Neck Resizing and Case Trimming

[3006loader]

Do you still need to trim your brass if you only neck resize it? I was under the impression trimming was only for brass that you full length resize, but I recently had trouble chambering some rounds in my rifle. I thought it was either because the cases needed to be trimmed or the OAL was too long.

[Snyper]

I trim all my brass the first time I load it so they will all be consistent.
After that, just trim as needed no matter what method you use.

If you have problems with chambering, maybe you neck sizing isn't enough.

[cw308]

3006loader
Are you reloading for accuracy ? Trimming is for safe chambering, your chamber has all stop points. One is OAL.when the neck is to long chambering & pressure problems will happen. The case has to be short enough , when round is chambered & fired the neck has to be short enough to be able to release the bullet. I trim .005 from max. I trim every firing. Fire forming cases should be checked & measured even with easy chambering. You want to know what's happening to your brass as far as neck & head splitting. I kind of sound like a Doctor. Be Safe, hope I helped

[Reloadron]

Neck Resizing and Case Trimming
Do you still need to trim your brass if you only neck resize it? I was under the impression trimming was only for brass that you full length resize, but I recently had trouble chambering some rounds in my rifle. I thought it was either because the cases needed to be trimmed or the OAL was too long.

To each their own. I full length resize my .223 Remington and .308 Winchester which may be shot in any of several rifles. Following full length resizing I always trim as I want my brass uniform in as many ways as possible. Even with neck sizing only eventually the brass will need to be full length resized. As to problems chambering some brass? This is where a good case gauge comes in handy or use your rifles chamber as a case gauge, meaning before charging and seating a bullet attempt to chamber your brass. Use a gauge cut with a reamer to minimum chamber specifications. Sheridan Engineering comes to mind.

Ron

[3006loader]

Thanks for the replies. I load for both accuracy and cost effectiveness. I didnt know a case being too long could cause pressure spikes, thanks for the info. My main concern is does neck resizing make the case longer in the same way that full length resizing does? From your post Cw308 I'm guessing it is a yes. With full length sizing, I trim every time. With neck sizing how much less frequently will I have to trim?

[cw308]

3006loader
I only shoot one rifle Rem.700 308 my trimmer is set up to cut a 308 case to 2.010 that's .005 shorter then max. Reloadron's advice is the same as mine. I found F/L sizing more exact & accurate. Case prep is very critical, when sized right makes very accurate & trouble free reloads.

[3006loader]

OK. Let me try to rephrase this. The maximum CASE OAL for 30-06 is 2.484". If I buy some once fired brass, then, full length resize it to 2.484", THEN neck only resize, is the case going to be longer after just neck resizing? OR does the case get longer ONLY with full length resizing?

[243winxb]

The case gets longer with full length resizing. When FL sizing, the case body is made smaller. This makes the head to datum (shoulder) and trim length longer. Repeated firings of neck sized brass will expand till its hard to chamber. As this happens , the head to datum and trim length will get longer. Always trim brass when the maximum trim length is reached.. On 30-06 , remove .010" less then maximum. 2.494" is max.

[243winxb]

I recently had trouble chambering some rounds in my rifle.

Soon or later, you must full length resize. This will push the shoulder back a few thousand.