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Hot Topic (More than 10 Replies) Muzzle Velocity is not consistent, why. (Read 11121 times)
Sharps1874
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Muzzle Velocity is not consistent, why.
Apr 29th, 2006 at 2:23am
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      I bought a Chrony Gamma Master Chronograph and finally used it the last two days with my sharps. I noticed that my muzzle velocities from my Sharps has a wide range of variance in it’s Muzzle velocity. I own a Shiloh Sharps Sporter #1, 45-70 with a 30” barrel that has a .459 bore. I already have the Lyman 457132 (535 gr Postell) bullet mould. I’m using IMR 4198 at 25 grains, with CCI Large Rifle primers. I’m using a RCBS digital scale, backed up with a standard Redding scale to check my powder loads. I cast my own bullets with in a grain of each other. I shoot 5 fowlers to heat my barrel up. Then I shoot and I have gotten from boxes of ammo that I have loaded to very as much as 100 fps. Yesterdays shots went from 1104 fps to 1205 fps, with most shot from the 1120’s to 1140’s range. Then a string of 10 or 15 would go to the 1170’s fps to 1182’s, or up top just over 1200 fps. Yet today I finished ammo from a box from yester day that had 15 left and shot 35 more from another box of the same load and bullets and they all were in the range of 1170’s fps to 1278 fps. Then when a friend shot 15 more bullets of the same box that I had my last 35 from his range went from 975 fps to high 1000’s fps, with none in the 1100 fps. Can some one explain this what seems to me to be a strange inconsistency of the Muzzle Velocities that I’m seeing over the last two days? Granted I’m using the same powder, yet I’m sure some of the loads have come from different containers of new gun powder that I had to put into my powder measurer the fill it so I could continue to load. Could there be that much of a difference from the powder of the same type from the same company? How could my friend and be shooting the same group of bullets from the same box of bullets and have about a 200 to 250 fps difference? And don’t tell me this has to do with the wind, the sun and the rotation of the earth. My Chronograph is 8’ from the rifle and it’s not getting any errors, and it is with in the recommended distance. This really has me wondering what is making the Muzzle Velocity very so much.
  
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harry_eales
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Re: Muzzle Velocity is not consistent, why.
Reply #1 - Apr 29th, 2006 at 8:35am
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Hello Sharps 1874.

Getting consistant velocities or as near consistant as possible requires total consistancy in your reloading and shooting technique.

All your cases should be from the same manufacturing batch, as should the primers and the powder. If your shooting previously reloaded brass then all should have been shot the same number of times. No die settings should be changed during reloading at all. Try weighing your bullets before and after running them through a lube/sizing die. Select only those that weigh exactly the same. 

I'm not familiar with the powder your using, I've not used it myself, but does it fill the case to the base of the bullet? If not, then it is possible that the powder in each case will be exposing a different surface area to the primer flash.This can effect the burning chateristics of the powder. Try holding the case vertically and tapping the cartridge rim to settle the powder against the primer flash hole and keep the round as upright as possible when loading it into the breech. Alternatively, use a case filling medium over the powder to hold it in place.

You mention firing five rounds to foul the barrel, how rapidly did you fire? Every round you fire will heat up the barrel and cause minute but measurable dimensional changes especially if fired rapidly. Try firing one fouling round, leave the breech open for say 10 minutes then fire one round through the chronograph screen. Wait 10 minutes for the rifle to cool and fire another round and so on. This will certainly give you more consistant results. 

When you were shooting, were your loaded cartridges exposed to sunlight? If so they may have gradually warmed up during the time you were shooting. Best to keep all loaded ammo in the shade, out of direct sunlight so that an even cartridge temperature can be maintained. The warmer a loaded cartridge gets the higher the pressure it developes when it is fired, even a 5 degree change in temperature can make a considerable difference in muzzle velocity. Again it's consistancy that is important.

I think that on your second days shooting the air temperature was cooler than the day before, hence the lower velocities obtained.

If your absolutely consistant with your reloading, the way you load the rifle and the timing of your shots you should get velocities with no more than a 50fps variation. (Factory made ammo will vary more than that).

