Thread: 175 grain 7mm rem mag won't load

The neck will stretch with firing and resizing and crimping, and I always check mine. The fastest way for me to "measure" them is in the case trimmer. Set it to the proper length, put each case in and turn the handle.

Originally Posted by Gunner3456

The neck will stretch with firing and resizing and crimping, and I always check mine. The fastest way for me to "measure" them is in the case trimmer. Set it to the proper length, put each case in and turn the handle.

In general, this statement(although I don't think there is any stretching during the Crimping or Bullet Seating process) is correct but ONLY if your Case Trimmer is set to the "minimum" OAL. Many rifles may not need to be trimmed that short and you can also loose overall case capacity by doing this. The 7mm Remington Magnum is WELL known for "stretching" the cases it uses.
Doing the Sizing and then Trimming with NEW Brass should be done to whatever the "shortest" case is in the box or batch. But, the Maximum and Minimum MUST always be considered when doing your trimming. A Box or Batch(500/1,000 or more shipped loose in a cardboard box) might contain all of the cases which are either too Long or too Short for a particular caliber. Sizing will also "stretch" the fired case; especially in the neck area and especially when Neck Sizing only is done. If you don't have a Carbide Expander Plug then you do need to remember to add Lube to both the Outside and the Inside of the Case Neck.

Originally Posted by KKG

In general, this statement(although I don't think there is any stretching during the Crimping or Bullet Seating process) is correct but ONLY if your Case Trimmer is set to the "minimum" OAL. Many rifles may not need to be trimmed that short and you can also loose overall case capacity by doing this. The 7mm Remington Magnum is WELL known for "stretching" the cases it uses.
Doing the Sizing and then Trimming with NEW Brass should be done to whatever the "shortest" case is in the box or batch. But, the Maximum and Minimum MUST always be considered when doing your trimming. A Box or Batch(500/1,000 or more shipped loose in a cardboard box) might contain all of the cases which are either too Long or too Short for a particular caliber. Sizing will also "stretch" the fired case; especially in the neck area and especially when Neck Sizing only is done. If you don't have a Carbide Expander Plug then you do need to remember to add Lube to both the Outside and the Inside of the Case Neck.

When the neck is stretched out with bullet seating, and then pressed back when neck sizing, the metal will stretch in length. The case and shoulder are constrained by the chamber and will simply be fire-formed. The neck is the unconstrained part in length. It's complex, but even some of the case shoulder can be pushed out into and become part of the neck on the first couple of firings. Brass is soft and the act of working metal stretches it, makes it thinner, and hardens it. Eventually it cracks.

Originally Posted by Gunner3456

When the neck is stretched out with bullet seating, and then pressed back when neck sizing, the metal will stretch in length. The case and shoulder are constrained by the chamber and will simply be fire-formed. The neck is the unconstrained part in length. It's complex, but even some of the case shoulder can be pushed out into and become part of the neck on the first couple of firings. Brass is soft and the act of working metal stretches it, makes it thinner, and hardens it. Eventually it cracks.

I think you're thinking is backwards in this matter but I'm not going to waste space any longer on this site.

"...Cases stretch as they’re used, and periodic trimming may be required..."

rifleshootermag.com

I think it had to do with the Ogive of the bullet. Backing it off Max OAL worked like a charm.

Glad to hear you found it.

Originally Posted by kibs45

I think it had to do with the Ogive of the bullet. Backing it off Max OAL worked like a charm.

Glad to here you got it. I figuered if everything was the proper size it had to be an oal issue.