Adjusting The Crimp On Mec Super 600

In order to obtain maximum production speed it will be necessary to arrange components properly. Empty cases should be positioned to the left of the tool. A box or the MEC E-Z PAK should also be placed on this side. Wads should be positioned to the right. If paper components are to be used and you don't have the MEC E-Z Wad Dispenser, stacking the wads before starting actual reloading operations will also help to obtain increased speed of operation.


Under some conditions, such as when abrasive powder or heavy shot is to be used, it may be desirable to operate charge bar manually. To do this, remove bar lock and return spring, pull cotter (D) and remove actuating rod (A). See page 2.


The Model Super 600 is the simplest and speediest of the progressive type tools. While it is actually more simple to operate than the single stage type presses which operate one shell at a time, more attention must be paid to detail, since the misloading of one shell may affect the characteristics of all the shells in the press at that time.

It is best, therefore, to segregate your shells as to make and type and to remove from your bench ell but the components to be used in the particular type shell being loaded. This will eliminate the possibility of accidentally using the wrong size primer or the wrong size wad, etc.

If you must develop your wad column, you may find that passing a single shell through the various stages will be helpful.

approx 9/16" WADDING

While wadding is primarily concerned with the sealing and cushioning of the 'IxTTytI rapidly expanding gases given off by the explosion of powder, an important secondary function is performed. It is in connection with the volumetric capacity of the empty shell itself and that of the powder and shot charge used.

Very simply, the quality of the crimp on the finished shell is very much affected by the space taken up by the components column. A rule of thumb relating to this calls for a difference between the level of the shotcharge and the mouth of the open shell. The dimension should be approximately 1/2 inch for 12 gauge plastic shells (9/16 inch for paper shells). Use a dimension of 1/2 inch for 16 gauge, 7/16 inch for 20 gauge, 3/8 inch for 28 gauge, and 5/16 inch for .410 bore paper shells. Reduce approximately 1/16 inch for plastic shells. REMEMBER that this is an approximate dimension which may have to be adjusted slightly to suit the method of crimping used on your particular reloader.

In the beginning, PICK UP ALL OF THE COMPONENTS USED TO MAKE THE FINISHED SHELL AT ONE TIME, the empty shell in the left hand and the correct wad column in the right hand, and then place them all into the press at one time, making sure that the handle is not operated until your hands are empty. This will eliminate any possibility of forgetting to include one or more components.

Be careful in making adjustments. Your MEC loader has been carefully tested and adjusted at the factory and is set to produce the standard 2-3/4 or 3 dram target load, using either high or low base type target shells. If only high base wad shells are to be processed, it may be preferable to adjust the reprime tube of your loader. Position the tube to seat the primer properly with the least amount of spring compression. Too low will cause the press to fail to close completely and result in faulty depriming and crimping or in squashing the base wad which may obstruct the flashhole and cause faulty ignition. Too high will fail to seat the primer.

In making adjustment, bear in mind that each station depends upon the others and an adjustment at one station may affect the operation of one or more of the others. IMPROPER ADJUSTMENT AT ANY STATION MAY MAKE THE UNIT COMPLETELY INOPERATIVE.


First, check the MEC bar chart. The wad columns given for the particular loads are reasonably close, but must be altered depending upon conditions which vary with the individual. Make and type of wad, wad pressure and condition of the hull are some of the variables. Load one shell at a time until you have developed a wad column which results in a desirable crimp.


No. 1 Lock the charging bar to the left (See page 4). No. 2 Insert shell in gate (See page 5) and deprime. No. 3 Index shell to station G, page 3 and reprime. Release Bar Lock and powder will be charged on the upstroke of the handle (See page 5). No. 4 Index shell to station H, page 3 and seat wad column. Shot will be charged on downstroke. Lock charge bar to the left at completion of handle stroke. No. 5 Index shell to crimping station J, page 3 and crimp. (Use crimp starting station 1, page 3, if necessary). No. 6 Finish crimpand resize at station K, page 3 and remove shell. When a suitable shell is obtained, you may load carrier per instructions.


To process 3" shells, remove cap screw at base of column. Pull column upward 1/4 inch and fasten, using top hole in base and top hole in column. Additional item required is the 460-10A spacer. This item, along with instructions for adjustment, is available upon request.


Pick up everything you are going to use and put it into the unit at one time. If you do not operate the handle until you have emptied your hands, you will never make a mistake. To operate most efficiently, see page 6 and follow instructions given.


...with oversize shells (paper)

1. You may be using too many wads. If the crimp bulges when the shell is finished, or if bulging or crushing of the paper adjacent to the brass base is evident, your wad column is too high. If the crimp tapers inward and has an opening in the center, the wad column is not high enough. In either case, correct your wad column so that the resultant crimp is tapered inward slightly. This will insure maximum locking in of the contents as the toggle action will cause the shell to withstand considerably more abuse without spilling shot.

