Author Topic: Two good clusters in one ladder test...?  (Read 506 times)

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Offline thejanitor

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Two good clusters in one ladder test...?
« on: August 20, 2010, 12:36:47 PM »
Hi everybody- just working up another load for the 7mm08 and when shooting the ladder method had two decent clusters, one on the low end and one also on the high end with several strug upwards in the middle.... I have not seen this before and will work with both groups as they were actually very good clusters, but wanted to ask if this is common for others? I was under the impression that there was supposed to be only one area in the powder and bullet combo that would reach that area of balance. (if a balance can be reached with the combo being used....)
I don't mean to dredge up any arguement over the to ladder or not to ladder, as I have done both, but thought it odd to have two decent seperate groups- over two grains apart.
Rem 9 1/2 primer - IMR 3031 - Speer 130
P.M.s or postings here with info are very welcome. Thanks thejanitor

Offline jhalcott

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Re: Two good clusters in one ladder test...?
« Reply #1 on: August 20, 2010, 04:53:21 PM »
 Reminds ME of the time I worked up a load on Friday after work for a ground hog trip on Saturday. I had a 3/4 to 7/8th" group with one 5 shot batch. Went home and loaded 50 of that loading. Next day I couldn't hit the ground for trying?!?!? Back at the range the "group" went over 2 INCHES/5 shots. Only thing I can figure is MY wiggles coincided with the loads inconsistencies to form a super group. Since then I take more time and shoot more than 1 five shot group to test a load.

Offline thejanitor

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Re: Two good clusters in one ladder test...?
« Reply #2 on: August 20, 2010, 07:33:40 PM »
I thought I was solid on the bench.... But there is always that pulled shot or the flyer. I just thought I would ask if someone else noticed it happening and I was just in the dark about it. I loaded up to cover both clusters just to see what happens and which one was a true group and which one was just an accident. We will see, worst case is I get to shoot 9 extra shots this weekend -kind of a win win for me. thejanitor

Offline PowPow

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Re: Two good clusters in one ladder test...?
« Reply #3 on: August 21, 2010, 02:21:37 AM »
I have had two "sweet spots" on the ladder several times.  In my mind, there is nothing illogical about it since its based on barrel harmonics, and sine waves cross zero more than once.  I investigate both sweet spots, but the higher load always ends up winning.
The difference between people who do stuff and people who don't do stuff is that the people who do stuff do stuff.

Offline wncchester

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Re: Two good clusters in one ladder test...?
« Reply #4 on: August 21, 2010, 04:03:23 AM »
"..wanted to ask if this is common for others?"

It is not uncommon.  I ignore the low speed and concentrate on making the faster work.
Common sense is an uncommon virtue

Offline rugerfan.64

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Re: Two good clusters in one ladder test...?
« Reply #5 on: August 21, 2010, 04:13:29 AM »
Here is a link that I beleive you will find interesting. It may possibly clear things up for you. I have used it a few times since I found this site and the results have proven out for me.

 http://www.optimalchargeweight.embarqspace.com/#


Offline thejanitor

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Re: Two good clusters in one ladder test...?
« Reply #6 on: August 21, 2010, 07:41:15 PM »
Thanks for the replies! I will check out the link tonight. I didn't get to the range today, but might tomorrow.
I am glad I wasn't the only one to have it happen. Always hate to look dumb in front of everyone, but it's something I kind of got used to as a kid.  :P   ;) 
thejanitor

Offline tacklebury

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Re: Two good clusters in one ladder test...?
« Reply #7 on: August 21, 2010, 07:44:54 PM »
I too got two sweet spots in my groups.  One was about 1.5 gr. below max and one was about 7gr. under max.  Personally, I like the lesser recoiling round better and poi drop is not too significant in my .45-70 BC, so I went with the lower for my regular load.  8)
Tacklebury --}>>>>>    Multi-Barrel: .223 Superlite, 7mm-08 22", .30-40 Krag M158, .357 Maximum 16-1/4 HB, .45 Colt, .45-70 22" irons, 32" .45-70 Peeps, 12 Ga. 3-1/2 w/ Chokes, .410 Smooth slugger, .45 Cal Muzzy, .50 Cal Muzzy, .58 Cal Muzzy

also classics: M903 9-shot Target .22 Revolver, 1926 .410 Single, 1915 38 S&W Break top Revolver and 7-shot H&R Trapper .22 6" bbl.


Offline flashhole

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Re: Two good clusters in one ladder test...?
« Reply #8 on: August 22, 2010, 02:42:39 AM »
It is good practice to do the laddert test more than once and overlay the targets.  This helps eliminate misleading information.