Testing 308 Loads at 100 Good Enough OR ?

[GNERGY]

When I went to work up loads for my long range 338 Ultra mag I was told to test loads at 300 yds because of the heavier bullets didn't stabilize till then, and that turned out to be true.
I have been testing some loads for my 308 at 300 yds but with all the wind and the mirage here in Az. I am starting to wonder if the elements aren't giving me grouping problems. Wind was between 4 to 9 mph today. When I had the other 308 barrel on here it was cooler temps out so testing at 300 yds was no problem.
Should I be testing at 100 yds and then expect what groups good there to be accurate at 500. How do you guys that shoot F class or long range work up your loads. I am getting tired of wasting bullets and powder.
What do you guys do.
Tarey

 

[rabbit fingers]

Try this. http://optimalchargeweight.embarqspace.com/ocw-instructions/4529817134. works for me.

 

[necchi]

Yup, the OCW really helps narrow down the variables quickly.
Once you have it near the optimal at 100 you can move out to 300 with confidence and work the variables in a smaller range to dial it in where you want it.

 

[Leaddog]

A .308 is fairly easy to get a good load. What bullet, powder, case, etc. are you using? What barrel and twist?

I do my preliminary development at 300 and finish at 600. Generally, a load that shoots at 300 should be good at 600, but not always. For me, 100 yards does not give me the feedback I am looking for.

The first thing you should know is that you aren't shooting groups. You should be shooting to the same point of aim and looking for the load that will give you minimal vertical dispersion. Shoot 5 rounds of each charge, not 3. Pick your load development days when conditions are best. Early morning or early evening when conditions are stable. Shoot from a bench. Use a Chrono.

Let us know what your components are and we'll pick up the conversation.

 

[GNERGY]

Charlie,
I shoot at 7 am a couple times a week but the weather is a crap shoot.
My rifle is a
Rem 700 SA Devcon bedded in a Bobby Hart LRT laminated stock.
It has a Shilen 2 oz trigger,
EGW 20 moa base with Burris XTR rings holding a Burris 6x-24x50 Black Diamond
The barrel is a Rem 5R stainless 11 1/4 twist. I cut 2 inches off of the barrel before I installed it on this action so it is now 22 inches plus a brake I made and installed. It shot it's best groups with 175 VLD's and 39.5 gr N-540 at half inch at 300 yds. The guy I bought it from is older and got tired of the recoil and rebarreled to a 6.5x47 lapua
I was trying to get it to shoot the 168gr Sierras because they are cheaper.
The original barrel on this action was a 20 SPS Tactical and it shot 168 VLD's into an inch at 300 and into 3 at 500 meters. with 44gr 8208.
I shoot off a bench with a bipod and rear bag and it is really solid. I have tried Varget, 8208, and AA 2520 and have some loaded with H 4895. I am using Hornady match brass neck sized to give me .003 neck tension. The brass necks were really inconsistant so I reamed all the necks to .305 after sizing. I am using Fed match primers. I was seating then .010 off the lands and the groups that looked promising I tried seating them from touching to .100 off the lands.

I still have 3 boxes of 168 gr Sierras to test and then I will have to go with the Bergers.
Tarey
Hope that explains it all.

 

[markm87]

Ahhh... the high power range. That's our summer home.

 

[Keith Glasscock]

I test at 300 yards regardless of conditions. The attached photo shows a "group" I shot last week while proofing the barrel I had spun back on. Conditions at the time were winds from dead calm to 5 mph from 3 o-clock. Like Charlie, I make no attempt to compensate for the wind while proofing a load or barrel. I use one point of hold and let them fly.

By calculating the aerodynamic jump, the 5 mph difference makes a 0.55" difference in vertical. By removing that from the no wind shot (low right) I get a total vertical of about .7" (The center 3 shots).

Needless to say, I need a little more tuning on this load, but it is good enough for F-class (barely).

Small groups are nice, but knowing what the bullets will do when the wind switches is priceless.

Hope this helps,

 

[Leaddog]

Tarey - If your rifle shoots the 175 VLD's to a half inch at 300, you are there. Sell your 168's and forget about them. You already have your load.

 

[amlevin]

Ahhh... the high power range. That's our summer home.