2. The shells you are using may be moist. This is certain to cause trouble, and especially so, when oversize wads, or too much pressure, or a combination of both enter into your loading operations. Paper shells DO ABSORB MOISTURE, and their size is directly related to the moisture content of the paper. Hot weather, when high-humidity conditions are unnoticed, will give you your greatest trouble with oversize shells. Your cases may be as much as .015" larger than when working during the winter or during the season when your storage and working area is heated. Dehydrating your cases in the oven of your kitchen range at a temperature of approximately 200'" will give surprisingly good results.

3. Check the wads you are using to be sure they are of the correct gauge. Oversize wads will exert too much side pressure on the wall of the shell, causing it to expand when ejected from the resizing die. The same condition results from too much pressure on the wad column. Whenever upward pressure is necessary to extract the shell from the crimping die, it may give trouble if your gun has an exceptionally small chamber. Soft cases will tend to swell slightly during storage, and this, too, could cause trouble. Immediately inspect any shell that requires excess extracting pressure. Remember, any shell that requires high extracting pressure has expanded much more than one that extracts easily.

4. The brass base of the shell may be oversize. This portion of the fired shell varies widely and is sometimes so large that it is impossible to resize by conventional methods. Because of the excessive pressure necessary to extract it from the crimping die, it is advisable to perform a preliminary operation on some domestic and foreign shells, using the special resizing apparatus that is shipped with each Press. The use of this equipment is fully explained on page 8.

...with longitudinal crease

This crease usually occurs in paper shells which are considerably oversize. Firing in a large chamber plus humid conditions tend to enlarge the problem. A quick resize does not allow time for the paper fibres to squeeze together and collapsing of the case results in the crease. Slowing the resizing operation improves results or may eliminate the crease entirely.

...with crimping die sticking

Remember, the results that you get from your Loader will, to a great extent, depend upon the condition of the crimping die. The bore of the die is made to exacting tolerances and should be protected between periods of operation. A light coating of oil is suggested as a rust and corrosion preventative. Be sure to remove all oil and check for possible rust and pitting before actual use.

1. Check your shells for moisture. If necessary, dry them as explained in part 2, above.

2. Check your shells for dirt or other foreign materials.

3. Check for oversize wads. To get good results you must use quality components.

4. Check for oversize brass. Resize as explained on page 8 if necessary.

5. Do not lubricate paper shells. This softens the paper arid makes them difficult to resize. In addition, the finished shells will expand in storage.


Uniform ignition requires confinement of the powder. Loosely confined powder results in muzzle flash, a loud report, light recoil and little velocity. It is suggested that the wad exert some pressure on the powder after the crimp is formed. Shells having a composition base wad should be inspected after the primer is seated to be assured that the flash hole is unobstructed. Use primers of the appropriate size.

...with misfires or poor ignition

1. Check your powder and primers for moisture or dampness. Never expose the powder to air for any extended period. Most powders will absorb moisture from the air, especially under humid conditions. This will affect the burning characteristics as well as the weight. Whenever checking the weight of your charges, always use fresh powder from a sealed can and agitate to a certain extent to assure uniformity of mixture. Always check the weight of your charges during actual machine operation since movement of the machine will greatly affect the weight of the powder charge especially if it is of the fluffy or less dense variety. Be sure to store your primers in cool dry surroundings.

2. Check the bases of your shells for "dishing'.' If you find this condition, exert more pressure during the Repriming operation. This will flatten them. Poor detonation or misfire is often caused by the firing pin not striking the Primer with the proper impact due to this "dishing!'

3. Be careful not to run out of powder or shot. Many cases of poor ignition or misfire are caused by the loading of several shells before noting that the powder container is empty. A light shot charge often produces muzzle flash or blast.

4. When you have misfire with the Primer showing evidence of good contact with the firing pin, you may have accidentally used a spent primer.

...with charging bar operation

1. Check condition of grommets. Jambing, shearing shot or excessive powder leakage is usually related to the condition of the grommets. If worn, remove and replace or reposition with worn spot in new position.

NOTE: Special neck dimensions of MEC containers were determined to hold grommets in position and contribute to accurate charges. Avoid substituting another type.

2. String or threads of shot bag material will cause the charge bar to bind and fail to return to charge powder.

3. Under some conditions, powder residue can build up, causing sluggish action. Generally an application of powdered graphite will be adequate, although removing and cleaning bar and slide may be required to assure positive action.

4. Return spring stretched or damaged. ...with wad feeding

Condition of the mouth and manufacturers tolerance in the length of fired shells may dictate that the Wad Guide be positioned slightly lower than factory assembly for ideal operation.

...with split cases

Case splitting is usually due to stuffing the wads into the wad guide. This practice spreads the fingers and prevents the wad guide from dropping into place on the case. Damaged fingers could produce the same result.

CAUTIOM: Too low will crush shell mouth, too high will result in turret plate striking wad guide when handle is depressed and can cause bent guide rod.

...wad guide fingers (part 453 —specify gauge)

The fingers are held in position by the cap screwed to the body of the wad guide. TO REPLACE

1. Unscrew cap and discard damaged fingers.

2. Position replacement and tighten cap. ...WITH PRIMER FAILING TO SEAT

1. Wrong size primer.

2. Reprime tube not set properly. See page 2. ...PRIMER FEED, FAILURE TO FEED 1. If primers fail to drop, tighten chain in increments of one bead until satisfactory operation is obtained.

