Cartridge Case length importance/dillon XL750 for gas gun reloading.

[Jkedsnake]

Hello All,

I'm looking for some advise and opinions regarding case length variations and how important this is while reloading .223/5.56 on my Dillon XL750.

All my experience reloading has been on a Forster single stage on 6.5 creed and 300 win mag, so those cases were perfectly sized and trimmed as necessary but I now have 2000+ mixed brass I bought online to load.

I have already de-crimped, chamfered, cleaned and sized all brass using the Lee ultimate sizing die, after doing some random measuring some cases measure between 1.738 and 1.782, .022 longer than max spec for .223.

I imagine this would be an issue during seating and crimping, specially using the DAA seater/crimp die on the Dillon progressive press.

These rounds are specifically being loaded to fire out of a AR-15 platform during practice/carbine classes, I am using SS109 62 gr. bullets and Vihtavouri N540.

So my question: Is it necessary to trim all cases? and if so, to what length? spec or the shortest case I can find?

Is it worth putting even more time into this or is it necessary?

Thank you all for your time.

Regards

 

[TheOfficeT-Rex]

Different brass lengths will cause different levels of crimp. How much different depends on the die. How much it affects the end product, well, that's up to you to determine if it meets your needs.

Brass too long may not fit the chamber in your gun. I'd check that first.

 

[smoothy8500]

imagine this would be an issue during seating and crimping, specially using the DAA seater/crimp die on the Dillon progressive press.

Skip the crimp. Variations in length will affect crimp, and it’s not needed.

As to exceeding max length, I’m not one to give expert advice on that. There are differences of opinion on safe/unsafe at what length.

 

[Rocketvapor]

1.182" may be getting close to the end of the chamber and jam/crimp the neck into the bullet.
Here is a 22N borescope pic of two lengths.
I would suggest trimming to 1.170" MAX.

 

[Molon]

1. With proper and consistent neck tension (and I mean actual tension, not outside diameter of the case-neck) there is no need to crimp.

2. If you are committed to crimping, do it in a separate station from the seating station.

3. You should be measuring the actual chamber length in your barrel to make sure you're not constricting the case mouth upon chambering the round.

....

 

[99mpower]

1. With proper and consistent neck tension (and I mean actual tension, not outside diameter of the case-neck) there is no need to crimp.

2. If you are committed to crimping, do it in a separate station from the seating station.

3. You should be measuring the actual chamber length in your barrel to make sure you're not constricting the case mouth upon chambering the round.

....

what attachment is THAT!?!?! i need one of those.. i have all the other parts/pieces

 

[spife7980]

what attachment is THAT!?!?! i need one of those.. i have all the other parts/pieces

It’s a Sinclair depth gauge on the case that’s on a hornady tube everyone knows about.

 

[Haney]

1. With proper and consistent neck tension (and I mean actual tension, not outside diameter of the case-neck) there is no need to crimp.

2. If you are committed to crimping, do it in a separate station from the seating station.

3. You should be measuring the actual chamber length in your barrel to make sure you're not constricting the case mouth upon chambering the round.

....

You beat me to it , I was just going to say the same thing . These gauges are the best way to confirm your actual chamber . I pretty much never trim my .223/556 . I use these in all calibers and have never found a rifle that needed to be trimmed to book specs .