Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Rifles, Bullets, Barrels and Ballistics


Reply

A good day shooting leaves me with some serious ladder test questions.

 
LinkBack Thread Tools Display Modes
  #1  
Old 02-13-2006, 12:47 AM
Platinum Member
 
Join Date: Jun 2007
Posts: 1,515
A good day shooting leaves me with some serious ladder test questions.

Well today was fruitful to say the least. I did a break in on my nephews gun that went surprisingly well. I shot a 300 yard group with Wildcat 169.5 grain ULD RBBT HPs and the ULD flat base HPs. I will post the pictures of this in another post tomorrow. I have to say I am EXCEEDINGLY happy with the group made with the RBBTs.

The topic of this post is, at the least, perplexing. We shot a ladder test with my brothers .338 win mag and had surprising results. The velocity increased with the increase in powder for the most part but the impact string went up and down. Alot. I was expecting something that resembled the velocity string. I expected the bullet holes to rise and settle then rise and settle. No such luck. In fact the last shot was only an inch and a half higher than the first shot but the extreme high and low shots were over 6 inches apart.

I will post pictures of the actual target and the velocity and shot graph tomorrow (it is too late and I'm too tired to mess with it right now) but I wanted to get all you experienced ladder testers on stand by for this one. I have no idea what is hapening on this one. I actually have a theory. I am wondering if the gun was taking a toll on my brothers shoulder. He said that he was doing fine and he did keep shooting in a group (somewhat) or rather the shots were coming out near each other. They just weren't rising up the paper.

Please keep an eye on this post for the incoming info. I really dont want to shoot this ladder twice if we can put together a satisfactory node from the info gathered.

Thanks guys. [img]/ubbthreads/images/graemlins/wink.gif[/img]
__________________
GRAVITY. It's not just a good idea. It's the LAW!
Reply With Quote
  #2  
Old 02-13-2006, 03:01 PM
Platinum Member
 
Join Date: Jan 2004
Location: Blackfoot, Idaho
Posts: 8,089
Re: A good day shooting leaves me with some serious ladder test questi

[ QUOTE ]

The topic of this post is, at the least, perplexing. We shot a ladder test with my brothers .338 win mag and had surprising results. The velocity increased with the increase in powder for the most part but the impact string went up and down. Alot. I was expecting something that resembled the velocity string. I expected the bullet holes to rise and settle then rise and settle. No such luck. In fact the last shot was only an inch and a half higher than the first shot but the extreme high and low shots were over 6 inches apart.

[/ QUOTE ]

NOthing unusual about that, at least in my experience. Post the pics and velocities and I'll willingly post my ever so humble opinion. Yah, right.

Include Powder, primer, stock/bedding type, etc.

Waitin' to hear.
__________________
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!
Reply With Quote
  #3  
Old 02-13-2006, 05:43 PM
Platinum Member
 
Join Date: Jan 2003
Location: The rifle range, or archery range or behind the computer in Alaska
Posts: 3,515
Re: A good day shooting leaves me with some serious ladder test questions.

Barrel harmonics have more to do with where the bullet will strike more so than inconcistent velocity string. Up to 600 yards or so, then good old gravity and time of flight will really do its damage and you WILL notice bullets high and low due to bad velocity strings.
__________________
Long range shooting is a process that ends with a result. Once you start to focus on the result (where the shot goes, how big the group is, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.
Reply With Quote
  #4  
Old 02-13-2006, 08:59 PM
Platinum Member
 
Join Date: Jun 2007
Posts: 1,515
Re: A good day shooting leaves me with some serious ladder test questions.

Here it is. The raw target. Components are new win brass, wrm primers, 250 gr SGKs, H4831sc powder. Rifle has the rear tang and front of reciever and lug bedded. BBL is free floated but not by much. Rifle was shot from front rest and rear bag. Trigger pull is a light 3.5 to 4 lbs (it will be used while traveling cross country sometimes). Rem 700 stainless. 40 deg. 3100 ft ele. mild 90 deg cross wind (5mph or less) coming from l to r. 10 rounds through bbl since last cleaning prior to starting test. No less than 1 minute between shots. Often more.


Here is the graph showing the actual height relation of the shots. The first shot in the above picture was a test shot that was given #1 so shot #20 is actually #19 on this chart.


Here is the velocity graph. The red vels (8,18) were "no reads" so I put them between ajacent shots. The green vel (16) was identical to shot #15 and we didn't notice if the chrono beeped or not.