If primers drop too early and tend to tip in the openings of the carrier, loosen chain in increments of one bead to arrive at the proper adjustment.

2. Not centered over opening when handle is depressed. ...WITH CARRIER FAILING TO INDEX

1. Index spring, 615-C, broken.

WAD holds flange in place for tightening.

3. Column spring may be rotated counter clockwise to increase, clockwise to decrease pressure on index pin, controlling degree of intensity of click stop indexing.

...primers fail to fall into seating assembly see"NOTE" page 5, and preceding paragraph.

...unsatisfactory crimp

1. Improper adjustment of crimp die. See page 2 and 11.

2. Crimp starting head should be positioned to a depth that closes the shell to approximately one half of it's open diameter. Starting folds too deep will scallop edge of crimp, too shallow may leave opening or may crush shell mouth upon crimping.

3. Build up or trapped foreign material in crimp dies will result in irregular crimp.


Although not mandatory with some types, a star crimp head is desirable to return the crimp folds to their original locations, six or eight point, as the situation demands. On plastic shells, eight point closures predominate, although some are closed with six segments. Because of varying characteristics, the depth to which the folds are started will sometimes be reflected in the finish crimp.

The older SP cases, still available from dealer inventories, were unskived and required a friction or heat seal to close the opening at the center of the crimp. Upon firing the seal is torn away, and upon reloading, the area previously sealed appears as an opening. Thinning the mouth of the tube materially assists in reducing the size of the opening. A Bodkin arrow-head or plumber's reamer serves well as a chamfering or skiving tool.

Depending upon the condition of the case mouth, a crimp equal or superior to the original can be obtained by indexing the shell to form new folds exactly opposite of the original on previously heat sealed cases.

Some older compression formed cases will not satisfactorily accept standard size overpowder wads and it has been suggested that overpowder wads be one gauge smaller than the shell and that softer filler wads, such as Remington MoldTite or Winchester Western molded fiber complete the wad column.

We suggest you avoid 3 inch 12-20-410 shells which were previously roll crimped.


All friction points are lubricated at assembly. Routine inspection should assure adequate lubrication of cam and cam follower at crimping station, bar actuator and point of contact on end of charge bar where a light grease is recommended. Machine oil is suggested for carrier, column, handle linkage, clamp screws and other friction points.

CAUTION: Only dry lubricant, such as powdered graphite is to be used on the charge bar slide or at any point where lubricant may contact powder.


The MEC Rammer Tube is arranged to provide any wad pressure from 30 to 120 pounds. Using the hex wrench provided, loosen the safety clamp, "A" Set rammer tube to desired position (lower it to increase pressure —raise it to decrease) and tighten clamp. Indicator marks "B" and "C" should be used as a visual aid in making the adjustment. Check your setting by reading actual pressure on gauge face while applying pressure on correct wad column with machine handle in full lowered position. This will always be the actual pressure being applied to wad or wads. When tightening clamp, avoid overtightening. Moderate clamp pressure will hold tube to properly seat primer or wads, while retaining safety feature in allowing tube to move should it meet with an abnormal obstruction.

Mote: Spreading safety clamp slightly with screw driver blade inserted between clamp ends will allow the tube to be readily located at the desired position.



Cam is properly adjusted to give best overall results on all varieties of 2-3/4 inch shells. To obtain best possible crimps on certain types of cases, it may be necessary to adjust the cam slightly.

To Adjust: If crimp is not centered, or if crimp has a spiral configuration, loosen Cam Adjusting Lock Screw (A) and rotate cam in direction of arrow. If opening at the center of crimp is evident, rotate cam in opposite direction.

NOTE: When adjusting, move cam only a fraction of an inch at a time, testing frequently. A 1/32 inch move may be sufficient.

To increase depth of crimp, loosen locknut (B) and screw crimping punch (C) down.

Mec 600 Wad Pressure



Die is completely adjustable for radius. Loosening lock screw (a) : ; and screwing the Crimping Sleeve r~; down will increase the radius, daimmq while moving it in the opposite

RADlUb direction will decrease it. When

-ADJUSTMENT ma^jng adjustments or checking the finished shells, be sure to operate the press handle to the positive stop at the bottom of its stroke.



MEC Charging Bar —A complete assortment of "quick-change" charging bars is available for any load or gauge. See charging bar chart packed with each loader or write to MEC for a complete list of bars. List also recommends proper bar for any combination of shot and powder.


Detach spring at"X7 remove bar stop screw, slide bar out, replace with bar or bar and bushing of your choice. Replace bar stop screw and attach spring. See Photo No. 2, Page 4.

IMPORTANT: When ordering parts or accessory equipment, be sure to state make, model, and serial number of reloader on which they will be used, along with part numbers. See list packed with loader.

Mec Punch Crimp Adjust






12, 16,20, 28 and .410 gauges —fitted in beautiful lifetime chrome

Dimenzion Roll Crimpers

Was this article helpful?

+1 0


  • christina
    How to adjust the crimp on a mec super 600?
    4 years ago

Post a comment