Bullet choice vs bushing choice

[cohunt]

if you are not going to turn the necks you then try a tighter bushing, use a mandrel to expand the inside rather than the outside with a bushing,

if you do the calculations-- you are using a .292 bushing--- take off .264" for the bullet, then divide whats left by 2 for what your brass thickness is .292-.264=.028"/2=.014" of brass thickness--this would be "0" neck tension
usually .014" is on the thicker side of brass, and with those numbers you would have a ".000"" neck tension --- most brass (even the best stuff) will have at least a .0005"-.001" variance in thickness on the same case (I have found some bad brass to be up to .004" thickness variance)

assuming you have an average brass neck thickness of .014" you can go the other way-- .264" bullet + .014"+.014" = .292--if you want a .002" neck tension then you need a .290" bushing to get at least .001" neck tension

this is why I use expander mandrels--- a bushing will push irregularities to the inside, and does not take into account any variances in brass neck thickness so you wont get a consistent neck tension unless you neck turn to the exact same thickness on each piece of brass---if you use an expander mandrel, you can size down smaller than you want, then use the expander mandrel to size back up to the exact same size for each and every piece of brass as you are making the "hole" the same size each time (as long as your brass is all annealed the same for like spring back)--I also like the expander mandrels as I can "fell" the neck tension with a mandrel better than I can with a busging and then it can help me make the decision if I want/need to anneal the necks as eventually you will develop different spring back between each piece of brass after firing multiple times

Redding recommends that if you don't neck turn that you use their expander ball, if you do neck turn then you can take the expander ball out and use just the bushing

https://www.redding-reloading.com/tech-line-a-tips-faqs/136-bush-size-quest

anytime you change brass, or bullets you may need to change your bushing size if you are only using .001" neck tension as its such a light tension if anything changes you may need to adjust (also you may need to adjust once the brass becomes work hardened if you are not annealing)

your first step would be to measure the bullet outside diameter to see if you are getting a variance between different bullets

 

[Okanogan]

I suspect you may be correct that approaching the problem from the ID with a mandrel will make mute whether or not slightly different bullet diameters seat correctly or not. If I understand it correctly, to make sure it always works out the die will originally undersize the neck slightly and the expander mandrel will slightly undersize the ID to make sure everything snugs up nicely. I'm assuming the trade off is it slightly over works the brass in the neck.
I'm not disagreeing with your suggestion but I already have the Redding bushing S die and the rifle/ reloads seem to be shooting fairly well. As long as it continues to shoot well, I think I can achieve the same thing with a slightly undersized bushing -either a .290 or .289. If the Bryan Litz Applied Ballistics Vol 2 was right, I'm not giving up much if anything by varying neck tension as long as the all my bullet selection seat correctly.
My original intent with the post was to see if others had noticed variation in bushing selection requirement based on their bullet selection. It would seem the answer by omission is no. In my case, it seems that only part of the answer is the bullet selection itself so the remainder has to be in my set up/ components, with the most likely contributor being the ADG brass.
For what it is worth, I did run a expander mandrel through the virgin brass before resizing it but of course that will not change the varying neck tension that might occur for a number of reasons when using a bushing.

 

[cohunt]

Regular dies that use expander balls will surprise you on how small they size the necks of you dont use the expander ( since they have to take into account tolerances of chambers and different brands of brass they undersize considerably) but - in 30+ years of reloading/shooting I've never split a neck and ive used just about every die/bushing/expander/mandrel/collet die type out there-- I just prefer using a floating mandrel to get my neck tension, there is more than 1 way to skin a cat though. It just seems to help my concentricty by using the floating mandrel rather than expander balls or just bushings alone.

 

[Mikecr]

My direct input to the question is that this is the first time I've ever heard of bullet selection affecting bushing choices.

 

[Bob Wright]

No on bullet selection. It can only be brass related, i.e. neck tension brought about by variation in wall thickness, sizing the necks and springback. Without the ability to measure all of these variables, its a guess. Hopefully not an internal taper or donut condition is confounding your seating operation.
Neck turning correctly makes a big improvement.

 

[misterc01]

I initially measure neck wall thickness of my brass with either a ball micrometer or an RCB Master Case Gauge. If it is consistent all around, fine, if not, then I turn it. The expand with a mandrel and the end result tells me what bushing to use. I use .003 neck tension (after spring back) and so far that works for me.

