod. For the last 4 shots I had the remote readout and printer on a diferent shooting bench. Before that I was having trouble with a guy shooting some 300 Win Mags on the bednch two spots over...It was making the printer go nuts... Maybe the Chrony is messed up. I'll try it with factory .243's and see what it does...
Jack

[Don McDowell]

12 feet is awfully close for getting decent readings with bp loads. 15-20 ft will deal you less fits.

[montana_charlie]

63 Gr. of Goex 2F by volume,
If I have found my 'best load' while doing everything in the most exacting fashion I could devise, I might switch to volume measuring to save time and effort...if it didn't screw up the load.
But, during the period when I am actually measuring results...group sizes, velocity numbers, 'whatever'...I would only load weighed charges.

I'm not saying volume charges can't be highly consistent. I'm saying that when one isn't, you are unlikely to know it.
It appears you may have had three 'light charges'.

As for the variation amoung the other shots in the string, more compression might help the load burn more efficiently.
It's a 'thing' with Goex.

CM

[boommer]

For what this is worth, on my crony cloudy days ,complete over cast I'll get my best readings with no screens and for sunny to partly cloudy I cut out cardboard 3"wide and spray painted it white. The only reason I notice this is because those cheap plastic cracked and I'M TO CHEAP TO BUY NEW ONES. 15 feet out with any heavy concussion round, and if your your using wads if they don't separate well = problem. Crony with black loads is a different animal .

[Boz330]

I'm with Don and Charlie. Your chrono is awfully close for BPCR. I had problems like that the first time I tried to chrono loads and cured the problem moving everything farther out. I thought that it might have been the smoke. More compression for the Goex might give you a more consistent burn. As far as the accuracy that is pretty good but as the distance increases, if those readings are accurate, things will go south pretty quick.

Bob

[Don McDowell]

Goex doesn't necessarily follow the internet wisdom about the compression thing. Ever tried to use compression in a muzzleloader?
Those low readings could be coming from case neck tension, and it could just be freak readings due to the chrono to close to the muzzle and smoke.

550 grs is a terrible heavy bullet for the 45-70 in the first place and 63 grs is a pretty light charge, not to mention the volume thing (there could of been a variation of several grains from case to case). That low velocity and you stretch the range out further bullet stability is liable to go to the dogs...
Take a page out of the odg's book, they seldom if ever used a bullet over 500 grs unless they were running it with a powder charge of 100 grs or more.

[montana_charlie]

550 grs is a terrible heavy bullet for the 45-70 in the first place and 63 grs is a pretty light charge,
The Pedersoli chamber has a deep throat, so your bullet should set out pretty far when seated to touch the lands. That should leave room for a good charge of powder.
The PGT bullet (specifically designed for that chamber) sets out two grease grooves when chambered in a 45/70...and it weighs 550 grains.

If you raise the powder charge to (say) 65 grains, that will increase the compression to (perhaps) .200". Those who think compression helps Goex usually say that something greater than .200" works for them...and one says that .385" is the ideal compression amount (but he shoots a 'longer' case).

CM

[WildmanJack]

Well, lots of great suggestions her. I'm going to start weighing all my charges instead of volume loading, I'm also going to increase my load a bit, and move the chrony out a bit more. I am also going to weigh EVERY round as it comes out of the mold and make sure that they are within a couple of tents of each other. I know for a fact that some were a a few grains heavier or lighter than the norm. So I'll post my results, but it'll probably be Friday before I get to the range since I play music all day Thursday.. Thanks a million guys...
Jack

[cajun shooter]

Jack, You should listen to what has been given you by the above members as it is all good. You must be hanging out with people who shoot the subs as that is where that load by volume bull comes from. When you are trying to find a cherry load either black or that other powder, I can't remember what it is called you should always WEIGH YOUR CHARGES!! I have compressed Goex Cartridge over .300 with good results. Seat that bullet to where it is just touching the rifleing. Try using a powder charge of 68 grs. and up. If you can get a target stand and put a piece of cardboard on it with a shooting hole cut in the middle. Make sure you place some weight on the base. This will keep any muzzle blast from your chrony. Good luck and good shooting. Let me know how you come out. Your Friend David

[Lead pot]

Vibration from wind and concussion is a big killer for the accuracy of a chronograph. It doesnt matter who makes the unit I have a Pac pro and a CED Millennium. The CED is very sensitive and I get readings like you have with both units if they are to close to get the concussion.
I set my screens out 10 yards and the other at 210 yards and the close brain box way off to the side behind the muzzle with a piece of plywood shielding it from the blast when I take readings for bullet BC. You will see your ES tighten up when you eliminate the vibrations.

5 grains variation in bullet weight and 3/10 gr powder at 30 feet does not make much difference in the velocity, not what your getting anyway.

