Case neck tension ?

If bullets move to soon, powder will not burn correctly. The neck should expand .002" on bullet seating, to give about 35 to 45 lbs bullet pull. Measured on a 223.
 
Provided its tight enough to hold your bullet in place, consistancy from one round to the next is probably more important than the amount of it.
 
when I reload and seat the bullets if some seat easier than others then the case neck tension is different and will cause a loss in accuracy, right ?
Should I sort the easier seating from the harder seating ?
 
When you seat bullets and you feel a obvious difference in the effort it takes to seat the bullet. Separate those tight or loose rounds and compare them at the range. That should give you your answer to the accuracy for your rifle load combonation.
 
How important is this in accuracy of a cartridge ? Is there a way to measure it ?
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How important? There are factors, same for annealing, there are simple rules that govern annealing.

If I hunted with a rifle with open sights it would be a s SantFe/National/Golden State Arms 03 or a Ross 1905 303. If I hunted with the Santa Fe 03 I would use the ammo it came with. that would be 2 boxes of R-P that was purchased with the rifle from Sears.

What does neck tension have to do with 'it' (accuracy)? Nothing.

Then there is that part about measuring neck tension: I can measure bullet hold or bullet grip. All of my gages that measure hold and or grip are calibrated to measure in pounds, my gages are not calibrated to tensions, and I do not have a conversion for tensions to holds. I do have tension gages, one more time, my tension gages are calibrated in pounds. The first tension gage I used was calibrated in thousands of pounds. The face on it was as large as the face on a school clock.

Bullet hold, I want all the bullet hold I can get, again, there is no way to measure tensions so I am the only reloader that is forced to measure bullet hold in pounds. For me? 45 pounds is a good number. Again, I have no conversion that allows me to go from tensions to pounds. What I can do is measure interference fit, I can also measure crush fit. When crush fitting I have instructed others to stand back, way back. When fitting with a 100,000 pound press, once the crush is started there is no backing out.

Now there is a small bullet seating press that is hydraulic. I know, if there was some way to calibrate the gage in tensions it would be calibrated in tensions, or interference fit, there is hope for 'crush fit'.

F. Guffey
 
Should I sort the easier seating from the harder seating ?
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It cant hurt. Some neck turn and use bushing dies without an expander, to get the same neck tension. I use a Redding Type S FL sizing bushing die for my 243 win.
 
when I reload and seat the bullets if some seat easier than others then the case neck tension is different and will cause a loss in accuracy, right ?
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Inconsistancy would probably be a better description than loss of accurracy. Is this a matching set of brass with same number of reloadings, or is it mixed?
 
Get a Lee Factory Crimp die, it causes a slightly higher start pressure which allows for a more uniform pressure curve, less velocity variation and improved accuracy.
 
Read about neck tension, bought the Redding S Type bushing dies Full & Neck. Recommended 1-2 thousands. Federal brass is on the thick side, Measured neck thickness at 6 & 12 o'clock .015 on both ,totaling .030 plus 308 cal bullet,total .338 ordered a .337-.336 & .335 only change I found was my runout was average of .003 from the standard RCBS F/L die average runout .001 I don't neck turn & I size with the expander ball. Works fine for me. I use the bushing neck die without the bushing or expander ball only the pin, to remove the primer before cleaning the brass & sizing. In reloading we just keep on trying new things. I just changed after 25+ years of tumbling with corn & walnut media to wet rotary tumbler with stainless steel pins, now that was a good change, just love the way it cleans.
 
So, you are saying that you got .003 runout from your bushing die and .001 from your RCBS die? If so, that would mirror my experience.

Punctuate. :D
 
"when I reload and seat the bullets if some seat easier than others then the case neck tension is different and will cause a loss in accuracy, right ?
Should I sort the easier seating from the harder seating ?"

I often load in lots of 100. Within that lot, there may be some cases with discernibly looser/tighter necks. I set those aside and mark them as "sighter" or "scope check". Truthfully, at 100 yards, I don't see much variation between those and the regular run. At longer range???????? probably so.
 
About to post a new thread but this looks spot on to my question.

I am loading once-fired, fire-formed Sako brass and finished my first reload last night and noticed a significant variation in seating tension. I am seating Berger and Sierra bullets. I am using a RCBS Competition resizing and seating set.

I am getting variations in seating pressure using the same bullet-case combo while working up various loads, ie. getting variable pressure from bullet to bullet sometimes.

do I now need to enter into the neck-tension-optimizing world?

Thanks from a newbie!
 
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do I now need to enter into the neck-tension-optimizing world?
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I am not sure it is a working world, seems to me it is a talking world. There are no conversion charts for tensions to pounds. I can seat bullets and measure resistance to seating in pounds.

I have tension gages, all of my tension gages measure in pounds.

F. Guffey
 
There does seem to be a lot of talk that all boils down to measurements.

Since I am working up loads and shooting at 100 yards to determine optimal load combinations for my rifle, will I note a difference at 100 yards? Or is this a long range issue that will come up as I move farther down range?
 
.002 neck tension is what you would want to shoot for. Now again you can have 100 cases that are set exact, but you will feel some seat easier then others. It will cause an accuracy issue at long range, short range probebly not a big factor.
There are other things you nneed to look at. Are the necks annealed?. Brass from same lot number is a good start , but in no way means you will be consistant from case to case. Also ( for those that do not wet tumble or use pins. The inside neck of your case. It will have carbon build up on it. Different levels of build up will also mess with your seating tension. You can run a case neck brush down them to help even that out. Those that wet tumble or sonic clean have a different issue to deal with. I tried Sonic cleaning and found out that after that you need to go to media for a while anyhow so I just got rid of the sonic cleaner and stayed with media. Cases will vary no matter what you do.
I know long range shooters that will buy in lots of 500 and cull out 100 or 200 that they want to keep. Ask yourself this- Ever been out shooting, 100 rounds loaded perfect, powder is dead nuts on, seating depth dead nuts on,necck tension perfect. I mean the world is great right now. You go to shoot those rounds and you find that some are just not hitting where you know they should even though you know you did not pull, the shot was perfect, the moon and sun lined up right, but for some reason they just did not hit right. This is a case issue. The ones that did not hit right, put them off to the side and don't use them for accuracy loads. The case is the issue. Reloading it is not going to make it shoot better the next time either. Keep this in mind- The one thing that throws necks off more then anything else is the expander ball being pulled back up and out of the neck, it has a tendancy to pull the shoulder up and also pull neck to one side or other, how much is determined by how much lube and tension you have on neck. This is probebly more then you were looking for, but just throwing in my 2 cents.
 
I believe if a person finds bullets seating with tight and not so tight pressure and you want to know weather the accuracy is effected. Then separate the loads and see if you can live with the variation in accuracy you are looking for. If you except the variation then don't worry about the bullet to case tension. If you see your accuracy is not acceptable then sort out the cases you find to be the problem. If that doesn't help then look some where else to solve you accuracy problems.
 
4runnerman,
Your great answer practically tells me there are case issues that need to be sorted out after shooting and cannot be easily predicted beforehand.

Longshot4,
I am working up my loads in groups of 5 and did not sort out the hard from the soft seating bullets. I'll take your advice and do that next time after I narrow down the loads.

For the purpose of determining best load and bullet combinations for my rifle, it sounds like making that determination at 100 yards will not be significantly affected by neck tension at that range.
 
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