High pressure signs on “average charge loads”?

[TimberHunter]

Loaded up some 308 today to see how the rifle likes IMR 4064 and Nos BT 165. While shooting I started to notice a little bolt resistance around 43 grains (COAL at 2.800”). I also started to notice ejector marks in the case head around 43 grains.

Per the Nosler book, high pressure shouldn’t be hitting until around 44.5 grains.

I shot the next higher charge (43.5) and bolt was a little sticky and there are ejector marks (red arrows). I stopped and didn’t shoot the 3-44 grain loads I had

I measured the shoulder datum line using the Hornady gauge and it showed shoulders on the fired cases from today (second time these Hornady cases have been fire) .624-.626. Factory loded Barnes ammo showed the shoulder around.627 (this factory loaded ammo is a hot load in my rifle with stiff bolt and ejector marks on the brass).

I usually go for a few thou bump on my FL die so I was shooting for the shoulder to be at .624 which easily loads into the gun (checked by removing the fire pin) so not sure if I’m giving the rifle too much head space and it’s creating?

Thoughts?

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[lennywd87]

What’s your COAL, are you seeing any rifling marks on the fired case necks? I’d think it’s more of a case capacity issue otherwise.


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[nhyrum]

I bet it's hornady's soft as baby stool brass. But yes, those are signs your load is too hot.

Every batch of hornady brass I've used has maxed out in middle of the book loads. I've even had hornady factory ammo blow primers. Ditch the hornady and get something better. Or, don't load to where you get a sticky bolt lift/ejector mark, which means you're stuck to middle of the road loads

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[TimberHunter]

What’s your COAL, are you seeing any rifling marks on the fired case necks? I’d think it’s more of a case capacity issue otherwise.


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Followed the nosler book for COAL, 2.800. All cases were just under the trim length by a few thousands.

I just removed the fire pin again from the bolt and messed with the due so the shoulder grew approx .002-.003 (shoulder at .628) and tried to chamber, I was meet with a lot of resistance from the bolt. Size piece of brass again, this time shoulder shoulder at .626 and there was a lot less reinsurance but still a little resistance

That makes me think the shoulder is somewhere around .626 so sizing the shoulder down to .624 shouldn’t be creating the high pressure issues

Hmm...?


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[nhyrum]

42.5 also looks like it could hot with the cratering of the primer, but that can also be slop around the fitting pin hole

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[TimberHunter]

I bet it's hornady's soft as baby stool brass. But yes, those are signs your load is too hot.

Every batch of hornady brass I've used has maxed out in middle of the book loads. I've even had hornady factory ammo blow primers. Ditch the hornady and get something better. Or, don't load to where you get a sticky bolt lift/ejector mark, which means you're stuck to middle of the road loads

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Good to know, thanks for the info. Also means I have to be happy with mid range velocities as well correct?

I have been loading for my 270 win for a few years and it likes 58.3 grains of H4831SC. Nosler book shows max at 59 grains. I’m loading to Nos box COAL. That’s in Hornady and win brass and I have not seen any high pressure signs.

Neck tension on the 270 and 308 are both the same at .002” of tension


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[TimberHunter]

42.5 also looks like it could hot with the cratering of the primer, but that can also be slop around the fitting pin hole

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You are correct, that’s the very first high pressure thing I noticed when I was checking each piece of brass after each shot


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[nhyrum]

Good to know, thanks for the info. Also means I have to be happy with mid range velocities as well correct?

I have been loading for my 270 win for a few years and it likes 58.3 grains of H4831SC. Nosler book shows max at 59 grains. I’m loading to Nos box COAL. That’s in Hornady and win brass and I have not seen any high pressure signs.

Neck tension on the 270 and 308 are both the same at .002” of tension


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That's just par for the course with reloading. Books are written in a laboratory type environment.

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[lennywd87]

Followed the nosler book for COAL, 2.800. All cases were just under the trim length by a few thousands.

I just removed the fire pin again from the bolt and messed with the due so the shoulder grew approx .002-.003 (shoulder at .628) and tried to chamber, I was meet with a lot of resistance from the bolt. Size piece of brass again, this time shoulder shoulder at .626 and there was a lot less reinsurance but still a little resistance

That makes me think the shoulder is somewhere around .626 so sizing the shoulder down to .624 shouldn’t be creating the high pressure issues

Hmm...?


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Yeah your probably right there. I have heard Hornady brass is quite soft as well. I like Winchester, lapua or norma.