 

[Sengoku]

If you run a 168 Berger @3150 you're still below and outside a 130 JLK @3250 at the 1000yd line. The 147 ELD-M @3150 shows up 150fps faster than the 3150 168 @1k in addition to less drop and drift. The 180 hybrid would have to start 3200+ to catch the 6.5 SAUM with 147s or 130s. The 7mms are great, but to say the 7mms will always be superior, that's not accurate. Keep in mind these are low pressure, mag length loads, run double base at 65k psi and see how much the 6.5 SAUM pulls ahead. Not trying to argue here, but the 6.5 SAUM packs as much punch into 2.930 as you're going to get.

 

[Okanogan]

All bullets for the same caliber should be the same diameter, except for those rare times when they apparently are not. I appreciate all the folks who showed an interest in the thread. Because it is not common, I thought posting video comparing the 153 Hybrid vs 156 EH seating might be of interest to those who contributed. Unfortunately, it seems I'm unable to post video unless I am willing to create a You-tube channel so the two pictures are the best I could do.
One is a 153 Hybrid that's fallen through into the case, and the second is a 156 EH that I can't seat any deeper in the same case one minute later regardless of how hard I push with my finger. Same cartridge in same condition in both photos, only the bullet selection has changed. I'm not trying to drag the thread on, just providing some evidence that unusual things happen sometimes. (I saw a photo of a Wolverine on a Washington state beach in a news article yesterday or I wouldn't have thought that possible either.)

 

[Bob Wright]

If you have a 1" micrometer that measures to .0001. You can measure the bearing surface near the ogive/bearing and then the boattail/bearing and see if it has a pressure band on the one that does not enter the neck. I have a copper bullet that has this feature.
Second, you can measure the difference between the two bullets and make a call to the manufacturer if these vary.
Find a buddy or a gun shop that can assist if you need to.
You cannot do this with calipers with enough accuracy.

 

[Okanogan]

My calipers only measure to 0.001 though they sometimes seem to offer up a .0005 after the last digit. I agree if I had more accurate measurement tools I would be better able to tell the true difference in diameter and bullet shape. As noted previously I mic'd out the bullets at .264 and .2635 but I don't have extreme confidence in my measurements when I am pushing the limits of my mic. At this point I'm just going with the anecdotal evidence that one bullets goes through a hole that the other will not, which I agree is not something I have encountered before.
If I really concerned, I would contact Berger but both bullet types shoot well for me as long as I seat the bullets with enough neck tension. I'm curious whether the new box of 500 153.5 Hybrids I have coming will be similar. I think the 153.5 Hybrid is fairly new and perhaps I just got a fluke box as Berger fine tuned their early production.
I'm looking at the whole issue as more of an oddity than a true problem to be solved. (especially in my rural area with limited local capabilities)

 

[Bob Wright]

My calipers only measure to 0.001 though they sometimes seem to offer up a .0005 after the last digit. I agree if I had more accurate measurement tools I would be better able to tell the true difference in diameter and bullet shape. As noted previously I mic'd out the bullets at .264 and .2635 but I don't have extreme confidence in my measurements when I am pushing the limits of my mic. At this point I'm just going with the anecdotal evidence that one bullets goes through a hole that the other will not, which I agree is not something I have encountered before.
If I really concerned, I would contact Berger but both bullet types shoot well for me as long as I seat the bullets with enough neck tension. I'm curious whether the new box of 500 153.5 Hybrids I have coming will be similar. I think the 153.5 Hybrid is fairly new and perhaps I just got a fluke box as Berger fine tuned their early production.
I'm looking at the whole issue as more of an oddity than a true problem to be solved. (especially in my rural area with limited local capabilities)

My Hammer bullets across the bearing is .0005 larger than the Barnes in the same weight class.
Measured some 160 SGK's and they have both taper and out of roundness about 0003.
Natural variation.
So, an old machinist will know a 1.0000" pin will not fit in a 1.0000" hole, lol. The variation your seeing could be roundness, taper, size etc. One slips in and one doesn't. Just set your neck tension for both the same way. You'll be fine.