Too much neck tension???

[crashlanding]

No, I believe its the RCBS chamfer/deburr tool.

So the easiest thing to rule out is get a vld style chamfer tool, around $20-$30. I had the same issue on a 7mm wsm and Barnes copper bullets, Winchester brass. The vld chamfer and learning to anneal took care of the issue

 

[Peter Morton]

I had a nickel-plated Federal 300 WM case blow out on the first reload. I threw them all out and bought some Peterson. I'm still working on loads and neck tension--- but the Peterson stuff is great.

 

[Varmint Hunter]

The easiest solution would be to run an expander mandrel into those cases. For whatever reason, it sounds like the ID of the resized cases is just too tight.

 

[lancetkenyon]

Expanding mandrel. .306".

 

[dennisinaz]

I no longer use the standard deburring tools as supplied by RCBS et al. Just get a regular machinist style with the fine blades. Much better results

 

[308win]

Nickel plated brass = headaches

 

[FEENIX]

Nickel plated brass = headaches

Yep! I stopped using them a loooooooong time ago.

 

[tim_w]

If you really want to eliminate issues going forward dump the nickle plated brass. It's great if you leave ammo exposed for months/yrs to the elements or are around salt/brackish water. Great for LE. But its a headache as it effects the hardness and thus force per various interfence fit measurements.

Regardless to find your "neck tension" amount of interference fit between neck and bullet

Start with this:

* Start with a fired deprimed case (don't bother priming it as this can be a dummy case for now.)

* Make sure your expander button is properly setup.

* Lightly lube your cases: empiral wax is a good standard to rule lube out as causing any issues.

* Size a case and then measure the cases outside neck diameter (middle of the neck). Measure it 3x.

* Run your neck deburrer and get a good clean chamfer on that case mouth edge.

* Seat a bullet being careful to hold the bullet straight as it goes into the die.

* Measure the loaded cased neck as you did above.

What is the difference between the sized and with bullet seated cases outside neck diameters? Should be somewhere in the 0.002-0.005 range? Go ahead and post the 2 measurements as well.

Once we get those measurements we can help you further.

With nickle plated I would stay at the 0.002 range. (Dump the nickle plated cases)

Going forward if your going to get your brass to reload from using commercial loaded ammo purchase ammo with standard brass only cases. Open the box to confirm no plating.

------------------------------

Based on your questions I am assuming your somewhat new to rifle handloading??

If so there are a few tool that will allow you to make ammo that is custom fit for your rifles chamber and throat. None of it is difficult and a decent set of calipers us all that's needed.

A tool to measure your case from shoulder to base and one to measure tge loaded case from tge bullets ogive to the case base. They are bullet and case comparators. Lots of different manf of these tool kits. The popular ones all work well.

A mandrel die makes it much easier to control and change neck tension and easier to limit runout on the necks.

You can make some really good ammo with just these limited tools.

 

[Nimrodmar10]

I no longer use the standard deburring tools as supplied by RCBS et al. Just get a regular machinist style with the fine blades. Much better results

How do you use that on the outside of the necks?

 

[VinceMule]

The Chamfer is also a "bullet guide". I put a very heavy chamfer on all my case necks where the chamfer goes to the outside of the neck. Years ago, heavy chamfers were thought to be the cause of split necks, thus the trend to just de burr the case mouth a little. Too little chamfer is often the cause of bullet scraping.

You can also roll the bullet in motor mica or other moly powder, bullets will glide into the neck. Hornady and Forster make little trays with plastic brushes on them for lubing/cleaning case necks.

Forster Original Case Neck Lubricator

The Forster Case Neck Lubricator features three brushes attached to a tough, impact resistant case with holes for bench mounting. The brushes...

www.midwayusa.com

Imperial Dry Neck Lube 1oz Powder

Imperial Dry Neck Lube is graphite based powder and is designed to reduce the drag and chatter of the cartridge case neck within the sizing die and...

www.midwayusa.com

With these two hacks, my brother and I have never had any issues with Ni-plated brass. I can not prove it, but the Ni-plated brass from Win and Rem seems to be a tad tougher than std non-Ni-plated brass. I shoot the Ni plated brass in 7 Rem mag, 270 Win, and 280 Rem.

 

[MarkInPA]

I got to go along with everyone mentioning the nickel plated brass.

 

[keen.on.it]

If you really want to eliminate issues going forward dump the nickle plated brass. It's great if you leave ammo exposed for months/yrs to the elements or are around salt/brackish water. Great for LE. But its a headache as it effects the hardness and thus force per various interfence fit measurements.

Regardless to find your "neck tension" amount of interference fit between neck and bullet

Start with this:

* Start with a fired deprimed case (don't bother priming it as this can be a dummy case for now.)

* Make sure your expander button is properly setup.

* Lightly lube your cases: empiral wax is a good standard to rule lube out as causing any issues.

* Size a case and then measure the cases outside neck diameter (middle of the neck). Measure it 3x.

* Run your neck deburrer and get a good clean chamfer on that case mouth edge.

* Seat a bullet being careful to hold the bullet straight as it goes into the die.

* Measure the loaded cased neck as you did above.

What is the difference between the sized and with bullet seated cases outside neck diameters? Should be somewhere in the 0.002-0.005 range? Go ahead and post the 2 measurements as well.

Once we get those measurements we can help you further.

With nickle plated I would stay at the 0.002 range. (Dump the nickle plated cases)

Going forward if your going to get your brass to reload from using commercial loaded ammo purchase ammo with standard brass only cases. Open the box to confirm no plating.

------------------------------

Based on your questions I am assuming your somewhat new to rifle handloading??

If so there are a few tool that will allow you to make ammo that is custom fit for your rifles chamber and throat. None of it is difficult and a decent set of calipers us all that's needed.

A tool to measure your case from shoulder to base and one to measure tge loaded case from tge bullets ogive to the case base. They are bullet and case comparators. Lots of different manf of these tool kits. The popular ones all work well.

A mandrel die makes it much easier to control and change neck tension and easier to limit runout on the necks.

You can make some really good ammo with just these limited tools.

Thanks a lot, I will get some numbers when I'm back at the shop at my dad's place.
Yes, I've only been reloading for a year, and mostly just new brass in my .270 win. Bought the 300 WSM a couple of months ago and the only brass I can find is Nosler, $180 for 25 up here in Canada, so it only makes sense to buy factory ammo. Bought 2 boxes of Hornady outfitter as it was all I could find not even knowing it was nickel plated, but have since found a source for Hornady American whitetail for near half the price of the outfitter, just gotta go out and shoot em for the brass!
Thanks for the replies and help guys! Been real busy with a newborn and work lately, hopefully get to reloading again soon haha, will definitely take this all into account and let you know how it goes!