Quite surprised with max load!

[Ganderite]

I have used a number of ordinary rifles as pressure guns with strain gauges. Pressure signs did not become noticeable until well over max.

In my observation the only reliable way to avoid excess pressure is velocity. There is no free lunch. Excess velocity results from excess pressure.

i have a small collection of blown up guns. Only one is from my doing. The others are donations. One cost a guy his eye. Most were caused by pistol powder in rifle cases. My contribution was a double charge of pistol powder.

As I said before, I have seen a rifle that would not handle a "Start" load.

 

[Andy]

Well I've been on CGN for a while, but if some of the posters are to be believed, then this is a "watershed moment". Fear has always been the major influencer, and if someone dared to exceed a published max load, even without "pressure signs" they were piled on with warnings about it just being a matter of time before they died in a red mist of shrapnel. Now it's been suggested that many published max loads, even some mid and starting loads are over pressure, with or without the trusted "pressure signs".

I can only guess what's next here, but I won't be changing my behaviour.

P.S. Congrats to the OP on the accurate load.

 

[hometownhero]

I am curious about something. Here is a question to all that said "I have seen a rifle that couldnt handle a starting load" How does it shoot factory ammo then? All the start loads I have seen/looked at seem very very slow when compared to factory ammo. Take the standard 150gr bullet in a 30-06. Min charge with say varget is 41gr and 2500 fps. All the factory ammo I have pulled apart for that caliber the case is packed with powder and velocity is ~2900 fps. That is a big jump form the min load data.

 

[rral22]

To the OP: I guess it's nice to have an accurate load.

I guess it's just fine for you to continue to ignore the safety advice you get from manufacturers, from manuals, and from old reloaders. What can they possibly know that you don't already? What could possibly go wrong?

 

['Boo]

How does it shoot factory ammo then? All the start loads I have seen/looked at seem very very slow when compared to factory ammo.

The worst over-pressure loads I have ever used were factory Winchester Supreme 180 grain Fail-Safe 30-06 cartridges. It blew the primer and blew off the extractor of the commercial FN Mauser I was shooting. The case head markings were almost obliterated. The shot jammed the bolt up so hard I had to use a piece of 2"x4" to beat it open. The rim of the case showed ~.0003" expansion when compared to the unfired case. According to Ken Howell in order for brass cartridge case to show expansion at the rim the pressures need to be in the 85,000 psi range.

I contacted Winchester who told me to send them the remainder of the cartridge so they could examine them. I sent the cartridges back and never heard from them again.

 

[H4831]

Well I've been on CGN for a while, but if some of the posters are to be believed, then this is a "watershed moment". Fear has always been the major influencer, and if someone dared to exceed a published max load, even without "pressure signs" they were piled on with warnings about it just being a matter of time before they died in a red mist of shrapnel. Now it's been suggested that many published max loads, even some mid and starting loads are over pressure, with or without the trusted "pressure signs".

I can only guess what's next here, but I won't be changing my behaviour.

P.S. Congrats to the OP on the accurate load.

Very well said, Andy.

 

[Ganderite]

Most aviation accidents occur because of a bad combination of factors or events. Same thing with guns.

The defect can be invisible until the right combination of events.

A 30 cal barrel is typically something like 0.300 x .308" Yours might be 0.298 x 0.3065 (Tight barrels were all the rage at one time for target shooting.) The rifle might work great for a long time until one day Fearless Fred decides to load some 200 gr Round nose, flat base bullets (long bearing surface) and starts them into the rifling. Powder is a double base, shot on a hot day. Everything is going well, until Fred stops shooting to talk to the range Officer. Meanwhile a round is cooking in the hot chamber. The investigators are left trying to figure out why the rifle worked ok for 5 years and for 40 rounds until it blew.

There is a lot of talk about headspace. Excess headspace is not necessarily dangerous. Lots of 308 has been shot in 3006 chambers (a half inch of excess headspace!!)


Fearless Fred has a badly chambered rifle. The chamber was cut 100 thou too shallow. The barrel was installed 100 thou forward, so the headspace is perfect. But the case head is unsupported. Most commercial and military brass has a web high enough to cover this unsupported section with solid brass, so for the last 20 years Fred has never had a problem.

But then one day he makes some ammo using Santa Barbara brass, that has a very low web, so that only the case wall is covering the open space between the barrel and bolt head. Fred has never bought into this theory of start with the START load, so when the case lets go he not only wrecks the rifle, but loses part of his hand and cheek, too.

I have investigated quite a few mishaps. very often there were small indicators before the KABOOM that something was not quite right. You have a better chance of an early warning if you start low and work up.

