Long range load development at 100 yards.

[Erik Cortina]

308 win using N140 and Berger 185 Hybrids
100 yards

Thoughts?

Between groups 3 & 4 looks good. Any chrono numbers?

 

[savageshooter86]

no chorno available to me :-[

 

[BradY]

New 284 shehane barrel


Note 53 is actually 53.1 as I was testing in 0.3gr increments, I missed the .1 as I was focussed on the mosquito bent on sucking the life out of me rather than finishing what I was writing.

At this point Im looking at 52.5 to 53.4 but will be focusing closer on 53gr for now. Quite impressed with the size of that node!

I have a buddy in the US at the moment and hopefully he brings me back a nice new Magnetospeed V2 or V3 next week to do more testing with.

 

[savageshooter86]

Your last two groups seem like they are starting a node. Any pressure signs there? 52.8-53.1 look ok too

 

[Erik Cortina]

BY1983, 53.7 and 54.0 look good. Do you have chronograph data?

 

[BradY]

Possibly, but 52.5-53.4 the groups are pretty much smack on 30mm from my datum line, where 53.7 is 20mm and 54 is 10mm so not on the same level.

The first shots of 52.5 and 53.4 went high, I had cleaned prior to those tests and fired one fouling shot before starting the tests, yet consistently the second shot after cleaning was out of the group, with the third and rest being into the group. At least it showed consistency.

Erik- My magnetospeed is sitting on a shelf somewhere in Texas hopefully, it will travel to the southern hemisphere to me sometime next week. Until then Im chronographless.

 

[BradY]

I took another look at the sheets today. While im convinced that 52.5-53.4gr has something in it, Im going to load more and test 53.7 54 and 54.3gr again (no pressure signs) as there could well be something else up there. Might be able to borrow a magnetospeed wednesday and get an idea of velocity.

I will say the 53.4gr group I shot with my joystick hard to one side (had to lean on it) and think this really upset the gun handling.

 

[BradY]

Well you guys were definitely onto something! I loaded up 53.7, 54 and 54.3 but changed projectile from the berger 180 vld to the 180 hybrid. Ive never found much difference between the two. Obviously its not a bad thing! Still havent played with seating depth yet, nor have I got any chrony data.


On the way out I came across this angry little devil too!

 

[Brians356]

Well you guys were definitely onto something! I loaded up 53.7, 54 and 54.3 but changed projectile from the berger 180 vld to the 180 hybrid. Ive never found much difference between the two. Obviously its not a bad thing! Still havent played with seating depth yet, nor have I got any chrony data.

Forgive my intrusion, but may I ask: Are you testing at 100 yards?

 

[Erik Cortina]

Well you guys were definitely onto something! I loaded up 53.7, 54 and 54.3 but changed projectile from the berger 180 vld to the 180 hybrid. Ive never found much difference between the two. Obviously its not a bad thing! Still havent played with seating depth yet, nor have I got any chrony data.

Forgive my intrusion, but may I ask: Are you testing at 100 yards?

Have you read the thread name?
Please don't hijack this thread. If you don't agree with the process, simply don't do it and move on.

Thanks.

 

[Brians356]

Well you guys were definitely onto something! I loaded up 53.7, 54 and 54.3 but changed projectile from the berger 180 vld to the 180 hybrid. Ive never found much difference between the two. Obviously its not a bad thing! Still havent played with seating depth yet, nor have I got any chrony data.

Forgive my intrusion, but may I ask: Are you testing at 100 yards?

Have you read the thread name?
Please don't hijack this thread. If you don't agree with the process, simply don't do it and move on.

Thanks.

Thanks, that answers my question.

 

[BradY]

Yes certainly testing at 100yds. This isn't a bench gun it's all shot laying down in normal f class position. Need some more 180 hybrids before I can do seating depth.

 

[Brians356]

Yes certainly testing at 100yds. This isn't a bench gun it's all shot laying down in normal f class position. Need some more 180 hybrids before I can do seating depth.

Thanks for the drama-free answer.

 

[Erik Cortina]

Yes certainly testing at 100yds. This isn't a bench gun it's all shot laying down in normal f class position. Need some more 180 hybrids before I can do seating depth.

