|
|
|
Discussion Forums
Forum Index
> Precision long range hunting and shooting
> Bullet Jump Research
Bullet Jump Research
@ 05:15 pm (GMT) |
VinceHi EveryoneJust read an article on bullet jump https://precisionrifleblog.com/2020/04/28/bullet-jump-research-and-load-development-tips/ Seems to be using similar principles to an OCW test but looking for a wider band of seating depths instead of powder charges that deliver consistent impacts vertically, primarily relevant for PRS type competitions with high round counts where throat erosion is an issue. Not sure this is particularly relevant to hunting but I found it interesting so thought I would share Cheers Vince |
Replies
@ 12:40 pm (GMT) |
Rob BirdRe: Bullet Jump ResearchI mean, it's not IRRELEVANT to hunting if one plans on shooting beyond 400 yards. Case in point: the other day at the range, I was load testing. I put three rounds into my mag and then slid the bolt forward, but it didn't feel like it chambered the round. So I slid the bolt back a bit to look and it didn't pull back a round, so I brought the bolt the rest of the way back and picked up a round and started to chamber it, but it jammed. It turns out that I HAD chambered the first round, but the extractor didn't grab it to pull it back. So, even though I didn't push the second round forcefully, I think that it pushed it in some (I had to eyeball it) because my neck tension isn't all that high. I am going to re-test that load because I now am doubtful of the seating depth of that round. I am seating at 10-12 thou off the lands so, according to this article, every bit matters, and especially if it was 20 thou difference! Suppose this happened out hunting, or if the seating depth changed for some other reason due to unintentional mishandling.The part I found very interesting was, as explained in a linked article, going from .6 MOA to .1 MOA groups at 100 yds only changed the chance of hitting a 10" target a few percentage points. I know that every little bit counts, but that is encouraging. |
@ 10:12 pm (GMT) |
Anders ÖsterbergRe: Bullet Jump ResearchI think you should lock at this video ☆Not just chasing the lands aspekt , but that you very well can tune or un-tune your load wit very small changes in OAL . https://youtu.be/9FKq8Jj8YEI |
|
@ 12:27 am (GMT) |
Anders ÖsterbergRe: Bullet Jump ResearchMaybe you should look at this one first so it will be in the right order..https://youtu.be/9FKq8Jj8YEI |
@ 04:34 am (GMT) |
Scott StruifRe: Bullet Jump ResearchIf Erik’s statement, “Seating depth will tune any load,” is true, then there’s no reason a hunter should reject a certain bullet because “my gun doesn’t like it.” In other words, terminal performance should always dictate bullet choice. There would be no reason, for instance, to choose a VLD for for hunting large deer species because it shoots the most accurately with minimum jump, when a VLD is likely to explode on a shoulder shot, or pencil through on a “meat-saver” shot. |
|
@ 07:15 pm (GMT) |
VinceRe: Bullet Jump ResearchHiIn terms of relevance Rob, I was thinking in terms of how low volume my long range rig is so I have the luxury of going for the best seating depth as long as no jamb is involved. The .222 is another story and that may be worth looking at as it gets a lot of rounds through it chasing rabbits, wallaby, goats and fallow. Thanks for the link Anders, I watched it shortly after reading the article, in the shooting disciplines Erik is involved with there is so much technology involved in eliminating the shooter from the equation that the ability to see and measure these variables is probably enhanced. Scott 100 % agree with your statement, obviously the degree to which you can tune a given projectile may vary from rifle to rifle but if you are developing a hunting load and you claim to be an ethical hunter you will stick to projectiles that are suitable for the animal and ranges involved, and limit your range based on the accuracy of that load in your rifle only. If the only way to shoot accurately at extended ranges on game is to use a projectile that is not suitable then your primary focus is not ethics. Cheers Vince |
|
@ 05:44 am (GMT) |
Scott StruifRe: Bullet Jump ResearchAfter I commented, I reviewed the relevant section of Nathan’s reloading book. It’s the first of his books that I bought. It had been a couple years since I read it. I liked Erik’s sine wave analogy. It helps to visualize how to find the accuracy node(s). He mentioned that his method works for long-throated cartridges, such a 308 with mag-length limitation, and even factory ammunition. This was all covered in the reloading book (with the exception of reseating factory ammo) . . . plus so much more, such as concentricity, copper fouling, when to try a different bullet, etc. |
|
@ 05:28 am (GMT) |
Rob BirdRe: Bullet Jump ResearchThanks for that link, Anders! I think I started to watch the first one some time ago but for whatever reason, I didn't finish it. I'm glad I watched it again. It makes sense. I liked that he finds his good ES first then tunes it. I will definitely try this on my next load experiments.I can't remember right now if Nathan says something similar in his reloading book. If he does, then I must not have been ready to absorb it when I read it! All the more reason to keep learning, even when you think you're starting to get something down. |
|
@ 03:49 pm (GMT) |
Scott StruifRe: Bullet Jump ResearchHi Rob. I’ve been following your AI build thread, too. Congratulations! Sounds like you’ve found a “node.” The Reloading book goes into concentricity for further tuning, as well as neck tension and increasing the powder charge to make up for jump. But you’re already pretty much there! Thanks for keeping us posted on your progress. |
|
@ 02:13 pm (GMT) |
Rob BirdRe: Bullet Jump ResearchThanks! So it would seem, though I need to confirm it. Heading out on Sunday to do some longer distance shooting. |
Please wait
ABOUT USWe are a small, family run business, based out of Taranaki, New Zealand, who specialize in cartridge research and testing, and rifle accurizing.
|
KNOWLEDGEBASE |
KNOWLEDGEBASE |