Home Forums Hunting & Shooting Ask The Gunwriters why reduced/downloaded rifle cartridges frown upon?

Here is Dr. Brownell's graph of pressure vs. powder charge for 3031 powder in a 30-06, behind a 220 grain bullet.

Below 30 grains, the pressure becomes more erratic.

Note that he got one reading of ~48KPSI with 20 grains of powder, a pressure very far from typical.

Although I think nobody fully understands this, the rule of thumb that evolved was that if you're using slow powder in a rifle, the case needs to be at least 2/3 full. I can't say that the rule is reliable, but it is true that there is demon that lives in small charges of slow powder in rifles. Just where he lives is not clear.

I shoot cast bullets for many reasons. I like cast bullet loads.

What happens when you do both? I recently bought a RAR in .223, then made some reduced loads for it! Of course, this was an experiment to cover the .22LR shortages, but I digress......

Informative post.

Do you know if Dr. Brownell determine pressure v.s. powder weight with Red Dot vis-a-vis C.E. Harris' 'The Load'?

I believe you have fun!

Denton, good info, thanks for sharing. Do you mind providing a reference? I'd like to read more about Dr. Brownell's work in this area.

Regarding the OP, I often use reduced loads for subsonic/suppressed shooting, even in large cases, but rarely run reduced loads for any other reason. I use cast bullets for most of my suppressed/subsonic loads as well, which in my experience are more consistent and less prone to stuck bullets in highly reduced loads.

That describes it 'to me'.


Jerry

Personally, I find "reduced" loads often are much better for specific tasks.

Loading a .223 with 32-35 grain Hornet bullets and 8-12 grain loads of Green Dot makes for a superbly useful round to vaporize small varmints. It does so with very reduced noise levels and virtually no recoil. While ultimate maximum range is reduced a little, they are still well more than enough to whack coyotes with. Similar .243 loads are equally an improvement for that work. Using the very light weight, very fragile bullets at 2000-3200 FPS instead of 22 lr/22 Mag makes for a lot of fun and quiet fun at that.

Less in this case is actually more.

[size:17pt][i]Reference for Brownell Data[/i][/size]

Dr. Brownell did this formal paper for Dupont, plus he published a series in one of the gun mags about the same time.

If you search through the article and look at the oscilloscope traces you can see small ultrasonic oscillations riding on the pressure curve in some places. Current equipment would deliberately filter out those oscillations. In his popular press articles, he found some disturbing large, fast spikes riding on the curve with reduced charges of slow powder.

He was using a Tektronix 564 oscilloscope. I worked at Tek not much later. Brownell was coached by some friends of mine, who also trained me in physical measurements so that I could be the regional physical measurements support guy when I was a Field Engineer.

I don't think it presents any particular danger to back off 2-3 grains in large case rifle loads in order to manage recoil. I think the trouble begins when the case has a lot of empty space and slow burning powder.

There are exceptions, John! I've been dinking around with reduced loads since 1968 when I was a sophomore in HS. Back then it was 155gr. plain base cast bullets over 6gr. Red Dot in a .30-40 Krag. Can't say how many thousand shots of that load I shot away in the backyards of my life in that and similar cartridges. I still shoot that and similar loads in all my .30's, none bigger than an .30-06. Cheaper than premium .22 LR's.

Loads like that do indeed buy a lot more trigger time for the buck. The gas it takes to get to the range and back costs me more than an afternoon of shooting.

A wise man told me once that all a bullet has to do is go fast enough to make a hole in the paper. When hunting season rolls around, up the ante, sight-in, go hunting.

I got into reloading back in 2000 with the help of several of the folks on this august forum (back then we were on shooters.com) for the specific reason of downloading 357 Mag, 44 Mag, and 30-06.

I'll speak about the latter one first. I was shooting 30-06 at whitetail deer and wanted a load that could work at treestand distances, and I really did not need more. I ended up shooting about 5% off MAX with H4895 under a 165 grain bullet, and after all this time, I have not found a better deer killer inside 250 yards.

I was also raising two sons to hunt deer, and I found a 12 yr old could handle a 30-06 as long as it wasn't loaded up to the MAX.

