Author Topic: Can I exceed safe pressures without even a slight pressure sign?  (Read 775 times)

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Offline teddy12b

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Can I exceed safe pressures without even a slight pressure sign?
« on: November 13, 2008, 06:25:59 AM »
I started this because this topic was starting to hijack another guys thread.

This is a re-routed thread.  The question is....Can I exceed safe pressures without even a slight pressure sign?
This thread came about because I mentioned that I loaded up some 168gr barnes tipped triple shocks stepping up in 1/2 grain increments all the way to 59.5 without seeing even the slightest pressure sign and it was brough to my attention that this could have been exceeding the safe pressure capacity of my rifle.  My 30-06 got the 168gr tipped TSX bullets up to 3000 fps out of a 24" barrel and I want to make sure that's completely safe.

For safe pressures I have been referencing hodgdon's website as my source.

http://data.hodgdon.com/main_menu.asp

This website show a 30-06 using 58.0gr of irm 4350 reaching 2903fps without telling the barrel length.

Offline yooper77

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #1 on: November 13, 2008, 09:04:27 AM »
The quote below is from: http://www.gboreloaded.com/forums/index.php/topic,156035.msg1098678572.html#msg1098678572


You’re going to compare apples to oranges and accept the results?

I don't get where I'm comparing apples to oranges.  The same bullet can be used in either caliber, most 300wm barrels are 24" some are shorter some are longer, and the speed it leaves the barrel is what it is.

I'm not trying to pass my 30-06 off as a 300wm, but it can get into that range.  I appreciate the notes from noslers book, but lets compare apples to apples by using the barnes data.  Barnes puts a note inside a box of their bullets saying you can load them with an extra grain of powder (maybe 1.5 grain I don't remember and haven't read it in a while.)

I have never read that that pressure limits can be exceeded without any signs.  I paid very close attention looking for pressure signs when I did this little experiment.  I did this little experiment on one occasion and haven't loaded anything but the accuracy load since.  I had planned on using the max load if I ever got a chance to go elk hunting or something of that nature.  Could you point me in the direction of the information about exceeding pressure limits without any signs of it?  I'm not saying your wrong, I'm just saying that I've never read it yet and I will have no problem admitting I'm wrong and thanking people for keeping me and my rifle safe.


*Sorry for starting to hijack the thread, for the pressure discussion go here.
http://www.gboreloaded.com/forums/index.php/topic,156282.new.html#new


Hodgdon does show barrel length, you just need to see it from the print option.

OK, I don't see how Barnes reloading data follows your statement saying they put a note in their boxes of bullets allowing .5 gr or 1.5 grs higher.


http://www.barnesbullets.com/images/30-06SpringfieldWeb.pdf

The Barnes bullet reloading data for the 30-06 Springfield and 168 grain Barnes TSX bullet shows 50.0 grains of IMR-4064 load as the maximum, but Hodgdon shows 50.8 grains of IMR-4064 as the maximum for a 168 grain Hornady HPBT bullet.

I have never seen Barnes bullets loaded with more powder then any standard lead copper jacketed bullet, because they would cause too high pressure.

Nosler's new E-tip seams to solve Barnes bullets problem, since they state you can load their new copper bullets with the same loading data of lead copper jacketed bullets.

As for reloading to the maximum charge, I don't exceed the manufacture recommendations, since I always develop the best load within the book data.

yooper77

Offline teddy12b

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #2 on: November 13, 2008, 09:39:14 AM »
Thanks for pointing out the barrel length shown on the printing view.  I never print them so I never saw it.

I have a couple boxes of barnes bullets at the house.  I'll double check the paper that comes in the box and post the results.  What I was trying to get across with that statement is that we can add a little more powder safely in a cartidge when compared to a regular bullet, like the ones we're talking about from the hodgdon website.  I'll try to scan & post a copy of the paper and that'll hopefully explain it better.

I can't speculate about how Nosler's new E-tip would perform in my 30-06.  They sound great, but I'll probably never load them up for a pressure test.  Just too expensive to keep doing that all the time with different bullets.

