Varget & .308

buskeen · July 18, 2013, 10:48 AM

Hello gents,
I am new to .308's. I shoot mostly 6.5's. To make it short I have 10 lbs of Varget with some 175 and 185 gr Berger HPBT's. Primers will be FED210M with new Lapua brass. I was wondering if anyone could get me started on a load development path for this combo. The gun is a Remington 700 and I have replaced the factory barrel with a 26" 3 groove Lilja Sendaro contour. The action is stock but has been trued by my gunsmith and I added a Jewell trigger and custom stock. I heard 45 grains was a good start?
Any help would be appreciated.
Thanks,
B

joneb · July 18, 2013, 11:42 AM

Quote:

I heard 45 grains was a good start?

I would start a 42.0gr with the 175s and 41.0gr with the 185s.

Jimro · July 18, 2013, 12:06 PM

45 is a max charge for a 175 SMK. I expect it is beyond a max charge, as the max charge for the 190 SMK is 44gr.

Data from hodgdon.com

175 GR. SIE HPBT Hodgdon Varget .308" 2.800" 42.0 2583 42,600 CUP 45.0C 2690 48,600 CUP

190 GR. HDY BTSP Hodgdon Varget .308" 2.740" 41.0 2452 46,100 CUP 44.0C 2536 49,100 CUP

Start at the starting charge. Work up in .3 gr increments until you get the accuracy you want.

Jimro

Bart B. · July 18, 2013, 01:21 PM

If you're running an OCW test, I would use 1 grain increments of charge weights as 3/10ths of a grain typically won't tell you much about two adjacent loads. They're too close together. Several adjacent loads' bullets will print on top of each other. You would have to shoot 20 to 30 shots per load to find the group center for comparison with any reasonable degree of accuracy.

Here's data using a 175-gr. Sierra 30 caliber HPMK with IMR4064 powder testing at 300 yards:

42.2 grains, 2500 fps, 26.65" drop
44.4 grains, 2600 fps, 24.65" drop
2.00" (.67 MOA) drop change for a 2.2 grain change in charge weight.

Same bullet and powder charges, but at 600 yards:
42.2 grains, 2500 fps, 137.34" drop
44.4 grains, 2600 fps, 126.12" drop
11.22" (1.87 MOA) drop change for a 2.2 grain change in charge weight.

How much drop difference does a 3/10ths grain charge weight change make at each range?

Other powders with approximately the same burn rate will have different drop differences per 3/10ths grain change in charge weight, but not much.

**Unclenick** · July 18, 2013, 01:27 PM

Buskeen,

Keep in mind that the Hodgdon data is developed in Winchester brass in a 24" barrel. Your Lapua brass is heavier (less room inside). It will take as much as 1.1 grains lower charge weight in your Lapua brass to get the same pressures Hodgdon did if your chamber and bore dimensions are identical to theirs. Chances are that they are not identical, but, that is what load workup is for.

Phil McGrath · July 18, 2013, 07:16 PM

You didn't say what type of shooting you have planned for this rifle? That would help narrow down a starting point. Are you loading from the rifles box mag or single loading? if loading from the mag this will limit the rounds COAL.

What reamer was the chamber cut with? and witch Berger 185, LRBT or Hy-brid?

A note on the 185 Berger's, there long and need too be loaded long 2.90-2.96 coal or the bullets shank intrudes into the brass and you have a hard time get enough powder into them.

Jimro · July 19, 2013, 12:45 AM

Quote:

If you're running an OCW test, I would use 1 grain increments of charge weights as 3/10ths of a grain typically won't tell you much about two adjacent loads. They're too close together. Several adjacent loads' bullets will print on top of each other. You would have to shoot 20 to 30 shots per load to find the group center for comparison with any reasonable degree of accuracy.

That's not how an OCW loadup works. The goal in the workup is to find the three shots that are most consistent across a 0.6 gr spread of powder charge (or a 1.0 if you use 0.5gr increments).

The technique isn't to load up a whole bunch at each charge range, just starting to max in predictable increments, then shoot and record the entire lot from least to most charge. The three shots that are closest together and closest in charge are the "most promising" for further development, as they showed little POI shift between three powder charge ranges.

