LR BR folks - bushings vs mandrel

[Hengehold]

I shoot 1000yd NRA highpower not BR. I have noticed that x-count has improved by removing ammo with erratic neck tension (some noticeably light and some noticeably stiff) after seating by hand on a single stage press. Average cull rate for my ammo seems to be around 10%. I use Lapua brass exclusively.

When using a FL die and bushing only I noticed the percentage of cases with noticeable variance in neck tension increased dramatically, cull rate increased from 10% to 20%-30%. I went back to using an expander mandrel and it immediately corrected the problem and cull rate went back down to about 10%.

After reading about others having success with the bushing only approach, I may give that process another try and see what the results are on a second attempt. Perhaps there were other factors at play that I was not aware of such as seating too close to a doughnut for example.

-Trevor

 

[memilanuk]

I shoot 1000yd NRA highpower not BR. I have noticed that x-count has improved by removing ammo with erratic neck tension (some noticeably light and some noticeably stiff) after seating by hand on a single stage press. Average cull rate for my ammo seems to be around 10%. I use Lapua brass exclusively.

When using a FL die and bushing only I noticed the percentage of cases with noticeable variance in neck tension increased dramatically, cull rate increased from 10% to 20%-30%. I went back to using an expander mandrel and it immediately corrected the problem and cull rate went back down to about 10%.

After reading about others having success with the bushing only approach, I may give that process another try and see what the results are on a second attempt. Perhaps there were other factors at play that I was not aware of such as seating too close to a doughnut for example.

-Trevor

I'm in a similar boat... I'm shooting F/TR, not LR BR (yet). And I think I might have painted myself into a corner with the (lightly neck turned) brass on this barrel - the difference between the fired neck dimension and the loaded round dimension, and the bushing sizes required to get there... seem to start doing some odd things past a certain point.

Very frustrating when you hit a point where bushings suddenly go from sizing as expected ie a 334 bushing yields a 334 neck OD, to a 333 bushing yields a 330 neck OD. And of course, right in between there is where I think I want to be for neck tension. And yes, I've checked the sizes of the bushings, and they are what they say they are. And yes, I've checked with something more accurate than the backside of my calipers

I might be able to get where I want to go by stepping down the necks in two passes through different sized bushings... but at that point, I think I'd rather not do two passes through the sizer, and just use an expander mandrel to fine-tune what I want for neck ID.

I certainly plan to experiment with the 'bushing only' approach with some of my other guns/calibers where there isn't such a... generously sized... neck in the chamber.

 

[Northridge]

I shoot 1000yd NRA highpower not BR. I have noticed that x-count has improved by removing ammo with erratic neck tension (some noticeably light and some noticeably stiff) after seating by hand on a single stage press. Average cull rate for my ammo seems to be around 10%. I use Lapua brass exclusively.

When using a FL die and bushing only I noticed the percentage of cases with noticeable variance in neck tension increased dramatically, cull rate increased from 10% to 20%-30%. I went back to using an expander mandrel and it immediately corrected the problem and cull rate went back down to about 10%.

After reading about others having success with the bushing only approach, I may give that process another try and see what the results are on a second attempt. Perhaps there were other factors at play that I was not aware of such as seating too close to a doughnut for example.

-Trevor

My “cull” rate on paper is just the opposite

Shawn Williams

 

[Northridge]

Double sizing can be very affective Monte give it a try

Shawn Williams

 

[tvaught]

The very basic "challenge" that @Alex Wheeler has opened my eyes too ->

Is to ACTUALLY TEST (@ the intended competitive distance) whatever it is your doing, in terms or processes or practices... and validate or discredit the sacred "truths" that we hold as shooters.

The next eye opener (for me) was as noise levels change in your competitive system (most of the time we are improving so noise is trending lower, but as we intro "new" (reamer, lot#s, barrels, etc)) into our system, the noise can creep in unknowingly, and some stuff that used to matter doesn't and vice versa.

Test more. Then test again.

 

[Northridge]

The very basic "challenge" that @Alex Wheeler has opened my eyes too ->

Is to ACTUALLY TEST (@ the intended competitive distance) whatever it is your doing, in terms or processes or practices... and validate or discredit the sacred "truths" that we hold as shooters.

The next eye opener (for me) was as noise levels change in your competitive system (most of the time we are improving so noise is trending lower, but as we intro "new" (reamer, lot#s, barrels, etc)) into our system, the noise can creep in unknowingly, and some stuff that used to matter doesn't and vice versa.

Test more. Then test again.

That’s definitely the “key” Tim if my testing says do it that’s all I need but every system continues to evolve, very Little is a “line item” constantly gaging “potential”

Shawn Williams

 

[memilanuk]

Double sizing can be very affective Monte give it a try

Interesting... do you mean another trip back through the F/L sizer, just with different size bushings... or a F/L sizer for step one, and a neck sizer for step two?

 

[Northridge]

Interesting... do you mean another trip back through the F/L sizer, just with different size bushings... or a F/L sizer for step one, and a neck sizer for step two?

full length size and a bushing larger than target bushing then target bushing size will give a different result vs target bushing only if your attempting something outside of what you have… just running sizing and bushing twice is a common thing guys do with success as well

Shawn Williams

 

[L.Sherm]

Is my thinking because doing it in 2 steps gets more consistent sizing because you are not trying to push as much brass at once Shawn? In the necks?

 

[Northridge]

Is my thinking because doing it in 2 steps gets more consistent sizing because you are not trying to push as much brass at once Shawn? In the necks?

Could be part of the equation I suppose but double working the brass definitely gives a “modified “ result on paper even if static measurements are equal after task result on paper will be different… sometimes not having enough choices out of your on hand bushings can be manipulated with a approach as this


Shawn Williams