If you watch Long Range Black Powder Rifle matches where similar rifles to yours are used, you will note that no one fires rapidly, they often take several minutes between shots, allowing their rifles to cool down. You can bet your last 10 cents that each of them will have taken great care over every round thay have loaded. They have enough to worry about with wind conditions, bullet drift and site adjustments etc.

I hope this helps,

Harry
  
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leadball
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Re: Muzzle Velocity is not consistent, why.
Reply #2 - Apr 29th, 2006 at 9:36am
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My suggestion, go to Wal-Mart and get some WET foral foam from the flower arrangement dept, cut it about 1/4 inch thick and push the foral foam [wad] down to about 1/8 to 1/4 inch from the powder, this wad stopped the wide velocity readings in my 45/70 Peabody.       leadball
  
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iowa
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Re: Muzzle Velocity is not consistent, why.
Reply #3 - Apr 29th, 2006 at 12:07pm
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Sharps 1874:  I might be able to give you better advise if you were having problems with shooting Black in that Shiloh, which you should be doing, as ES and SD numbers will be much much less:::but I'd try a different smokless powder.  40-50 fps deviations are not unusual with smokless, but your numbers are crazy.  I'd try AA 5744.  But use a tight crimp.  I have shot this powder in my Shiloh with the Postell and it works reasonably well.   Best regards steve witt
  
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Dale53
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Re: Muzzle Velocity is not consistent, why.
Reply #4 - Apr 29th, 2006 at 5:31pm
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Cutting the floral foam (it comes in a block - the porous green stuff) is easy on a table saw or even a bandsaw (Hey! I learned that here on this forum). I have used it in my .32 Dell for several years. Just remember to seat it off the powder .100"-200".

Dale53
  
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Sharps1874
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Re: Muzzle Velocity is not consistent, why.
Reply #5 - Apr 30th, 2006 at 1:22am
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harry_eale

           Yes I am using all Winchester brass, not sure if everyone would agree on my choice…yet as I see it…it’s my money and my choice of brass. I did my research on brass…and I liked the data for Winchester for my 45-70. 

           All my cast bullets are weighed with in a grain. IMR 4198 has been around a long time and it is a proven powder that I have researched that produces very good loads per load data that I read. My Mentor Bullet Caster, had told me in the beginning of my shooting the Sharps, was to tap the base of my bullet and to keep the tip up to keep the powder at the base closest to the primer, that’s what I do all the time. 

           I did not wish to get into a case filler when I first started out, yet I’m at that point now that I’m looking at trying it out. I have a friend that will give me some kapok to try out and I’m sure I can buy kapok if it works for me. 

           I try to duplicate the same conditions that I have when I shoot for competition, where I have 20 minutes to shoot my fowlers and my 10 shots for score. I try to keep a rhythm. I don’t think that It’s practical to wait 10 minutes in my practice when I don’t have that much time to do it in competition. I do understand what you are getting at. Yet I did wish to explain why that part of you suggestion is not practical for me. I can take 1 to 2 minutes to include my fowlers. 

           I’m out doors when I’m shooting up on the ranch as I was doing last Thursday and Friday. Only the bullets that I had out were exposed to a shaded area, no direct sunlight. All my other load were in Case Boxes closed and in a range bag. I was not aware that a 5 degree change in temperature would make such a difference, thank…that is very good info to know. Yes consistency is very important. Every bit of knowledge helps not just me, but so many others that never say anything on these forums yet use what we discuss, thanks once again. 


I would like everyone to understand that one day I will go BP, yet I would rather stay with Smokeless for now. I do wish to work out as much as I can with my smokeless, before I go to BP. 
   

   


  
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boats
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Re: Muzzle Velocity is not consistent, why.
Reply #6 - Apr 30th, 2006 at 7:21am
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I would try another powder before I changed anything else.  I generaly say bullet fit is the prime cause of problems in a single shot. However with a big case like the 45/70 smokeless powders have a hard time burning at the proper rate. And Smokeless that does not burn properly is inconsistent. For a clue look for unburned grains or large amounts of residue in the barrel.

