Aerotech enlarged aft closure

[r66astro]

I picked up a J420RM reload kit. It mentions "enlarged aft closure". The nozzle fits the standard aft closure. I am confused, I can not find any info on the enlarged aft closure on Aerotech website. Anyone here know anything about this?
Thanks Bill
Arcadia, Florida

 

[DAllen]

As I recall, once upon a time the 38mm aft closures came in 2 different sizes and the smaller of which is no longer made and all reloads now work with the larger aft closure.

 

[dhbarr]

You have the "large". Rarely see the "small" anymore, I'm told. e.g. https://www.rocketryforum.com/showthread.php?60970-Aerotech-enlarged-aft-closure

 

[r66astro]

Thank you very much! Not confused now.
Bill

 

[jimzcatz]

And if by chance you get a smaller one, just take a unibit and enlarge the hole.

 

[r66astro]

And if by chance you get a smaller one, just take a unibit and enlarge the hole.

Thanks... Luckily I have lathes and mills.
Bill