Reloading 6.5 Creedmoor

[Ernest T]

You will be OK with the fired brass you already sent hornady.
I wouldn't send in a lapua too.
You will be close enough as you are really looking for a starting point for your best seating depth.

Okay, thanks

[Ernest T]

I actually found Lapua SRP brass in 6.5 CM and ordered 100! Getting closer to being able to reload. Of course, now I'll have to send the Lapua brass to Hornady to make another modified case for the headspace gauge. It'll be nice to have a choice of reloading with small or large rifle primers.

The brass arrived today, talk about quick shipping.

[Ernest T]

It turns out the throat in my gun is very generous, for lack of a better word. Its so long that any Hornady 140 ELD Match bullet seated to the lands won't fit in the magazine. Instead of working back from the lands, I decided to start at magazine length and work my way back while also working my way up the load chart. I didn't get any good groups with lower powder loads or longer cartridges. Things got interesting at 39.5 grains of RL-16 and lengths less than 2.178 CBTO. The distance to the lands for that bullet is 2.264 so I'm a minimum of .086" off the lands if I did the math right.

Except for the flyer, this was the best group.

https://photos.smugmug.com/Firearms/i-CKkHmJJ/0/3cffabd6/L/Target%201-L.jpg

This one was CBTO 2.178.

https://photos.smugmug.com/Firearms/i-S2k2GcT/0/546a4453/L/Target%202-L.jpg

I changed the CBTO by .015 with each load, so I have a lot of area to explore between groups now that I know the approximate CBTO length and load that works. The best group was 3/4", but I had a few like the one above that were smaller except for one flyer. I also found out that I have enough concentration to shoot about 40 rounds before my ability wanes!

[celltech]

Did you try anything above 39.5...that seems like a light load. I would think you have room up to ~42gr. With the SRP brass and the OEM firing pin dimensions you will likely start cratering/blanking primers before you see any stress on the brass.

[Ernest T]

Did you try anything above 39.5...that seems like a light load. I would think you have room up to ~42gr. With the SRP brass and the OEM firing pin dimensions you will likely start cratering/blanking primers before you see any stress on the brass.

I made it to 40.4 grains before quitting. I had another load with me, 41.2 grains, but didn't think I wanted to shoot 20 more rounds that day. I contemplated loading the last load of 42.1 grains, but I've backed off the max length of the cartridge quite a bit at 2.163 CBTO and didn't want to take a chance with a max load. There's a lot of bullet in the case with the 140 ELD match.

[Dave Hoback]

Why such a large jump? Why not load longer? Gain case room, lower chambers to boot. After all, it was designed to run long.

[Ernest T]

Why such a large jump? Why not load longer? Gain case room, lower chambers to boot. After all, it was designed to run long.

I want to use the magazine. The throat is so long that loaded to the lands, the bullet is considerably longer than 2.900".

[Dave Hoback]

Wall, sure… but don’t you currently have them considerably shorter than 2.900”? I load 260 & use Magpul AICS mags. I can load aprox 2.850” in those. At some point in the future I’ll be using the Metal mags which allow 2.960”. Which mag are you using, and what is max length it will accept?

[Ernest T]

Wall, sure… but don’t you currently have them considerably shorter than 2.900”? I load 260 & use Magpul AICS mags. I can load aprox 2.850” in those. At some point in the future I’ll be using the Metal mags which allow 2.960”. Which mag are you using, and what is max length it will accept?

It's an AICS 308 mag with a 2.850" opening. If I remove the binder plate its right at 2.920, but that's longer than the distance to the feed ramp so I'd have to notch it to use bullets that long. I've been looking for a bullet jump that the gun likes that will fit in my mag with the 140 ELD match bullets. My experience so far seems to mirror this article.

https://precisionrifleblog.com/2020/04/28/bullet-jump-research-and-load-development-tips/

[CFJunkie]

Sounds like you have a plastic mag for your 6.5mm CM.
I initially had a plastic AICS mag that would only support a max OAL that was in the range of your mag.
I bought a metal mag that allowed a 2.895 OAL.
That got my reloads into a jump range that improved the accuracy.

Now that my 6.5mm CM has 4,000 rounds down the tube and the chamber has eroded enough that I have to load out past what the mag will allow for my heavier match bullets, I have to single load them. As long as I can keep in the same jump range, the accuracy hasn't suffered, even though most would claim the barrel should be shot out.

[Robinhood]

> 2.900 for a Savage short action magazine. that makes the Dark Eagle look good. It has been said that your loads are at the bottom end and you might try something near 41.5 H4350. Adjust your seating depth.

[Ernest T]

I'm still working toward higher loads, but the groups have improved with more powder and shorter cartridges. Even at 2.163 CBTO, the COAL is just short of the SAAMI spec for 6.5 CM and the 140 ELD Match bullets.

[CFJunkie]

My best results are with a jump between 10 to 19 thousandths.
There were some much longer jumps that produced accuracy almost as good, but the best results were in the 10 to 19 thousandths range.

Unless you're measuring every group for every load, and are shooting multiple groups with each load, you'll have a hard time finding a difference.

[Ernest T]

My best results are with a jump between 10 to 19 thousandths.
There were some much longer jumps that produced accuracy almost as good, but the best results were in the 10 to 19 thousandths range.

Unless you're measuring every group for every load, and are shooting multiple groups with each load, you'll have a hard time finding a difference.

I am.

[Robinhood]

Have you thought about being consistent with 2.800 and finding the load. Then work the CBTO to fine tune?

[Ernest T]

Have you thought about being consistent with 2.800 and finding the load. Then work the CBTO to fine tune?

No reason except I wanted to see if different loads performed differently at different lengths.

[charlie b]

Yep, they do :)

I usually get a decent powder charge first. Then explore seat depth. Then might tweak the powder again, see if 0.1 or 0.2 gn makes a difference. Usually it does not unless the seat depth changed a lot.

[Ernest T]

Yep, they do :)

I usually get a decent powder charge first. Then explore seat depth. Then might tweak the powder again, see if 0.1 or 0.2 gn makes a difference. Usually it does not unless the seat depth changed a lot.

I think I went about it the way I did because my main issue was COAL vs CB to the lands. I probably could have saved time and powder doing it your way. I learned a lot and got some practice in so it wasn't wasted.

[charlie b]

And, as long as you kept the records, you still have good info.

I'd probably start over with the Criterion barrel. Did you buy it new or was it on the gun when you bought it? FWIW it looks like a thin profile so no more than 3 rounds before letting it cool. If the first series does not show improvement I'd make sure all the copper is out of it. Maybe even clean between strings.

[Ernest T]

And, as long as you kept the records, you still have good info.

I'd probably start over with the Criterion barrel. Did you buy it new or was it on the gun when you bought it? FWIW it looks like a thin profile so no more than 3 rounds before letting it cool. If the first series does not show improvement I'd make sure all the copper is out of it. Maybe even clean between strings.

I bought it new and it’s got a heavy threaded barrel. I’ve got 150 rounds through it now and shoot very deliberately, 5 rounds at a time. It’s never really been too hot to touch.