300 win mag OAL question

[rhantz]

I recently got a 300 wm and want to develope loads for it. I used the Hornady OAL gauge to find the lands and took five readings (slowly and gently pushing the bullet until it hit the lands) and the ave. was 3.0 to the ogive. If I seat the bullets with .3 of the load bearing surface into the brass the length is 2.878 to the ogive.
The questions are:

Do I just live with the jump?

Am I missing something (doing something wrong)?

Should I try seating with less than .3 of the load bearing part of the bullet in the case to reach the lands or would this cause even more problems?

Thanks in advance - Rick

 

[bax]

What weapon do you have?
Stock barrel or custom barrel?
What bullet did you use for those measurements -- that is what manufacturer, weight, and "model"?
When you say ".3 of the load bearing surface" do you mean three tenths of an inch?
Do you have a velocity target in mind?
Hunting or target shooting?

 

[rhantz]

1) What weapon do you have?
The firearm is a new TRG42.
2) Stock barrel or custom barrel?
Stock
3) What bullet did you use for those measurements -- that is what manufacturer, weight, and "model"?
Berger 210 VLD
4) Do you have a velocity target in mind?
No, starting with a moderate load (76 grs Retumbo), wanted to play with the seating depth first.
5) Hunting or target shooting?
Target only

 

[bax]

1) What weapon do you have?
The firearm is a new TRG42.
2) Stock barrel or custom barrel?
Stock
3) What bullet did you use for those measurements -- that is what manufacturer, weight, and "model"?
Berger 210 VLD
4) Do you have a velocity target in mind?
No, starting with a moderate load (76 grs Retumbo), wanted to play with the seating depth first.
5) Hunting or target shooting?
Target only

First. If the bullets shoot then it doesn't matter. If they don't shoot, you will use something else. In my case, they MUST fit in my magazine -- to me, that is more important than accuracy. In my rifle, I can make a 210 VLD round that shoots great but it doesn't fit in the magazine. If it fits into the magazine, it doesn't shoot worth a damn. I cannot make a round that both fits in the magazine and shoots so I have 80 or 90 bullets that have no real future. There is a good chance that magazine length will limit your seating depth. I haven't looked at a TRG42 in a while so I cannot say what the magazine length is. You should check that.

The 210 VLD is a long pointy bullet so you have to seat it further out in order to get the the same jump. When I made rounds with it, I went for a 0.018 jump and the rounds were very long. Please keep in mind, the secant ogive is more forgiving of seating depth. You will probably have to shoot it to find out.

Consider using a bullet with a tangent ogive like Sierra 220s or 240s. The 220s are long and the 240s are really long -- mine measure 1.586. Unless the throat in your TRG is VERY long, there will be lots of bullet in the case with 240s. FWIW, I have a 9-twist barrel and that is necessary for 240s.

BTW, I didn't give up much on accuracy. I attached a .6 MOA target I shot at 1,000 yards a couple weeks ago. The rifle is a rem 700 with a magazine. It isn't stock but it isn't fancy like your TRG. Others have shot better but others and I have shot worse. I was pleased with it.