Forster Full Length Competition Sizer die question

[birddog28]

I am using this for my 6.5X47. I have developed a load based on the virgin Lapua brass. When I run the once fired brass through the die, the neck is quite a bit more narrow that the virgin brass. I'll have to put my micrometer on it to measure the differnce.

I'm not getting any pressure signs from the increased neck tension and POI shift seems minimal. Should I let it ride or go to a full length bushing die?

I can see that I could have a poblem when I eventually have to chase the lands when the round count gets high. It looks like if the projectile is seated long then the brass could be more narrow behing the round right before the shoulder. Thanks . Jim

 

[Winchester 69]

Re: Forster Full Length Competition Sizer die ques

Forster will modify your die to your spec if you want the die to do less. It may not be effective if you ever have some thin brass.

 

[birddog28]

Re: Forster Full Length Competition Sizer die ques

Thanks for the input. So if the neck is thinner (brass) then it won't achieve enough tension to produce the proper ammount of pressure?

 

[Winchester 69]

Re: Forster Full Length Competition Sizer die ques

If the brass is thinner, it requires a tighter sizing diameter to achieve a similar inner diameter, which determines the tension. A bushing or custom sizer achieves the I.D. without benefit of expander. To accommodate varying brass thicknesses, standard sizer reduce to a small diameter and allow the expander to produce the finished I.D.

You can have Forster reduce the amount that it squeezes the brass, but in doing so, it limits how thin the brass can be and the die still be effective.

 

[Winchester 69]

Re: Forster Full Length Competition Sizer die ques

My initial reading of your contention was that the Forster die is overworking the brass during the sizing process. On re-reading, I'm uncertain as to what your problem actually is.

Is the bullet moving in the case while in the magazine during operation? If this is the situation, you may need to crimp your ammo.

If your fired brass's necks are of excessive diameter, then you have a large chamber.

 

[birddog28]

Re: Forster Full Length Competition Sizer die ques

No, its just that the die necks the case down to a smaller diameter that the virgin Lapua brass.

 

[JLM]

Re: Forster Full Length Competition Sizer die ques

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: birddog28</div><div class="ubbcode-body">No, its just that the die necks the case down to a smaller diameter that the virgin Lapua brass. </div></div>

Are you running the expander ball?

 

[birddog28]

Re: Forster Full Length Competition Sizer die ques

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JLM</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: birddog28</div><div class="ubbcode-body">No, its just that the die necks the case down to a smaller diameter that the virgin Lapua brass. </div></div>

Are you running the expander ball?

</div></div>

Okay, you have to educate me on that expander ball...Is it the wider part of the decapping rod or something else?

 

[Winchester 69]

Re: Forster Full Length Competition Sizer die ques

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: birddog28</div><div class="ubbcode-body">Okay, you have to educate me on that expander ball...Is it the wider part of the decapping rod...? </div></div>
Affirmative.

 

[birddog28]

Re: Forster Full Length Competition Sizer die ques

Okay, I got you. Yes it should be engaging the inside diameter of the neck.

Do you think that the difference in neck tension is anything to worry about?