This morning I  looked at Handloaders Propellant profiles.  They say 4198 may need wads to get up to proper pressure. Also interesting  was the comment on 4759. Handloader's book  mentions when it was out of production many shooters of old cartridges had to go to 4198 with less than satisfactory results. 

2 F Black would be my first choice, If you need a smokeless load 4759 would be the way I would go. It's not always the best but 4759 will never be wrong in a large straight side case. It's the only thing I ever use for smokeless in anything larger than a 32/40

If either of those don't have any problems then you can go back to the 4198 and see if you can alter the burn rate with more bullet pull. I  have had good luck with the Lee collet dies to put a firm crimp on large bullets. That will generaly get powders burn rates up. It's a personal thing but a wad would be the last thing I would do.

Boats
  
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monkeyboy
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Re: Muzzle Velocity is not consistent, why.
Reply #7 - Apr 30th, 2006 at 9:36am
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     Before I went to black powder,I used 28grs of AA5744 with a 1/4 sheet of TP to hold the powder back in the case.Groups @ 100yds averaged 1 1/2"-2",SD's in the 6-8 fps range.Going to black cut those SD's in half! FWIW--Monkeyboy
  
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montana_charlie
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Re: Muzzle Velocity is not consistent, why.
Reply #8 - Apr 30th, 2006 at 4:59pm
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Sharps1874,
You didn't respond specifically to one point that harry_eales made, so here it is again...
Quote:
Try weighing your bullets before and after running them through a lube/sizing die. Select only those that weigh exactly the same.


How do your bullets weigh AFTER being lubed?
CM
  

Retired...twice.  Now, just raisin' cows and livin' on borrowed time.
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Schutzenbob
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Re: Muzzle Velocity is not consistent, why.
Reply #9 - May 1st, 2006 at 5:42pm
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If you haven't already thought of these; #1 How well does your firing pin strike the primer? Does it give the primer a good hard wack? Does the pin strike in the center of the primer? #2 Have you tried raising the muzzle up after you load each cartridge, so that the powder will be back against the primer. That might help too. Let us know.

Bob
  
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Sharps1874
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Re: Muzzle Velocity is not consistent, why.
Reply #10 - May 2nd, 2006 at 1:03pm
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I’ll try to cover all the question the best that I can, so this may be another long one. Let me say hear and now, the Chronograph was always intended as a tool and nothing else. 

boats,

     To change a powder would be a major change. One thing that I have learned over the years is make small changes. There can be something that I can improve on that I’m doing now that could make all the difference in the world. And it’s my feeling that I have more then one thing going on with the velocities. I have very good tight bullet fit. 

     I have my last brass that I shot to clean and prep t reload them, I’ll take a look to see what if any residue of powder is in my brass, good suggestion, thanks. Yes, I have read some of the same info on IMR 4198, and just 4198 as a whole. Yet it’s still a powder that so many are shooting with, and having great success. Wads are out for me, yet I’m trying to hook up with a friend of mine that has Kapok that he and others are using to try out soon. I’ll keep in mind 4759, yet for now I am gong to do what I can before I rule out IMR 4198. 

     I already have 2f for when I start loading for BP. 

     
  
monkeyboy,

           I’ll keep the AA5744 in mind, yet I’ll use Kapok instead of TP, thanks. 

montana charlie,

           I’ll have to get back to you on the weights of my cast bullets before and after being lubed. I have so many that are already lubed that I need to shoot those up. I do have some that are cast and not lubed and more that I am casting yet not lubing until ready for them, I’ll get back to you on that when I do them. 

Schutzenbob,

           The firing pin strikes very well. I look at my brass during my case prep. I’m going that today. That is one of many things that I look at. Raising the muzzle has been done in the past. I do admit that I did not do the muzzle lifting last week, yet I always tap the base of my case to settle my powder. 



