Partial sizing of straight wall case for TC Contender?

[RoadKill]

My first post may have been comprised of too much mindless chatter - But I would still like to know if anyone has sized brass fired in their 14” 44 Mag Contender only far enough to get a grip on the new projectile? My ¾” 100 yard groups doubled after normal resizing of the once fired Winchester factory primed brass. I used no crimp on Speer 240 gr. JSP and a much lighter JHP ahead of midrange loads of 2400 and Winchester primers. The only difference was the use of an RCBS sizing die vs. Winchester factory brass prep. Thoughts?

[Wrangler John]

You'll need a carbide sizing die that sizes the "neck" portion only (try Redding or R.C.B.S.) these are designed to size the "neck" portion only. The old Lee Loader also uses a neck only die, that's the loader that uses a soft face hammer or arbor press to press the case into and out of the die (like the Wilson benchrest hand dies). You will still need to size the entire portion of the case where the bullet resides, and that can change depending on the weight of the bullet. Short sizing will not produce any improvement in accuracy, the entire bullet needs to held tightly.

I loaded thousands of .44 Mags for IHMSA competition in the past, for Contenders, S&W's, Dan Wesson, and Ruger revolvers, what I learned was that most accurate loads using 2400 or Winchester 296 (or its twin H-110) required the heaviest crimp possible that can be applied without bulging the brass. This means one has to trim the brass to a uniform length - and I mean consistently within .001" in length. In many cases I used a file type trim die as it maintains the square relationship between the case mouth and body, but be aware that some trim dies are also FL dies, check for base sizing, which you don't want if "neck" sizing only. A sloppy collet and lathe type trimmer may not be precise enough for the truly obsessive handloader. It also means that mouth chamfering has to be minimal inside and out, and case mouth belling adjusted to accept whichever bullet that is being loaded just to the point where seating can be accomplished without collapsing the mouth or shaving the bullet base. Expander stem may have to be reduced in diameter if too loose (ruling out the plunge cut, one piece Hornady expander).

The heavy crimp determines ignition consistency, along with a magnum primer. A heavy and consistent bullet pull is what we're aiming for, anything else will profoundly effect accuracy. A medium or light crimp will destroy accuracy.

The bullet selected will also determine crimp by the depth of the cannelure or crimping grove. Crimping should be done with a separate crimp die, using a roll crimp. Cast bullets should be crimped into the crimp groove.

Also, use a magnum primer for Aliant 2400, or Win 296/H-110 I have experienced pressure excursions and hangfires with standard primers. Primer pockets and flash holes can be uniformed for consistency. Depth of the pocket ensures uniform firing pin strikes, especially in handguns.

Some fellows used to place a mark on their case rims to orientate the case exactly the same in the chamber, or place the head-stamp up when firing it for the first time. Too much for me though, I could shoot a possible score consistently without that. Many .44 Mag revolvers were capable of 1.5" groups at 50 yards, the Contender could run .75" and so could a .357 Maximum.

That's about all I know - just remember that everything mentioned here applies to all straight wall magnum handgun cartridges.

[RoadKill]

Thanks Wrangler John. The 44 loads were done 20+ years ago in regular RCBS dies with adjustment per their instructions except for just enough “crimp” to bump a slight flair back straight for use in the single shot. Revolver loads got just enough crimp to discourage recoil from relocating seating depth. Looks like I’ll be trying different dies and crimping habits.