I've heard of bullet jump but this is a leap of faith

[RedRyder]

Just got a case of Prime 260 ammo and the first thing I did was measure case head to ogive of the loaded round. The measurements for 5 randomly selected cartridges were 2.131; 2.131; 2.136; 2.136 and 2.132. Since I just got a new CF barrel put on, I've been taking measurements to determine OAL and, using a Sinclair seating depth gauge my cartridges will be considerably longer. As in 2.164; 2.167; 2.161; 2.163 and 2.139 (not sure what was going on with the last one).

I can't speak to all manufacturers but I know that typically cartridges are loaded to SAAMI specs. And I know handloads will typically be longer. I just didn't expect the Prime to be .03* shorter.

If they shoot well, I guess I've learned something new.

 

[Precision Underground]

Most factory ammo is a bit short to avoid jamming the bullet on shorter chambers.

 

[Supersubes]

2.16x measurement is a touching in the chamber measurement, or that’s with some jump already?

If the prime is a .030 jump in your new chamber, I’d say that’s spot on perfect.

 

[XLR308]

2.16x measurement is a touching in the chamber measurement, or that’s with some jump already?

If the prime is a .030 jump in your new chamber, I’d say that’s spot on perfect.

I would have to agree, I have seen a remy700 in 308 that certain bullets would damn near fall out of the case before contacting the rifling.

 

[Mr.Kirk]

http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/

 

[Mr.Kirk]

It’s ok to jump. I went to .050 on this test. .04-.05 didn’t make it in the folder, but looked like.06 would have matched .030.

 

[47guy]

Here’s my buddies 6.5CM with 140ELDMs .060 off he cold bored 1 his son hit the other on his second shot

 

[Peter Laurvick]

The jump on my 300 Win Mag and 215 Berger Hybrids is .080 and loving it. Been good out to 1-mile so far. And if it was much longer I’d be limited to single feeding it

 

[b6graham]

.030 is will within reason. pretty normal jump

 

[ken4570tc in WY]

More good info on the Hide!! This expands my challenges to find best accuracy as I begin load development for my .243 Ruger precision. I wasn't thinking about seating depths more than .030 from the lands but I will now check it as far out as .060. Thanks!

 

[47guy]

i always start at .020 off and look for 3 groups that are about the same...take the center load and go .010 off and .030 off and shoot them for groups...this tells me if they want to be closer or farther off...if i have a 1/2" or better i shoot it at 500yds if it holds im done until i get a couple hundered rounds through the barrel and then ill come back and double check and make adjustments as needed.

i have not shot more than 35 rounds for load development in the last 10 or so barrels....i stopped chasing 1 hole loads a long time ago...i am capable of shooting 1 hole groups but not off a barricade or any obstacle

 

[RedRyder]

2.16x measurement is a touching in the chamber measurement, or that’s with some jump already?

If the prime is a .030 jump in your new chamber, I’d say that’s spot on perfect.

That's with NO jump. Bullet was contacting lands/grooves

 

[ken4570tc in WY]

More good info on the Hide!! This expands my challenges to find best accuracy as I begin load development for my .243 Ruger precision. I wasn't thinking about seating depths more than .030 from the lands but I will now check it as far out as .060. Thanks!

Update, I read and printed off the Berger Bullet seating depth recommendations for the VLD's and think it is probably applicable to just about any bullet. Same basic theory as the OCW ladder test to narrow down possible sweet spots. If I read it right, there should be one with a wide range of seating depth that would lend itself to setting up a load that doesn't require chasing the lands.

 

[Skimafia]

The first time I measured my chamber and compared it to the recommended load lengths by Sierra, I about freaked. I measured the jump to be almost .030 exactly. I thought it was way too much. Checking here, I found that its pretty typical to jump that amount.

 

[goinghunting]

I Have a Sendero in 300 wm that some factory Black Hills with 200 eldx are gonna jump like .220. Yeah like a quarter inch.

 

[CJS-6.5]

That's a long jump. Do you think they'll make it?

 

[918v]

Jump is good for lowering pressures when you’re at max.

 

[ken4570tc in WY]

Many factory rifles in the past used a long jump (free-bore) but were still very accurate. If I remember correctly, Weatherby was noted for having a long 'free-bore'.

 

[CJS-6.5]

It's all about alignment. If a reciever isn't true it will benefit from less freebore.

 

[Kinetic Moose]

Yeap, I have a weatherby accumark that has a monster jump and doesn't like short rounds as a result. ELD or SMK's stretched out to within 020 of the lands and it's a tack driver,, always thought it was just a worn barrel until I saw this.