Case trim size question

[BirdDog50]

Question for you master reloaders. All my reloading books record the trimmed case dimension of 2.61 for the 300wm. I measured my reloading cases after run them through the Redding FL die and they measure 2.60 & change. Any issues if I reload these cases? Thanks

 

[FEENIX]

Question for you master reloaders. All my reloading books record the trimmed case dimension of 2.61 for the 300wm. I measured my reloading cases after run them through the Redding FL die and they measure 2.60 & change. Any issues if I reload these cases? Thanks

No! SAAMI is 2.620.

 

[Dmagna]

You will be fine

 

[dok7mm]

It's a good idea to purchase the gauges from Brownells to know chamber length of each caliber you use, just to be safe. Even with my reamer prints, they are .010" + off sometimes, so I always check with those gauges.

 

[BirdDog50]

Thanks guys - I really appreciate the intel and your willingness to help!

 

[elf]

I check every piece of brass; new and used.
I then trim to SAMMI minus .010 on each.

 

[Stammster]

Unlike many other cartridges, the 300WM case has a very short throat. Much less than even a bullet diameter.
As stated above, trim 0.010 less than SAAMI min. I.e. 2.620 - 0.010 = 2.61".

If you've already run then through the FL resized and bumped the shoulder correctly, and only ended up at 2.60", then you must have trimmed them too short last time or your calipers are off. Nothing you can do except reload and shoot them. After 2-3 more firings they should grow to > 2.61".

I wouldn't worry about 2.60", as generally SAAMI min is 0.020" under max, and trim to length is 0.010" under max. Nothing bad happens at < SAAMI min, you just have less bullet /case neck bearing surface. As I mentioned above, 300WM is already much less than others (I.e. 30-06).

 

[skipglo]

No! SAAMI is 2.620.

Load away....they stretch!

 

[mdmiller]

^^^ I second that^^^

 

[BirdDog50]

Thanks again guys! I am starting to work up some test loads to determine best powder bullet combo for elk size LR game.
Testing out Hornady ELD-X 200gr, Berger VLD Hunting 210gr & Hummer Hunting 199gr.to see which one the gun likes best.

 

[MagnumManiac]

Just a heads up, the SAAMI spec for the area just ahead of the max cartridge length of 2.62" actually has a .040" buffer ahead of it. You can measure this, Brownell's sell a chamber length gauge, and then once determined, you can trim .010" under this length and still be safe.
I trim my comp brass to .005" under and hold it there for the life of the barrel/brass.

Cheers.

 

[AZShooter]

Here is the video explaining how to use the chamber length gauge that MagnumMania mentioned:

Trigger Times | Brownells

Trigger Times | Brownells

www.brownells.com

 

[BirdDog50]

I have ordered the Sinclair Chamber gauge...Thanks!

 

[Blackhawk]

Question for you master reloaders. All my reloading books record the trimmed case dimension of 2.61 for the 300wm. I measured my reloading cases after run them through the Redding FL die and they measure 2.60 & change. Any issues if I reload these cases? Thanks

They will function and work.
However I myself would reduce the charge weight by 5% just to be safe. Your next firing should bring them back to your chambers specs. Unless your cases were trimmed too short to begin with.