Long Range Hunting Online Magazine


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


Reply

SLOW VELOCITY 270WSM - 7mm.RM

 
LinkBack Thread Tools Display Modes
  #1  
Old 01-14-2009, 01:27 PM
Bronze Member
 
Join Date: Sep 2008
Location: Italy
Posts: 32
SLOW VELOCITY 270WSM - 7mm.RM

Hi guys,

i have a "velocity" problem with my more accurate reloads.
I made a lot of test, to find the best load with the Nosler Accubonds, in my rifles, TikkaT3.lamin/stainless 7mm.RM and Sako75 sinth/stainless .270WSM.
The best accuracy loads i have found are theese:

- 7mm.RM (TikkaT3) - 24" barrel
Accubond 140 grs. x 66.00 H4831
Aol = 3,290"
brass = Norma
primer = Fed GM215M
Vo = 2.850 fps.
distance = 185 yds.
group = 0.825" 5 rounds (with 1st. round - barrel clean)
group = 0.472" (the others 4 rounds)

- .270WSM (Sako75) - 24" barrel
Accubond 130 grs. x 65.00 H4831
Aol = 2,870"
brass = Remington
primer = CCI250M
Vo = 2.965 fps.
distance = 185 yds.
group = 0.787" 4 rounds
group = 0.551" first 3 shots

...... why my loads don't go over 3.000 fps / 7RM and over 3.100 / .270WSM ? ... i really don't understand ! ...

I would like to know your point of view about theese poor energy loads, consulting the Hodgon data manual (on line), i should stay about 1grs./1.5grs. less the max charge ..... but i can't understand theese results.
i really don't want use a magnum caliber .... with the result of 7.08 or a .270w ... HELP ME ...

(The strange distance, 185 yds. , it is the max i can in my pistol-shooting-range)

Thank you so much for your help.

Luca
__________________
Shoot slow, do everything else fast.
Reply With Quote
  #2  
Old 01-14-2009, 06:14 PM
Bronze Member
 
Join Date: Nov 2007
Posts: 51
Re: SLOW VELOCITY 270WSM - 7mm.RM

These two are excellentand very accurate cartridges but are not known as speed burners. If you want speed you should get the 270 weatherby mag, 7mm wby or a 7mm stw.
__________________
Lost in Thought, Please send Search Party!
Reply With Quote
  #3  
Old 01-14-2009, 11:00 PM
Platinum Member
 
Join Date: Dec 2001
Location: Winterville, NC
Posts: 1,469
Re: SLOW VELOCITY 270WSM - 7mm.RM

wheelgunner,
You're right in being concerned. Both your 7RM and 270WSM should be spitting those selected projectiles at over 3200fps. I have a 7RM, it has a 26" tube and I'm getting 3200 + with IMR4350 and 150gn Ballistic Tips. I just traded my 270WSM but I was getting over 3300fps with 130gn NBT's. I suggest you try a different powder. IMR4350, 4831, 7828, H4350, Retumbo, H1000, RL22, AA3100, Hunter, Big Game all come to mind. All are good powders for these two rounds and produce better velocity than you're getting.
Not sure where or how you're getting your velocity. You may be using a bump chronograph. The only thing the two rifles/cartridges have in common is the powder and chrono (I assume). Let us know. JohnnyK.

Last edited by johnnyk; 01-14-2009 at 11:04 PM. Reason: forgot someting
Reply With Quote
  #4  
Old 01-15-2009, 05:41 PM
Junior Member
 
Join Date: Dec 2005
Posts: 23
Re: SLOW VELOCITY 270WSM - 7mm.RM

At what range is the Crono and are you sure it is not the Crono that is just reading slow?

I have played with the same 270WSM load and saw around 3100 FPS for the exact same powder and primer combo using the same powder amount.

H4831 is a good powder for the 270WSM. R19 or H1000 (which really fills the case) has been better for me.
Reply With Quote
  #5  
Old 01-16-2009, 10:31 AM
Silver Member
 
Join Date: Feb 2008
Location: Memphis Tn
Posts: 319
Re: SLOW VELOCITY 270WSM - 7mm.RM

I reload for both my 7mm Rem Mag(Ruger 77 Mark II) and my 270WSM(Winchester Model 70) and have had to slowly work up the powder charge above what is listed to get the velocity that is given in the reloading manuals. I think it is because both my guns have a long throat and it take more powder to achieve the stated velocity.

I think that Johnnyk is correct. I have gotten my top velocities using Magpro or RL-22 in both guns. I load RL-22 because I get good velocity and better accuracy with it than with Magpro.

So my suggestion is to get some different powder and slowly and carefully work up the load, using your chronograph as guide. Watch for any pressue signs such as a sticky bolt .You should be able to match your goal.

I have gotten over 3200 ft/sec from both guns using 140 grain bullets and the correct amout of powder(both my guns have 24 inch barrels). With RL-22 I am using more than the manuals state as max.

So be careful and work up slowly, at .5 grains at a time.
Reply With Quote
  #6  
Old 01-19-2009, 09:22 AM
Bronze Member
 
Join Date: Sep 2008
Location: Italy
Posts: 32
Re: SLOW VELOCITY 270WSM - 7mm.RM

Thank you to everybody for yours repplies.
I'm just come back from an hunting week-end in Hungheria (roe-deer), and the loads we are talking have stopped 4 roe-deers from 140 mt. to 205 mt. with the accuracy i was tested.

Regarding the repplie about the chrono distance (from the muzzle), it's about 3/4 meters .... and i will try again with another chrono (from a friend) if there will be differences.

Now i would like to try 67.00 - 68.00 for the 7mm.RM and 67.00 for the .270WSM (66.00 just tested, but the groups was a "buckshot-group").

i'll let you know .... thank you again !

Luca
__________________
Shoot slow, do everything else fast.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: SLOW VELOCITY 270WSM - 7mm.RM
Thread Thread Starter Forum Replies Last Post
My .264 win mag loads are too slow Hutt Reloading 5 10-03-2009 06:01 AM
Slow Day Buffalobob Upland Bird Hunting 1 09-02-2009 09:18 PM
New Tikka Velocity is SLOW. bkondeff Rifles, Bullets, Barrels and Ballistics 4 03-22-2009 08:46 AM
Slow twist barrels and high velocity.. ol mike Rifles, Bullets, Barrels and Ballistics 18 03-27-2007 09:24 PM
Powder Too Slow? Kevin Rifles, Bullets, Barrels and Ballistics 7 03-09-2006 12:54 PM

Current Poll
Do you wear hearing protection while hunting?

All times are GMT -5. The time now is 11:15 PM.


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