I was doing some load testing the other day, and didn't get a real definitive answer as to which powder charge my rifle liked best so I'm looking for some advise where to go next. My rifle is a Remington 700pss 26in heavy barrel free floated, I Shooting off sand bags at 100 yards. I let the barrel cool for a few miniutes between shots. The load was 168SMK over Varget, win LR primers, R-P neck sized brass seated to 2.800in. I started at 42.0grns working up in 1grn increments to a max load of 46grns. All groups where 5 shot, unless noted flyer. 42grn load grouped to what I thought was pretty good for a starting load at .411 all touching but stringing horizontally. 43grn had a shot that I pulled but 4 shots grouped into .494 with some vertical stringing. 44grns was generally a pretty good group with one shot just a hair outside the main group. All 5 shots together grouped .486. 45grns might have better potential with 3 shots into basically one hole but the other two shots opened the group up to .402. Now 46grns was a bit strange 3shots went into .167 the other two shots where also on top of each other but opened the total group up to 1.096. So I'm not totally sure we're to go from here. I also have some 168grn Berger hybrid hunters I want to try but at $50+ a box I don't want to waste a box chasing my tail. Thanks!
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308win load help.
- Thread starter b money
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Repeat the same loads several times. You have have 1/2 inch 5 shot groups if I read correctly. I would pick targets apart after you put a few sessions together. My 5 shot groups always open up a bit more. Don't chase the tail yet. "If" you want to tweak anything, try switching primers.
First off, I think 46 grains of Varget under a 168 in a .308 case is a bit too hot. Unless your bullets are under size and the bore's over size.
Your tests have demonstrated what I've observed over the years shooting few-shot groups; 5 or less shots in each. In my opinion, yours are all statistically equal. A few grains spread in charge weights for 168's in all the .308 Win barrels I've worn out with Sierra's 168's show insignificant difference in accuracy through 200 yards with several makes of powders, primers and cases. Doesn't matter if each load shoots to a slightly different point of impact relative to the aiming point; that's normal and adjusting the sight will fix that. And the bullet's jump distance to the rifling increased about .070 inch from when the barrel was new to some 3000 rounds later as the throat advanced from wear and all rounds had the same OAL length.
If your marksmanship qualities are good enough to shoot different loads into 1/2 MOA or thereabouts at 100 yards hand holding a bag-rested rifle to your shoulder, quit testing loads and pick one at random and start shooting for fun instead of testing.
Should someone shoot several dozen 5-shot groups with any load, they'll typically have a 3X to 4X extreme spread from the smallest to the largest group. And the smallest group is rarely the first group shot.
You're effectively rolling several pairs of dice when shooting groups. Each pair will average 7 (zero in their spread) and a few boxcars (12's, maximum spread) as well as a few snake eyes (2's, minimum spread). Each pair represents the variables in each of the three parts of the shooting system; you, your rifle and your ammo. Smallest groups happen when all the variables are at their minimum, or cancel each other out. Biggest ones happen when they all add up in one direction. And humans holding onto rifles typically have the variables with the biggest MOA values in pointing the barrel at the same place from shot to shot.
Dozens or hundreds, if not thousands of rifle ammo testers will disagree with the above. So be it.
For those wanting to see how 5-shot (or 10-shot) group sizes vary across several, go to this web site then download each match's file, open it and see how the top ten's group sizes varied across several of them. As well as how they varied at different ranges.
http://www.benchrest.com/showthread.php?93618-2015-NBRSA-Nationals-Complete-Results
Your tests have demonstrated what I've observed over the years shooting few-shot groups; 5 or less shots in each. In my opinion, yours are all statistically equal. A few grains spread in charge weights for 168's in all the .308 Win barrels I've worn out with Sierra's 168's show insignificant difference in accuracy through 200 yards with several makes of powders, primers and cases. Doesn't matter if each load shoots to a slightly different point of impact relative to the aiming point; that's normal and adjusting the sight will fix that. And the bullet's jump distance to the rifling increased about .070 inch from when the barrel was new to some 3000 rounds later as the throat advanced from wear and all rounds had the same OAL length.
If your marksmanship qualities are good enough to shoot different loads into 1/2 MOA or thereabouts at 100 yards hand holding a bag-rested rifle to your shoulder, quit testing loads and pick one at random and start shooting for fun instead of testing.
Should someone shoot several dozen 5-shot groups with any load, they'll typically have a 3X to 4X extreme spread from the smallest to the largest group. And the smallest group is rarely the first group shot.
