16ga.com ~ View topic

Joined: 22 Feb 2020 Posts: 35 Location: United States

Hey guys,

I've been experimenting with different hulls, given scarcity and availability.

I've had an issue with once fired hulls (remington and others) and new cheddites where they chamber well as I produce them, but after a while the crimp ever so slightly expands to where they are tight going into the chamber.

I chalked this up to using sg16 instead of sg16s wads for 1 ounce loads

I loaded up some new cheddite hulls with 7/8 oz loads and they seem roomy enough, using the sg16 wads. But as I double check these after a couple of weeks to make sure they will fit my chamber (checking both my citori 16 and and my sweet 16 auto), they are slightly tight. I'm wondering if they will cycle my auto. I can push the final crimp back down on them and get them back to spec. But I wonder if they will expand again.

The crimp change is not really visibly noticeable. I can post a pic of my crimps if that helps.

I'm wondering if it is something I'm doing wrong, or if these brand new cheddites just want to bounce back a little on the fold. Six point crimp by the way and I'm using the metal crimp starter with the sharp edges.

Joined: 04 Mar 2019 Posts: 1841 Location: Central ND

The issue probably is that the crimp shoulder does not have a nice radius on it when you originally loaded the hull. The loads you reloading are nothing special and are used by many folks, including me in semi auto's and pumps.

To put the proper radius on the hull you will need to adjust the cam if you are using a MEC single stage press. Or adjust the final die downward if using a MEC progressive.

Also the crimp depth should be at least .055" deep.

If either the depth is too shallow or the radius not formed properly the hull will mushroom and you will have the problem that you are having.

The wad(s) you are using have nothing to do with it, or at least shouldn't.

The hull on the left will not open or mushroom, the hull in the right because of the shallow crimp and badly formed radius on the shoulder of the crimp, will have the tendency to open up and chamber on the tight side.

Both hulls are the exact same length and have the exact same components in them. The only difference was the position of the cam on the Sizemaster I used to load these two hulls. Both hulls are twice fired.

Joined: 22 Feb 2020 Posts: 35 Location: United States

thanks so much. I will work with this. I'm using a sizemaster reloader as well. I have been confused as to whether to back off the final crimp or to adjust it down a little. My crimps don't seem to have a nicely formed shoulder, so hopefully this will make a difference.

Joined: 22 Feb 2020 Posts: 35 Location: United States

running shells through the final crimp, and I'm measuring approx. .080 inner depth on the radius wall. If this crimp holds, it will solve a long running problem I've been having.

Joined: 04 Mar 2019 Posts: 1841 Location: Central ND

The crimp depth should be .055" to .065". As you increase the depth you also increase the chamber pressure. .080" is a bit too much.

To adjust the crimp depth back off in 1/4 turn increments on the plunger on the final crimp die on your Sizemaster. Don't touch the cam adjustment.

Joined: 22 Feb 2020 Posts: 35 Location: United States

ok, will adjust. Can't believe I've gone this long and not known any of this. I have a 12 gauge sizemaster and it seems a bit more tolerant than the 16

Joined: 04 Mar 2019 Posts: 1841 Location: Central ND

As the gauge gets smaller the adjustments get more critical.......a 16 is a joy compared to the .410!!

Joined: 22 Feb 2020 Posts: 35 Location: United States

I've always wanted a 28 gauge double gun. Maybe I don't after all. Besides, the way things are going, I would never be able to find components and I'd have to take out a loan to afford a new mec sizemaster

Crimp Adjustments --

Think like this: Cam adjust is for finished shell length, and crimp plunger adjust is for crimp depth.

When first using a new or newly overhauled machine, or for any given hull, I find it useful to use a factory-loaded shell of the same hull type. Loosen the cam and plunger adjustments and back them off quite a bit. Put the "factory load" in the crimp station and hold the lever down. Then adjust the crimp plunger down until it contacts the top of the factory load fairly firmly, and after that, adjust the cam till the die contacts the crimp edge of that factory load. From there, further adjustments will be minor.

In case some adjustments are needed, you can sneak up on them in an orderly way: Re-load a hull, crimp it with only a partial stroke and see if it closes properly in the center - i.e. without a swirl of other evidence of starting the hull edge too far down, such as a crumpled hull wall. If that looks OK, finish the crimp stroke on that shell and take note of the depth. Then, if need be, adjust the plunger to get that 0.060" or 1/16th inch or so depth that MSM2019 talks about as ideal.

Cheers!

Joined: 22 Feb 2020 Posts: 35 Location: United States

well this is all very educational for me. I think I've been navigating my way through these issues by dead reckoning over the years. Not really understanding much. It all worked out ok until I did something that caused me to start getting bulges in my cartridges a while back and I had to make significant adjustments. I got myself back in the ball park but never got things adjusted quite right.

Max Smoke, That is a GREAT technique, thanks for posting.

I had used a similar technique on the finish station of the 650 when I converted it. Never thought to fiddle with it on the crimp station Rolling Eyes

Now I will look upon my reject pile with even more regret Embarassed