Ever found Max published load data that indicated an over pressure situation?

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fouled bore

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This is really just a survey to see if anyone has ever had a case in which published load data, using the published components, feel was too hot and was possibly over pressure in their gun. I am only talking about loads that were made using the same bullet, powder and COL as published. The only variable is the case and primer being different from what is published. I am not endorsing to start working up a load a close to max. I do believe in starting low and working up. I am just interested in seeing what the possibility is in finding a max published load that could be close to being unsafe when working one up to that level.
 
For 40S&W, Lyman #49 used .401" groove diameter test barrel instead of more typical .400" and shows some max charges higher than powder manufacturers' max charges (Perhaps Lyman #50 will test with .400" test barrel).

So I now recommend reloaders slug their barrels and if their groove diameter is .401", to use Lyman #49 load data but if it is .400", to use more conservative powder manufacturer load data.

Page 362 of Lyman #49 showing .401" test barrel

attachment.php
 
It's been a long time ago, but when I first loaded the .300 win mag there was a lot of variation in loading manuals. I can remember loading up to near max based on one manual and having sticky hard to extract cases. Looking at another manual I was several grains over their published max for the same load.

This was back in the 70's. There just wasn't the availability of resources that you have today.
 
Yes, once with a max load of W748 - turns out the cases has oversized flash holes designed for lead-free primers. Difficult extraction and a primer puffed out like a three-lobed muffin top! WOW! last time I'll ever let that happen
 
I've been reloading since 1962.
I learned early on that what was safe in the firearm used in developing loading data for publication in a reloading manual may not be safe in my personal firearms.
Some published loads for the 44 Magnum showed definite pressure signs in my Ruger Super Blackhawk.

Since then, I consider all published load data as "suggestions".
I always start with the published "starting load" and carefully work up.

As a further discussion of pressure estimation, I use the technique used by Ken Waters of Reloader Magazine fame.

Basically, this is a measure of brass expansion at the web.
I first fire a box of several different factory loads and measure before and after expansion.
Assuming a reasonable standard deviation, I average the expansion and this becomes my personal pressure limit for that gun.

Once that level of expansion is reached, no further increase in charge weight is attempted.

Of course any other indication of high pressure is also looked for.
Some brass is softer that others and a maximum safe load in a different lot of brass may show excessive pressure in this batch.

This being said, I chase accuracy rather than brute power in my reloads.
Most accurate loads are at about 80-85% of listed max most of the time.
Out of the 29 different cartridges that I reload, only the 300 Weatherby Magnum requires near max loads for best accuracy.

Since best accuracy is usually found at upper midrange pressures, I've always wondered why some people try to blow up their guns with over pressure loads.
Shooting the equivalent of Proof loads has an accumulative over stress on a gun.
Your gun was designed to safely operate at a certain maximum pressure level.
The proof load is only to prove safety of operation, and is only fired once.

As to the original question: All guns are slightly different, all batches of brass and powder are slightly different.
While these differences are very low, they can domino into an unsafe combination with a listed maximum load.
Always start low and work up carefully.

Don't expect any published maximum load to be safe in your gun.

If you need more power than published loads, BUY A BIGGER GUN.

My 2 cents,

Steve
 
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Yes, I have found where published loads were too hot. This is with a 223R using LC brass, which has less volume than most. I had over pressure signs 0.2-0.3gr before published max. I have also found the reverse too. Where published loads were so low they were over 1 gr off compared to other sources.
 
Yes. Many years ago I had a custom 22 BR rifle built. It did not have the tight neck so I didn't need to turn necks. But, it shot max velocities (and I assume pressures) with a mid-range load per the books. I figured it had a tight chamber or bore. I used it for several years as a prairie dog gun. I even set the barrel back once and rechambered with the same reamer and still got max velocity with a light to medium load.
 
I had an... experience... with Speer's 10mm data for Unique. It's quite a bit higher than some other manuals. Combine it with some possible setback...
 
I got sticky bolt lift on 40.7g of H4895 shooting 180g Nosler BTs, OAL 2.800, which is almost 2 full grains below Hodgdon's published website data of 42.5g max.

Didn't believe it the first time. Fired 2 more with same result. Pulled the remaining rounds and verified my charge weight of 40.7g
 
I was thinking of starting a thread along these lines after an experience this past weekend. I just got a pound of BE-86, and loaded some 9mm 124 gr FMJ to test. Alliant's website shows 5.8 gr max load, 1.12" OAL, with Fed 100 primer. I used CCI 500's, and 1.15" OAL, and loaded 5 each at 5.0, 5.3 and 5.6 gr.

Well, the 5.0's felt a little snappy (I had read some other reviews stating this). The first two 5.3's felt REALLY snappy, and the brass was ejected about 12-15 feet away, so I stopped. Pulled the last three 5.3's and all five 5.6's. Verified data and charge weights. It just seems too hot of a load.

This weekend, I'm gonna try 4.6 and 4.8 gr loads.
 
Blue68f100 said:
Yes, I have found where published loads were too hot. This is with a 223R using LC brass, which has less volume than most. I had over pressure signs 0.2-0.3gr before published max. I have also found the reverse too. Where published loads were so low they were over 1 gr off compared to other sources.
Click to expand...

