OAL & Fail-to-Eject?

[WNC Seabee]

I picked up a new-to-me Kahr KP45 this week and got it to the range for the first time today.

I loaded it up with some Berry's Hollow Base Round Nose with an OAL of 1.255". I got a fail-to-eject on 10 of 10 rounds! It wasn't the classic "stove pipe", the empty casings were stuck parallel to the barrel caught between the top of the slide and back of the barrel lug.

Well, I was plenty irritated that I got a new gun that needed work. So I picked up my SA 1911. I got the same problem!

Switched to a load w/ OAL of 1.200 and all was well. Both pistols ran smooth.

So, what would OAL have to to with fail to eject? I can understand fail to feed...but by the time eject happens, the bullet is well on the way and OAL is no longer an issue, right?

 

[243winxb]

Maybe the 1.255" oal rounds made less pressure because of the longer length? What powder and how much?

 

[WNC Seabee]

hmmm....hadn't thought of that.

Load #1 with all the FTE:
TiteGroup 4.2gr
Berry's plated HBRN 185gr
1.255"

definitely felt like a "soft" load, which is what I was going for.

Load #2 that worked:
TiteGroup 4.4gr
Berry's plated HBRN 185gr
1.200" OAL

Load #3 that worked:
Hornady 230gr LRN
4.4gr Titegroup
1.200" OAL

I'm very new to reloading and was working "down" to a softer load. The 4.4gr sure packs a kick, especially with the Kahr's 3.4" barrel!

BTW, that Kahr is incredibly accurate even with the longest mushiest trigger pull I've ever felt.

 

[243winxb]

load #2 has more powder and bullet seated deeper than #1. So #2 would build more pressure.

 

[rfwobbly]

Seabee -
243Win is correct. The "power" to operate the weapon is directly proportional to the chamber pressure, which in turn is directly proportional to the volume inside the case under the bullet AND the powder burning in that volume. You've set the volume larger and the powder smaller, so it's a double whammy against good operation.

Secondly, you're using a very fast powder on a very heavy bullet. This is like hitting a bowling ball with a baseball bat. An instantaneous whack is hardly going to get it going. May I suggest a slower powder that's going to "push" rather than "whack".

Hope this helps!