Question about seating depth

OK, seating depth question..and plunk test.  I have run another small batch of 45 app was ammo and changed my seating die out a bit so my plunk test would show the case to be even with the hood.

Here is the question.  After the gun gets dirty after who knows how many rounds, would that being flush with the hood now be out a bit because the chamber is now getting dirty?  The reason I ask is I went to the range with my newly seated ammo and it fired great, but then as the gun got dirty I noticed the slide not going back into battery all the way..Not a lot but enough where I could not engage the safety.  Thats what caught my attention.  If I pushed on the slide with my thumb with some force it would go all the way into battery.

After getting home I took the gun apart and plunked the left over ammo I had from that batch and notice some, not all would now be proud of the hood!  If I pushed with my thumb it would seat level with the hood.

I'm at a loss.  I could seat deeper but now that throws out that plunk to be flush with the hood theory.  I know I'm missing something here.  

Anyone please help

LOL, My white mac keyboard is now covered in powder fouling and gunk because I forgot to clean my hands after taking the gun apart...OH BOY!

Thanks

Are you using Lead Bullets?
I find expermenting with OAL by shooting groups is the way to go.
Function comes before accuracy.
I have not had a problem with a dirty chamber keep the slide open. I load like you did. Its headspacing on the bullet. If its keeping the gun open, you are probably too long. How many rounds did you fire before it started to fail ? What was your crimp?
Do you know how it groups with your standard load so you can compare it to the new OAL?

Enjoy expermenting
David

David R wrote:Are you using Lead Bullets?  
I find expermenting with OAL  by shooting groups is the way to go.  
Function comes before accuracy.  
I have not had a problem with a dirty chamber keep the slide open.   I load like you did.  Its headspacing on the bullet. If its keeping the gun open, you are probably too long.  How many rounds did you fire before it started to fail ?  What was your crimp?
Do you know how it groups with your standard load so you can compare it to the new OAL?

Enjoy  expermenting
David

Thanks Dave

Groups about the same as my other load.  Yes, lead bullets.  fired about 50 rounds before it started acting up.  My crimp is .463..well as close as I can measure anyway

Lablover, I think there may a problem with how your seating the bullet. The 45 was designed to rest on the case rim not the bullet hitting the lands. The 45 with a L-SWC should only have about a thumb nail of bullet protruding past the case on the flat part of the bullet. I am surprised you were able to get any of them to feed reliably with the OAL long enough to touch. I am assuming some of those things because your auto-correct really messed up the description of your load.

Len

Two choices

What Len said. Don't worry if the case head is a little below flush when you plunk test, as long as it's not above.

Len, tried to clean up my description a bit better.  I’ll try to get a pick.  These are 190 gr swc

190 gr on left. 160 gr on the right

What jumped out to me on your picture is that I don't see any sign of the case being re-sized. An over size case will cause lots of problems. Maybe I'm just not seeing it.

Len

LenV wrote:What jumped out to me on your picture is that I don't see any sign of the case being re-sized. An over size case will cause lots of problems. Maybe I'm just not seeing it.

Len

They have all been thru a Dillon sizer. I’ll check in the morning to make sure it’s set up close enough to the shell plate.  Sized cases drop right in the chamber fine

The round on the left looks like the bullet could be seated a little deeper, I use about a finger nail length of the main diameter showing.

Seated 10 thou deeper and no issues with 100 rounds.  I think I might go a tiny bit deeper just to be safe.  Accuracy was spot on

What is your dimension base to shoulder of swc

james r chapman wrote:What is your dimension base to shoulder of swc

0.936

After just now seeing a post by Jon a while back looks like I still may be too long.

And I was using numbers that I had used for my RO with factory barrel.  It now has a Kart and never took that into consideration.

Be sure your kart had a finish reamer run Into it after it was fitted to set the throat..

jglenn21 wrote: Be sure your kart had a finish reamer run Into it after it was fitted to set the throat..

Yes it did.  Just verified with Smith

I totally know what I did wrong here.  I have the spare barrel from my RO and I was using that as a case gauge for my loaded ammo...Not thinking that the cart would be tighter.  After Jimmy posted his response about the finish reamer it went click in my head.

Man, what a boob!  Thanks to everyone for helping me keep my sanity.

Joe

Joe, I’d still seat it to Jon’s recommendation of .920 
Jim

james r chapman wrote:Joe, I’d still seat it to Jon’s recommendation of .920 
Jim

I can do that..I have a question?  The 190s I use have a different shoulder than the normal 200 gr SWC design.  If you look at the photo above you will see the difference.  Where on that shoulder?  I'm thinking the top part of the shoulder?  Thanks a Million for the help

Personally I would measure to the squared portion of the shoulder, not the top of the radius. So basically the shortest dimension.

But, if you measure to a flat surface you might be a little shot but still within range. I just leave my bullet shoulder seater set so all cast bullets seat the same.