OAL with VLD Bullets

MacD · Posted: Wed Jan 14, 2015 3:13 pm Post subject: OAL with VLD Bullets

Got my cases and bullets delivered today and wow are the bullets long. The PRVI is 1.243" and the Hornady 1.332. The minumum OAL for both based upon the powders I have chosen (IMR 7828, H100V and Varget) is, from the Hodgdon site, 3.030". This pushes both bullets into the case past the shoulder, the PRVI by about .03 and the Hornady by about .12. Is this normal for these type of bullets or should I be seating closer to the lands? Pushing both out so the bases are even with the start of the shoulder leaves a jump of about .09 for both. (While I don't have the necessary insert for my comparator I used calipers to compare ogives and they both appear to be equal distance from the bullet base.) Any suggestions or advice from those with VLD loading experience?

Azar · Member Joined: Jan 04, 2010 Posts: 275 Location: Utah

I haven't used VLD bullets, but in general I'd start as close to the lands as possible and then work shorter. It simplifies things by only giving one direction to "tune" your COAL and moving further from the lands will reduce pressure. No pressure surprises when adjusting COAL.

PaulS · Posted: Wed Jan 14, 2015 4:43 pm Post subject: Re: OAL with VLD Bullets

The folks at Berger say that .040 off the lands works for most but also acknowledge that having a longer jump doesn't affect accuracy.

You can read about their findings on the Berger site.

I have been entertaining the idea of trying VLD bullets in my 257 because it is the only gun I own with a fast enough twist to keep them stable on impact. The longer the bullet is the faster your rifling needs to be. I was reading about the sonic transition stabilization and while a 3006 is fine with cup and core bullets to nearly 220 grains with a 1:10 twist the 180 grain VLD bullets need a faster twist when velocities are between 1.2 times the spped of sound and down to 0.8 the speed of sound. Some 180 grain VLDs key-hole through the targets in that velocity range but seem stable above and below the transonic velocities.

Going into game animals requires more twist to keep the bullets stable in that change of densities too. I don't think a bullet that tumbles on impact with game is necessarily less lethal but it is less predictable in the damage it does.

Elvis · Posted: Wed Jan 14, 2015 8:02 pm Post subject: Re: OAL with VLD Bullets

consider magazine length...... it may stop equation before it begins.

slimjim · Posted: Wed Jan 14, 2015 8:29 pm Post subject: Re: OAL with VLD Bullets

PaulS wrote:

I have been entertaining the idea of trying VLD bullets in my 257 because it is the only gun I own with a fast enough twist to keep them stable on impact. ... Going into game animals requires more twist to keep the bullets stable in that change of densities too.

Rifle twist is optimized for bullets to stabilize in the air mass. You can't increase rifle twist to be fast enough to stabilized a VLD on impact. Bullets have to shorten in length on impact or they tumble. I've tested to many to count.

Bushmaster · Posted: Wed Jan 14, 2015 8:30 pm Post subject: Re: OAL with VLD Bullets

Speed of sound:

760 mph

1125 fps

A bullet must break the sound barrier in the barrel with enough barrel left to re-stablize the bullet before it leaves the muzzle.

In rifles this is rather easy. In magnum pistol/revolvers this is a bit more tricky.

You are correct Elvis...The magazine may solve your dilemma. Bullets that go deeper then the shoulder will not make any difference. Most of my .30-06 loads using the Sierra 165 gr HP and 180 gr SP extend below the shoulder.

slimjim · Posted: Wed Jan 14, 2015 8:37 pm Post subject: Re: OAL with VLD Bullets

PaulS wrote:

I was reading about the sonic transition stabilization and while a 3006 is fine with cup and core bullets to nearly 220 grains with a 1:10 twist the 180 grain VLD bullets need a faster twist when velocities are between 1.2 times the spped of sound and down to 0.8 the speed of sound. Some 180 grain VLDs key-hole through the targets in that velocity range but seem stable above and below the transonic velocities.

