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  #1  
Old 06-22-2019, 09:32 AM
bfoosh006 bfoosh006 is offline
 
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Default List of what powders not to use after another.

Good morning, Ladies and Gentlemen.

Years ago, I had a list of what powders not to use after a different powder at the various 200yd v. 600yd stages.

The list basically was accrued from other shooters experience, and was a "don't use this powder after a different powder was used" .. because precision will be "off" until the barrels bore settles into / seasons into the different powder.

I have seen this happen frequently, when shooting 10rd groups.

The first 5rds will slowly tighten up , then the next 5rds will produce a more realistic representative group.

I understand it may be the firearm settling in... but have seen it happen far to frequently to blame it on my bench holding technique ( yeah, it could be me... but the regularity of the "season the bore" thing is more then repeatable )

Any way... I had a list decades ago of powders not to fire after a different powder, and I can't seem to find it... after decades of searching.

I was hoping some one here could recollect that list.

And if so, and while dated with older propellants, could post the list or point me in a direction to the list.

I have tried to find it for so many years, I fear my memory and Google search is becoming skewed.

Thanks for looking , and wish me luck !
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  #2  
Old 06-24-2019, 05:59 PM
navyrifleman navyrifleman is online now
 
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An interesting theory regarding powders.

Certainly, a new load with different components will produce different results, but I am not sure that it is because one particular powder specifically follows another.

Any rifle will take a few rounds to settle in when shooting at the range - to warm up, and "dirty" up if it has been recently cleaned.

And some powders seem to be better than others when it comes to the gas actuated semi auto rifles.

Good luck in your search for this list.
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Old 06-25-2019, 02:40 PM
fartblossom1953 fartblossom1953 is offline
 
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Your absolutely right to ask the question. I learned this the hard way in ATC matches. The best thing to do is find a powder that works for the bullet weights you plan on using and stick with it at the short and long line. It takes more than the two sighters to foul the barrel when changing powders but once settled in your original dope will be good. You also don't want to change from or to molly coated in the middle of a match. Ask me how I know
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Old 06-25-2019, 03:25 PM
Unclenick Unclenick is offline
 
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Yes, this is a long-known phenomenon. If you think of fouling as a sort of high viscosity hard grease, the weights and thicknesses left behind by each powder's characteristic fouling are different. And Fartblossom1953 is correct that two sighters often won't settle it. I think this is one reason the National Match Course starts with standing offhand, where most shooters can't tell the difference as the fouling settles in.

Generally speaking, I think double-base powders leave a thicker powder residue behind. Powders with graphite coatings leave more, but it may be more lubricative than non-graphited powders like Varget leave behind. I should think, since their formulations are very similar, that you could probably trade off between the old standard IMR numbers without a problem, switching say, from 3031 to 4895 to 4064 without difficulties. I don't know about their newer controlled burn rate powders.
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  #5  
Old 06-29-2019, 06:59 PM
Gewehr43 Gewehr43 is offline
 
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OP:
Well I have good news and bad...…
I also have heard about this issue, Sierra , Zediker (Sp?) and possibly Hornady all discuss it in their books.
I do have "the list" you are referring to...….But its on my home computer and Im away from that for around another month......ill see about getting it.....

BTW..... my only concern about the list was its origins.
Do you know about where/who created it?

Can you maybe send me an email? It might be easier to send that way.

PS: They described it more as the first couple of rounds BTW, not really a long string.

PSS......OP sign in here and use the search function and use "Powder Compatibility," Ive posted about this here.
See if you can find it. It was part of another OP's thread, I think.
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Last edited by Gewehr43; 06-29-2019 at 08:19 PM. Reason: clarity
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  #6  
Old 06-30-2019, 12:13 AM
HighpowerRifleBrony HighpowerRifleBrony is offline
 
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Quote:
Originally Posted by Gewehr43 View Post
OP:
Well I have good news and bad...
I also have heard about this issue, Sierra , Zediker (Sp?) and possibly Hornady all discuss it in their books.
I do have "the list" you are referring to....But its on my home computer and Im away from that for around another month......ill see about getting it.....

BTW..... my only concern about the list was its origins.
Do you know about where/who created it?

Can you maybe send me an email? It might be easier to send that way.

PS: They described it more as the first couple of rounds BTW, not really a long string.

PSS......OP sign in here and use the search function and use "Powder Compatibility," Ive posted about this here.
See if you can find it. It was part of another OP's thread, I think.



Found it: http://forums.thecmp.org/showthread....+compatibility
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  #7  
Old 06-30-2019, 05:20 PM
bfoosh006 bfoosh006 is offline
 
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Thats the exact list !!! Thanks to all and especially @Gewehr43, @Unclenick and @HighpowerRifleBrony.

You folks might find this fairly interesting as well...

Twist rates, muzzle brakes, powder's effecting drag variations.
https://precisionrifleblog.com/2019/...in-ballistics/

Again Thanks to all !!! I have looked and looked for that buried treasure.

Quote:
Originally Posted by Unclenick View Post
Yes, this is a long-known phenomenon. If you think of fouling as a sort of high viscosity hard grease, the weights and thicknesses left behind by each powder's characteristic fouling are different. And Fartblossom1953 is correct that two sighters often won't settle it. I think this is one reason the National Match Course starts with standing offhand, where most shooters can't tell the difference as the fouling settles in.

Generally speaking, I think double-base powders leave a thicker powder residue behind. Powders with graphite coatings leave more, but it may be more lubricative than non-graphited powders like Varget leave behind. I should think, since their formulations are very similar, that you could probably trade off between the old standard IMR numbers without a problem, switching say, from 3031 to 4895 to 4064 without difficulties. I don't know about their newer controlled burn rate powders.
Thank you, that is a great explanation, that my "mechanically inclined mind" can fully accept.

Last edited by Big_Red; 07-08-2019 at 12:40 PM. Reason: Combine consecutive posts
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  #8  
Old 07-05-2019, 04:08 PM
Gewehr43 Gewehr43 is offline
 
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One question though...….where or who made the list?
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  #9  
Old 07-05-2019, 11:23 PM
HighpowerRifleBrony HighpowerRifleBrony is offline
 
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Quote:
Originally Posted by Gewehr43 View Post
One question though....where or who made the list?

BECoole on the US Rifle Teams Nat'l Match forum. I don't see his real name and he claims to have been P100. He's active and doesn't get called out from what I see.
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  #10  
Old 07-07-2019, 09:57 AM
Unclenick Unclenick is offline
 
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The list includes compatibility between VV's N1xx powders, which are single-base, but not going from an N1xx to an N5xx, the latter being VV's double-base powders. This indirectly confirms what I suggested for the old IMR numbers which, like the VV N1xx numbers, have very similar formulation because they rely on grain geometry (perforation count and location) to control progressivity and so don't need to be as different in deterrent concentration as spherical propellants do. I note N540 to N550 gets the nod, so I suspect all N5xx can follow one another on the same principle.
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