Velocities are as follows:
1 2341
2 2320
3 2365
4 2398
5 2413
6 2422
7 2476
8 no read (2500)
9 2526
10 2559
11 2554
12 2568
13 2583
14 2603
15 2645
16 2645?
17 2626
18 no read (2640)
19 2660

OK lets see if we can make heads or tails of this. Maybe a reccomendation on a next step.
__________________
GRAVITY. It's not just a good idea. It's the LAW!
Reply With Quote
  #5  
Old 02-13-2006, 09:20 PM
Platinum Member
 
Join Date: Jun 2005
Location: Yakima, Washington
Posts: 3,833
Re: A good day shooting leaves me with some serious ladder test questi

4kedHorn:

What is the powder charge increment for each load?
__________________
ss7mm
Reply With Quote
  #6  
Old 02-13-2006, 10:31 PM
Platinum Member
 
Join Date: Jun 2007
Posts: 1,515
Re: A good day shooting leaves me with some serious ladder test questi

.4 grains starting at 64.3 and ending with a published max of 71.5 from hodgdons "05 manual.
__________________
GRAVITY. It's not just a good idea. It's the LAW!
Reply With Quote
  #7  
Old 02-13-2006, 11:01 PM
Platinum Member
 
Join Date: Jan 2004
Location: Blackfoot, Idaho
Posts: 8,089
Re: A good day shooting leaves me with some serious ladder test questi

Which choke tube are you using? [img]/ubbthreads/images/graemlins/grin.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]

I'm thinkin! I'm Thinkin!

How are you holding the rifle as in shoulder pressure, hand on forearm? That is, are you pulling in snugly into your shoulder with your trigger hand with your other hand on the sand bag?

The reason I ask is that when my bbl was "barely" floated I was pulling it down against the stock sometimes when shooting off of pedestal rest. Then I got my handy dandy inletting tool and hawged things out so now you could drive a humvee in there.

Check the free float while at the shooting bench. You get in your shooting position get your buddy to run a business card all the way to the recoil lug. If any resistance at all, consider some work on it.

My standard for free floating is 5-1s together all the way to the recoil lug. Depending on the rifle I some times fold the 5 1s long ways.

I've found that a good solid hold into the shoulder, the other hand squeezing the sand/beanie bag and letting the muzzle do whatever it wishes has been best for me. It also more closely duplicates conditions when shooting prone from bipod.

You're not using REM 9 1/2 Primers, are you?

I'd consider starting the test @ your #10 load and go up from there.

In my Win. which seems to be a bit unusual as I can approach RUM velocities I got the following results with REM Cases and 4831sc:

71.5 gr = 2596
74.7 gr = 2788

Mine didn't like SC as much as it liked some other powders.

Also, 20 shots in less that say 30 minutes @ 40 degrees temp. your bbl should have been pretty darn warm. Remember it will be warmer on the inside than on the outside. I'd consider shooting it, removing the empty, pointing it in the direction of the wind, leave the bolt open, then walk down to the target, kick some dirt/sand/snow/etc, then come back and shoot the next shot.

I'm a bit confuxed regarding the relationship between trigger pull and traveling across country? [pull is a light 3.5 to 4 lbs (it will be used while traveling cross country sometimes).

I wouldn't switch powders, but may consider switching primers, unless you're using Feds, until the randomness is removed and more consistency is achieved. Then consider changing powder if you think you need to.

Another thought. Stand the rifle on the recoil pad. With screw driver in one hand and your other hand (dail indicator works better but your hand will be pretty sensitive) loosely holding the rifle around the barrel and fore end tip, loosen and tighten the receiver screws in different combinations. If you feel any movement or hear the stock squeeking as the action moves, then you may wish to revisit the bedding.

I'm not sure who I'm talking to, thus may have covered some stuff that you already have considered. Hey, just trying to help.

Good shootin'
__________________
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: A good day shooting leaves me with some serious ladder test questions.
Thread Thread Starter Forum Replies Last Post
Ladder test questions USMCSSGT Long Range Hunting & Shooting 2 07-25-2011 08:52 AM
ladder test help..... Ring Reloading 41 06-25-2011 11:28 PM
Audette ladder test questions Topshot Long Range Hunting & Shooting 15 05-19-2010 09:51 AM
ladder test questions littledevil2873 Reloading 1 04-13-2006 03:36 PM
Ladder test questions Boman Reloading 3 08-12-2005 07:59 PM

Current Poll
Do you archery hunt for elk?
YES - 29.61%
45 Votes
NO - 54.61%
83 Votes
Not yet, but I plan to. - 15.79%
24 Votes
Total Votes: 152
You may not vote on this poll.

All times are GMT -5. The time now is 08:23 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC