Home Forums Hunting & Shooting Hunter's Campfire Cartridge Progress

Naw, it's the stoppin' that hurts.

I didn't say you did.

Consider me [bleep] regardless.



Travis

338 Ultra Mag:

180 Accubond.... 102 gr. H1000 CCI Primer

3.675 COL Avg 3421 fps

AD 1.8 ES 4.9 SD 2.5

Temp. 30 degrees


Of course, I'm no expert................ but I did sleep in my pickup last night.

This absolutely sums up all the technology that has been exhibited here...

I don't know about technology. I know what works for me.

When the Ultra Mags first came out, I got one of each: 7mm, 300, and 338.[the 375 -which may be the best of the bunch- came later]

I got two boxes of factory shells, one with the 225 gr. Nosler Partition, and one with 250 gr. CoreLokt, for the 338. So...... I knew what velocities to expect from those two bullet weights and still be in the "safe" realm.

Because the Swift Scirroco impressed me in the 7 Ultra as far as killing well, I tried the 210 gr. in the 338.

92 gr. AA 3100............ 3280 fps ..... ext. mark
94 gr. RL 22...............3357........... too hot!
98 gr. RL 25...............3354........... warm
95 gr. IMR 7828............3286........... warm
96 gr. RL 25...............3162........... warm
90 gr. RL 22...............3205.... no pressure signs
92 gr. RL 22...............3290.... sticky bolt
94 gr. IMR 7828............3260..... BINGO!

My point is that if a man is willing [and able] to spend the time, he can develop good loads for his own rifles by following the instructions given in most manuals as far as detecting pressure signs.

Measuring case head expansion served me well with the 7 mm and 300 Ultras as there was no load data available when I started. The 300 only had one bullet loaded in factory ammo, and there was no factory ammo available for the 7 MM.

It was not necessary with the 338 Ultra since I had two factory loads to use as a reference.

The idea that it is dangerous for us to work up our own data because we have to load PAST the Max. to determine what is Max has a certain validity as a THEORY.

When someone can point to modern cartridges causing catastrophic failures in modern actions by going to the point of extractor marks and sticky bolts and then backing off, I'll revisit my ideas on the subject.

As far as 2700 fps being adequate for most hunting, I'll agree with that with one caveat:

IF the hunter has ABSOLUTE confidence in the accuracy and killing power of the rifle,cartridge combo at the ranges he limits himself to.

I don't like being limited because of inferior equipment.

I shot a 308 for 35 years.

Ken,

Pressure and heat are definitely linked, but by no means directly correlated in rifle cartridges. My example of the .308 Winchester and .300 Winchester Magnum is a good example. The SAAMI pressure level for both is over 60,000 psi (as I recall 62K for the .308 and 64K for the .300). The .300 burns out barrels quicker not because of 2000 more psi but because the duration of the heat from its larger powder charges lasts longer during each shot.

Big case? Big fire. Little case? Little fire.

Pressure shmessure.

Travis

I love it when the discussion gets all scientific like that.

I'm sure Kenny is ringing the 1000 yard gong weekly with VLD's.

The case head expansion method of measuring pressure is notoriously unreliable, especially when no factory ammo is available for comparison.



Why would it take a catastrophic failure for someone to realize they are over the top?

A round may cause enough pressure to get stuck in the chamber, which may end a hunt. Sounds like reason enough for me to stay away from crazy people loads.



How would an extra 400 fps change this statement?

Ken, what kind of barrel life do you expect with your 220 cartridge compared to 220 swift .

So if I loaded a 250 Savage with the max charge of IMR-3031 at 50K (case at 73% fill) and then loaded a 250 Savage with as much H50BMG that could fit in the case (110%), but at only 35K, the case with twice as much powder would do less damage to the barrel because it's at a lower pressure?

Your first two questions are frankly not worthy of answers.

The third is borderline, but I'll give you a break:

With identical bullets, 400 fps more velocity flattens the trajectory enough to be meaningful, not to mention increasing the bullet's killing range.

Neither of these factors are important to a man twisting turrets and poking holes in paper or ringing a gong.

They make a difference to a hunter.

You have got to be kidding me! Another [bleep] retard Texan on ignore.

Always good to know there are shooters out there who still develop handloads by pushing brass to the max, then backing off a smidgen.

Measuring CHE can work, but only if you have something to compare it to. There is no "magic" amount of expansion that guarantees safe pressures, because cartridge brass varies too much in hardness. This has been proven a number of times over the decades, but apparently you missed the memos.

I don't use the "ignore" feature. Reading posts from idiots is sometimes entertaining.

I just put the little magnifying glass next to their names to remind me that the poster is prone to idiotic posts.

They are free.

You have one on my screen.

My guess is if you load a .50 BMG to the gills with 3031 it will have a short barrel life due to pressure.

Nope, I got the memos. And I have the manuals that STILL offer it as ONE way to monitor excessive pressures.

Matter of fact, the first batches of Ultra Mag brass was REALLY prone to expansion. And extractor marks in factory ammo was not uncommon in the 300. Not so much with the 338 as I recall.

I measured the case heads of factory loads in the 300 and 338 BEFORE and AFTER firing. That was my basis for comparison. I pulled bullets and powder from some and used that brass to compare expansion in my loads.

Do you know of any modern catastrophic failures of rifle actions due strictly to excessive pressure?

And where did you read that I "backed off a smidgen"?

Once data became available, I saw that the loads I settled on as max for my rifles were less, - or in one case, equal to - the max loads in Nosler and Hodgden data.

Last time I looked, the 210 gr., 338 Scirroco was still off the market. I called the owner of Swift and pointed out that the starting load for a 200 gr. NBT was well over max for a 210 Scirroco, and , in the absence of any data for the Swift, lots of guys might do like me and start from there.

I don't know if that played a part in his decision, or not, but he DID offer me a box of bullets for free.

You were applying pressure and wore him out?