Velocity Testing Trouble

[blaserman33]

I’m starting out with 6BRA and have been trying to do velocity testing to find a load range with a decent velocity flat spot but I am not finding any. I have done it shooting singles of each charge wait, I have done it shooting 3 of each charge weight, and don’t see much of a flat spot. Most 6BRA’s end up around 30.6 or 31.1, and in one test there was a node from 30.6 to 30.8, and in a different test a node at 30.8 to 31.0. I start to get heavy bolt lift at 31.0 and real heavy at 31.1. I’m posting my numbers below in case I’m looking at it wrong so any advice is appreciated! When I shot the test with 3 shots at each charge weight I fired those for groups and 30.4, 30.6 and 30.8 had the best groups with the least vertical spread at 100yrds. I loaded up 15 at 30.6 based off my first test and had a SD of 5.7 and ES of 18, should I just call that good?

Test 1
30.2gn=2,922
30.4gn=2,940
30.6gn=2,956
30.8gn=2,958
31.0gn=2,975

Test2
30.2gn=2917, 2931, 2921
30.4gn=2943, 2949, 2954
30.5gn=2960, 2955, 2947
30.6gn=2976, 2966, 2965
30.8gn=2978, 2969, 3000
31.0gn=2986, 3010, 2997
31.1gn=3010, 3013,3010


Test 3
29.2gn=2767
29.4gn=2827
29.6gn=2864
29.8gn=2877
30.0gn=2898
30.2gn=2909
30.4gn=2936
30.6gn=2951
30.8gn=2969
31.0gn=2974

Test 1 & 2 were loaded with a tuned Chargemaster and taking what it gave me, test 3 I ran the Chargemaster .1gn light and trickled up more carefully. I also started with lower charge weights for test 3 in case my node was much lower than where I was looking but it doesn’t seem that way.

sorry for the long length!

 

[TheOfficeT-Rex]

If the load does what you need it to do for your game, I'd call it good.

You don't mention what powder/bullets, but with both N140 and 8208XBR I haven't seen any real 'flat spots.' I ended up picking a good speed and lowest SDs and moved to seating depth.

 

[blaserman33]

I’m using H4895 and Berger 105’s. I actually accidentally did another test with a different lot of powder which had higher speeds, but again, it didn’t have much of a flat spot except a little bit at 30.8 to 31.0.

I think the 30.6 load would be good enough for what I need, I was just hoping to find more of a “node” so that my load isn’t as sensitive. I guess I’m just wondering if other 6BRA users have a similar experience. I have a little bit of
RL-15 powder that I have been using for fireforming but don’t have as much so hasn’t thought much about switching powders, although my local store did have a couple 5 pounders of RL-15 the other day but expensive.

 

[Rocketmandb]

Welcome to my 6 BRA narrow node club (6BRANNC)

The narrow flat spot you have is EXACTLY where my narrow flat spot is, which is 30.6 - 30.8. Only, I get a sticky bolt at 30.8, so I don't even get a full .2gr out of it.

What barrel are you shooting? I'm assuming it's a 26", as your speed is very close to mine as well (depending on temp, I get 2940 - 2960).

Note that with your Test 3 data, it doesn't look like it's a node, but your other 4 shots show very limited difference between the two.

 

[Rocketmandb]

As an aside, when, like you, I couldn't find a clear node doing a ladder, I ended up going back to good old 5-shot groups. Here's a pic of my 300 yard groups - 30.6 (left) and 30.7 (right). The 31.1 below was from Varget testing.

 

[blaserman33]

Note that with your Test 3 data, it doesn't look like it's a node, but your other 4 shots show very limited difference between the two.

what do you mean my other 4 shots? Are you talking about the 4 shots below 30.6?

 

[Dthomas3523]

Just load 29.7 or 30.7 (whatever speed you prefer) and do seating depth to dial it in.

As long as your ES is inside your desired size at distance, you’ll be perfectly fine.

 

[Rocketmandb]

what do you mean my other 4 shots? Are you talking about the 4 shots below 30.6?

You did 5 shots for each charge weight. For 30.8, you have one that's out at 3000 fps, but that could have been a bad load, etc.

If you take that one out, for all your remaining 7 shots across 30.6 and 30.8, you get an ES of 27 and an SD of 8.4. I assume these were done on different days, different conditions - if so, that's not bad. I'd bet if you load up 10-20 at like 30.7 and go shoot/measure, you'll find the ES drops by a fair amount, and SDs go down at least a couple fps.

EDIT: I missed the last sentence in your first post where you've already tested 30.6. Without knowing your reloading process, I'd say you're in pretty good territory. What were your groups like?

 

[SporterII]

High temps of 60* ?

 

[blaserman33]

You did 5 shots for each charge weight. For 30.8, you have one that's out at 3000 fps, but that could have been a bad load, etc.

If you take that one out, for all your remaining 7 shots across 30.6 and 30.8, you get an ES of 27 and an SD of 8.4. I assume these were done on different days, different conditions - if so, that's not bad. I'd bet if you load up 10-20 at like 30.7 and go shoot/measure, you'll find the ES drops by a fair amount, and SDs go down at least a couple fps.

EDIT: I missed the last sentence in your first post where you've already tested 30.6. Without knowing your reloading process, I'd say you're in pretty good territory. What were your groups like?

That makes more sense. I thought you were talking about just Test 3, not across all 3 tests. And yes, these were shot on different days with slightly different conditions.

When I did test at 30.6 I wasn’t shooting for groups, I was shooting steel at distance, more just checking the speed and ES/SD. But it shot as expected, and when shooting for groups 30.6 and 30.8 have always done best. I think I’ll just load up some at 30.6 and 30.7 and play with seating depth.

I wish my Autothrow/Trickle V3 would show up already so I can quit the slow as Chargemaster and Trickle up method. God is it slow.

 

[blaserman33]

High temps of 60* ?

Temps were in the low 70’s. Test 1 might have been high 60’s, like 69* IIRC