Rem 700 vs load dev .308

[benchracer]

I just recently started shooting my .308 @ 1000 yards at Ben Avery Shooting Facility near Phoenix. I had done a quick and dirty load development with 155 SMK Palmas just to get started. I thought I had a stable load that would work, but found out otherwise when I was all over the paper during my third practice session. When I re-checked my loads @ 200 yards, the groups had gone from about MOA to 3+ MOA.

After carefully going over my rifle and giving it a thorough cleaning, I base-lined it with a box of 175 FGMM, which confirmed that I had a problem with my loads, not my rifle or scope.

Today, I completed seating depth tests using Varget and 155 SMK Palma, 175 TMK, and Berger 185 Juggernaut bullets, generally following the methodology of the Berger Seating Depth Test.

I modified the test for the 155 Palma bullets because the bullet itself is too short to get anywhere near the lands. Because of that, I shortened the test increment from .040 to .030 and worked forward from the standard mag length of 2.8.

The Palma bullets did their best work .130 off the lands, which doesn't leave a lot of bullet shank in the case. If I were to build a rifle specifically for these bullets, I would go with a longer barrel and shorter chamber throat.

Both the 175 TMK and the 185 Jugg did their best work at .080 and .120 off the lands. The TMK shot very well and the Jugg was spectacular. What surprised me about the Jugg is that it delivered good results with 3 of the 4 seating depths tested, which seems to run contrary to the reputation Berger bullets have for being sensitive to seating depth.

Here are the results of the seating depth tests:

 

[benchracer]

The next step will be powder charge workups. I plan to stay with Varget for the 175 TMK and 185 Juggernaut. I intend to test the 155 Palma with Varget, 8208 XBR, and AR-COMP.

 

[gohring3006]

Tagging in Benchracer, I'm getting ready to start load development for my nephew's 22" Savage .308. I have some 178 grain Hornady BTHP to try, but I might consider the 185 Jugg...

 

[tbrice23]

The next step will be powder charge workups. I plan to stay with Varget for the 175 TMK and 185 Juggernaut. I intend to test the 155 Palma with Varget, 8208 XBR, and AR-COMP.

You've got some good pwders to work with, just don't forget about IMR4064. Hard to beat Varget though.

Could you do load development at 2 to 300 instead of 100?

 

[gohring3006]

You've got some good pwders to work with, just don't forget about IMR4064. Hard to beat Varget though.

Could you do load development at 2 to 300 instead of 100?

I thought about Relaoder 17 and the 175-185 grain bullets. But I have plenty of 4064, do you guys think that would be better?

 

[tbrice23]

308 winchester has so much barrel life I cant see any reason not to try it out.

When my last 308 discovered 4064 it never saw Varget again.

 

[benchracer]

You've got some good pwders to work with, just don't forget about IMR4064. Hard to beat Varget though.

Could you do load development at 2 to 300 instead of 100?

I generally do my load development @ 100 yards to take environmental effects out of the equation. When I do the powder charge workup, I use a chrono and tune the load for low SD. The part of the range at Ben Avery that is generally accessible to the public goes out to 200 yards. Once I have the charge workup done, I will shoot @ 200 to ensure my low SD loads are not producing excessive vertical spread.

I then have the option of shooting my chosen loads in the 500 yard club match held at Phoenix Rod and Gun Club, before finally taking them to the 1000 yard line at Ben Avery. In addition to practice sessions there, they have periodic Palma format matches shot @ 800, 900, and 1000 yards. Developing and verifying my final loads @ 100, 200, 500, 800, 900, and 1000 yards should tell me a lot.

I know there are a lot of shooters who advocate doing load development at long range. That has never been something that worked well for me. Past a certain point, I have found that it becomes difficult to separate environmental factors from the variables being changed during load development. I prefer to do my development at shorter ranges, verify the loads using chrono data, and confirm the effectiveness of the combination by shooting at longer distances. I have had very good results in the past using that methodology.

 

[tbrice23]

Sometimes I feel like environmental factors obscure my results also at longer ranges during load development .

But it really helps me monitor conditions. Thats half of my battle there.

 

[benchracer]

I thought about Relaoder 17 and the 175-185 grain bullets. But I have plenty of 4064, do you guys think that would be better?

I personally like RL-17 a lot. But, I have had trouble buying it in quantity. A lot of people report temp sensitivity issues with it. Depending on your application and expected conditions, RL-17 might be worth a try.

I am developing match loads, so my priorities are different than they would be if I were developing a hunting load. I have Varget in quantity, so I plan to use it. Problems with availability and lot-to-lot consistency of Varget may eventually force me to switch to something else. If I do, 4064 will be high on my list of replacements. It has an excellent reputation.

 

[benchracer]

Sometimes I feel like environmental factors obscure my results also at longer ranges during load development .

But it really helps me monitor conditions. Thats half of my battle there.

Development of my personal methodology was also heavily influenced by practical considerations. I generally have no trouble finding some place to shoot and test out to 100 yards. Access to longer ranges has typically been more sporadic and involved longer travel distances and greater time commitments for each shooting session. If I limited myself to only doing load development at long range, I would never get anything done.

 

[mobenzowner]

I have tested Varget, IMR4064, IMR4895 and always come back to IMR4064 for the .308. I still have some Varget, but I save it for my 69 grain .223 loadings.
I did have very good luck with IMR4895 with 150 grainers in the .308.

 

[MudRunner2005]

I thought about Relaoder 17 and the 175-185 grain bullets. But I have plenty of 4064, do you guys think that would be better?

Hodgdon CFE-223 is slower than Varget, so with the heavier bullets it might net you some better velocities at lower pressures. I haven't tried it, just thinking outloud. I use CFE-223 for my 6.5 Grendel. Which, looking back, seems kind of backwards...Seems like I should be using Varget in my 6.5G, and CFE-223 in my .308 Win...

I might have to do some testing...

 

[tbrice23]

Hodgdon CFE-223 is slower than Varget, so with the heavier bullets it might net you some better velocities at lower pressures. I haven't tried it, just thinking outloud. I use CFE-223 for my 6.5 Grendel. Which, looking back, seems kind of backwards...Seems like I should be using Varget in my 6.5G, and CFE-223 in my .308 Win...

I might have to do some testing...

There's one I haven't tried.

My Service Rifle Comp friends swear by it.

 

[gohring3006]

Hodgdon CFE-223 is slower than Varget, so with the heavier bullets it might net you some better velocities at lower pressures. I haven't tried it, just thinking outloud. I use CFE-223 for my 6.5 Grendel. Which, looking back, seems kind of backwards...Seems like I should be using Varget in my 6.5G, and CFE-223 in my .308 Win...

I might have to do some testing...

I have a couple of pounds of CFE 233. I might have to just give it try...