Pressure signs way below max load

[FEENIX]

You might also want to re-visit page 80 your latest Hornady reloading manual.

 

[Mc Fraser]

I have that tool and I used it.
To clarify, I measured the CBTO for a 215 Berger VLD Hunting with 2 methods and 5 measurements each, all 10 measurements came in very close:
1. Sharpie
2. Hornady Overall Lenght gauge with Hornady 300 wm modified case.
And I measured the distance from the bolt face to the ogive with the cleaning rod.

 

[DT400]

I have that tool and I used it.
To clarify, I measured the CBTO for a 215 Berger VLD Hunting with 2 methods and 5 measurements each, all 10 measurements came in very close:
1. Sharpie
2. Hornady Overall Lenght gauge with Hornady 300 wm modified case.
And I measured the distance from the bolt face to the ogive with the cleaning rod.

Hmm OK I wonder if you just have a tight barrel. Have you called Krieger about it? Maybe the barrel needs to be slugged.
Has the barrel been scoped just to see? Couldn't hurt. Maybe if there have been a bunch of rounds through it it has gotten severely copper fouled. Doubtful if that barrel is hand lapped but you never know.
How is the accuracy? How many rounds down the pipe since de-coppered if at all?

Darrell

 

[DT400]

Dupe post mods please delete

 

[Bravo 4]

I've had a rifle whose max load was the start load in more than one manual. Even had the bullet out past factory spec (SAAMI?) OAL. Shot really well just didn't take as much powder to get there.

 

[Alibiiv]

Hmm OK I wonder if you just have a tight barrel. Have you called the Krieger about it? Maybe the barrel needs to be slugged.
Has the barrel been scoped just to see? Couldn't hurt. Maybe if there have been a bunch of rounds through it it has gotten severely copper fouled. Doubtful if that barrel is hand lapped but you never know.
How is the accuracy? How many rounds down the pipe since de-coppered if at all?

Darrell

This was my thought right at the get-go when I first started reading the post. To eliminate a lot of measuring/mis-measuring/nomenclature and all the reloading stuff.....did you try a box of factory ammunition out of your rifle; go back to basics????? Did this condition start out from the beginning when you first started shooting the new build? Manufacturing processes can be subject to human error as with any product. Also I would be measuring the bullets that you have been using, I doubt this is the problem, however at this point I would not rule out anything.

 

[Ted Sierocinski]

Ladies and Gents,
I have a Win M70 in 300 win mag that has a 29in Krieger barrel with a brake and glass bedding done by a reputable gunsmith.
I understand how min and max loads from reloading books work, however beyond that could you think at any other reason why I see pressure signs below max load. I use Norma brass new and fire formed and I constantly see pressure signs 1.5 to 2.5 grain below max load with with different powders and bullets. H1000 imr 7828ssc, retumbo

 

[SlugFester]

Ladies and Gents,
I have a Win M70 in 300 win mag that has a 29in Krieger barrel with a brake and glass bedding done by a reputable gunsmith.
I understand how min and max loads from reloading books work, however beyond that could you think at any other reason why I see pressure signs below max load. I use Norma brass new and fire formed and I constantly see pressure signs 1.5 to 2.5 grain below max load with with different powders and bullets. H1000 imr 7828ssc, retumbo

What kinda speed are you getting? It's possible your chamber and barrel are just pressured out.

Your going by what standards, what barrel length? I have a 29" Benchmark and things are very different with it compared to shorter barrels. Just a thought but I'd try to find someone with same rig & see what they experienced.

 

[Ted Sierocinski]

Have someone else other than the gunsmith that chambered the rifle to check the headspace. I had a similar problem with a 220 Swift and the headspace was off. The powder scale accuracy verification is essential and weighing a small caliber bullet is a good quick check. I assume that you are using the scale for other reloading without problems. Also any chance of mislabeled powder.

 

[Will Gray]

Weight a couple of 100g bullets to verify your scale. What high pressure signs are you seeing, ejector hole marking the case or sticking cases and flat primers (change primer brand)? Are the primer pockets enlarged? Try some other brass. Shoot a box of commercial ammo (heavy bullets) and see how they do.

 

[Sam Summey]

Ladies and Gents,
I have a Win M70 in 300 win mag that has a 29in Krieger barrel with a brake and glass bedding done by a reputable gunsmith.
I understand how min and max loads from reloading books work, however beyond that could you think at any other reason why I see pressure signs below max load. I use Norma brass new and fire formed and I constantly see pressure signs 1.5 to 2.5 grain below max load with with different powders and bullets. H1000 imr 7828ssc, retumbo

Are your bullets jammed into the rifling? How much "freebore is there". I feel a magnum should have at least .020 freebore before the bullet engages the rifling.
Most long range folks are shooting heavy long bullets, give them a little jump to get the bullet moving. I had one customer bring in a 264 WM with the ejector pinged into the bolt. He said he used his regular powder charge but switched to a monolithic bullet. It is substancially longer that a lead cored bullet thus taking up more of the internal volume of the case. End result excessive pressure.

 

[dragonfly]

Your talking about a quality barrel, but two things, Is your chamber free bored somewhat? If not probably should be. Have you checked the bore dia. is it close to the min. You are talking about a 28in. barrell Those combinations could cause pressure problems. I have A .300 h&h 26 in. barrel with the same problem. I can't get close to max loads from the book. Tight bore I think is my problem.

 

[mmsports]

Something is definitely wrong with the numbers above. I am looking at my Hornady for 212 ELD-X and 3.34" is the recommended COAL, this is "not" the same as CBTO.

I think you're measuring your CBTO with the gauge insert; 3.750' - gauge (normally 1.00") = 2.750" which makes sense. To measure the COAL, remove the remove the insert, zero the caliper and measure from base of the brass to the tip of the bullet.
This is my .300 WM with 200 NAB...

View attachment 145682
View attachment 145683
CBTO

View attachment 145684
COAL

Great Pics Feenix!!

 

[DT400]

I have that tool and I used it.
To clarify, I measured the CBTO for a 215 Berger VLD Hunting with 2 methods and 5 measurements each, all 10 measurements came in very close:
1. Sharpie
2. Hornady Overall Lenght gauge with Hornady 300 wm modified case.
And I measured the distance from the bolt face to the ogive with the cleaning rod.

When you used the Hornady COAL gage you used your current bullet right? You have to do this measurement for each type of bullet/weight/manufacturer etc. I have heard of the cleaning rod method...IMHO that's got to be less accurate then the Sharpie method.

It sounds like you likely have correct measurement from using the COAL gage.
BUT
One question, after you have measured using the COAL gage how hard is it to get the bullet out of the gun? Can you just turn the gun muzzle up and the bullet just drops out with a light rap in the side? If the bullet requires using a cleaning rod or dropping the gun on the butt it's too tight. Ideally the bullet should just fall out when the muzzle is pointed up. It is a delicate process and requires a very light touch.

Darrell