The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools Search this Thread
Old December 12, 2018, 11:20 AM   #1
oley55
Senior Member
 
Join Date: September 6, 2013
Location: JAX, FL
Posts: 317
is this a below minimum charge weight?

I have found a couple loads that show great promise in my 308win Savage FCP10, 24" barrel that depending on source and method are at or may be below minimum. Using LC (11) brass, Varget, Hornady 168hpbt match.

Reloading sources say if using mil brass to reduce the max load by 1-2 grains. And rule of thumb for determining min load is to reduce the MAX by 10%.

Loading sources MIN/MAX:
Lyman 24" barrel - 41.0/45.7
Hodgdon 24" barrel- 41.0/45.0
Sierra 26" barrel- 38.7/43.5

Applying the MIL brass rule -1/-2 and subtracting 10% for a start load I have:

Lyman- -1gr=40.2, -2gr=39.3
Hodgdon-1gr=39.6, -2gr=38.7
Sierra- 1gr=38.25, -2gr=37.4

Depending on the alignment of the stars, I have had some good results 39.1-39.5. However, 39.1 has been the best (5/8" at 100 yds) and most repeatable. These were all worked up before I finally got tired of the unexplained flyer/s and got semi-serious about carefully processing my brass. I have just spent the better part of three weeks sorting, prepping, resorting, and re-resorting brass, and I am ready to see if my efforts have made a difference and to start evaluating seating depths.

The longest range readily available to me is just 200 yds, so a low end load is not a concern (at least for now).

So, just how thin is the ice using this 39.1gr load? North Florida temps often fluctuate by 40-50 degrees from day to day in the winter. Would firing this min load become potentially dangerous on one of those colder 30-40 degree days?
__________________
“Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem.” ― Ronald Reagan
oley55 is offline  
Old December 12, 2018, 12:53 PM   #2
USSR
Senior Member
 
Join Date: November 14, 2017
Location: Finger Lakes Region of NY
Posts: 762
You will be fine with that load, although personally, I would bump it up to somewhere between 40.0gr and 41.0gr. Also, the very best thing you can do is ditch the USGI brass and buy some Lapua brass. Aside from the quality of your bullet, your brass is the next most important factor in developing accurate rifle loads. Hope that helps.

Don
__________________
NRA Life Member
NRA Certified Metallic Cartridge Reloading Instructor
USSR is offline  
Old December 12, 2018, 01:41 PM   #3
T. O'Heir
Senior Member
 
Join Date: February 13, 2002
Location: Canada
Posts: 11,048
What does your manual say?
"... using mil brass to reduce the max load by..." 10% of the Start load, not 1 or 2 grains from the Max. The regular Start load for a 168(the Sierra HPBT, not the Barnes) and Varget is 42.0. Means you're safe at 37.8 with milsurp brass.
And you do not load according to the barrel length.
__________________
Spelling and grammar count!
T. O'Heir is offline  
Old December 12, 2018, 02:38 PM   #4
oley55
Senior Member
 
Join Date: September 6, 2013
Location: JAX, FL
Posts: 317
thanks for the response. I was trying hard to validate my method so that I wasn't committing a critical error.

fyi the "reduce by 1-2 grains" is as per both the Lyman and Sierra manuals. No percentages listed, unless elsewhere besides under 308 WIN.

Quote:
And you do not load according to the barrel length.
I only included the barrel lengths because the lowest published loads came from the 26" test barrel, and assumed barrel length may have been pertinent in some way unknown to me.
__________________
“Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem.” ― Ronald Reagan
oley55 is offline  
Old December 12, 2018, 02:58 PM   #5
oley55
Senior Member
 
Join Date: September 6, 2013
Location: JAX, FL
Posts: 317
Don,

granted I may be trying to make diamonds from coal, but I must prioritize my hobby funds, and right now the budget (aka the Spouse) doesn't support Lapua brass.

I hope that does not diminish anyone's impression that I am committed to learning and improving my reloading abilities.
__________________
“Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem.” ― Ronald Reagan
oley55 is offline  
Old December 12, 2018, 03:44 PM   #6
jmr40
Senior Member
 
Join Date: June 15, 2008
Location: Georgia
Posts: 9,528
Do you have, or can you get access to a chronograph? A max load with Varget should give you about 2770-2780 fps. The powder charge to get to 2770 fps will vary depending on the brass and other factors, but 2770 is the max load regardless of what the manuals say the powder charge is. My manuals show 46 gr with Winchester brass. I use 46 gr with 165/168 gr bullets and get about 2740 fps from my 22" barrels.

With LC brass you'll probably hit 2750ish with 1-2 gr less than 46. I'd use more than 39 gr, my manuals show 42 as the starting load. I seriously doubt if you'll have any issues with 42-43 gr, but above that and you might, might not. But without a chronograph you're driving blind.

Varget is one of the more temperature stable powders so that is good. You can expect about 1/2 fps velocity change for every 1 degree temperature changes. A 50 degree temperature swing will probably only show about 25 fps change in velocity.
__________________
"If you're still doing things the same way you were doing them 10 years ago, you're doing it wrong"

Winston Churchill
jmr40 is offline  
Old December 12, 2018, 03:49 PM   #7
F. Guffey
Senior Member
 
Join Date: July 18, 2008
Posts: 7,072
Quote:
I hope that does not diminish anyone's impression that I am committed to learning and improving my reloading abilities.
Don't worry about me. I have headed to the range with 12 different loads in 12 different case/head stamps with 12 different bullets. That would be 12 different loads of 10 rounds each. A few would say that would be an effort to find something the rifle liked. To start to finish I do not adjust the scope, I use one point of aim.

What I am looking for is tight groups that do not open up and I do not have flyers. Out of the groups I do have them move around but the groups do not open up and I do not have flyers. And then I load another 120 rounds of 12 different loads using 12 different head stamps.

If the groups got better by using Lapur cases I could not stand it.

And then there are other rifles that will not do 'it'; I sent one back to Winchester, we had words. I was thinking about that the other day. I thought about loading up another 120 rounds; and then I got over it. I gave the 120 rounds to a man that has my old 300 Winchester/Weatherby. He now has my old 7mm57, 270 Winchester / Bruno.

F. Guffey
F. Guffey is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 07:35 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.05083 seconds with 8 queries