How Much Jump Do 142 LR AB’s Like?

[xphunter]

How Much Jump Do 142 LR AB’s Like?
.264 Diameter bullet.
If there is a distance that seems to work or range that seems to work better, it would be nice to know ahead of time-Thanks!

 

[SJB358]

I’d start at .050 off and move in .025 increments. Bet you’ll find something you like.

 

[JD338]

I’d start at .050 off and move in .025 increments. Bet you’ll find something you like.

^^^^^This^^^^^

JD338

 

[DrMike]

Scotty nailed it. I found that 0.100 inches of jump with the ABLR was well-nigh universal regardless of caliber.

 

[longrangehunter]

I’ve tried them close to the lands and have gone as far as .150” off , and yet never could get them to shoot even with various powders.

Hopefully they will work for you. I’ll assume you are testing these in your two Swede’s?

 

[xphunter]

I’ve tried them close to the lands and have gone as far as .150” off , and yet never could get them to shoot even with various powders.

Hopefully they will work for you. I’ll assume you are testing these in your two Swede’s?

15.9” 6.5 PRC

 

[longrangehunter]

15.9” 6.5 PRC
View attachment 26930View attachment 26931

Right after I posted that I thought I’ve got the wrong guy….., It’s not like I’m dumb! I used to have a Remington XP100R in 260 Remington with the Kevlar stock when it first came out…. But now it’s remembering which forum member is who? You’d think with a username like xphunter I’d know better?

 

[xphunter]

No Problem.
I get stuff turned around all of the time

 

[xphunter]

Thanks on the info guys.
I thought the LR AB's like a lot of jump typically, but I couldn't remember for sure.

 

[NYDAN]

Ernie, although most people have good results with longer jumps, I have had some good results with about 0.030" jumps with the ABLR. Specifically, 0.030" jumps with the 129 gr. ABLR in the 6.5 Creedmoor, and the 150 gr. ABLR in the 7mm WSM. I can provide targets if you like. I also have an idea of why, if you want to hear it.

 

[xphunter]

Ernie, although most people have good results with longer jumps, I have had some good results with about 0.030" jumps with the ABLR. Specifically, 0.030" jumps with the 129 gr. ABLR in the 6.5 Creedmoor, and the 150 gr. ABLR in the 7mm WSM. I can provide targets if you like. I also have an idea of why, if you want to hear it.

Explain away!

 

[NYDAN]

Ernie,
I think there are several things that contribute to the results I have seen with these two bullets:

• The jacket is thinner than the AB's in the area of ogive (requiring less force to start engraving).
• The long tangent ogive of the bullet results in a more gradually engagement of the bullet into the lands (resistance builds less fast).
• These light bullets ABLR bullets (129 gr. 6.5mm and 150 gr. 7mm) have a relatively short bearing surface (requiring less force to engrave into the lands).

So, I think these combined factors makes these lighter ABLR bullets respond more like cup and core bullets than bonded bullets.

Loading them gets complicated due to:

• The long, tapered point can be difficult to seat with such short bullet jumps without exceeding the magazine length. (I am very near maximum C.O.A.L for the magazine in the 7mm WSM).
• The long boat tail may result in the bearing surface of the bullet not extending to the bottom of neck of the cartridge. (This is the issue with my 6.5 Creedmoor and why I opted to use the 130 gr. Sierra Tipped Game King).

Good luck with your load development.

 

[Ralt71]

How Much Jump Do 142 LR AB’s Like?
.264 Diameter bullet.
If there is a distance that seems to work or range that seems to work better, it would be nice to know ahead of time-Thanks!

My reference is in a .284 at 175gr. I loaded these in my Tikka Tex 7mm Mag.

During load development I started at .018 and went in .003 increments to .036. The area around .024 (.021, .024, .027) was very tight and it started opening back up at .030 and shifting right on me. I didn't try the larger jump like I have learned on this forum and haven't messed with that round. 5 shot group, 4 in the same hole, cold barrel shot was slightly left.

 

[Ralt71]

Here is my final shot string, on my home made load development target haha. I use our old calendars from work to build targets for development haha.

Like I said 5 shots, cold barrel shot was a little left (I don’t like this but don’t know how to fix it, it’s close enough for hunting though)