Bullet "jump"

[Judd]

I have narrowed my load down and now I am ready to start messing with OAL. I saw in the sticky loading write ups to start at .010 but it didn't say how far to go? When testing how far off the lands will y'all go looking for a load that shoots well?

Thanks.

 

[1lnbrdg]

Re: Bullet "jump"

Look at what Berger says about jumping bullets. It's in the article down around VLD bullet design:

Berger Bullets

 

[MALLARD]

Re: Bullet "jump"

not more then .200 off the lands.

i would test at .000 ,.025 and .060 off the lands ,just to see what happens, and then from there refine my increments

 

[Judd]

Re: Bullet "jump"

Thanks guys, glad I asked because no way would I have thought going out that far was alright. The Berger was a good read, again thanks!

 

[Paladin2147]

Re: Bullet "jump"

Well just remember, if it needs to feed from a mag...... Or do you enjoy single shot?

 

[Paladin2147]

Re: Bullet "jump"

Dbl post

 

[Fuzzball]

Re: Bullet "jump"

I've learned it's rarely helpful to seat closer than 15 thou with my own factory rifles and common bullets so I usually start there and work back after finding the best charge. I sometimes find the 'best shooting' seating window to be as narrow as 10 thou so I do my seating experiments in 10 thou steps, that way I won't skip over what I'm looking for. I've never needed to go down more than about .150" off but I've known others who needed to go a bit deeper.

Once I've identified the good jump range for my load I seat in the middle of it so normal small OAL variations won't blow my accuracy.

 

[seanhagerty]

Re: Bullet "jump"

What are thoughts on jamming ?

 

[Judd]

Re: Bullet "jump"

Uploaded with ImageShack.us

Here is my target, shot at 100 yds (longest I had access too)...going to work with the center one. #5 target was shot with factory Hornady ammo I bought just to get some brass prior to loading.

This was shot at .010 jammed so will play with #3 seating depth and see if I can't get it even tighter.

 

[Fuzzball]

Re: Bullet "jump"

"What are thoughts on jamming ?"

My thoughts are jamming seems to work great for maybe 80% of BR shooters with their single shot rifles with custom tight chambers and soft seated bullets.

 

[flashhole]

Re: Bullet "jump"

T"his was shot at .010 jammed so will play with #3 seating depth and see if I can't get it even tighter."

Not sure what that means. It was either .010" off the lands or jammed into the lands.

I usually end up about .005" off the lands when doing load development.

 

[Judd]

Re: Bullet "jump"

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: flashhole</div><div class="ubbcode-body"> It was either .010" off the lands or jammed into the lands.</div></div>

Sorry for the confusion...it was jammed into the lands. Measured with a modified case 3 times then took the average and added .010 to get it jammed, to be specific on how I came up with that.

Now I am going to take the powder charge with target #3 and bring the bullet back off the lands. I liked the way that Berger described it so I'll try that next and shoot it and see what the gun likes.

 

[1J04]

Re: Bullet "jump"

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Judd</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: flashhole</div><div class="ubbcode-body"> It was either .010" off the lands or jammed into the lands.</div></div>

Sorry for the confusion...it was jammed into the lands. Measured with a modified case 3 times then took the average and added .010 to get it jammed, to be specific on how I came up with that.

Now I am going to take the powder charge with target #3 and bring the bullet back off the lands. I liked the way that Berger described it so I'll try that next and shoot it and see what the gun likes. </div></div>

So are you saying that you're gonna seat it .040 and then possibly .080 deeper and so on per Berger? You may well pass the sweet spot if you go that much. I'd go half that, you won't be sorry. Just did it this weekend. Too much fun letting the gun tell ya what it likes . Have fun and let us know your results please.

 

[Judd]

Re: Bullet "jump"

Yes, that is what I was saying....but I'll do it by .020 just to try it. What is the negative to having more bullets to shoot?

 

[1J04]

Re: Bullet "jump"

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Judd</div><div class="ubbcode-body">Yes, that is what I was saying....but I'll do it by .020 just to try it. What is the negative to having more bullets to shoot?

</div></div>

Exactly, and possibly less if you hit "the spot" early. Too much fun, really. Please let us know what you did and how it worked out. I've been impressed, and lucky on the last five guns I did. 300 Winchester Mag, 2 Remington 700 7MM Mags, 270 Winchester, and a Remington 700 25-06. Surprising how the results stand out once you know what you're doing/looking for. Love this stuff. I gotta compilate my data and get some pics together, just helps make that much more sense of what we're looking for. All factory guns hopefully being tweaked to their potential.

Good Luck

 

[Judd]

Re: Bullet "jump"

.040 shot just over 1/4" at 100 tonite...going to stick with it. Ironically the OAL is the same as the Creedmoor 140gr factory loads.

Looks like it is going to be a shooter I need to load up and get me shoot as well as the gun

Thanks for y'alls help!

 

[1J04]

Re: Bullet "jump"

How cool. That's a quick fix. Appreciate the follow up.