Thanks for the drama-free answer.

The quality of my answers depends on the quality of your questions!

This is a 100 yard load development thread, and you asked if he was shooting at 100 yards!

Anyway, enough hi-jacking already. I'll have to get this thread back on track.

 

[Erik Cortina]

Has any of you so far encountered a really good group with bad groups on each side while seating depth testing? If you had not been doing a proper detailed and incremental test, would you have went with that group?

 

[Erik Cortina]

I posted more detailed instructions on how I do my testing on page 1 of this thread. Let me know if you have any questions.

Here is the update:

Update: 9/17/14
Some of you have asked for more detailed instructions on how I do this. Here they are:
1. Find Jam by seating a bullet long on a dummy piece of brass (no primer nor powder) and apply die wax to the bullet ogive and record it's base to ogive length.
2. Chamber the round and close the bolt.
3. Snap the bolt open and measure the base to ogive measurement. If it is shorter than previous measurement, this is your jam. Do it a few times with different cases to make sure.
4. Load a known powder/primer/bullet combination. I load 4 of each powder charge in 0.5 gr. increments and seat bullets at jam - .020". I use one shot of each to get barrel fouled up and also keep an eye for max pressure at the same time. You can also use these rounds to break in a barrel if you are inclined to. If I encounter pressure on the hotter rounds, I will not shoot groups with the other loaded rounds and will pull bullets when I get back home. Do not shoot in round robin style because position and natural point of aim will be compromised.
5. Shoot 3 shot groups starting from lowest to highest. All groups are shot over a chronograph.
6. Examine target and find the place where consecutive groups line up vertically and ES is the lowest and speed increases the least from one group to the next.
7. Load to the middle of the powder node and do a seating depth test.
8. Load 3 shot groups starting from Jam - 0.005" all the way out to Jam - .040" in .003" increments.
9. When you find the seating depth test that shoots the best, load towards the longest side of the node to allow more room for throat erosion.
10. Final step is to load the new seating depth and load 5 shot groups in 0.1 gr. increments 0.5 gr. on each side of node (if pressure limits are not reached). This will cover an entire grain of powder and you will be able to pinpoint where the powder node starts and ends. In the summer, load towards the low end of the node, and do the opposite in the winter.

HAPPY SHOOTING!

 

[trailrider121]

Bingo! Thanks Erik for the very nice breakdown on how to load development at 100 yards. . I have use your method and works great. Number 8 has really surprised me with tuning bullet seating depth in .003" increments. Again, thanks for the great write up!

 

[BradY]

Has any of you so far encountered a really good group with bad groups on each side while seating depth testing? If you had not been doing a proper detailed and incremental test, would you have went with that group?

Have found one odd bad one in amongst good groups- usually operator error!

Would also like to hear your thoughts on primer testing with all of this as well. In the case of say a 6BR you have choices of BR4, CCI450, FGMM, russian primers etc. Would you be happy to use the OCW charge and seating depth then fire 10 shot groups with different primers to determine what had the least vertical spread and smallest ES and continue using that brand at long range?

 

[6BRinNZ]

Has any of you so far encountered a really good group with bad groups on each side while seating depth testing? If you had not been doing a proper detailed and incremental test, would you have went with that group?

Yes

No

The thing this thread does is create a process that allows evaluation of groups against criteria that will produce consistency, its probably the one thing that is most apparent to me. I can rock up to the range on any day and expect to shoot good groups. Previously I would settle on a good load - go back say a month later and it would be a shocker.

While bullet shortages mean that I can't test to the full extent of what you have listed (You need to stick barrel tuner in there somewhere ) I have a good level of confidence in the foundations of the load. I just can't test to find the full extent of the width of the nodes for powder, seating depth and tuner.

Season starts this weekend so I'll be able to report progress over the season as I have a 300 this weekend and 1000 in about 2 months time.

 

[Dzombo]

Hi guys

I decided to give the jump test a shot. 155.5gr Fullbore Bergers in my F-TR rifle shot prone off a Duplin bipod. What do you think, 82.77mm or a bit shorter to leave some room for error?