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[TimberHunter]

That's just par for the course with reloading. Books are written in a laboratory type environment.

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Sounds like I may need to get a larger caliber gun and load it on the lighter side to accomplish what I’m going after.

With a 20” barrel and suppressor, I’m about 80-100fps off the book for each load. That means a 42.5 grain load puts me somewhere around 2530 FPS with a 165 grain. 1250 ft lbs and 1800 FPS at approx 475 yards. I’m looking for those number out to 650/700 yards. May need to go to a 7mm mag, 280 AI or 300 WSM. Considering those calibers in the savage 110 ultralight or bergara ridge wilderness

Bummer because the recoil on this 308 is nice


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[nhyrum]

I mean, don't knock the 308.a change of brass and maybe a more efficient bullet and you could maybe get there.

I'm a big Lapua brass fan, but know other brands are going to be a lot better, that you won't have to shell out that much for.

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[TimberHunter]

I mean, don't knock the 308.a change of brass and maybe a more efficient bullet and you could maybe get there.

I'm a big Lapua brass fan, but know other brands are going to be a lot better, that you won't have to shell out that much for.

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Are you referring to the Berger bullets?


I have about 200 pieces of Hornady brass (some new, some factory once fired)... I thought Hornady was decent brass lol

I have about 60 pieces of nosler brass and about 40 pieces of federal brass I could try out


Edit... I found new Lapua brass for about $0.85/each, that’s not too much more than I pay for Hornady

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[nhyrum]

Are you referring to the Berger bullets?


I have about 200 pieces of Hornady brass (some new, some factory once fired)... I thought Hornady was decent brass lol

I have about 60 pieces of nosler brass and about 40 pieces of federal brass I could try out


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Berger tends to be my go to. But there are others. Just saying that bullet selection could help you stretch the legs on that 308. I know there's a video of a guy shooting a 20" barreled 308 a mile, it was at steel, so energy wasn't a concern

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[brad407210]

I've been having similar issues with the Hornady brass, across several different calibers I've been hitting getting ejector marks below book max loads. You can get the stuff pretty cheap so I still run it for target loads if a mid range charge shoots well, but I've migrated over to better brass if I'm trying to max out hunting loads.

 

[ericwh]

Were you shooting these over a chronograph?

 

[TimberHunter]

Were you shooting these over a chronograph?

For this trip I forgot to bring the chrono. I’m going to try some nosler brass and difference bullets (rifle didn’t seem to like the 165 BTs) and I will chrono the 44 grain loads plus the new loads I’m going to put together

Speaking of chrono, I have a run of the mill Caldwell chrono, is there much adavate to more expensive chronos? It worked for me in the past to get my rifle out to 550 yards and I’m looking to make this 308 a hunting rifle out to 700 yards


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[willfrye027]

For this trip I forgot to bring the chrono. I’m going to try some nosler brass and difference bullets (rifle didn’t seem to like the 165 BTs) and I will chrono the 44 grain loads plus the new loads I’m going to put together

Speaking of chrono, I have a run of the mill Caldwell chrono, is there much adavate to more expensive chronos? It worked for me in the past to get my rifle out to 550 yards and I’m looking to make this 308 a hunting rifle out to 700 yards


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try Lapua scenar 155gr over some Varget. If you can get around 2900 that will accomplish your goal.

i shoot them in my 30-06 at only slightly more speed than what some guys get out of the .308. It’s a target bullet but track record for excellent performance on game. I’ve only killed one deer with them so far but zero issues. I shoot steel out to 700 with them and could go a lot further if I had the place to do it.

 

[ericwh]

Since you are loaded to book length I was just curious if your velocities were aligning with the manual (after deducting for barrel length).

I also have a caldwell and, if I am loaded to book specs and shooting a barrel of book length, I generally have pretty good correlation.

 

[rayporter]

Speaking of chrono, I have a run of the mill Caldwell chrono, is there much adavate to more expensive chronos? It worked for me in the past to get my rifle out to 550 yards and I’m looking to make this 308 a hunting rifle out to 700 yards

your chrono is probably fine. are there better? dont know about that but there are a couple that are a lot easier to use.

you dont have to align them with your rifle and you dont have to go down range. and they give more data.

the rifle does not lie--if it says you have high pressure then you have high pressure for that load.

 

[nhyrum]

Really, when it comes to the traditional box chronos, I don't really think there's much hardware difference. I wouldn't "trust" ced pro chrono any more than your casual l caldwell.

Now, try and compare those too a doppler system like the labradar... Yeah I see a clear winner there

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