Problem starting 55 grain bullets into cases

F

FoghornLeghorn

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The dies are RCBS SB for 223.

The cases have been swaged, sized, tumbled, trimmed and primed.

The bullets are flat base and won't "start" into the case mouth. They simply sit on top of the case mouth. Obviously, boat tail bullets start fine. But flat base are another story.

Is there another step for loading flat base bullets?
 
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What type seating die are you using? I had the same problem with a Lee seating die but switched to the Hornady sleeve seating die which helped. Can you check the diameter of your case neck? Check the diameter of the neck expanding button. If it is under size it can make the case mouths tighter than they should be. The ID of my cases usually run about 0.002 smaller than bullet diameter.
 
Flare the case mouth just enough to get the base started without catching the edge of the case or bullet .
Some like to inside chamfer the heck out of the case mouth but I prefer not to cut away metal .
The Lee Universal Neck Expanding Tool is perfect for putting a slight flare on any caliber case mouth .
Gary
 
You can use a Lee flaring die, but tiny as that neck is, you run the risk of losing resized neck tension. As mentioned earlier just chamfer the mouth a bit.
 
Lyman M die spaces the neck and it also has a flare in it you can do a hint of flare with if need be.

I have no issues with using the M die with no flare but I also chamfer (I use a Geraurd Trim Trimmer so it does the case trim length as well as chamfer and de-burr.
 
Chamfer the case mouth (a step you should be doing after trimming, anyway), chamfer the inside (rcbs and others make tools for this) and the outside to remove burrs and brass bits left from the trimmer cutter.

Chamfer the inside of the case mouths to create an angle (slope) so that flat base bullets enter without issues.

Some cases need more than others. I've found .22 Hornet brass to need a bit more chamfer than most others, without enough, the thin brass of the neck gets crushed (Wrinkled, deformed) rendering the case a loss.
 
Yes, I deburr the cases and chamfer the necks. I just don't like removing a lot of metal. But these are once fired cases so no big deal.

Thanks for the advice. I chamfered some more and the bullets are seating fine. From now on I'll stick to boat tail bullets.

Thanks again.
 
There's nothing wrong with flat base bullets (which don't actually have a square corner on the base) in some situations they are better than boattails, they just need a slightly more careful brass prep.

Sometimes the flat base bullets group the best in some rifles. Don't overlook the possibilities just for a bit of convenience the loading process.
 
Removing brass from the mouth does not hurt a thing . To stick to boat tail bullets makes no sense, you are missing some of the most accurate bullets in production . I shoot flat base to 300 yards, and win .
 
Yep. As Bryan Litz explained, it is easier in the manufacturing process to make a flat base that is symmetrical than it is to make a boattail that is symmetrical. This often leads to superior short-range accuracy from the flat base. They just lose out on ballistic coefficient, and with that, wind bucking ability for longer ranges. Short-range benchrest matches are pretty universally won by flat base bullets.
 
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