Just curious, but did you happen to look up a 300wm on hodgdons website?  On there website the 30-06 maxed out at 2,903 (imr 4350) with a 168gr bullet and the 300wm with a 168gr bullet had a max of 3,129fps (imr7828) and a lowest minimum of 2,738fps (H380).  My only point in this is that a 30-06 at the high end will be somewhere in the middle range of a 300wm.  Not saying one's better than the other but I prefer a 30-06.

Offline yooper77

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #3 on: November 13, 2008, 09:46:19 AM »
No, I didn't look up the 300 Winchester Magnum load data, I don't use belted magnum rifle cartridge, since they are not needed for my use.
- I too like the 30-06 Springfield for anything I am able to hunt.

I understand about the cost of just trying bullets, but I wont rely on Barnes bullets, since I witnessed the old X-bullet fail to open on an Antelope, so I ban all Barnes bullets for my use.

I also don't live in California, so I have no use currently for non-lead bullets.

yooper77

Offline Graybeard

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #4 on: November 13, 2008, 12:10:58 PM »
Short answer. Yes definitely.

In fact you can at times go to blue pill proof load pressures and still see none of the "traditional pressure signs" folks tell you to watch for. There are none-no-nada reliable signs that you are in unsafe territory until the gun comes unglued on you. When that happens you know beyond all doubt you went too high. Until then there is nothing reliable to go by.


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I am not a lawyer and do not give legal advice.

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Offline wncchester

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #5 on: November 13, 2008, 12:13:11 PM »
" The question is....Can I exceed safe pressures without even a slight pressure sign?"

The answer is ... yep.

And it's normally so for hand guns and lever rifles.
Common sense is an uncommon virtue

Offline LaOtto222

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #6 on: November 13, 2008, 12:30:50 PM »
I hate to rehash what is been said, but yes you can exceed max pressure levels with out a slight sign. I know; it happen to me. I have a .223 that I worked a load up with. I kept going up, because there were no signs of pressure - absolutely none. To top that off, I had exceeded everyone's max load, but the powder companies load, but still under their max. by a little.  Life was good, very accurate loads and no pressure signs. Then I got the new published data from the powder company and the particular load I was using was down sized considerably - more in line with the other data I had...Hmmm. I then got a chronograph and ran some of my "safe" pet loads over it. Average - on the North side of 3650 fps with a 50 grain bullet - Yikes. Needless to say, I do not load mine up that high any more and never will. I was getting close to 22-250 speed out of a 223...That just is not right.
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Offline teddy12b

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #7 on: November 13, 2008, 03:57:02 PM »
This is one of those things were there are enough people telling me this that I won't push my luck with it anymore.  Thank you guys for saving me a possible injury and from damaging my rifle.

I found the piece of paper in the box of triple shock bullets that I had mentioned earlier.  My scanner isn't cooperating so I'll type this in:  "The reduced bearing surface of the triple shock-x bullet may result in reduced pressures compared to the barnes x-bullet.  To compensate for this and achieve maximum velocity it may be possible to exceed the maximum load listed by 1 or 2 grains, working u pin 1/2 grain increments.  Watch for signs of excess pressure - i.e., once-fired case head expansion of more that .0005", sticky bolt lift, flattened primers, or shiney spots on the base of the case.  If any of these signs appear, reduce your load by one full grain.  If you don't feel comfortable with this procedure, we suggest simply using X-bullet loading data."

I didn't experience any of those pressure signs and now the question is, where do I safely stop with IMR 4350 in a 30-06?

With a 30-06, a 168gr bullet and IMR 4350:

Sierra software says to stop at 56.0grs with a 26" barrel
Barnes #3 says to stop at 59.5 (moly coated) doesn't say barrel length
Barnes #3 says to stop at 57.0 (165gr x-bullets) doesn't say barrel length
Barnes #4 doesn't list imr 4350 so I'm kinda hosed there.
Noslers #5 says to stop at 57.0 (165gr & 168gr data combined) with a 24" barrel.
Noslers #6 says to stop at 57.0 (165gr & 168gr data combined) with a 24" barrel.
Hornady #7 says to stop at 57.0 with a 23 3/4" barrel.
Swift #1 says to stop at 53.5 (165gr scirocco) with a 24" barrel.

I have a couple more books, but I'm getting tired and I think that gets the point across.  My point being where do I safely stop?  I'm guessing that 57.0 of IMR 4350 is a good place to call it quits.  Would anyone disagree?