     

« Last Edit: May 2nd, 2006 at 9:32pm by »  
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40_Rod
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Re: Muzzle Velocity is not consistent, why.
Reply #11 - May 3rd, 2006 at 8:37am
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74

If you try 5744 do not use a wad to constrict the powder. I shot 5744 over a chronograph with the powder loose in the case and with the powder constricted with a wad .100 of the powder. The loads with the powder shot tighter Sds and gave tighter groups.

40 Rod
  
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Ray_Newman
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Re: Muzzle Velocity is not consistent, why.
Reply #12 - May 3rd, 2006 at 1:14pm
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40Rod: my experiences w/ Accurate Arms XMP5744 in a Browning 1886 & a .40-65 Browning BPCR were just the opposite of yours.

The XMP5744 loads w/ a wad shot much better groups. I placed a one-quarter sheet of toilet paper in the case to act as wad. 

I have no idea as to ES & SD as I didn't chronograph the loads.
  

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Re: Muzzle Velocity is not consistent, why.
Reply #13 - May 31st, 2006 at 2:03am
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well by golly,  i finally found a person to share a secret with. try IMR 3031. a friend did a bunch of work in the early 70's with 3031 and a trapdoor. very impressive ! i think it was written up in Handloader or Rifle magazine. i believe he used a large pistol primer but you would have to check that out. dont remember the load though. 
one thing to check is to see if the bullet is sealing the bore..... seat the bullet out until it is where it would be when chambered, insert a primed case-no powder- and pull the trigger. you wont hear a thing except the hammer strike. wait 3 seconds and open the breech. if the bore is sealed the case will come flying out and land 6-8 feet away. the bullet base will be covered with soot. if the bore is not sealed the case wont fly out and the bullet will have soot down the sides.  yes this is big mojo but it works Smiley Smiley Smiley Smiley Grin
  

ah heck  AA#9,4227,300MP, as long as it goes bang
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Sharps1874
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Re: Muzzle Velocity is not consistent, why.
Reply #14 - Jun 1st, 2006 at 12:26am
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dave_j

     I do have IMR 3031. I use it for my 30-06 and 30-30 loads. I’m doing some reloading Thursday. I’m thinking about trying the IMR 3031 and see what it does. I’ve done a check, and since I seat my bullets out as far as I can, they are seating. I recently got a small sample of Kapok to use; I just have not done that yet. I have a feeling that my powder is not burning the way it should because the powder is not staying together in one spot directly over my primer. 

     When I did my research on what powder to use. The IMR 4198 looked the best over all. And as I found out from the guys that I shoot with, those that shoot smokeless use the IMR 4198. In my research, I found descent load data for IMR 3031 and the IMR 4064 for my 45-70. I already have both the 3031 and the 4064 for my hunting rifles. I have planned to try them out eventually. 

     Thanks for the input and the suggestions. 
  
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J.D.Steele
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Re: Muzzle Velocity is not consistent, why.
Reply #15 - Jun 1st, 2006 at 6:01pm
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I've used 3031 extensively in the 45-70 since the late '60s, with very good results provided I did two things. It's been my experience that the best results with 3031 are obtained when 1) heavy charges are used and 2) a heavy crimp is applied.

It appears to me that the ignition is much better when the pressure is up when using this powder; light loads gave me lots of unburned powder and poorer accuracy in almost every shooting session. Lately I've been using ReLoder 7 with good success.
FWIW, good luck, Joe
  
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Sharps1874
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Re: Muzzle Velocity is not consistent, why.
Reply #16 - Jul 22nd, 2006 at 9:55pm
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We had our monthly shoot at the Richmond Gun and Rod Club. As I had mentioned, none of the previous test loads stood out by themselves. So I took the Kapok load and increased it’s gun powder to 26 grs of IMR 4198, with my 535 gr bullet. It did very well; better yet, it’s the best of the loads so far. Now I need to improve the nut head behind the rifle. Seems the shooter needs to get back to the basics of shooting. My Sharps is forcing me to do so, it’s not as forgiving as my hunting rifles have been. I had some lengthy discussions with the other shooters about my shooting, and the next steps I need to do. I find myself very privileged and lucky to know them and that they are open to helping me. After many hours and thousands of rounds, my time will come and I will be much better…I sure hope so. I do not plan to mess with this load until after next months shoot, I’ll see how I do there, now that I’m happy with what I have now.
  
