To trim or not to trim. That is the question

[K22]

If you tell me the caliber in question, I will measure the appropriate Sinclair slug for you. Then if you know the ID of your chamber neck ...

PS I have 22, 6mm, 25, and 270 slugs, but no 6.5mm or 30 cal.
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223 Rem and 243 Win.

 

[Brians356]

223 Rem and 243 Win.

Sinclair Chamber Length slug diameters:

22: .249"
6mm: .267"
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[K22]

22 = .249"
6mm = .267"
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Thanks again - I'll try it.

 

[cw308]

If 1.750 is minimum and 1.760 is maximum , I would trim all to the center range 1.755 , if your cases haven't stretched to that you are good to go but don't allow it to reach max. , could bind the case mouth causing pressure problems or worse. I'm a benchrest shooter , I trim all my cases to the same length every firing . No shortcuts in reloading.

 

[BenPerfected]

What is you favorite case trimmer?

 

[jackson1]

Wilson, the only one that I can consistently trim to the same length with in 0.001". There may be others out there, but my 40 year old popular brand trimmer is all over the map. Could be my lack of knowledge related to trimmer operation, but when ever I measure other people's brass, I find the same variation in lengths.

 

[Medic505]

forget what a manuel says.

These numbers in manuels are junk. Not even worth referencing.

This is exactly how Manuel lost an eye and his right hand.

 

[KevinThomas]

If 1.750 is minimum and 1.760 is maximum , I would trim all to the center range 1.755 , if your cases haven't stretched to that you are good to go but don't allow it to reach max. , could bind the case mouth causing pressure problems or worse. I'm a benchrest shooter , I trim all my cases to the same length every firing . No shortcuts in reloading.

Bit of confusion here, concerning Maximium, Trim-to and Minimum. For the 223 Rem, 1.760” is SAAMI Max. The 1.750” Trim-to shown in the manuals is merely Max -.010” and is NOT the SAAMI Minimum, which is Maximum -.020”, or 1.740” in the instance of the 223 Rem. This is true for most cases; true Minimum will be Maximum -.020”. The Trim is a somewhat arbitrary figure, which sits roughly in the middle between min and max.

 

[NorCalMikie]

Best thing is: Know what you're looking at and don't trim till YOU need/want to. And you don't learn that over night.

 

[cw308]

I use the RCBS TrimPro trimmer , has worked very well for me . With accurate reloads , consistency is the important thing . Trimming all your cases to the same length is one important step . If you have the time trim .

 

[clunker]

New to reloading. Regardless of what length you choose to trim at, all rounds should be trimmed to the same length (at least if you want to consistently hit the same target). Is that correct? Wasn't sure if I misunderstood an earlier post.

 

[Billy 30-06]

New to reloading. Regardless of what length you choose to trim at, all rounds should be trimmed to the same length (at least if you want to consistently hit the same target). Is that correct? Wasn't sure if I misunderstood an earlier post.

For best accuracy cases should be trimmed to the same length and chamfered . Some new brass don't have square mouths.
Billy

 

[JFrank]

The reloading manual has two values for case length; maximum case length (in this case 1.760) and case trim length (in this case 1.750).

I have fired this brass twice. I have measured the cases and they average 1.752.

Should I trim the case back to 1.750 or is it OK to forego the trimming AND if I should trim to 1.750 why is it important to trim for .002?

Thanks for your advice.

Purchase a Wilson case gauge for SAMMI chambers,
one end identifies the correct trim length min and max, the other end identifies headspace min and max.
Quality tools that are very simple

 

[danny]

Trimming brass to SAAMI specs is for people who would prefer not to experience blowing up a rifle; due to the excess length causing your loaded round being crimped when you chamber it and pull the trigger. I watched an AR-15 disentegrate when a guy who told me that SAAMI chambers were waaaaay too long to bother trimming cases.

I know a guy that admitted that he could not see case headstamps without reading glasses (which he did not wear during a match). All brass that was where "his" brass was, got picked up and taken home. At home, the brass eventually was reloaded. It went right from being the brass that he picked up to brass prepping with no inspection being done to the brass. He did get other people's brass mixed in. At times, he got some "interesting" results.

Danny

 

[danny]

The reloading manual has two values for case length; maximum case length (in this case 1.760) and case trim length (in this case 1.750).

I have fired this brass twice. I have measured the cases and they average 1.752.

Should I trim the case back to 1.750 or is it OK to forego the trimming AND if I should trim to 1.750 why is it important to trim for .002?

Thanks for your advice.

The rule is that you are supposed to check your cases, and if they are at or longer than than the maximum, trim them to the "Trim To" length. With the amount of brass I use, I'll be "blanked" if I am going to check every one and then do a trimming operation on them if any get excessive in length, and there is absolutely no way I am going to measure a handful or so as a "representative example" to make a decision from. I run them through my Giraud Trimmer each time.

Dsnny