Why are some cases tight and others loose?

[bitbythebug]

I have many rifles but my 28 Nosler has given me the most grief in reloading. I resize and prime every case. I then trim them to precise length. I then load a bullet and some cases are loose and some are tight to very tight chambering. I turned all the necks and that doesn't help. What can possibly be the matter. I am not a competition shooter and don't have competition dies but have shot and reloaded for over 50 years. What am I missing. The tight cases seem to have pressure issues which cause fluctuations in velocities, which make it hard to be consistently accurate. Need some positive help.

 

[Koda_]

What brass are you using and how are you sizing the cases?

 

[memtb]

I know that this is very unlikely, but……have you mik'd a few bullets to make certain they are not the problem.

Again, highly unlikely……but wierd stuff does happen! memtb

 

[MagnumManiac]

This problem is caused by a Classic issue amongst cases based on the 404 Jeffrey.
The shoulder resists being sized by 2 things, cases becoming hard take more effort and springback is insufficient, also, the web resists sizing and this also requires more effort. So, essentially some cases size ok due to their softer condition and others don't.
Annealing should cure this, but I do not recommend trying to size more, because the softer brass will be too small.
Steep shoulder angles also resist sizing…

Cheers.

 

[Koda_]

I know that this is very unlikely, but……have you mik'd a few bullets to make certain they are not the problem.

Again, highly unlikely……but wierd stuff does happen! memtb

I have had this happen once. Im lucky to have caught it before firing...

 

[bitbythebug]

This problem is caused by a Classic issue amongst cases based on the 404 Jeffrey.
The shoulder resists being sized by 2 things, cases becoming hard take more effort and springback is insufficient, also, the web resists sizing and this also requires more effort. So, essentially some cases size ok due to their softer condition and others don't.
Annealing should cure this, but I do not recommend trying to size more, because the softer brass will be too small.
Steep shoulder angles also resist sizing…

Cheers.

Makes sense. I will try and anneal those cases and report back. Thanks

 

[bitbythebug]

Makes sense. I will try and anneal those cases and report back. Thanks

You got me thinking so I watched some videos on annealing and they identified another problem that I'm having, neck splitting. So I think annealing will greatly help my problem. Thanks for your responses.

 

[Hugnot]

Check diameter variations just above web, like about .2 inches.

 

[FireFlyFishing]

How many firings on your cases?

 

[ShtrRdy]

You got me thinking so I watched some videos on annealing and they identified another problem that I'm having, neck splitting. So I think annealing will greatly help my problem. Thanks for your responses.

Maybe you should get some new brass and pick up where you started having trouble.

 

[azarcher10x]

Anneal and use a small base die. After a couple of reloads on my RUM, the cases would stick in the chamber after firing. I thought I was having pressure issues at first. Ran the cases through the small base die and problem fixed!

 

[memtb]

Check diameter variations just above web, like about .2 inches.

This could offer a valid reason for neck turning of the cases! Of course……they "could" end up being loose! memtb

 

[PddPdd]

I have many rifles but my 28 Nosler has given me the most grief in reloading. I resize and prime every case. I then trim them to precise length. I then load a bullet and some cases are loose and some are tight to very tight chambering. I turned all the necks and that doesn't help. What can possibly be the matter. I am not a competition shooter and don't have competition dies but have shot and reloaded for over 50 years. What am I missing. The tight cases seem to have pressure issues which cause fluctuations in velocities, which make it hard to be consistently accurate. Need some positive help.

Do you have headspace gauges to measure and compare the headspace (dimension between base of brass and a datum on the brass shoulder) between cases that fit fine and those that don't? This would probably be caused by excessive stretch in your brass around .2" above the brass base. I use a body sizing die to deal with this excessive stretch directly after annealing. It can be caused by the brass being loaded hot prior to firing some nominal loads to size the brass to your chamber. Too much pressure causes excessive case stretch and increased material thinning and diameter at the .2" datum. In my experience Nosler brass is prone to this issue. ADG brass is thicker and stronger and not as prone to this condition.
Hope that helps.

 

[VinceMule]

I once had brass from 3 different brands tested over a lot#. The brass varied 6% by brand and 12% over the three brands.

So, this has been a real eye opener. You can anneal the necks, but you have to live with the Rockwell hardness of the web and shoulder.