doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Hartin Crimp explanation

Am I correct that a shell having a Hartin crimp is simply a 23/4” hull with 1/4” trimmed off and a thin card wad used on top of the shot column to close the reduced crimp? No change in loading components? Thanks

The Hardin crimp was to alleviate the problem of a hole in the center of the crimp, no matter what the cause. Yes it was a OS card to cover the hole. I never tried to trim a 1/4" off a shell then use my normal date to see what happens. When I trim a 1/4" I'm roll crimping. Why would you trim a 1/4" and fold crimp ? If it's for 2 1/2" shells with a fold crimp, then adjust your load stack height with a different plastic wad of fiber cards. Maybe your idea will work. Good luck and let us know.

I was trying to make 2 1/2" shells for use in a beautiful WJ Jeffery, I never should have sold. Another story. Using a mec grabber reloading press without modifying the press presented a problem. What I came up with was cutting the hulls using a dremel bit in a drill press was the best method I found. Then I experimented and found the best solution was a 16 ga overshot card. This filled in the gap from the missing 1/4" of hull. This allowed me to load a 7/8 oz or 1 oz (depending on the wad) load without adjusting the reloader and get a nice crimp . Greg Moats called me and asked if he could write it up for Shooting Sportsman.

Thanks for the responses. Nitrahs answer seems to confirm my premise. I’ll see if it works on my PW

My press is a MEC 600 jr,and my short chambered guns are in 12, 16 and 20 gauges. For those I load 2-1/2" shells.
All of my shells are cut down from fired 2-3/4" factory ammo. At first I tried using a 1/4" spacer under the crimp
stations. They looked pretty good and there was no hole in the crimp; but given a short period of time and most of
the crimps started to open up because the new crimp shoulder had moved down below where the original crimp
memory had been. This caused some shells to be bloopers and others to allow the shot charges to be loose in the
shell box, quite frustrating. Then I learned of the "Hartin crimp". It was both simple and brilliant. I haven't had any
problems using this method to load short shells.

Jack Kuzepski

Nitrah's method is the easiest way to make short shells that I have ever found. I agree with Jack K.

Jack, the brass crimp starter BP sells is great to give a uncrimped hull memory. Far, far better than MEC’s plastic crimp starter. Sharp edges on the brass tool really put the pleats in the hull.

https://www.ballisticproducts.com/Super-Crown-Crimper-Large-Bore-6-Point/productinfo/0740006/

I turned a adjustable brass shell trimmer on my metal lathe. It hold one of those snap off exacto knife blades. When chucked in a small drill it will trim hulls to 2 1/2 " perfectly. Couple seconds each and everyone exactly the right length. They do not need skiving I found out to crimp nicely. I use a Tyvek UltraThin Overshot shotcard (Ballistics Products) and adjust my crimp to fold a nice crimp. Most loads are nearly closed in the center but some loads would leave about a hole just large enough for most of the shot to run out into your pocket or shell bag. With this setup I can load 300-350 shells an hour on my Spolar. The thin Tyvek layer works perfectly and does not add too much thickness to get good crimps.

In trimming hulls for my 2" 12 gauges, I prefer using a Harbor Freight 2" chop saw and a plastic jig an Ebay seller made. The jig is clamped in the saw's vise. The jig has a groove in which sits the shell's head's rim. The drop of the saw precisely cuts the hull which is rotated by turning the head a few degrees as the blade drops partially through the hull. The hull is precisely trimmed in a few seconds. The Ebayer offered 2.5" jigs, too. Gil

Joe,
Thanks for the link to BPI, it looks like a nice upgrade to the plastic crimp starter.
Been quite a while since I ordered anything from them, looks like I'll be back i touch
with them.

Jack K

Just use appropriate size washers on the pre crimp and final crimp stations. You can buy a short kit from MEC for a 600 JR. but washers are less expensive. I have been doing this for over 20 years with great results. I don't know if they make a short kit for a progressive but on a single stage press it is easy.

I seem to remember some old (Federal?) shells with a frangible overshot disc. Assume this was another attempt to reduce the loss of shot in the center of the patterns. Anyone else remember these or am I just dreaming?

You also can make a wood spacer to go under the last three stations on a Mec Jr - like the one Mec will sell you made from metal. Go on their web site to see what their spacer looks like.

Remember, the shell holder on a MEC 600 type machine is a stamped piece of metal and has lips underneath to hold it down to the press's base. If using the same shell holder in a short kit you'll need to grind/cut these little lips off. Don't worry, this is what MEC does. The heavy center column spring will keep it perfectly aligned.