Fair weather shooter I go there every week, rain, shine, snow, wind, whatever. Range is only closed three days per year. I find that it's less crowded when I have to wear the "winter woolies". Go figure 8)

 

[GNERGY]

I still want to get the Sierras to shoot because they are cheaper and I have a lot of them. I went out friday and the wind was going from 4 to 9 mph but it was from behind me, so I decided to just test at 100 yds. Using H 4895 and the 168 Sierras seated .020 off the lands 44grs shot 3 in .3 and 44.5 grs went into .5 and when I put the 2 targets over the top of each other all 6 went into the 2nd targets 1/2 inch. ;D So I loaded some up at different seating depth so see if I can improve on those groups. Then I'll try them at 300yds and then 500.
I received my Berger 168 gr Hybrids from Powder Valley and am going to load some of those for testing on monday if time permits.
Tarey

 

[readyon3]

I'd give reloader 15 a try, it's performed the best in my 308. How far are you planning to shoot those 168's? I switched to 175's after running into trouble with the 168's anything farther than 700 yards.

 

[dtucker]

I like your bipod, who makes it?

Charlie,
I shoot at 7 am a couple times a week but the weather is a crap shoot.
My rifle is a
Rem 700 SA Devcon bedded in a Bobby Hart LRT laminated stock.
It has a Shilen 2 oz trigger,
EGW 20 moa base with Burris XTR rings holding a Burris 6x-24x50 Black Diamond
The barrel is a Rem 5R stainless 11 1/4 twist. I cut 2 inches off of the barrel before I installed it on this action so it is now 22 inches plus a brake I made and installed. It shot it's best groups with 175 VLD's and 39.5 gr N-540 at half inch at 300 yds. The guy I bought it from is older and got tired of the recoil and rebarreled to a 6.5x47 lapua
I was trying to get it to shoot the 168gr Sierras because they are cheaper.
The original barrel on this action was a 20 SPS Tactical and it shot 168 VLD's into an inch at 300 and into 3 at 500 meters. with 44gr 8208.
I shoot off a bench with a bipod and rear bag and it is really solid. I have tried Varget, 8208, and AA 2520 and have some loaded with H 4895. I am using Hornady match brass neck sized to give me .003 neck tension. The brass necks were really inconsistant so I reamed all the necks to .305 after sizing. I am using Fed match primers. I was seating then .010 off the lands and the groups that looked promising I tried seating them from touching to .100 off the lands.

I still have 3 boxes of 168 gr Sierras to test and then I will have to go with the Bergers.
Tarey
Hope that explains it all.

 

[GNERGY]

I only plan on shooting the 168's to 500 yds.
Tha bipod I made myself and have had soo many people ask me about it I am making some more, just a little smaller than that. I made that one out of material I had laying around and it weighs 7 lbs. I just finished a light weight prototype that weighs 2lbs 14 ounces for guys that shoot F class. I have to go to work right now but will post a pic in the morning. I have some parts in different stages of machining and hope to get them assembled in a couple weeks. Way cheaper than the other bipods on the market. The only problem is I make all the parts myself so it takes some time.
Pics in the AM
Tarey

 

[amlevin]

GNERGY---

It looks stout enough to double as a jack for changing a flat tire 8)

 

[GNERGY]

I can stand on them and I weigh 206
Here is the original and the light weight prototype for F Class shooters.

I originally just built one for testing loads because they are so sturdy, but a couple of the guys at the range wanted me to make them one. And then a guy wanted to see if I could make one less then 4 lbs for him to shoot F class with. I also have a middle size that is good for the shooter that doesn't need to make weight and just has fun with it like me. I sold the only one of those that I have finished at this time.
So this is the first light weight one I did so far and it weighs 2 lbs. 14 ozs.
I was thinking of making the adjusting handle in the middle of the adjusting rod so it is easier to get to if you are shooting laying prone.

I only have a Bridgeport to make them on so it takes a while. I didn't want to post about them till I have a couple made to sell. I use stainless hardware on them and thay have a brushed aluminum finish. I am going to ask $150. plus shipping. If you only knew how long it takes to machine the parts you would know I couldn't do this for a living. I do it because I like it and they are one of a kind made in the good old USA. Hope that doesn't sound too korny.
Thanks
Tarey
If you are interested in one shoot me a PM and I can put your name on a list. I have 1 name on the list so far and enough material in the works to complete 4 middle size ones and 4 light weight ones. You have to be patient, I'm just a guy doing this in his spare time.