Seating Depth Berger VLD's

[Ronin]

I have used 140 Bergers regularly in my 6.5x284 for several years, always seating them +.010" into the lands.

 

Now, I am developing a consistantly , accurate load for my 7mm/270WSM F Class gun using 180g Bergers.

 

I have found a consistant load that shoots the 180's at 3000 fps with an es in single figures, however accuracy is not as I had hoped -, don't get me wrong, the rifle shoots in the .3"s, but I would like better.

 

I am considering altering the seating depth - at the moment I am seated +.010" into the lands.

 

Bergers site recomends looking for a "sweet spot" bettween 0 and - .150"

 

I was considering changing the seat depth in .010" increments to minus .050".

 

 

This will (I think) have an effect on the pressure in the case, ive run this in QL and I am fine beyond this depth (minus .050"), but wonder if anyone else (using Bergers) has found that contarary to popular belief and myth that the VLD's shoot more consistantly when seated out of the lands.

 

I obviously don't want to burn out the barrel before I find my "hummer" load

[devilishdave]

From what I understand when you load in to the lands it takes more resistance to initialy get the projectile moving thust it gives a split second for pressure to build up. when you ar shy of the lands the round will start moving much easier and thus the pressures wont buil up as much so -50 thou should give you less pressure than +10 Thou.

 

Dave

[Ronin]

Understand your thinking Dave, but, seating the bullet deeper in the case creates less case capacity and increases the internal pressure.

 

For instance, at the moment I am running a COAL of 3.162" and comfortable pressures estimated on QL at about 58000psi

 

If I reduce OAL to 3.112 (minus .050") using the same load, pressure increses to an estimated 59000 psi, (within acceptable levels still)

 

Now if I take the same load and reduce OAL to say 3.052" (minus .150") pressure increases to the reigon on 63000 psi and result potentially a blown gun.

 

 

Having found the optimum node of powder charge I am postulating over altering seat depth in ten thou increments to +.020" and - .050" either side of my current seat depth.

 

I'm really going about things the lazy way by asking rather than experimenting as time is of the essence at the moment

 

 

 

 

 

(For those that intend to run their 7mm WSM at 2.900" OAL this discussion wont affect them as the load will be adapted for the seat depth)

[TC]

Ronin,

 

Are you taking in to account the recommended +/- 7200 psi Shot Start (Initiation) Pressure for touching/not touching in QL?

 

If not this should more than offset your reduction in COAL.

 

Tony

[onehole]

I run 3 calibres on vlds namely 223 with 70vlds,a 6brnorma1/8 with 95vlds and a 6.5/47 with 130vlds.Now all these rifles have loads made up to run at least 10 thou in could be a bit more,it can be difficult to be just that precise with vlds sometimes?!

I just thought 10 thou was probably a good place to be and not based on any experimenting really but at least it was far enough in to last a good while before chasing the lands.Load/powder developement was done from this base and over at least 5 different charges and in each case when tested at 200 yards {not 100} a clear winner raised its head with only one load and always towards what I would generally say was a safe but getting close towards what was probably maximum.

Perhaps this is where vlds like to be ie running fast for the given and correct twist and seems to work in these rifles anyway.

Lower bc or less pointy heads seem to have more accuracy nodes or are more forgiving in work ups and very often exhibit a low velocity but superbly accurate load on occasions.JMO and findings yours may not?Onehole.

[Berger]

I have used 140 Bergers regularly in my 6.5x284 for several years, always seating them +.010" into the lands.

 

Now, I am developing a consistantly , accurate load for my 7mm/270WSM F Class gun using 180g Bergers.

 

I have found a consistant load that shoots the 180's at 3000 fps with an es in single figures, however accuracy is not as I had hoped -, don't get me wrong, the rifle shoots in the .3"s, but I would like better.

 

I am considering altering the seating depth - at the moment I am seated +.010" into the lands.

 

Bergers site recomends looking for a "sweet spot" bettween 0 and - .150"

 

I was considering changing the seat depth in .010" increments to minus .050".

 

 

This will (I think) have an effect on the pressure in the case, ive run this in QL and I am fine beyond this depth (minus .050"), but wonder if anyone else (using Bergers) has found that contarary to popular belief and myth that the VLD's shoot more consistantly when seated out of the lands.

 

I obviously don't want to burn out the barrel before I find my "hummer" load

 

why dont you load 1 of each seating depth you intend to try and shoot it and then check for the usual pressure signs,that what I do,I have a large lump of oak in my workshop which works well,

I have just loades some 162 gr A Max and have had to back off a full 1.3 gr because of the extra pressure due to seating the bullet to fit into my mag

I also had to do the same with 140 gr 7mm VLDs

[Ronin]

Thanks for the replies guys.

 

Ive also had some helpful advice from one of the F Class guys on the site.

 

I loaded another batch of rounds yesterday and set them at

 

+.020"

 

+.010"

 

- .010"

 

- .030"

 

- .050"

 

Took them and the Barnard to Warcop today for some longer range testing. (at 930mtrs)

 

The range at Warcop is a field firing range, for those that don't know what that is, it means that you cannot walk out and check your target after youve shot - well you could, but you woulnt be coming back

 

So with this in mind I set up on a earth scrape at 930mtrs (closest thing to 1000 yards I could find) that wasnt being shot at.

 

The target was a tree stake in a line of Fig 11's .

 

I didnt use the chronograh, just wanted to see how the various seating depths were "grouping" at one clik.

 

To be brutally honest its damn difficult trying to picture a group in the earth, so a true picture wasnt formed.