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Sharps1874
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Re: Muzzle Velocity is not consistent, why.
Reply #17 - Aug 30th, 2006 at 2:26pm
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It’s been awhile since I’ve updated my findings. As I had mentioned before, it would take time to do the research, and now it’s been done. 


I have finalized my 535-grain bullet load for now. I went with the IMR 4198 with 26 grains and .5 grains of Kapok. What a fine load. This may not be the load that works for anyone else, yet it’s fine in my Sharps. 


Again, some of you wonder why IMR 4198 and not something else, simple. Not all rifles shoot the same or shoot well with all powders. You use in your load a powder that shoots well for your rifle, even if it is not a good powder for someone else’s rifle. You should only worry about your own rifle, and what works for it. In my case, IMR 4198 works just fine in my Sharps, and I’m comfortable with WP. Perhaps one day I’ll try a different WP, or yes…even go BP. But for now, I need a solid load for both bullets that I shoot…and yes, I need much more trigger time with my Sharps. It’s a sweet rifle to shoot and so much fun. 

I hope that none of you got the impression that I’m trying to improve my shooting by finding some kind of a miracle load. Lets be practical, if I’m a lousy shooter, no load will improve my shooting. Yet, I’m trying to get a good load that will give me a nice grouping, then I can concentrate on my shooting and not my load. If I’m confident in my load, then I can focus on my shooting, and not worry about the load. 

Next November will be my one-year anniversary of when I first shot my Sharps. I think that I have done well in just 10 months. I’m shooting rounds that I have loaded with bullets that I have casted myself. And I’m happy to say that they are as fine of a bullet as my Mentor Ron in El Cerrito, CA makes. For those of you that know Ron, you know what I’m talking about…great bullets by Ron. 

OK, I’ve been shooting my 420 grain bullets with IMR 4198, loading 27 grains with .6 grains of Kapok. This has turned out to be a great load for my Sharps. This months shoot up at Richmond, CA…I used the 420s in the competition. I would have done much better if it were not for the nut behind the rifle. The Chrony ranges anywhere from 1350 to 1386. The 420-grain bullets are at the same range in MV as my 535-grain bullets that are using the same powder with 26 grains and .5 grains of Kapok. I think that I found my loads for both bullets. I did load one more test load for the 535-grain bullets. I increased the powder to 26.5 grains. I just wanted to see what the MV was, and how they group. I’ll shoot them sometime in September up at Richmond with one of the guys that I shoot with there. What I need now, is no Chrony, and much more trigger time with the rifle. My Chrony is now taking a well-deserved rest. 

It is currently hunting season, so I’m splitting my time between Deer Hunting and shooting the Sharps. After September, I’ll have more time again to shoot my Sharps and get the trigger time that I need. Unfortunately, the September shoot at Richmond I’ll have to miss, that’s the closer of Hunting Season…and yes you guessed it…I’ll be hunting. 

And no, I have not forgotten about the Paul Jones 570 grain bullet mould. Every shooter must have at least one dream, or hope for something more. This will happen one day, but not soon. Before I get it, I’ll have to find some load data for the bullet. The 570 might just be a bust for me, yet I’m hoping that it will be a fun bullet to shoot. I’m off tomorrow for a one day hunt then the weekend for the long hunt. 

I would like to hear what all of you are using in your loads to include what brass for the 570-grain bullets, the 535 grain bullets, and the 420 grain bullets. I hope you all are enjoying shooting your rifle as much I am with mine. 




  
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Sharps1874
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Re: Muzzle Velocity is not consistent, why.
Reply #18 - Sep 12th, 2006 at 12:30am
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I made one more change to just my 420s. I increased the Kapok to .6 grains, it's made a real difference. My 535s are still at .5 grains of Kapok. This wednesday I'll be trying 26.5 grains of IMR 4198 just to see what it does.
  
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