I have loading for a while and pretty much just stick to the data in the manuals. However, I have recently begun to questions whether some of the loads in the manuals that are near maximum might be building a little more pressure than is desirable. I have been looking at the primers and notice that they seem to get flatter as the loads move closer to maximum, but what other signs are there that I can use as indicators that the pressure is going to high? Also, if the signs that indicate that there is a higher amount of pressure are not present at the maximum or near maximum loads, do you guys consider going up about another 1-3% on your hunting loads? I have no interest in trying to do something unsafe, but I want to get the most out of a hunting load also and I know that there can be variances between guns that may allow the use of more powder in some scenarios. If you have any pictures of over pressure signs, I would certainly appreciate it so I would have a better idea of what I am looking for. Thanks.
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Too much pressure
- Thread starter head2h2o
- Start date
Re: Too much pressure
Stiff opening bolt, flattened primer or pierced primer, brass shavings on the bolt face, a shiney spot on the case head where it might have rubbed the ejector hole in the bolt, black speckles and molten metal splattered all over your safety glasses when the case head seperates... These are all things that indicate high pressures.
Look on the web for used books on handloading by Nonte. He has a couple of very good books on the subject.
Keep reading everything you can find on the subject. I've been loading since 1972. I learn new stuff all the time. If anything says "safety", go back and read that section again.
Stiff opening bolt, flattened primer or pierced primer, brass shavings on the bolt face, a shiney spot on the case head where it might have rubbed the ejector hole in the bolt, black speckles and molten metal splattered all over your safety glasses when the case head seperates... These are all things that indicate high pressures.
Look on the web for used books on handloading by Nonte. He has a couple of very good books on the subject.
Keep reading everything you can find on the subject. I've been loading since 1972. I learn new stuff all the time. If anything says "safety", go back and read that section again.
Re: Too much pressure
Guns that can blow up before brass failure, in an incremental work up, should be given book loads.
Guns that are stronger than the brass can have a load worked up to the threshold of brass failure, and then back off a safety margin for reliability. Vernon Speer in 1956 wrote that that safety margin should be a 6% reduction in powder charge.
Today I am shooting 7mmRemMag 162 gr HNDY SST H4350.
Hodgdon says max load is 58 gr.
I found the threshold of shorter brass life [easy primer insertion] at 67.5 gr
I have just shot ~50 rounds at 65.5 gr.
That is not a full 6% reduction.
Am I getting away with it?
Not really, the bolt is a little harder to lift.
Guns that can blow up before brass failure, in an incremental work up, should be given book loads.
Guns that are stronger than the brass can have a load worked up to the threshold of brass failure, and then back off a safety margin for reliability. Vernon Speer in 1956 wrote that that safety margin should be a 6% reduction in powder charge.
Today I am shooting 7mmRemMag 162 gr HNDY SST H4350.
Hodgdon says max load is 58 gr.
I found the threshold of shorter brass life [easy primer insertion] at 67.5 gr
I have just shot ~50 rounds at 65.5 gr.
That is not a full 6% reduction.
Am I getting away with it?
Not really, the bolt is a little harder to lift.
