243AI

[ken s]

Has anyone improved a 243 in a handi.was thinking about it to save on brass stretch. i would think they would take it as there will be less back pressure. or not. need some input guys.thanks.
                           ken s

[naedlaen]

There are several issues involved in "improving" a HandiRifle.

1.  Headspacing of rimless cartridges is done from the shoulder.  In an AI (rimless) chamber the regular cartridge (before fireforming) headspaces on the neck/shoulder junction.  Typically to do this, a gunsmith moves the barrel back in order to set the correct headspace.  This gets complicated on a Handi.  The 243 Win could probably be improved to 6mm Rem as the case is longer, allow the AI chamber to be cut without having to set the barrel back.  NOTE that rimmed cartridges headspace on the rim until fireformed, then can be resized to headspace on both the rim and shoulder.

2.  The brass stretch in a Handi is probably going to be more than a bolt rifle regardless of the case shape.  Inherent in the design of the rifle.

This is not to say that it (243 AI) could not be done, it just needs to be approached carefully.  Start with a minimum chamber rifle.  Talk to a knlowledgable smith that does this type of work.

Look for Fred M's post about AI in another post on the subject.  

Neal

[cheatermk3]

I did just what you're thinking about; I had my 'smith rechamber my 243 to 6mmRem AI.  I had exactly the problems naedlaen brings up.  

If you're trying to decrease/eliminate stretch in your brass, I suggest staying away from max loads.  Then, get yourself a collet-type sizing die, and size the case necks only, just enough to grip the bullet.  You will need to figure out just which size collet will be needed to do this.  Remember, cases blow out to fill the chamber at the instant of firing, then spring back after the pressure spike, about .003" overall in the diameter dimension.

If you have the tools, or are gung-ho enough to get them, you may be able to take 308 Win cases, neck them down to 243, then fit them to your chamber by turning the necks down, or reaming them, so you get a "tight neck" situation, resulting in a fired case that doesn't need sizing, or only minimal sizing, to grip the next loaded bullet.  A significant amount of luck, in terms of your rifle's chamber dimension and the wall thickness of the necked-down 308 brass, will be needed for this to work.  And, it might all be for no real gain due to the handi's inherent flexing.

I strongly advise against going the AI route.

[Fred M]

I have found a collet die does not work well with a Handi, because of the stretch in the action and lock up. Nothing bad about that as long as you keep that in mind when you pour powder into the cases.

From my observation with all sorts of wildcats the spring back of brass is only about 0.0006" at the most, and if the elastic limit of the brass is exceeded there is no spring back. In a Handy, unlike a bolt gun, if you don't set the shoulder back 0.002" to 0.003" you will run into inconsistant lock up hence poor accuracy.

With this loading procedure you can only get about eight reloads from a case and that defeats the purpose of an AI where you ordinarely could wear out a barrel with a batch of 100 empties fired in a rifle with zero headspace.

[ken s]

Thanks for the input, guys.  You are absolutely right, Fred.  Collet dies don't work.  Was not trying to get more power with the AK.  Thought maybe it would prevent some case stretching, and maybe improve sticking cases.  Still have one once in awhile.

Like you said, Fred, the shoulder needs to be set back, and if I put the shell holder tight against a regular 243 die when resizing that should do it.  Or not?

This has been the most @#%&* contrariest, in other words, a real bitch of a rifle that I have ever owned.  Would have quit a long time ago had I not been so stubborn.  Tried every load I could think of.  Got lots off this forum, and Steve's pages.   Have enough bullets to start a small war.  Only one I found was an 80 grain Nosler ballistic tip, and that's not a deer bullet.  And that's what I wanted.  Oh well, enough bitchin'.  Thanks anyway, guys.

                      ken s

[Mac11700]

ken s:

Why not just use it as a good  coyote/varmint rifle as is...and pick up a good deer barrel...seems it would be easier and less time consuming...or..even look for one of the older 243 barrels...I have a few co-workers that have some of the older ones...and they don't have any problem with geting them to shoot good with the 85 grain partitions or the 95/100 grain loads...those 243's are good little rifles if you can get them to shoot...


Mac