Why do people load so hot?

[Snuby642]

I keep things simple.

I start in the middle of "book" in 0.3g increments and watch the brass / primer . I watch the pattern on the groups and see it swing from stringing horizontal / vertical then go round then close up.

Rinse swish repeat till I get up to a full grain less than book. If I find a node past there it's probably where I stop. The next node is possible with some powders and sometimes not with others.

If I keep going and see a scatter load, that's it I'm done. Pull everything else no regrets .
Primer squish next 0.3g on some powders like cfe 233 for one.

Go back and bracket by 0.1 increments the node and seating depth depending on bullet.

The book max references a brand of brass, it doesn't specify new or fire formed to their universal receiver running 1 in 12 twist in a standard 24 inch barrel. Using (223 example) from most.

Do any of you run 1 in 12 twist in a 24 inch barrel?

Watch your brass, primers and ass at the range and read the pattern from your barrel just for fun.

 

[supercorndogs]

Back in 2020 I competed with a large frame AR in PRS Regional Gas division and learned a lot about pressure when it came to yearlong consistency with H4350 and Varget in a 6.5 Creedmoor. I don't recall the charge weight but settled on moving 140's with Varget in the mid 2600's and brought the regional season trophy home. Since then, I went back to open division with a bolt rifle and used the 6GT with Varget. I stayed in the 31.5-32.5 weight range over 6 barrels to make a consistent 2830fps load. Eventually I wanted to go slower and moved to a 6mm BR with 109 Hybrid's and 29 grains of Varget for 2725fps. For the past 9 months and 2367 rounds it has remained consistent and generally stays under a 5sd for any given shot string. Since slowing things down and jumping bullet's .055 or longer I have never had to retune a load in close to 10 barrels now. This in 6GT's, 6.5 Creedmoor, 6mmBR, 25GT and 6.5x47L. The exception was two barrels with tighter bores, which I will never do again. Otherwise, the loads have worked equally well in the next replacement barrel screwed on to the action provided the freebore was the same.

I love the amount you can see with the extra flight time when it comes to rifle sports... I also run a 25GT with 135 Hybrid's and a 6.5x47 with 135 A-tips in the mid 2600's for the same reason.

The looks can be priceless when speaking to shooters struggling with their combo that are running loads two or three hundred feet per second faster than you, and you just left them in the dust with a stage clean.

I have a feeling that a more modest load adds barrel life as well, but I have only shot out one-barrel and that was a 6GT that started to show signs at 3200 rounds and was definitively done at 3600ish when a 6 tenth windage shift occurred and I had lost about 60fps after cleaning... it still shot great though, LOL.

Great post. A 7mm-08 can push high BC bullet in that 2500-2600 range. Do you think there is point where the recoil is too much to make up for the extra flight time? It always seemed like the 6mm bullets don't have a real good b.c, the ballistics just looked good because of the velocity. I guess the 7mms might start running into action length problems also.

 

[CK1.0]

IMHO the old “go up until I see pressure and then back down a few tenths” mantra = the Dunning-Kruger effect in practice.

These days I’m more concerned with how “slow” I can go and still get repeatable/reliable single-digit SDs over 20 shots and still print small groups, not max MV.

For years I was told and read that that meant you needed a high case fill ratio (and a higher MV) in order to be able to do that… then I got a fancy powder dropper that lets me load all my rounds to the nearest kernel and a chrono that I can attach to my gun and track every single shot if I want to… and I don’t believe that anymore. These guns are lasers more often than not without ever really having to do shit and I’ll probably never take a shot that maxes out the elevation in my scope, so there’s just no need to push them, and if you want them to do the same thing every single pull, batch after batch, I’d argue it’s best not to.

 

[tekmann2377]

Back in 2020 I competed with a large frame AR in PRS Regional Gas division and learned a lot about pressure when it came to yearlong consistency with H4350 and Varget in a 6.5 Creedmoor. I don't recall the charge weight but settled on moving 140's with Varget in the mid 2600's and brought the regional season trophy home. Since then, I went back to open division with a bolt rifle and used the 6GT with Varget. I stayed in the 31.5-32.5 weight range over 6 barrels to make a consistent 2830fps load. Eventually I wanted to go slower and moved to a 6mm BR with 109 Hybrid's and 29 grains of Varget for 2725fps. For the past 9 months and 2367 rounds it has remained consistent and generally stays under a 5sd for any given shot string. Since slowing things down and jumping bullet's .055 or longer I have never had to retune a load in close to 10 barrels now. This in 6GT's, 6.5 Creedmoor, 6mmBR, 25GT and 6.5x47L. The exception was two barrels with tighter bores, which I will never do again. Otherwise, the loads have worked equally well in the next replacement barrel screwed on to the action provided the freebore was the same.

I love the amount you can see with the extra flight time when it comes to rifle sports... I also run a 25GT with 135 Hybrid's and a 6.5x47 with 135 A-tips in the mid 2600's for the same reason.

The looks can be priceless when speaking to shooters struggling with their combo that are running loads two or three hundred feet per second faster than you, and you just left them in the dust with a stage clean.

I have a feeling that a more modest load adds barrel life as well, but I have only shot out one-barrel and that was a 6GT that started to show signs at 3200 rounds and was definitively done at 3600ish when a 6 tenth windage shift occurred and I had lost about 60fps after cleaning... it still shot great though, LOL.

This is exactly what the "need for speed" crew is missing. Constantly pushing the bleeding edge and subsequently giving up consistency and staying in tune. But who care about modest, consistent loads and longer barrel life LOL?

Plus how can you have an exciting day at the range unless there is a slight temp bump and suddenly that "good load that only showed mildly flat primers but what 3 grains over book max" starts blowing primers left and right?