Did you actually test this LC brass in grains of H20 to determine it's actual capacity.

Most that have actually tested for case capacity in grains of H20 have found the Military 5.56 LC brass to have more case capacity, not less.

http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm

and here.

http://www.6mmbr.com/223rem.HTML
 
Steve Cover said:
As a further discussion of pressure estimation, I use the technique used by Ken Waters of Reloader Magazine fame.

Basically, this is a measure of brass expansion at the web.
Click to expand...

I've read that in his "Pet Loads" book. I've seen that method referenced elsewhere, but have also read that you need a blade-type micrometer that has more precision that the standard micrometer. I have thought about getting one, just have not gotten around to it yet.

What are you using for measurements?
 
a few years ago I was working my way up with titegroup in .45 0.1grains at a time. I stopped 2 or 3 increments before max and it was the hottest thing I'd ever shot in .45. Broke down the rest of the rounds. No damage to me or the gun but I wouldn't think of going hotter with that gun,powder,bullet combo
 
tcook90 said:
I was thinking of starting a thread along these lines after an experience this past weekend. I just got a pound of BE-86, and loaded some 9mm 124 gr FMJ to test. Alliant's website shows 5.8 gr max load, 1.12" OAL, with Fed 100 primer. I used CCI 500's, and 1.15" OAL, and loaded 5 each at 5.0, 5.3 and 5.6 gr.

Well, the 5.0's felt a little snappy (I had read some other reviews stating this). The first two 5.3's felt REALLY snappy, and the brass was ejected about 12-15 feet away, so I stopped. Pulled the last three 5.3's and all five 5.6's. Verified data and charge weights. It just seems too hot of a load.

This weekend, I'm gonna try 4.6 and 4.8 gr loads.
Click to expand...

Was the bullet the same one that Alliant used for the published load?
 
There have been lots of retractions over the years. People seem to think it's lawyers. I'm sure they are part of it. But most of it is the time pressure curve they are now able to see. Blue Dot is the perfect example and why a lot of loads aren't printed anymore. The pressure spikes extremely quick. It may not be over pressure but it's still bad.
 
Blue68f100 said:
Yes, I have found where published loads were too hot. This is with a 223R using LC brass, which has less volume than most. I had over pressure signs 0.2-0.3gr before published max. I have also found the reverse too. Where published loads were so low they were over 1 gr off compared to other sources.
Click to expand...
Was this also using the same bullet that was published with the load?
 
Ever found Max published load data that indicated an over pressure situation?
Click to expand...

Yes. The published data for the 5.7 mm Johnson (22 Carbine) was:
40 grain bullet, 14 grains IMR4227
40 '' '' 12 "" Hercules 2400
50 " " 14 " IMR 4198

I started with 12 grains of IMR4227 and loaded five rounds. The result was flattened case heads, primers backed out of their pockets and extruded back into the firing pin hole. I shudder to think what might have happened had I been foolish enough to start out at the whole 14 grains.

Also, the Hornady manual, 4th Edition (copyright 1991) lists a maximum load for their 60 grain .224 bullet in .223 Remington as 20.8 grains IMR4198. I ultimately worked up to a load of 20.5 grains giving good accuracy (as I judge accuracy) and good performance that causes no sign of distress to my brass. Having come up with a good load, I proceeded to load about 1,000 rounds, most of which was left behind with my father when I finished graduate school. I assume he's still got them unless he shot them up over the years.

Today, however, the published sources I've seen show a maximum load of 19.5 grains for the same bullet weight. I intend to keep the remnants of my 20.5 grain loads and use them, because they did accord with a published source in effect at the time and seem to work. That said, I would recommend that anyone loading the cartridge today adhere to CURRENT published data; not ancient history scratched on a cave wall someplace.
 
fouled bore said:
Was this also using the same bullet that was published with the load?
Click to expand...
Yes it was. The reason to ALWAYS work up your loads. I have about 6-7 different years of LC brass. I keep them separated for this reason. Most are pretty close to each other on volume but some are different enough to cause a problem. I've even take a load working from one year to the next and the group doubles. Took some tweaking to make it shoot the same..
 
Yes I have. Working with a friend trying to find an accurate 30-06 load with H414 in his Tikka bolt rifle while teaching him about reloading. Unsure the rifle model. Using the Hodgdon Manual with a 180 grain Projectile. The starting load seemed a bit much and the next step (10% of the difference) locked the bolt up and we had a time getting the brass out. All the proof pressure signs and more. Ended up at 1.2 grains under starting load with that rifle for a MOA load. The factory ammo all had stiff extraction as well. Basically why we went that route in the first place. Seemed like a really tight chamber and we did a chamber cast to verify that it was.
 
Had a case head blow out on a Stevens/Savage once, it blew the extractor out but I found everything but the detent ball which the hardware store had.
I was working up a 7-08 load and using two rifles to test with. The other was a 788 REM, the one I still have.
I'd have to look back but I don't think I was quite at max yet.

Sent from my XT1254 using Tapatalk
 
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