ES Flyers?

[Brendan]

Little bit of a long ramble here: I've been reloading for my 300 WM, and I'm running into a couple things I wanted to get an opinion on. SIG/ADG Brass, Berger 215, H1000, Fed 215M. Barrel is an HCA Carbon. Currently about 160 rounds through the barrel.

First, every time I've been out to the range my first, and maybe my second shot are slower than the rest I shoot that day (at that charge weight anyways). This is on a cold, fouled barrel, not touched since the previous range session. (Yesterday, my first 4 shots were 2834, 2886, 2884, 2894)

Second, I've been working in on some low-ES loads, and it seems like I'll randomly get an ES flyer that's 20-30 FPS outside the group. Taking an ES of around 15 and and blowing it out to 45-50. Let's say one fast shot out out of 5 with 4 in a nice tight ES band. Not sure I can pin it on the hottest barrel or heat soak either, I've had the last shot in a string be fine and a previous one fast. (An example from yesterday: 2911, 2947, 2907, 2912, 2930 - Different charge weight from before)

I am shooting off a bipod on a bench. So far have been using my Spartan, but may switch to something with less flex in it. Has anyone found bipod load and shoulder pressure to make a difference here?

I am not letting the barrel cool all the way back to ambient temp. I've tried shoot 3 in sequence, then cool for 15 minutes, I've tried 2-5 minutes between shots with the loaded round spending minimal time in the chamber before shots to avoid heat soak. Using a barrel cooler.

Reloading process - Charge weights are dead on to the 100th of a grain on an FX120i. Brass is 1X fired, annealed, neck sized down and then expander mandrel to set final size (Need to play around more with neck tension, .306 vs .307 mandrel). I did wet tumble the entire batch, light coat of sizing wax on the outside and inside of the neck (Q-tip) and then individually cleaned after sizing with a rag, and a clean Q-Tip for inside of the neck. Did not re-tumble, wax contamination a possibility? Brass trimmed, chamfered, deburred... Necks get a dip in dry-lube before seating.

Let me know if you have any thoughts. May just need to keep testing.

 

[tdhanses]

I just finished developing my load for my 300wsm but I’m using Bertram brass, RL26, CCI BR2 primers and the 215’s. I had a few loads that did the same thing, I’d get excited then a random one would destroy my ES. I would shoot 5 shots then let my barrel cool for 10 or 15 mins and it was 90* out In my last testing.

I‘m thinking you may just need to keep playing with either the charge or seating depth, maybe a primer change as this is what I did and have been able to get it to a very consistent ES and SD.

 

[Rob5589]

Seating depth, neck tension. I have found lower es/sd with CCI primers vs Federal.

 

[Brendan]

I've been mulling over the primer change too. I have Federal 210 GM's, but no CCI right now.

Some more data: No cleaning, no bore snakes, no nothing. Probably been 75 rounds since cleaned. Chrono is a Labradar. Currently testing between 75 and 76 grains of H1000 - long throated 300 WM. My COAL with the Berger 215 is ~3.76".

I know I'll get to a point and just say screw it - won't make a difference in my hunting ranges this year. But, want to do what I can to get as reliable a low-ES load as possible before moving on. After I get through the next 75 rounds, I may try no tumble, no expander mandrel, just neck size and not clean inside of the neck other than a quick brush.

My two most promising yesterday. Makes me think I may need to expand around these and test some more.

75.6 grains: 2911, 2947, 2907, 2912, 2930. Avg = 2921, ES = 40, SD = 16.8
75.9 grains: 2910, 2939, 2945, 2934, 2926. Avg = 2931, ES = 35, SD = 13.6

 

[tdhanses]

I will say I’m pretty impressed with my 300wsm slinging the 215’s at 2963ft/s, I would think the 300wm would be 100ft/s faster.

I’m also .045 off the lands but maybe try adjusting your seating depth first.

 

[wind gypsy]

I will say I’m pretty impressed with my 300wsm slinging the 215’s at 2963ft/s, I would think the 300wm would be 100ft/s faster.

Not with RL26 in the WSM and H1000 in the WM at comparable pressures at least. If he was using RL26 or N570 in the WM he could be getting 100 FPS more at comparable pressures.

 

[Djacker]

Following. Ive had the same issue with my new 7 saum.

 

[rayporter]

clean or not i have found the first shot to be a lower velocity many times.

 

[Brendan]

I will say I’m pretty impressed with my 300wsm slinging the 215’s at 2963ft/s, I would think the 300wm would be 100ft/s faster.

I’m also .045 off the lands but maybe try adjusting your seating depth first.

I haven't pushed it yet, and haven't tried anything but H1000. Haven't had any definitive pressure signs, but at the same time, if I find a node, I don't have any real need to push it faster. Not like 2950 vs 3050 will matter...

I did do seating depth tests, but only at one charge weight. Didn't really give me much to write home about in terms of ES, definite impact on group size though. I am going to circle back to it. I've tested .010 to .050, and and running tests now at .020.

 

[tdot]

You have a very similar loading process to what I'm doing, and sometimes I will have those weird random hi/low velocity rounds that throw off my ES, on some loads. I can't say I've found a single answer that always works, but the following have all worked to lower my ES atleast once.

- remove all lube from case/neck prior to seating bullet;
- decrease neck tension;
- change primers;
- double check brass dimensions and confirm that all pieces fit your chamber;


Most of my load/gun combos shoot slow on the 1st round. For my hunting rounds, I'll take a load that has an average ES, including that first round, vs a crazy low ES recipe, that would look much worse if I included that first round. I generally try to shoot the animal once, so that first round is the most important to me.

