243 case trim length 2.035 vs 2.030 safe or not?

[ColoradoElkHunter]

The standard trim length for a 243 case is 2.035 on nearly all load data specs. My son and I were setting up a new trimmer with the 3-way head. Didn't realize something had moved before we had 18 cases trimmed to 2.030.

We want to load either Nosler 55gr Varmageddon or Hornady 75gr V-Max bullets. SAMMI shows this should still be safe at 2.030 but I would much rather get the opinions of real people than a fact sheet. Do we throw these cases away or should it be ok to load?

Thanks for your input!

 

[75vmax]

Load up

 

[Bill Norris]

No worries at all. Load em Shoot em and F/L resize them. They will grow back.

 

[Ackman]

The standard trim length for a 243 case is 2.035 on nearly all load data specs. My son and I were setting up a new trimmer with the 3-way head. Didn't realize something had moved before we had 18 cases trimmed to 2.030.

We want to load either Nosler 55gr Varmageddon or Hornady 75gr V-Max bullets. SAMMI shows this should still be safe at 2.030 but I would much rather get the opinions of real people than a fact sheet. Do we throw these cases away or should it be ok to load?

Thanks for you input!

First get a chamber length plug from Sinclair and find out how long your chamber is.

 

[jghoghunter]

Load them and move on!

 

[LHSmith]

The only negative to the 0.005" shorter case is it allows for a tiny bit more area for a carbon ring to form. Clean the throat area occassionally with JB or Iosso on a patch or nylon brush and don't worry about it.

 

[pertnear]

I agree with Ackman. I have accumulated a pretty good set of Sinclair caliber specific chamber length plugs. It is surprising the variation in lengths from gun to gun in the same cartridge. I have a Sav 99/.250 that was giving me fits trying to properly resize my brass. I finally discovered that the chamber length was way under the chamber spec. Easy fix once I knew.

I've fired enough over trimmed brass to know that too short is no problem. Now too long, big problem!

 

[K22]

As others have said, slightly shorter not a problem.

The Sinclair chamber length plugs are nice tool to have and can save a lot of trimming if you're basing time to trim on the SAMMI specs since most chambers had longer chamber lengths. Just make sure you apply Sinclair's recommended safety margin specified in the instructions with the plugs.

PS: The plugs are not expensive and well worth the investment to save you from unnecessary trimmings.

 

[KY_Windage]

I'm cheap. When I get a new rifle I buy or pick up some fired brass. I try one, and if the bolt easily closes I measure until I find a longer one, then try it, and repeat until I find the one that is just starting to get resistance to the bolt close. Then I set my shoulder set-back dimension (with the FL die) at about .003" shorter than that.

After resizing I drop all cases in a Wilson Case Gauge to "measure" neck length. It is a Go/No-go situation. With some T&E I learn exactly how far the mouth of the case can protrude out the bottom of the Wilson before I am going to have resistance to closing. From then on, any case that feels too long goes into the que to be trimmed.

The Wilson is fast, fast. Way better than doing an OAL measurement on each case.

 

[NorCalMikie]

They will grow back.

Probably sooner than you want.
One thing to check is the "measured chamber length". Once you know that, and refer to it when sizing, then you'll know if you need to trim or not.
Most chambers are cut about .020 "longer" than listed MAX trim length.
That gives you more room before you need to think about trimming.
AND, different dies will effect the OAL of your sized brass.
Standard full length sizing dies (neck button) will pull the neck longer with each up stroke. Bushing Bump dies keep the length in place so trimming isn't needed for a long time.

 

[AlNyhus]

Knowing the exact case length dimension on a chamber is a must if you're a hand loader. Factory chambers in particular are often well in excess of SAMMI specs. to keep out of trouble.

These case length gauge plugs are handy, reusable and cheap. No more guessing what to trim to...with these, you know.

Good shootin'. -Al

 

[Edd]

The standard trim length for a 243 case is 2.035 on nearly all load data specs. My son and I were setting up a new trimmer with the 3-way head. Didn't realize something had moved before we had 18 cases trimmed to 2.030.

We want to load either Nosler 55gr Varmageddon or Hornady 75gr V-Max bullets. SAMMI shows this should still be safe at 2.030 but I would much rather get the opinions of real people than a fact sheet. Do we throw these cases away or should it be ok to load?

Thanks for your input!

The trim to length in the load data references are 2.035" because they picked the middle of the SAAMI spec. The SAAMI spec for case length is 2.045" -.020".