There is another explaination for the keyhole at longer range. The twist is too fast and the gyroscopic affect on the bullet does not let it nose over as the trajectory arcs down. This affect starts occurring after 500 yards.

Accuracy International's Long Range Sniper Rifle in .300 WM uses 1:11 twist to shoot 200+ grain VLD bullets.

slimjim · Posted: Wed Jan 14, 2015 8:42 pm Post subject: Re: OAL with VLD Bullets

MacD, I start my VLD bullets 0.010" off the lands and work back to fine tune my load once I have the OCW. Many times that close to the lands is beyond magazine length. I either feed them single shot or work to find an accuracy node within the magazine well. Quite often, manufactures list COAL data that is within SAAMI Specs. This is one of the issues I had with the .300 Win Mag I have been working up loads for.

MacD · Posted: Thu Jan 15, 2015 7:48 am Post subject: Re: OAL with VLD Bullets

Thanks for the comments. As I mentioned magazine length is not an issue as the mag is designed to take a stripper clip. This gives enough room for virtually any length rounds. I haven't calculated load densities so won't know till I get my powder and start loading if seating 0.03 or more into the case will compress the charges. I think I will start with the gap at 0.09 and work back from there.

After posting this I read the Berger Bullets article on COAL for VLD bullets. They suggest that there is a sweet spot between 0.030 and 0.040 wide within a range of 0.010 and 0.150 jump off the lands. I am going to order my comparator insert for 0.264 today. Can't wait to get started. Laughing

slimjim · Posted: Thu Jan 15, 2015 2:30 pm Post subject: Re: OAL with VLD Bullets

Berger bullets have been one of the most accurate bullets I have shot in my.270 and 6.8. However, don't expect them to expand or fragment if you use them for hunting. The 6.5, 6.8, and 7.0mm VLDs all have the same jacket thickness. The copper jacket is thick enough that it maintains its structural integrity on impact, will yaw 180 degrees, and exit tail first. I have never gotten one to fragment and some 7mm shooters anneal their VLDs to improve fragmentation.

chambered221 · Posted: Thu Jan 15, 2015 7:54 pm Post subject: Re: OAL with VLD Bullets

slimjim wrote:

However, don't expect them to expand or fragment if you use them for hunting.

So why does Berger claim them to expand and shed weight ???

Elvis · Posted: Thu Jan 15, 2015 7:54 pm Post subject: Re: OAL with VLD Bullets

slim try the 165 matrix

slimjim · Posted: Thu Jan 15, 2015 9:36 pm Post subject: Re: OAL with VLD Bullets

[quote="chambered221"]

slimjim wrote:

So why does Berger claim them to expand and shed weight ???

After testing bullets of different calibers and comparing to manufactures' claims, I have concluded that they list the performance of their most used bullets in that line (or best performing), typically .308 caliber. A good example of that is Nosler's new AccuBond Long Range. The performance claims are for their heavier .308 bullets. The .270 ABLRs will only match Nosler's claims at a higher velocity (same energy state).

BigBlue · Posted: Fri Jan 16, 2015 5:25 pm Post subject: Re: OAL with VLD Bullets

Doesn't Berger list some VLD bullets being suitable for hunting and others as strictly for target use? One question I have is which means more in determining the twist rate's ability to stabilize the bullets, the length of the bullet or the length of the surface that actually bears against the rifling? We usually see it expressly based more on the weight of the bullet.

Elvis · Posted: Fri Jan 16, 2015 7:40 pm Post subject: Re: OAL with VLD Bullets

now my good men...why would you be wanting to use a berger or VLD projectile in the first place???? unless you are considering trying to stretch the barrel or use it to shoot rodents what is the point.
you will/should run out of gas/energy before you run out of accuracy with 1"group. in which case a good quality cup n core type or better still a nosler partition will shite all over a target type projectile on game animals.