Anybody try the Forster "Precision Plus Bushing Bump Sizing Die" yet?

http://www.forsterproducts.com/Pages/precision_dies.htm

Sounds like a good approach to the neck sizing with a periodic bump approach many utilize.

I'm not certain they use an expander ball?

Who needs one?

I'll be interested to read the first (credible) reviews.

flaco

Flaco, I have not tried the new Forster Bushing Bump Die. I wonder if it touches the case body?? Or whether it is solely set up to bump the shoulder, as some (custom) BR dies seem to do.

The idea seems good, bushing dies are always very flexible with respect to the neck tension you want to achieve. It also sounds like a good idea that 3 bushings are included with the die (set). Invariably, you end up buying more bushings than you had orginally planned - at least that has been my experience with Redding bushing dies. Partial sizing of the neck is a technique used by many reloaders, and could well have merit.

If you look at the die Ordering Chart, you'll see bushing diameters shipped with each "die kit". That chart actually specifies very sensible bushing sizes - at least it includes bushing diameters matching what I have specified in the past when I ordered dies to be honed to a particular neck internal diameter. Exactly which bushing you might use depends on the wall thickness of the brass in question, and how much neck tension you like.

The die does not come with an expander, although Forster specifies one can optionally be installed. See: Die Instructions

On the surface, albeit with limited knowledge about the particulars, it seems this die is really a take-off of some of the custom dies often seen in BR (Neil Jones etc).

On the negative side, I have often (mostly, always?) had more runout with bushing dies than with "fixed" dies. If you believe runout is a bad thing, then I guess this might be of interest. I use quite a few Forster FL dies with internal neck diameter honed to allow sizing without an expander. This setup is not as flexible in controlling neck tension (you can't vary die internal neck diameter), it does touch the case body (so it is not really a "bump" die), and it does not allow partial sizing of the neck. It does, however, produce very straight ammo.

I'd also be interested in hearing how the new Forster die fares, in particular what kind of runout the die produces.

- mike

quote:

Originally posted by mho:

I use quite a few Forster FL dies with internal neck diameter honed to allow sizing without an expander. This setup is not as flexible in controlling neck tension (you can't vary die internal neck diameter), it does touch the case body (so it is not really a "bump" die), and it does not allow partial sizing of the neck. It does, however, produce very straight ammo.


- mike

Hey mike

I have been wondering about those Forster honed out FL dies. If they size the outside of the neck to a certain diameter then do you have to make the neck thickness uniform? I neck turn with a Forster turner and even if you turn brass off all the way around the neck thickness can vary by .0005" or so. Do you think these irregularities of neck thickness would affect bullet grip consistancy?

I have gotten brass that varies as much as .003" in neck thickness and vary in range from .012" to .017" (not on the same piece of brass, but you know what I mean). Being a first rate case prepper you are , what steps do you take before sizing with this type of die?

Trying not to hi-jack Flaco's thread, I'll quickly point out that the issue of case neck wall consistency is also of relevance to sizing with a bushing die.

Woods, I don't turn necks. When I try to get accurate loads - be it in target or big game calibers - I do sort brass according to neck wall variation. Depending on what brass I use and the caliber in question, I accept neck wall variations below .001" (small caliber, 1st rate brass, target) or .002" (big game). It is probably fair to assume that neck turning could improve my neck tension consistency. However, I have not gone down this path (yet?).

I do find that neck tension consistency can be a factor in accuracy. But I believe there are other factors (in adition to neck wall variation) to be observed in this respect. There seem to be few absolute truths in reloading, but I have found this one to be pretty much universal: "brass varies"! Even when working with new brass (i.e. excluding potential work hardening effects), I have found it very possible to get varying neck tension. What does it come form?? I don't know. What it has led me to, is that I normally don't rely on very low neck tension figures - even in small caliber, target type loads. Redding suggests neck tension (loaded minus sized neck diameter) as low as .001". Forster suggests neck tension as low as .002". I typically use .003" for small round calibers and .004" for big game calibers. I can't quantify this, but merely at the feel of seating resistance, I feel using a bit more neck tension helps me get more consistent in this respect. And I have seen group sizes come down with consistency in this area.

