Gene Beggs wind tunnel questions.

Gene,
Maybe my info is wrong or my memory is going but isnt the general variance with the culver measure +/- .2 which overall would for extreme = .4.
Yet as you pointed out it only takes going up or down .3 to bring it in tune.
Now I am confused



Vern, most group shooters go to the line with a block of twenty loaded rounds. With good technique, nine out of ten of those rounds will be within plus or minus one tenth of a grain. Yes, one or two will be off two tenths and once in a while for whatever reason, one will be off (usually heavy) by three tenths. Will this show up on the target outdoors? I doubt if anyone could tell the difference. Some things are worth worrying about and others are not. I weigh charges when setting my measure but after that I do not weigh each individual charge because experience has proven it isn't necessary.

I use an Oehler 35 chronograph in the tunnel with an indoor lighting kit. I believe the Oehler is about as accurate as you will find. With the 6PPC and my 6Beggs cartridge I usually see around 25 to 40 fps extreme spread in a string of twenty rounds. This with charges thrown with my Jones measure. On several occasions, for demonstration purposes only, I have taken the same case and reloaded it ten times weighing each charge on a laboratory scale that splits a tenth into ten parts and the extreme spread of those rounds often exceeds those of thrown charges. Never have I seen improvement in extreme spreads with weighed charges. It's just down-in-the-dirt not worth worrying about. Variations in primer energy contribute more to velocity spreads than slight variations in powder charge.

FWIW

Gene Beggs
 
Hi Gene,
OK I'll bite. Have you been able to correlate anything measurable with variations in primer energy (same brand and lot of primers)?
 
Gene,
Maybe my info is wrong or my memory is going but isnt the general variance with the culver measure +/- .2 which overall would for extreme = .4.
Yet as you pointed out it only takes going up or down .3 to bring it in tune.
Now I am confused

Well Vern, that's exactly why I personally believe there is an advantage to weighing charges instead of throwing them. How can you allow that kind of variation, and say it it okay to shoot loads that are in and out of tune in the same group? Now maybe some of the guys that have better luck throwing charges are capable of throwing them + or - .1 grains, but I've never achieved that level of accuracy. And what about the guy throwing 4198 instead of the finer grained powders? I personally have seen extreme spreads on weighed charges in the 3 fps range to be typical.

Michael
 
Hi Gene,
OK I'll bite. Have you been able to correlate anything measurable with variations in primer energy (same brand and lot of primers)?



No, not really. You will get excellent results with any of the primers normally used in BR. I am presently using Winchester WSR and Wolf SRM.
 
Well Vern, that's exactly why I personally believe there is an advantage to weighing charges instead of throwing them. How can you allow that kind of variation, and say it it okay to shoot loads that are in and out of tune in the same group? Now maybe some of the guys that have better luck throwing charges are capable of throwing them + or - .1 grains, but I've never achieved that level of accuracy. And what about the guy throwing 4198 instead of the finer grained powders? I personally have seen extreme spreads on weighed charges in the 3 fps range to be typical.

Michael



Good morning Mike

Thanks for joining the conversation. One thing I have noticed with all the thirties like you shoot is that single digit extreme spreads are the norm; not so with the 6PPC and 6Beggs. It seems that when you choke the cartridge down to smaller calibers, extreme spreads always increase significantly. With your 30, try chronographing twenty rounds with thrown charges and then do the same with carefully weighed charges. I think you will find you get just as good results with thrown charges. I don't understand why this happens but it surely does.

Come on down to Odessa when you can; we will try it in the tunnel.

Later,

Gene Beggs
 
So Jackie

How or what conditions do you practice in ?? It seems that one would practice and take notes in all conditions for whatever time of year it is...There is one thing for sure and that there is a ton of things come into play before pulling the trigger on the first shot...

Hope you are well their in Houston.
 
Hi gene ,I hope all is well with you and everybody, and might add that some barrels will shoot level velocities and some wont.It is a flip of the coin in that respect .In long range level velocites are a must and untill they are level the long range rifle just wont shoot to a competitive level.What I found is that every barrel has a velocity pattern that changes during the life of the barrel,so if there are signs of fairly quick fouling I dont even try to level them out untill they have at least 200 rds through them first.Then when I go to level them out sometimes a certain barrel just will not shoot level velocities no matter what I do_One barrel would not shoot level velocites untill I got to 400 rds and I was told this would happen by the barrel maker before I even got the barrel.His name was Barney Lawton and he has been a great mentor to me and many others and it turns out he was right on the money.The barrel proceeded to shoot single digit velocities for at least 10 shot strings every since and is still clicking along at 1700 rds through it ,Barney would say by shooting the rifle to lap the barrel rather then lapping the life out of it, a barrel can come out more consistant in the end of its life. God rest his soul. Tim in Tx
 
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Hey Gene
How the heck have you been ? Hope to see you at some matches this year.... Will you make the Seymour matches or the Tomball matches ??

I'm still using your wind probe...Let me clear that up...... My eyes see it but my brain still does not listen to it.. The wife says thatis called selective hearing which is what she describes as what I use around the house... Hmmmmmmmmmmm

Take care
Doug in Dallas
 
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