Jimro

buskeen · July 19, 2013, 06:01 AM

Thanks guys. I understand the concept of Dan Newberry's OCW method but I don't use it. I have my own method which requires more range time but I like that part of it!
I appreciate the tips on the loads to get started.

thump_rrr · July 19, 2013, 10:00 PM

With 180gr smk's my optimum load is 42.3gr of Varget in Lapua brass and CCI BR-2 primers.
It is pushing the bullet at 2650 ft/s through a 1-10 twist 24" barrel.

July 18, 2013, 10:48 AM	#1
buskeen Junior Member Join Date: June 24, 2013 Posts: 7	Varget & .308 Hello gents, I am new to .308's. I shoot mostly 6.5's. To make it short I have 10 lbs of Varget with some 175 and 185 gr Berger HPBT's. Primers will be FED210M with new Lapua brass. I was wondering if anyone could get me started on a load development path for this combo. The gun is a Remington 700 and I have replaced the factory barrel with a 26" 3 groove Lilja Sendaro contour. The action is stock but has been trued by my gunsmith and I added a Jewell trigger and custom stock. I heard 45 grains was a good start? Any help would be appreciated. Thanks, B

July 18, 2013, 12:06 PM	#3
Jimro Senior Member Join Date: October 18, 2006 Posts: 7,097	45 is a max charge for a 175 SMK. I expect it is beyond a max charge, as the max charge for the 190 SMK is 44gr. Data from hodgdon.com 175 GR. SIE HPBT Hodgdon Varget .308" 2.800" 42.0 2583 42,600 CUP 45.0C 2690 48,600 CUP 190 GR. HDY BTSP Hodgdon Varget .308" 2.740" 41.0 2452 46,100 CUP 44.0C 2536 49,100 CUP Start at the starting charge. Work up in .3 gr increments until you get the accuracy you want. Jimro __________________ Machine guns are awesome until you have to carry one.

July 18, 2013, 01:27 PM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Buskeen, Keep in mind that the Hodgdon data is developed in Winchester brass in a 24" barrel. Your Lapua brass is heavier (less room inside). It will take as much as 1.1 grains lower charge weight in your Lapua brass to get the same pressures Hodgdon did if your chamber and bore dimensions are identical to theirs. Chances are that they are not identical, but, that is what load workup is for. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

July 19, 2013, 06:01 AM	#8
buskeen Junior Member Join Date: June 24, 2013 Posts: 7	Thanks Thanks guys. I understand the concept of Dan Newberry's OCW method but I don't use it. I have my own method which requires more range time but I like that part of it! I appreciate the tips on the loads to get started.

July 18, 2013, 01:21 PM	#4
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	If you're running an OCW test, I would use 1 grain increments of charge weights as 3/10ths of a grain typically won't tell you much about two adjacent loads. They're too close together. Several adjacent loads' bullets will print on top of each other. You would have to shoot 20 to 30 shots per load to find the group center for comparison with any reasonable degree of accuracy. Here's data using a 175-gr. Sierra 30 caliber HPMK with IMR4064 powder testing at 300 yards: 42.2 grains, 2500 fps, 26.65" drop 44.4 grains, 2600 fps, 24.65" drop 2.00" (.67 MOA) drop change for a 2.2 grain change in charge weight. Same bullet and powder charges, but at 600 yards: 42.2 grains, 2500 fps, 137.34" drop 44.4 grains, 2600 fps, 126.12" drop 11.22" (1.87 MOA) drop change for a 2.2 grain change in charge weight. How much drop difference does a 3/10ths grain charge weight change make at each range? Other powders with approximately the same burn rate will have different drop differences per 3/10ths grain change in charge weight, but not much.

July 18, 2013, 07:16 PM	#6
Phil McGrath Member Join Date: July 14, 2013 Posts: 24	You didn't say what type of shooting you have planned for this rifle? That would help narrow down a starting point. Are you loading from the rifles box mag or single loading? if loading from the mag this will limit the rounds COAL. What reamer was the chamber cut with? and witch Berger 185, LRBT or Hy-brid? A note on the 185 Berger's, there long and need too be loaded long 2.90-2.96 coal or the bullets shank intrudes into the brass and you have a hard time get enough powder into them.

July 19, 2013, 10:00 PM	#9
thump_rrr Senior Member Join Date: October 12, 2010 Posts: 403	With 180gr smk's my optimum load is 42.3gr of Varget in Lapua brass and CCI BR-2 primers. It is pushing the bullet at 2650 ft/s through a 1-10 twist 24" barrel.