- mike

Because I live Forster, I will buy the new dies and try them, but I don't have great hopes.

I have had a half dozen sizers "honed" out the necks at the Forster factory with their Hardinge collet lathes.

Based on my measurements and analog interpolation with pin gauges, Forster honing to X is really X +.0009 -.0000 and bushings are X +.0000 -.0002.

If I partial size with Forster honed dies, how can the new dies do better?
The dies I have will make the conentricity all over the outside of the neck .00025" or better. This is with fire cases, not cases just wrecked with an expander ball.

How are they going to do better than that?

My guess is that Redding makes more money off their inferior floating bushing "S" die system, and Forster wants more money, results be damned.

Woods,
I had my Forster FL die honed to give me .003 neck tension a couple months ago and it works perfect. Both my 7mm08s shot in the .1s today.
I do not use the expander any more either. When I borrowed a concentricity gauge I found the worst to be out .001.

quote:

Originally posted by Dwight:
Woods,
I had my Forster FL die honed to give me .003 neck tension a couple months ago and it works perfect. Both my 7mm08s shot in the .1s today.
I do not use the expander any more either. When I borrowed a concentricity gauge I found the worst to be out .001.

Hey Dwight

I makes sense that you would have very little runout on the outside of the neck after sizing with one of those dies. My question is if you had the die honed to give you .003" neck tension, then do you allow for that with the type of brass you use or by meticulous neck turning?

I have some Nosler brass that has a neck thickness that varies between .0125" and .0135" and I just received some Remington brass that has a neck thickness that varies from .015" to .017". It seems to me that you would have to monitor neck thickness meticulously to use one of those dies.

Even neck turning is not perfect and has it's own variation which will create runout on the inside of the case neck. Now it's possible it will make no difference, I'm still contemplating that.

So, how do you know you are getting .003" neck tension everytime?

quote:

Originally posted by woods:
So, how do you know you are getting .003" neck tension everytime?

Woods, strictly speaking, we can't know. Variation in the neck wall thickness will be a variant, and will only be controllable if you neck turn or sort for neck wall thickness. The .003" is only a nominal figure obtained from whatever measurements we decided to make - assuming we did not measure every single case...

However, this will also be the case if you use a regular die - which on top of that will let you suffer from (expander generated) runout and overworking of the brass. There are also other factors involved in the actual neck tension obtained - brass springback is but one. We can try to control some of these factors as well (e.g. annealing), but since we can't quantify either cause or effect, we'll have a hard time ensuring we have got it all perfect.

In the absence of that, I have adopted the approach of seeing what my gun tells me. I use a bit more neck tension to attempt to minimize the effect of such variables, and then see what groups my gun produces. If the results are acceptable, I conclude I have taken the process far enough to satisfy me.

Could I get better results if I turned?? Possibly, perhaps even likely. It really also depends on the chamber for which you turn. It is probably an exercise in futility to turn for an (oversize) factory chamber. There will be too many other factors which might negate the positive effects of turning. For a custom chamber, the potential is better. Still, personally if I decided to turn, I would only do so for a target type rifle. For hunting, I'm normally way past the accuracy level needed to kill anything that walks on this planet. It is fun to shoot accurate rifles, but in reality field accuracy depends on many factors other than the rifle/load combination.

- mike

Woods,
When I measure a sized neck and compare to the OD of a loaded round there is .003 difference which is what I call .003 neck tension. The Neck sizing dies was set up this way from Forster and I sent them my FL die and asked them to make the same as the Neck die because it was working the necks too hard. Now if you think I will ever worry about .002993 or .0031 then it ain't going to happy. You or noone else can shoot good enough to tell the difference. I use Rem brass and I don't weigh it and I don't turn necks and I don't debur flash holes and I will not buy a concentricity gauge ever. I borrowed one just to prove my work is good. I would rather spend my time shooting.

Don't sweat the small stuff.
Dwight