Ladder test with BACO 403380E Paper Patched

Discussions of powders, bullets and loading information.

Moderators: Kirk, Lucinda

TexasMac
Posts: 2174
Joined: Sun Nov 04, 2007 5:29 pm
Location: Central Texas
Contact:

Re: Ladder test with BACO 403380E Paper Patched

Post by TexasMac » Sun Apr 04, 2021 3:44 pm

Per Chris’ suggestion I worked up a quick chart displaying the shot distanced from the point of aim. The horizontal axis is the shot number & vertical axis is the distance in inches from the point of aim. In this case one looks for the flatter portions of the graph where the shot-to-shot variance is minimized. As Brian (semtav) commented, if shot #10 is a shooter error (surely not :lol: ) than shots 7 thru 12 would be a clear indication of the sweet spot.

Wayne

Image
NRA Life (Benefactor & President's Council) Member, TSRA Life Member, NSSF Member, Author & Publisher of the Browning BPCR book
http://www.texas-mac.com

User avatar
PhilRich
Posts: 64
Joined: Tue Jan 03, 2017 4:06 pm

Re: Ladder test with BACO 403380E Paper Patched

Post by PhilRich » Sun Apr 04, 2021 6:47 pm

It appears that shot #10 is a "miss" and should be ignored since it is so far out of line with adjacent data points. If so, then the best loading with more than minimal compression is based on shots 9, 11 and 12.

SSShooter
Posts: 2655
Joined: Mon Feb 20, 2012 7:06 am
Location: Jersey Shore

Re: Ladder test with BACO 403380E Paper Patched

Post by SSShooter » Wed Apr 07, 2021 5:32 am

Good info. Hope to get to testing PP in my 40cal 16" twist GM-X barrel shortly.
Glenn

SSShooter
Posts: 2655
Joined: Mon Feb 20, 2012 7:06 am
Location: Jersey Shore

Re: Ladder test with BACO 403380E Paper Patched

Post by SSShooter » Fri Apr 09, 2021 6:42 am

Wayne - as I loaded for my ladder test it occured to me one can either hold the seating depth constant and have varying compression or can can vary seating depth and hold compression constant. Am guessing you held seating depth constant (which is how I've loaded for my test). Is that correct?
Glenn

TexasMac
Posts: 2174
Joined: Sun Nov 04, 2007 5:29 pm
Location: Central Texas
Contact:

Re: Ladder test with BACO 403380E Paper Patched

Post by TexasMac » Fri Apr 09, 2021 9:32 am

SSShooter wrote:
Fri Apr 09, 2021 6:42 am
Wayne - as I loaded for my ladder test it occured to me one can either hold the seating depth constant and have varying compression or can can vary seating depth and hold compression constant. Am guessing you held seating depth constant (which is how I've loaded for my test). Is that correct?
Glenn,

Yes, I kept the same seating depth. The only change I will be making when running future ladder tests is to use a higher power scope. My 10X Fecker is not really sufficient for 200yd ladder testing. So I'm looking for a higher power scope, but only for ladder testing.

Wayne
NRA Life (Benefactor & President's Council) Member, TSRA Life Member, NSSF Member, Author & Publisher of the Browning BPCR book
http://www.texas-mac.com

SSShooter
Posts: 2655
Joined: Mon Feb 20, 2012 7:06 am
Location: Jersey Shore

Re: Ladder test with BACO 403380E Paper Patched

Post by SSShooter » Fri Apr 09, 2021 11:17 am

Difficult to sort out whether it is more powder or more compression that makes the difference.

Sure like my side-focus 40mm Leupold. Cheaper & clearer glass than a 20X (or 24X or 36X) Unertl or Lyman STS. I use on my smallbore silhouette rifle.
Glenn

TexasMac
Posts: 2174
Joined: Sun Nov 04, 2007 5:29 pm
Location: Central Texas
Contact:

Re: Ladder test with BACO 403380E Paper Patched

Post by TexasMac » Fri Apr 09, 2021 11:55 am

SSShooter wrote:
Fri Apr 09, 2021 11:17 am
Difficult to sort out whether it is more powder or more compression that makes the difference.
Sure like my side-focus 40mm Leupold. Cheaper & clearer glass than a 20X (or 24X or 36X) Unertl or Lyman STS. I use on my smallbore silhouette rifle.
I hear you but I don't want to drill & tap more holes in my Sharps or Browning. A higher power Unertl or Lyman will fit the standard 7.2" block hole spacing currently used for the Fecker. What does concern me a bit is the possible effect of changing scopes just to run the ladder tests. A modern scope is much shorter and, although it will fit the 7.2" hold spacing, a Unertl or Lyman in 24X to 36X is significantly longer and heavier than the Fecker. It potentially can change the barrel harmonics and therefore the precision, possibly corrupting the results of a ladder test. Something to think about.

Wayne
NRA Life (Benefactor & President's Council) Member, TSRA Life Member, NSSF Member, Author & Publisher of the Browning BPCR book
http://www.texas-mac.com

beltfed
Posts: 1838
Joined: Sun Jun 03, 2007 10:07 am
Location: Central Wi

Re: Ladder test with BACO 403380E Paper Patched

Post by beltfed » Fri Apr 09, 2021 9:31 pm

Wayne,
The weight of the heavier Lyman STS or Unertl scopes will Still be supported
on the bases at 7.2" spacing, though, I suppose we might think that the weight up front-Objective Bell
may have some additional cantilever effect "down on" the front base
I expect also that since the scope bases are close(er) to the receiver, there will be less effect on the
harmonics which I expect are largely towards the muzzle
beltfed/arnie

Post Reply