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Bulge at base of bullet on pistol cases?

cwinncwinn Member Posts: 1,223 ✭✭
Hello

I've begun reloading around 2 months ago. Thus far I have only done straight wall pistol calibers, specifically 9mm, .45 acp, .44 Spc and MAG. After around 600 rounds of experimenting, all have been acceptably accurate and I had only 1 malfunction, a FTFeed with a .45 in a Glock 21.

My question is in regards to case diameters. It seems with most of my rounds, I can see where the base of the bullet lies becuase of a slight case bulge. This is with both auto and revolver cartridges. all have chambered fine and I never have extraction issues. Using RCBS dies, I expand the case mouth to the point where the bullet to be loaded can just be placed in the case about 1/32" roughly without falling out when turned over.

I notice that I never see a similar bulge with factory purchased ammo.

Am I doing something incorrectly? Is it something that is cause for concern or will shorten case life?

Comments

  • charliemeyer007charliemeyer007 Member Posts: 6,572 ✭✭✭
    edited November -1
    It sounds like the sizing die is on the tight side (or perhaps the bullets are a little large), thats why you see the bullet base edge in the case. If your ammo shoots good you will be just fine.
  • machine gun moranmachine gun moran Member Posts: 5,198
    edited November -1
    It may also relate to inside case-taper, and the seating depth of the bullet.

    I actually prefer some degree of a wasp-waist right behind the bullet in my pistol ammo, as it helps to prevent the deep-seating of bullets when they strike the feed ramp. Factory ammunition sometimes has a cannula right behind the bullet, to help prevent the rearward movement of bullets.
  • Rocky RaabRocky Raab Member Posts: 14,429 ✭✭✭✭
    edited November -1
    It is perfectly normal with reloads. The sizing die actually takes the case down a bit too much. That's why you have to use the expander plug to start a bullet. With a bullet seated, that "wasp waist" you see shows you just how much smaller the case is. It's even more apparent with cast bullets, which are a couple thousandths larger than jacketed ones.

    It's not a problem whatsoever, and even has slight benefits. The bullet fits tighter (better ignition and less movement on feeding or recoil), and the rounds feed easier.

    Your sizer has to accommodate brass of greatly varying thicknesses from brand to brand, which is why they are made a bit tight. The factory knows exactly what its brass thickness is, and they can use a sizer tailored to that - hence, no pinched waist.
    I may be a bit crazy - but I didn't drive myself.
  • cwinncwinn Member Posts: 1,223 ✭✭
    edited November -1
    Good to hear, thanks for all the info everyone.
  • navc130navc130 Member Posts: 1,247 ✭✭✭
    edited November -1
    Rocky R is correct. It's all a matter of sizing and diameters. Most pistol reloads will show this condition. I have shot reloads like that for years. It is normal. I have read that the factories size the case AFTER the bullet is seated to make a nice, straight looking case.
  • Hawk CarseHawk Carse Member Posts: 4,381 ✭✭✭
    edited November -1
    I think the "coke bottle" constriction under the bullet is an advantage, keeps the bullet from deep seating against the feed ramp in an auto, is proof that you have good bullet pull for a revolver.
  • Riomouse911Riomouse911 Member Posts: 3,492 ✭✭✭
    edited November -1
    I get those on .45-70 rounds I load. So far, no issues.
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