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I am trying to find a load my new Storm likes . I loaded 10 rounds 75 gr hornady vmax over 44.5 gr win 760 and 10 rounds of 75 gr sierra hp over same powder charge . At 100 yds the hornady were 3” high and sierra were dead on . At 500 yds the sierra were 15” lower than the hornady . How could 2 bullets of the same weight and with same charge be sofar apart . Looks like the hornady fly a lot flatter . I don’t have a cronagraph.
Assume the muzzle velocities are close enough to count — almost certainly the case for the large differences.
Then run both through a reliable ballistics calculator like http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
Start out with the 100 yard zero you observed for each bullet. Check the drop at 500 yards.
My guess is that the BCs aren’t that far different, since the three-inch difference at 100 yards translates by geometry to 15” at 500 yards
Thanks for the reply . I did what you suggested , kept muzzel vel. the same for each and put in the SD which is identical and the BC which is .330 for the Hornady bullet and .217 for the Sierra and the ballistics calculator spit out a 15 in. difference at 500 yds . Thanks for the tip , it was right on .
I have been loading since one year after Nixon resigned and have never found loads with significantly different components to print very close.
Each major load change is it’s own animal .... so to speak.
A different bullet of the same weight is a major load change for the purposes of this discussion.
At any sort of “range” you will need to develop a load that suits you for that rifle and shoot that one until another suits you and be sighted in for one at a time of your choosing.
You can fire other loads for group size in the meantime and here is how I capitalize on that:
I make my own targets on Excel, the spreadsheet program. I designed my targets around the concept of four solid black squares with an equal amount of white between them. I adjust the white space so that at my chosen power setting and range with that particular cross hair thickness I am left with jus a bit of white showing around the hairs.
These targets are labeled on the screen in a corner of the page in a way that suits me (within the file).
In the field my target stand is designed so I can rotate my target backer (used political signs) 4 Times 90 degrees thus giving me four “targets” on one target paper that have those four black squares. Typically I shoot my sequence of load tests in related groups on the same target ie. same case, primer, powder used, bullet, seating depth etc with the only change being powder charge between the four groups.
There is a tendency for newbies to hop around like a grasshopper expecting to find this magical load or that and it just lands in their lap.
Trust me, that is rare.
A fellow can hop around in this business and leap right over an excellent sweet spot for a particular rifle and never be the wiser or one can dig in and ferret out those gold nuggets of accuracy.
On another note, I never really got hair splitting accuracy from spherical powders such as in a large case like the 243. Unfortunatley it has always seemed that I had to resort to the stick powders to get a fine edge “on my sword”. I did have a real fly shooter in my 22-250 with WW760 for a while at half throttle .... that is until Winchester went from the metal can to the plastic jug! From then on my Canjar triggered 788 Remington was a boat anchor with that powder. I found my next thrill with Varget but never got it sub .5 MOA again .... just faster.
Like they say, “First your money, then your clothes!”
Best regards and good shooting
Three44s
Couple of quick questions.Quote:
Originally Posted by Three44s
#1 Why would you ever change the trigger on a 788? Pretty picky if you ask me, why not just use both hands instead?
#2 So if I dump powder from a plastic container into a metal one, or vice versa, it might ruin my accuracy?
Ive been known to use windshield washer jugs, rinsed out of coarse.
I never knew that and it might be one of the reasons I have trouble hitting things. lol
Thanks for the reply , you are right changing bullets really made a difference . Got some more loaded up , now go out and shoot some more .
I just experimented with my 243 AI loaded with the 69 Berger high bc. Loaded 3 Redding neck sized only and 3 collet neck sized only. They both shot right around 1/2" at 200 yds but the groups were about 2" apart. Must be a neck tension thing.
I did what JASmith suggested and ran both bullets through a ballistics program . The Vmax bullets with their .330 BC did shoot flater than the Sierra with their . 217 in the progam and that is what I saw on the range . Opened my eyes because I thought 2 bullets of the same weight would be closer . This reloading game is fun and I am learning a lot about bullet preformance that I never even considered before . Thanks too all you fellas that responded to my post .
It's always interesting,or frustrating,seeing what difference changing just one component can make. Always on that quest for the consistent one holer!
Well, when you have a trigger job done to the original and it starts firing through the safety, it might make sense to change triggers.Quote:
Originally Posted by yobuck
As to the difference between the metal can and the plastic jug, the lot number changed as well who might of made either lot of powder. The facts speak for themselves, the earlier lots (packaged in metal cans) shot right at .420” for five at 100 yds. When the barrel got dirty it shot .520”. You cleaned it and it went right back down to .420”
After 760 showed up in the plastic jugs I was lucky to get around .900”
I don’t care if a rifle says 788 on it, when it can shoot .420” and it’s trigger gets unsafe, I say it needs not only a safe trigger ...... it also deserves a GOOD ONE!
Hmmmm?
Three44s
Need to be careful about speculation and comments.Quote:
Originally Posted by yobuck
The metal vs plastic container might be coincidental to other events.
Changing container design is an indication that other changes in the powder manufacturing and production process happened. One can speculate that, at the very least, the lots are different.
Barrel erosion could have coincidentally caused the accuracy loss.
etc.
I had an opportunity to get acquainted with a avid prairre dog shooter with about twenty years on me at shooting and reloading. We told each other stories and then came out the targets. We chewed the fat up on side and down the other. This fellow was really into 20 cal and had developed his own wildcat in the bore size. He also had been making his own 20 cal jacketed bullets.
As we talked process he began to pull back from my assertions. Some of my case prep turned him off as too much trouble. He also questioned why I retained ALL my targets. I told him that I often learn more from my mistakes as I do from the good ones.
This fellow shooter went home, read up on the points I was making and sent word back that he had added to his repitiore and shaved some more off his group size.
Learning is fun and this game of handloading is a great teacher.
Best regards
Three44s
As a matter of fact I had just a wee bit of the old lot number left (metal can) and ran it .... accuracy was right there.Quote:
Originally Posted by JASmith
The barrel did fall off about two years later with Varget going from .625” to bullets going sideways ay 25 yds. and the rifle gathering dust ever since. A CZ527 in .223 took over the job.
Best regards
Three44s