[waksupi]

The load by volume measuring comes from muzzleloader black powder shooting. No idea what they do with inlines. I actually would eyeball volume measure for first working up BPCR loads, and then weight the charges just for consistency.


Jack, You should listen to what has been given you by the above members as it is all good. You must be hanging out with people who shoot the subs as that is where that load by volume bull comes from. When you are trying to find a cherry load either black or that other powder, I can't remember what it is called you should always WEIGH YOUR CHARGES!! I have compressed Goex Cartridge over .300 with good results. Seat that bullet to where it is just touching the rifleing. Try using a powder charge of 68 grs. and up. If you can get a target stand and put a piece of cardboard on it with a shooting hole cut in the middle. Make sure you place some weight on the base. This will keep any muzzle blast from your chrony. Good luck and good shooting. Let me know how you come out. Your Friend David

[Southern Son]

WildmanJack, the rounds with the lower velocity, did you notice if there was less recoil? with a 200+fps difference in velocity, I think that you would have noticed the difference at the butt. I have a Chrony with the LCD screan separate to the skyscreans and I have noticed that if I put the Chrony as far away as I can (the wire laid out straight), then I get very few dodgy readouts, except when I am testing loads with some kind of wad in them. When testing loads with a grease cookie or cardboard/LDPE wads, even with the Chrony as far away as I can get it, I still get the odd reading that don't fit in with the rest.

I have also notice that a fresh battery in the Chrony helps keep things predictable, if the battery is a littly flat, then I get alot of errors and dodgy readings. FWIW, I found that the batteries were flattening because when I put them inside the folded up Chrony, the top of the 9v battery was hitting the steel casing of the Chrony and when I went to use it next time, the battery would be flat. When I started puting a cover on the top of the battery, I started getting alot more trips to the range with the Chrony before it went flat.

[RMulhern]

More compression, go to 3F, and use a modified Postell or DT Money bullet with the upper two drive bands reduced to .4495" which will let you seat the bullet out two full grease groove! Use betwixt 75-80 grs. powder compressed enough to give you proper chamber fit to close the action. Low pressure loads create fouling galore; bout like burning pine knots in your fireplace! Hot loads burn much cleaner and IMO.....give much better obturation thereby preventing 'gassing' and leading!! Use either a .060" LDPE or same thickness veggie wad atop the powder charge. This procedure gives me EXCELLENT accuracy all the way to 800 yards in my 1885 Browning Hiwall!

[WildmanJack]

Southern Son,
Next time I get to the range I'm gonna set that Chrony out so far I'm gonna need a scop to see it LOL Really out to the end of the wire and put a sand bag on the readout. I was watching the wads and they were fluttering down before the chrony so they were not the problem. I did notice a very slight difference in recoil, but not enough to really start me thinking. I just figured it was me getting used to the recoil..
Mulhern,
I'll try more compression, but I have LOT of 2 FF and although I have thought about getting a postell mold I just haven't had the cash to do it yet. The mold I bought from Hoch is supposed to be a good one for my gun, when I load the boolet into the case I always have one lube groove out of the shell. Holy cow... 75 - 80 grains?? It's only a .45-70 !!!! Isn't that a bit HOT !! LOL
Jack

[RMulhern]

Hot? No....but it shoots like a HOUSE ON FIRE!

[WildmanJack]

Hot? No....but it shoots likes HOUSE ON FIRE!

LOLOLOLO I bet it does hahahahahah,. I'll try a few , man I'm glad I bought a Past recoip pad for my poor old shoulder !!! Thanks my friend...
Jack

[Southern Son]

WildmanJack, what RMulhern is saying is right. I was getting 75grains in mine with a 535 grain Creedmore boolit from a Brooks mould. He cut it so that I only have one grease groove inside the case. Off the top of my head, I think that I was getting 1100-1150fps with that combo.

[martinibelgian]

75grs should be getting about 1250fps with a 530-ish bullet.... Well, at least it does with Swiss 1 1/2Fg

[Southern Son]

75grs should be getting about 1250fps with a 530-ish bullet.... Well, at least it does with Swiss 1 1/2Fg

I wish we had Swiss. Here down under, we have a choice between Wano and smokeless. I had alot of my reloading records on my old computer, which has stopped working. The rest of them were on paper, and the removalists have put them somewhere that I have not yet discovered.

I know I was loading 75gr of FFg Wano, but I cannot find the loading records. I know that I was hoping for 1250fps (one group of long range shooters here in Oz have deemed that the minimum velocity needed to shoot in their 1000 yard match), but I know that I came up very short of 1250fps. When I turn up my notes, I will confirm the actual velocity.

[dave roelle]

I was using the past supressor with 74 gr 45-70 loads with the money bullet and experienced extreme horizontal stringing cause by butt movement associated with the past pad-----pay close attention to butt position and firmness of shoulder pressure to combat this difficulty------thanks again for montana charlie for the diagnosis of this problem for me.

keep well-stay safe

dave