For the record, i have tested IVI 7.62 and Winchester Supreme 308 ammo that ran over 60,000 psi. Both lots of ammo squeaked in just under the pressure limits. There are many correctly made and chambered rifles that do not handle this ammo. The ammo was brought to my attention by shooters that were blowing primers, scaring bolt faces and blowing off extractors. So yes, some factory ammo is too hot for some rifles.

 

[Longwalker]

Pay attention to Ganderite! He knows what he is writing about!

 

['Boo]

The defect can be invisible until the right combination of events.

Very well stated Ganderite.

What a lot of people don't seem to appreciate is that there are two ways failure can occur.

One way is the more or less instant catastrophic failure due to a load which stretches the cartridge case, the action or the barrel beyond it's limits.


The other, which takes place over time from repeated applications of loads which exceed the design limits, result in fatigue type failure. These are the really insidious types of failure.

 

['Boo]

Reading Bob Hagel's book, and his loads should be approached from 10% south of where he is at. Talk about loading to the nuts and driving full bore . . .

Even Ken Howell - who was at one-time his editor - makes no bones about Hagel's reloading guidelines and in fact calls some of his advice downright dangerous.

 

[H4831]

Mr.Ganderite, that is a lot of information, and of course your information on such things is always correct. Certainly nothing there I would dispute.
When I get a new to me rifle, new or used, I always test it out gently and quite thoroughly. I have several times taken a loading outfit to the range to load as I test. That way, I use the same case over and over as the loads get heavier, and carefully noting how hard it is to push a new primer in.
I have, or had, two 30-06 bolt action rifles. With rifle A I could get up to max book loadings and the velocity would be well below what it should be. I would keep increasing the load, always using the same case and by the time the velocity got up to what it should be, I would be well over loading manual shown maximum loads. And I couldn't detect the primers seating any easier, meaning my test had not increaded the size of the primeer pockets, meaning no excess pressure to worry about.
30-06 rifle B always showed about 100 fps faster than rifle A, with the same loads. Before rifle A got to it's maximum, the bolt on rifle B would stick, with the test load. Thus, my loads for rifle A had to be very well marked as being for rifle A, only.
Bob Hagel was mentioned earlier, with what appeared to be a note of derison in tone, but his book has a world of knowledge in it and no reason to be dangerous, if his precations are followed. In the book he mentions having rifles like my rifle A, which always run at low fps with a given load. He goes on to state that such rifles he has had always seem to make the most fps, for the calibre, than other rifles. This is true of my rifle A. I was able to get 2700 fps with 200 grain bullets of both Speer and Nosler variety, using Norma 205 powder. However, I was using only .5 grain more 205 than Norma shows for their standard load with 200 grain bullets and achieved almost exactly the same velocity as they showed in their manual, with half a grain less. Rifle A just needs a bit more feed to get up to speed. Also, I have often stated that the old Norma loading charts were the most accurate and reliable, of any loading manual I have ever seen.
By the way, this load and velocity is nearly identical to what Bob Hagel shows in his book, using 200 grain bullets and Norma 205.
So, if I am loading for rifle A would I start at the minimun load snown? No, with different components I would start at what the loading manual shows as maximum, because I know Rifle A will handle it without sign of a burp, and still have a lower velocity than the book shows.

 

[stubblejumper]

So, if I am loading for rifle A would I start at the minimun load snown? No, with different components I would start at what the loading manual shows as maximum, because I know Rifle A will handle it without sign of a burp, and still have a lower velocity than the book shows.

So where do you start if you are loading for rifle A for the very first time, with no previous history? I certainly wouldn't start with the load listed as the maximum.

 

[Ganderite]

A good example of rifle A vs rifle B is comparing a Remington to a Winchester. Remington uses (or used to - I have not bought one in 15 years) use a deep throat on their chambers as a safety valve. Winchester used a much more conventional chamber.

Remingtons would need more powder to get the same velocity, other things being the same.

If you were to start off with a MAx load developed for a Remington, and used it in a conventional chamber, you would be in proof load range. Trouble is that a well made rifle will run all day without a burp at 75,000 psi. Just a question of time before some other factor gets added in to the mix, and then KABOOM! But I shot this ammo for years with no problem!

I like to Chrony a round or two in my back yard, before I go to the range, to make sure my new rifle/load test is in the right range. I take the max velocity in the book as a speed limit.

 

[H4831]

So where do you start if you are loading for rifle A for the very first time, with no previous history? I certainly wouldn't start with the load listed as the maximum.

Of course I would not start at the max load first time with any rifle. I thought that would be clear from this statement I made.
"When I get a new to me rifle, new or used, I always test it out gently and quite thoroughly."
I thought the word gently would be interpretted to mean lighter load,