 

[Brendan]

Ok, picked up some CCI 250 and BR2 primers at lunch today, so have those to work with. Am going to try lighter neck tension, CCI 250 for my next round.

If those don't help, I'll have at least 50 rounds of brass that are shot 2X and should fit the chamber pretty well and can be sized the same and have the shoulder bumped back.

I'm using a Redding Competition 3-die set, so can neck and body size separately and probably good to mention I did not size the body or the shoulder after the first firing, was waiting to test until after the second firing (The 2x fired cases I tested still chamber, definitely getting a stiffer bolt close now though)

 

[bruceleroy]

How is the jump in ES affecting your groups at distance (beyond 300)? And, have you attempted the same testing with factory ammo? If so, does it do this as well?

 

[Brendan]

How is the jump in ES affecting your groups at distance (beyond 300)? And, have you attempted the same testing with factory ammo? If so, does it do this as well?

ES will affect your vertical dispersion. As you get to longer and longer range it's more important than your group size. If you want to see the impact - just plug into a ballistic calculator and and vary your speed. With an ES of 50 calculated from a larger number of shots, vary speed by plus/minus 25, and look at the drops for your range and bullet. I have tested factory ammo and it's worse.

Ballistics Calculator

The Berger Bullets Ballistics Calculator uses BCs (G1 or G7) to calculate trajectory and account for any external factors that may effect bullet performance

bergerbullets.com

Won't make a difference for my hunting ranges, but I can shoot steel out to 1200 yards and I'd rather get to a consistent low ES than not. If I get close to the season, I'll just pick my best load and run with it.

 

[bruceleroy]

I understand the idea of the vertical dispersion as theory and practical applications apply. I had a load with 308 that did that but made no difference at 600 yards. I was very puzzled. I decided to stop chasing the number because the result was adequate. Now with my 6.5 Grendel I have no margin for error. I tested with loads that shot a bit faster and it translated to ridiculous differences at long ranges past 800.
I wish I had a remedy. Mine corrected itself over time but it was nothing I did.

 

[Brendan]

I understand the idea of the vertical dispersion as theory and practical applications apply. I had a load with 308 that did that but made no difference at 600 yards. I was very puzzled. I decided to stop chasing the number because the result was adequate. Now with my 6.5 Grendel I have no margin for error. I tested with loads that shot a bit faster and it translated to ridiculous differences at long ranges past 800.
I wish I had a remedy. Mine corrected itself over time but it was nothing I did.

This definitely doesn't make a difference for my hunting ranges. With my setup a 50 ES is less than 2"of dispersion at 500 yards, but 10" at 1000, and 17" at 1200. Really, I just feel like I should be able to get it more consistent before moving on.

I've got some ideas I'm going to try out, maybe on Wednesday night, but possibly not until next weekend.

 

[bruceleroy]

Keep us posted please. I find these problems very interesting.

 

[Cahunter805]

Brendan
What are is your neck thickness? How much neck tension are you running? I’ve found about .003-.004 to be pretty ideal.
Your powder charge seems to be pretty good and is a very common charge with H1000. I would also recommend a primer test and seating depth test with your chosen powder charge.

 

[Brendan]

Brendan
What are is your neck thickness? How much neck tension are you running? I’ve found about .003-.004 to be pretty ideal.
Your powder charge seems to be pretty good and is a very common charge with H1000. I would also recommend a primer test and seating depth test with your chosen powder charge.

I forget neck thickness, but I've been sizing down .003 or .004, then using either a turning mandrel (.306") or an expander mandrel (.307") to expand out slightly from the inside of the neck. Those should give .002 - .0025" and .001 - .0015" for neck tension with a little springback. Funny, some people say use less, some people say use more... I can go back to not using the mandrel and try different neck tensions, which I will do in combination with 2x fired brass that has been fully sized with shoulders bumped if primers don't help.

I've tried seating depth tests (.01 off to .05 off) but only for one powder charge, and 4 rounds for each depth. Picked the best and went back to powder charge testing.

Have a lot of stuff to try, going to start with cleaning then re-foul barrel, and then try new primers. And, will try at a lower neck tension first before working up from there.

 

[live2huntelk]

Have you pm'ed Broz on here or long range only? As you already know, he is an authority on 300WM with 215 Bergers. I have experienced the same ES issues as you a few years back and never did figure out what was causing the variation. I am very interested in what you find out.....I am very detailed and what to understand and control as many of the variables as possible to become a better shooter.

I have a Manetospeed and always wondered how repeatable chronograph was....could not think of a way to validate the gage repeatability and reproducibility.

 

[Brendan]

Have you pm'ed Broz on here or long range only? As you already know, he is an authority on 300WM with 215 Bergers. I have experienced the same ES issues as you a few years back and never did figure out what was causing the variation. I am very interested in what you find out.....I am very detailed and what to understand and control as many of the variables as possible to become a better shooter.

I have a Manetospeed and always wondered how repeatable chronograph was....could not think of a way to validate the gage repeatability and reproducibility.

I've got a thread up on LRO too, but I think what it boils down to is I have a lot of things to try out.

Magnetospeed and Labradar are reported to be the two best and repeatable to my knowledge anyways. Although, there was a comment about the brake on the rifle potentially interfering with labradar accuracy...

Actually what has me the most curious is why the first and sometimes second cold bore (fouled barrel) shots are slow... Seems to me like those are the important ones, and especially for anyone who hunts and shoots ELR, even though that's not me.