Lost please help

[SAM1980]

I'm new to reloading, I have been working up various ladder tests using berger vld bullets out of my 1903 a3 custom. I have noticed that during the ladder tests that I would get drops in velocities for three or four rounds, even with .4 grain increases in powder charge. Anyone every see this in there test load work ups. What is causing this. I thought that I might have found some accuracy nodes at 51.8, 52.2, 53.0, and 54.0. So I loaded up some 4 shot group tests at these charges. Boy was I wrong it shot all over the place at 200 yards. Tightest group was around 3moa! the velocities started out high and steadily dropped off during each string. Some times as much as 80 fps.

Components are
Nosler 30.06 springfield brass
Winchester LRM primers
Berger 210gr target vlds
using 51.8 to 54.0 grains of H4350
Seat bullets .07 into the lands at 3.363 oval with horday oal gauge

 

[FearNoWind]

What are you using for a chronograph?
What are you using to measure your powder?
What are you using to measure your COAL (CBTO)?
CBTO variations will create the problem you describe.

 

[SAM1980]

Cbto?

 

[SAM1980]

Caldwell chrono, Lyman gen 5 digital despenser, horandy oal gauge w/ .30 cal comperarator on digital caliper

 

[Ridgerunner665]

Cbto?

Cartridge base to ogive...

Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) - Part 1 | Berger BulletsBerger Bullets

 

[SAM1980]

I have been measuring my rounds from base too ogive with a hornady oal comparator kit. I noticed while loading that they will measure a little different from round to round. But not much maybe .005 to .015. Would this cause that big of difference?

 

[Ridgerunner665]

I'm gonna go out on a limb here and say you probably don't have a VLD seating stem in your seating die...and you're seating bullets from the tip instead of the ogive.

Thats whats causing the varying seating depth...

Seating bullets from the tip isn't good...(1) they're often seated crooked (run out)...and (2) they're not seated at the same depth....both of which can cause velocities to vary and poor accuracy/

 

[SAM1980]

I'm using a forester micrometer die, and I don't think it is set up for VLDs, thanks for the input

 

[SAM1980]

My seating die is a forester ultra micrometer looked up on there website and they say that it will properly seat most vld bullets. So I took the stem out of mine and checked it using the burger target vlds that I'm loading and it is seating them from the ogive and not the tip.

 

[idaho elk hunter]

I know this sounds goofy since you are resizing. But you really need to check your neck tension on all of the loads. I think you will find a surprising solution to your problem. To fix it start with turning the case necks and firing a very hot load. Send the brass with the die to Forrester and have them hone to size.

 

[Unofficial Gun Addict (UGA)]

Sam,

Perhaps I missed it, but are you FL sizing, or neck sizing your cases. What dies are you using to size? It sounds like your scale may be throwing inaccurately, or your cases are varying dramatically in volume, unless you have a serious runout problem, but the forster die you have is excellent typically for VLDs which is why I purchased mine in the first place. Also, if the neck tension varies greatly, you will get results such as you described.

It was recommended to me to purchase the Lee collet dies here or at reloadersnest, which I've found to produce great results for neck sizing in both my 308 and 300 win mag. I seems odd to me that you are getting that much variance in your seating depth also, unless the seating stem is loose, or your case necks are vastly differing with respect to tension. My typical seating depth only varies by about +/- .0015 using the forster micrometer dies. This might sound stupid, but are you locking the seating stem nut down prior to seating? If it's not tightened down, at least a good finger tight amount, mine will produce a little more variance in seating depth... But not as much as you described.

I feel your pain. I was chasing an issue similar to yours and finally isolated it to my magnetospeed being attached to my rifles while working up loads and determining groups. Wasted quite a number of rounds til I figured it out. I sure hope you can get to the bottom of it sooner as opposed to later. I've been very happy with the redding FL dies, lee collet neck dies, and the forster micro seating dies for the VLDs.

 

[SAM1980]

I am using rcbs fl dies. I have no way of measuring neck tension, nor do I know how. I'm a newbie and thus far have been using the trial and error approach. All of this info is a big help guys thanks

 

[SAM1980]

What is runout?

 

[Unofficial Gun Addict (UGA)]

Bullet runout is when the bullet is not pointing away from the exact center of the cartridge.

Wow... Without sounding like a math book, that's the best way I can explain it. Check out youtube for bullet runout or bullet concentricity. A visual will help you understand it much better than I ever could.