 

I was pretty pleased that all the various depths made it to the earth around the stake, some pretty damn close.

 

Pressure was non existant up to the last (-.050") loading and then not much to speak of.

 

The -.030" load appeared better than the others, I will do the test again on paper later in the week and run the comp on those findings.

 

 

Sorry no pics.

[weejohn]

Ronin, how did you get on with the seating depth of the vld's. i am currently working on a load for my 243 using the 95gr bergers and my rifle seems to shoot best between -.040 and -.060 .

[col48]

Getting the Best Precision and Accuracy from VLD bullets in Your Rifle

Background

 

VLD bullets are designed with a secant ogive. This ogive shape allows bullets to be more efficient in flight (retain more velocity = less drop and wind deflection). While this result is desirable for many rifle shooters the secant ogive on the VLD bullets produces another result in many rifle. It can be difficult to get the VLD to group well (poor accuracy).

 

For years we encouraged shooters to use a base of cartridge to end of bearing surface OAL (I will use the term COAL to represent this dimension) which allows the VLD to touch the rifling or to be jammed in the rifling. This provided excellent results for many shooters but there were others who did not achieve top performance with the VLD jammed in their rifling. These shooters were left with the belief that the VLD bullets just won’t shoot in their rifle.

 

Other groups of shooters were discouraged by our recommendation to touch the rifling. Some of these shooters knew that at some point during a target competition they will be asked to remove a live round. With the bullet jammed in the rifling there was a good chance the bullet will stick in the barrel which could result in an action full of powder. This is hard on a shooter during a match.

 

Yet another group of shooters who were discouraged by our recommendation to touch the rifling are those who feed through magazines or have long throats. Magazine length rounds loaded with VLDs could not touch the lands in most rifles (this is the specific reason that for years we said VLD bullets do not work well in a magazine). When a rifle could be single fed but was chambered with a long throat a loaded round that was as long as possible still would not touch the rifling.

 

Until recently, shooters who suffered from these realities were believed to be unable to achieve success with VLD bullets. Admittedly, we would receive the occasional report that a rifle shot very well when jumping the VLD bullets but we discounted these reports as anomalies. It was not until the VLD became very popular as a game hunting bullet that we were then able to learn the truth about getting the VLD bullets to shoot well in a large majority of rifles.

 

After we proved that the Berger VLD bullets are consistently and exceptionally capable of putting game down quickly we started promoting the VLD to hunters. We were nervous at first as we believe the VLD needed to be in the rifling to shoot well and we also knew that most hunters use a magazine and SAMMI chambers. Our ears were wide open as the feedback was received. It was surprising to hear that most shooters described precision results by saying “this is the best my rifle has ever shot.”

 

We scratched our heads about this for awhile until we started getting feedback from hunters who were competition shooters as well. Many were the same guys who were telling us for years that the VLDs shoot great when jumped. Since a much larger number of shooters were using the VLD bullets with a jump we started comparing all the feedback and have discovered the common characteristics in successful reports which gave us the information needed to get VLD working in your rifle. We were able to relay these characteristics to several shooters who were struggling with VLD bullets. Each shooter reported success after applying our recommendation.

 

Solution

 

The following has been verified by numerous shooters in many rifles using bullets of different calibers and weights. It is consistent for all VLD bullets. What has been discovered is that VLD bullets shoot best when loaded to a COAL that puts the bullet in a “sweet spot”. This sweet spot is a band .030 to .040 wide and is located anywhere between jamming the bullets into the lands and .150 jump off the lands.

 

Note: When discussing jam and jump I am referring to the distance from the area of the bearing surface that engages the rifling and the rifling itself. There are many products that allow you to measure these critical dimensions. Some are better than others. I won’t be going into the methods of measuring jam and jump. If you are not familiar with this aspect of reloading it is critically important that you understand this concept before you attempt this test.

 

Many reloaders feel (and I tend to agree) that meaningful COAL adjustments are .002 to .005. Every once in a while I might adjust the COAL by .010 but this seems like I am moving the bullet the length of a football field. The only way a shooter will be able to benefit from this situation is to let go of this opinion that more than .010 change is too much (me included).

 

Trying to find the COAL that puts you in the sweet spot by moving .002 to .010 will take so long the barrel may be worn out by the time you sort it out if you don’t give up first. Since the sweet spot is .030 to .040 wide we recommend that you conduct the following test to find your rifles VLD sweet spot.

 

Load 24 rounds at the following COAL if you are a target competition shooter who does not worry about jamming a bullet:

1. .010 into (touching) the lands (jam) 6 rounds

2. .040 off the lands (jump) 6 rounds

3. .080 off the lands (jump) 6 rounds

4. .120 off the lands (jump) 6 rounds

 

Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:

1. .010 off the lands (jump) 6 rounds

2. .050 off the lands (jump) 6 rounds

3. .090 off the lands (jump) 6 rounds

4. .130 off the lands (jump) 6 rounds

 

Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. The remarkable reality of this test is that one of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005. Taking the time to set this test up will pay off when you find that your rifle is capable of shooting the VLD bullets very well (even at 100 yards).

 

Regards,

Eric Stecker

Master Bulletsmith

[foxing2night]

I think that col has hit the nail on the head???? I to have read all the bumff on vld,s???

Having used them now for the last two years in 100 yard br shooting with my ppc and not being able to get them far enough out so that i could jam them, I seated them so that they just kissed the rifling and the results have been very good!!!!!

 

So it just go,s to show that everything is not set in stone???

 

As i have read that a lot of people who first thought that there guns would not shoot with vld,s are having success seating off the rifling

 

All the best F2n