i need some help with a problem i have with my mec

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doddcameron

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hi, i just recently got a MEC sizemaster model sm77 and when i try to crimp the tops of my shells the bottom part of the plastic just above the brass crunches in and i dont know how to stop it, ive tried going lightly and slowly but if i go too slow i cant get a tight enough crimp but when i pull just hard enough it crunches in. if anyone could give me any pointers on this issue or any tips at all regarding the MEC sizemaster i would greatly appreciate it.

- thanks, Cam
 
you need to raise the depth of the crimping die. The last stage where you are doing the final crimp, there should be a nut and a threaded rod with a slot for screwdriver on the top.

Loosen the nut and turn the rod counter clockwise to raise it. Keep adjusting it as necessary until you get a satisfactory crimp.


Out of curiosity, what hulls, wads and shot charge weight are you using?
 
doddcameron said:
thanks, i am using winchester "ranger" hulls and winchester AA wads with 20gr. of WST and 1oz of 7 1/2 shot.
Click to expand...

If those are not the hulls called for in your load recipe the wad and shotcup may not be seating properly and your casing crushes as the loader tries to compress the crimp with the charge , wad and shot too high in the hull. One thing you should never do is substitute hulls in your recipes. Use the hull it calls for. The wrong hulls can cause pressures to rise dramatically when fired and can result in damage to your gun or injury to you. I have seen this happen personally on a few occasions and a gunsmith friend of mine has shown me more than a few cracked and split barrels and chokes that succumbed to improper loadings.If you have the correct hull then adjust your crimp die as stated already.
 
I have the same problem with the same press and with new Winchester AA hulls, but the older Winchester AA's are fine along with Remington Peter's hulls. So I just load those hulls now.
 
Just getting into the shot shell reloading bit but I have heard grumblings on the net and from a couple guys at the club that the new ones are "crunching" in the side walls when the crimp is being applied. Of course I heard this after I bought two flats of the expensive rounds with the AA hulls

Kastles
 
kastles said:
Just getting into the shot shell reloading bit but I have heard grumblings on the net and from a couple guys at the club that the new ones are "crunching" in the side walls when the crimp is being applied. Of course I heard this after I bought two flats of the expensive rounds with the AA hulls

Kastles
Click to expand...

Some of the AAHS hulls are a tad shorter than others ,and it doesn't take much to upset them.
I find that if I segregate them and re-adjust , things go fine.
Cat
 
try this
http://www.ballisticproducts.com/bpi/articleindex/articles/mecadjust/mecadj.htm

"The AAHS hull takes a little different settings than does the STS or AACF cases. The new cases are straight walled and the walls do not have the strength that the others do and are easily crushed if heavy downward pressure is exerted on the hull.

Start out with about 35 to 40 lbs of wad pressure. Then at the precrimp station, set the precrimp low enough that it closes the case mouth to a point it wil NOT accept the insertion of a standard pencil eracer.

Then at the crimping station, raise the crimp punch if you are getting a heavy crimp, until it gives a crimp of about 1/16 in. to 3/32 in. deep. Also a heavy taper at this point is bad and can be adjusted by setting the cam. Raise or lower as needed to get a small, not heavy, taper on the hull. Raising the cam reduces the amount of taper and lowering it add more taper. Do this in small steps of about 1/32 inch at the adjustment screw, until you get the appropriate setting.

When properly adjusted as above, the case crushing will go away. Also you generally find that the new setting will also work on the older cases just fine, and probably so on the STS cases also.

DLM "
 
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