After all this and the next time I go to the range with that rifle I'll be trying to work up a load for 190gr matchkings, go figure the rounds are already loaded.

I appreciate everyone being patient and taking the time to help keep me from potentially getting hurt and jeopardizing my families well being, not to mention keeping me from blowing up my favorite rifle.  I'd still like to learn more about this if there are any professional writing about this topic.

Offline jhalcott

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #8 on: November 13, 2008, 04:13:13 PM »
  I use a chronograph to tell me when I am passed the point of diminishing returns(where added powder results in LESS added fps). I also load for MAXIMUM accuracy rather than highest fps. I add the max charges and divide by the number of manuals to get an average MAX charge. If I don't get the accuracy I want by the time i get to that level, I try another powder.

Offline deltecs

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #9 on: November 13, 2008, 05:16:58 PM »
Start at 53-54 grains of imr 4350 using 165-168 grain bullets and SLOWLY WORK UP in grain increments until best accuracy is obtained with the brand of bullet, but do not exceed maximum reloading data.  I still would check for pressure signs and measurement of case base for each loading before shooting any increase in powder loads.  DO NOT EXCEED MAX LOADS IN MANUALS FOR BULLET USED.
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Offline LaOtto222

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #10 on: November 14, 2008, 02:43:34 AM »
I can not set here at my computer and stop you from doing any thing you want. It is your choice. But in many cases top accuracy does not mean highest velocity. You were given some pretty good advice in the 2 posts right above mine. I have gotten to the point of relying on a Chronograph to tell me when to stop. When you get to published max velocities you are in the ball park of top safe pressures. When the velocity gain is small for more powder, then it is another sign you have reached max pressure. Unfortunately there is nothing that will tell you, you have reached Maximum pressure with out good pressure testing equipment. It is just a best guess. Like I said you may find best accuracy before reaching max pressure. Work your way up in small increments, the accuracy should get better to a point, then start to drop off. You have found your load. If you get to the maximum published velocity and not getting the accuracy you want, then you need to start over with some other powder, bullet, etc. Do not be concerned about 100 fps or so. It really is not going to make that much difference to any game animal, or to a target. To me accuracy trumps velocity. Good luck and Good Shooting.
Great men have vision and resolve to make dreams come true.

Offline teddy12b

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #11 on: November 14, 2008, 02:55:44 AM »
I agree about the accuracy loads.  My rifle shoots the 168gr matchkings the best with 53.5 grains of powder.  That load gets me just under 1/2" at 100 if I do my part.

The tipped triple shocks were something I experimented with in the case that I might get to go out west hunting some day.  I wanted to have an accurate hunting load aready worked up and an accurate chart for it already made up.  They did shoot very well and I was able to reach out to 1000 yards with them for target shooting and just seeing what they can do.  Those bullets do a great job of not getting pushed around by the wind as much.  For hunting I just wanted to know the drop out to my comfortable distance of shooting.  The only problem is that for almost $1 a piece, they can set on the shelf until I need them.

Offline yooper77

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Re: Can I exceed safe pressures without even a slight pressure sign?
« Reply #12 on: November 14, 2008, 03:06:40 AM »
I found the piece of paper in the box of triple shock bullets that I had mentioned earlier.  My scanner isn't cooperating so I'll type this in:  "The reduced bearing surface of the triple shock-x bullet may result in reduced pressures compared to the barnes x-bullet.  To compensate for this and achieve maximum velocity it may be possible to exceed the maximum load listed by 1 or 2 grains, working u pin 1/2 grain increments.  Watch for signs of excess pressure - i.e., once-fired case head expansion of more that .0005", sticky bolt lift, flattened primers, or shiney spots on the base of the case.  If any of these signs appear, reduce your load by one full grain.  If you don't feel comfortable with this procedure, we suggest simply using X-bullet loading data."

This statement is funny to me, I see it as a attempt to recover from the old X-bullets high pressure failure.

I have never bought any Barnes bullets, so I didn't know about this note in the box of bullets.  My first hand experience with old Barnes bullets was from a 100 gr X-bullet out of a 25-06 Remington which run full length of an Antelope and never expanded.  The Nosler partitions are everything I need and I my controlled expansion bullet for deep penetration.

yooper77