You're effectively rolling several pairs of dice when shooting groups. Each pair will average 7 (zero in their spread) and a few boxcars (12's, maximum spread) as well as a few snake eyes (2's, minimum spread). Each pair represents the variables in each of the three parts of the shooting system; you, your rifle and your ammo. Smallest groups happen when all the variables are at their minimum, or cancel each other out. Biggest ones happen when they all add up in one direction. And humans holding onto rifles typically have the variables with the biggest MOA values in pointing the barrel at the same place from shot to shot.
Dozens or hundreds, if not thousands of rifle ammo testers will disagree with the above. So be it.
For those wanting to see how 5-shot (or 10-shot) group sizes vary across several, go to this web site then download each match's file, open it and see how the top ten's group sizes varied across several of them. As well as how they varied at different ranges.
http://www.benchrest.com/showthread.php?93618-2015-NBRSA-Nationals-Complete-Results
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I shoot 44gr varget with 168GR MK. I also shoot the 168 berger hybrid hunter with the same load. It is a hunting load so I wanted mag length. found my best seating depth for the bergers at 2.77.
What kind of pressure signs were you finding with 46gr? Was the bolt sticky?
personally I wouldn't do my load testing going up a full grain at a time. Fine tune it with loads 0.3 grains at a time maybe a 0.5 grain at a time.
then play with your seating depth. Obviously you are going mag length for a reason. Most people find that their rifles shoot better with the bullet closer to the lands but if mag length Is what you want then try a series with the seating depth 0.01 deeper each time.
Ok thanks for the info so far. It sounds like I will continue loading a few and get more trigger time. My range is 32 miles one way and it's always packed on the weekends so that along with the fact that I don't get to the range much(maybe 3 times a summer) is why I loaded in 1 grain increments. And as far as 46grns, it is the published max load for 168SMKs and Varget at a COAL of 2.800 as according to Hodgdon's annual load manual. And lyman was at 45.7grns. For pressure there was nothing really concerning to report, 2 of the fired primers had a tiny ripple in them(like the start of cratering) but when I say tiny I had to really look for it. So I will let 46grns lie where it is and probably focus on 44-45ish. And just try to get out and shoot more. Also I do have CCI 200 LR primers to try. I've been looking for match primers but they are no where to be found.
My rifle likes 44.5gr of varget(2208) with the 168 gr Berger VLD hunting lapua cases and br2 OAL 74mm. Personally I like to shoot 3 shot groups(always seem to get some pilot error with 5 shots) I started my loads at 42.5 and went to 45.5 at 0.5gr increments. Group size were 0.6 down to 0.2 and then appear to be heading back toward 0.5 at 45.5 gr. After re-testing my 44.5 gr load with 5 groups they were all between just under 0.2 and 0.4 moa. My rifle is a Wby Mark V trr it has been bedded and has a timney trigger fitted.
alaska
Well-Known Member
Suggest duplicate the Fed Match load
175gr MK
IMR 4064 @ 41.8
Fed 210 M primer
FC military Brass
175gr MK
IMR 4064 @ 41.8
Fed 210 M primer
FC military Brass
alaska
Well-Known Member
175gr MK
IMR 4064 @ 41.8
Fed 210 M primer
FC military Brass
2.80"
Another good load 45.0 of Varget
bR 2 primers in WW brass with the 175 MK
IMR 4064 @ 41.8
Fed 210 M primer
FC military Brass
2.80"
Another good load 45.0 of Varget
bR 2 primers in WW brass with the 175 MK
Jerry M
Well-Known Member
I suggest that you try another primer than the Winchester.
Rick Richard
Well-Known Member
My Rem 5 R loves 4064 and 168 AMAX.
wackinandstackin243
Well-Known Member
- Joined
- Dec 11, 2012
- Messages
- 208
I found varget to be overrated in my 308. I have found switching powder all together is more effective than tweeking the charge of the same powder.
I haven't found anything better than Federal Gold medal match factory which supposedly uses 4064. I don't like the Sierras for hunting so I plan on duplicating powder charge and base to ogive length with an Amax. 42.8 is supposedly the charge for 168s
I haven't found anything better than Federal Gold medal match factory which supposedly uses 4064. I don't like the Sierras for hunting so I plan on duplicating powder charge and base to ogive length with an Amax. 42.8 is supposedly the charge for 168s
MudRunner2005
Well-Known Member
Overrated...Can you elaborate on that?
Mine shoots 1/4 minute groups at 100 using 168-210gr Bergers, Varget, Fed 210M primers and Lapua brass...While achieving good velocities.
