Bullet Jump

[cjuve]

We had big es using chrono. had 1/2 moa at 100yd.( 338 lapua). Shot at 715 yds and kept same 1/2 moa accuracy. Figuring our chrono just not giving accurate speeds. Had a chrono set up on tripod at 10ft from muzzle. Then used a magnospeed(?) that clamps on barrel after we were done to test speeds and didnt show good es either. 60 ft es! But 1/2 moa at 100 and 715. ??

ES/SD are not the end all be all, although 60 FPS ES is probably pushing it. Like others I don't chrono graph a load until I am pretty much done, If I do it is more than likely just 1 shot so that I can get an idea about pressure and drop. I use to load for a 7 RUM the had high ES but consistently put groups on a plate at 1000 in the 6" range. At the end of the day the shots on target are what count and chronographs lie sometimes.

 

[oldmossy]

I would agree that he couldn't have consistent 1/2 MOA at all ranges, but it certainly is possible to shoot tighter that your chrony indicates, his 1/2 MOA at 715 is almost certainly due to positive compensation, be it purposeful or accidental.
When I started handloading I used the Audette ladder exclusively, didn't realize for years that I was tuning positive compensation for the specific range I did my testing at.

Im not sure what purposeful or accidental compensation means. Im assuming it means I cant measure.lol Which would be incorrect. Now, knowing exactly what I'm talking about. Or knowing much about reloading, or a whole list of other things...that could be argued. lol. Not that I'm all that new to this long-range game. But definetly learning more and more as time goes by. Anything I post on here is as accurate as I can possibly be. I've already learned thru the years that sometimes "I just don't know -I don't know" on certain things. lol. Things I thought were concrete, didn't turn out to always be so concrete. I'm on here to get answers to things that don't add up, and help people who are at the same level as myself by asking dumb questions other may be afraid to ask.lol

 

[DUSTY NOGGIN]

hom much longer is the 195???

 

[oldmossy]

Approx. .119 by another members numbers

 

[Rflshootr]

Seating depth can make all the difference in the world. I've had 2 factory hunting rifles that went from 1" 5 shot groups down to under .4" groups with a .005 seating depth change.
Another consideration may be to have the barrel set back with a shorter throat to shoot the 180's.

 

[cjuve]

I had a 7MM RUM built to shoot 195 elite hunters. And it shoots them really good. But the speed and killing effectiveness isn't that of the 180 hybrids that I shot for years. Running through different powder charges, we couldn't get the groups any better than 1 inch @ 100yds using the 180 hybrids. We didn't adjust seating depth, because we cant get to the lands with the 180s. My question is- How much effect does adjusting seating depth have when youre already jumping a considerable distance to the lands?
Im not a reloader, my buddy does it for me. I'm just wondering if he just didn't want to take the time to develop a load for the 180s. Or if the jump really makes no difference after a certain point.
I'd rather have 180s at 3200 than my 195s at 2930.
I tried researching this prior to asking but never really found a answer.
Thanks

Seating depth makes all the difference in the world. I have run several in the last couple weeks and fully believe that you don't know what the rifle is capable of if you have not explored it.

 

[skipglo]

I don't use my chronograph until I found a good load the main reason for this is people get hung up on a number get a load your rifle shoots and go with it and what you were saying a couple hundred feet per second a difference of 15 grains in the projectile you should plug both of those into a ballistic program and see about the energy down range I bet they are much closer than you think

Look at you go!

 

[338 dude]

Look at you go!

Thanks buddy!

 

[skipglo]

Thanks buddy!

Always!