With 357 Mag and 44 Mag, my theory was to load 38 SPL and 44 SPL loads in 357 Mag and 44 Mag cases. That would allow me to shoot lighter loads for practice while not eroding the chamber. I started with Unique and migrated over time to TiteGroup and Universal.

These are all middle of the road powders as far as burn rate. I mostly stay away from slow powders for specifically the reason that I don't want to encounter the demon.

It costs me time and more money to shoot reduced loads, and the recoil improvement wasn't world changing, so I stopped.

I played with 125 BTs and H4895 for a 30-06 for a little while. I normally use H4350 or IMR4350, with 150-180 grain bullets. Experimenting with 125 grain bullets and another powder meant more money buying more components that I probably wouldn't hunt with anyways. And the recoil, though noticeably reduced from 180 grain loads, was not that different from 150 grain loads. And it was certainly still more than a low recoiling 6BR or 22 LR max load.

If I want to shoot I prefer a low recoiling rifle. A 22 LR is probably the most fun for me (especially shooting cans or whatever with the kids), and the 6 BR takes care of longer range stuff.

If I want to practice with my hunting rifles I shoot them with full loads.

I've seen 7yr old girls have fun with both .223 rifles and downloaded "deer rifles". They couldn't really tell the difference. A 7lb 7mm-08 youth gun can actually have a bit of kick to it with full-house loads, but not with blue-dot loads and varmint bullets. It gets a person familiar with a rifle and lets them grow into it. Does it have the downrange ballistics of a varmint rifle? No, but it can still be a good tool for practice. I also download my Whelen single shot for primitive weapons season, simply because I don't like the recoil with full-power loads. Kills just fine at .358win carbine speeds.

Old farts have time. 😄 Plus arthritis and a miscellaneous pains😞

One of my nephews started out with a 7mm RM loaded to 7x57 power. Another nephew started out with a 308 at 30-30 levels.

One of my 06's shoots nothing but cast.

Sometimes it's nice to have camp meat. A reduced load works well for that.

Curious how his 20grn load that pressure spiked would be right in line with a 40grn powder charge...seems pretty clear he double charged on one.

Thanks Denton for the good info.

I've been rightly accused of dinking around with reduced loads in the past, basically as a means of producing a low-recoil practice load. I don't dink around with them any more, I've pretty much got it pegged.

Just load the case in question with about a 40-45% case capacity charge of AA5744, and you should be GTG. I've heard some folks like to us Trail Boss for this now, too, but I've been using 5744 with great results for a long time and it works really well. I first learned about this concept from the Speer Reloading Manual #12, which recommended a reduced .308 Win load using AA5744 and the 100 gr Plinker bullet to make a very light recoiling load suitable for young kids, small gals, etc, to learn how to handle and shoot a fullsize .308 caliber rifle. AA actually published a note about how to use this powder for reduced loads as well, some time ago.

I'll typically load 3 rounds each at 40%, 40% +1 gr, +2 gr, +3 gr, and +4 gr. (In other words, if a full charge of powder up to the base of the bullet was 50 gr, I'd prepare test loads of 20, 21, 22, 23, and 24 gr.) Take 'em to the range and see which one is most accurate, then use that as your practice load. So far it's worked well for me in .308, .30-06, .338 Mag, and .375 H&H Mag applications.

The other "reduced" load application I learned about from Paco Kelly's "Lever Rifles" book years ago. Simply load a long-for-caliber cast bullet over 2-4 gr of Bullseye. In my case, I tried it with a 6.5x55 Swede 1893 Mauser rifle, loaded with ~160 gr cast bullets. I got about 850 fps with that load out of my military Mauser (long barrel helps) that was quiet enough I could use it to shoot feral cats in the city without scaring the neighbors.

Not that I actually shot any feral cats, mind you. Certainly not any feral tomcats yowling around the house at all hours of the night when the neighbors she-cat was in heat and locked up in the old bat's screened porch for days on end. No, not me. This was strictly a theoretical sort of study kind of load development deal, sorta. Ahem.

I wonder if one could down load 223rem to 22lr levels with either cast bullets or hornet bullets?

If so what powder would you use? Unique? 2400? trail boss?

AA5744 or Trail Boss. Use 40% of case capacity as your hard deck, if you load below that you risk getting bullets stuck in the bore.

A cast bullet can be pounded out of a barrel fairly easily without harming the bore. A jacketed bullet, not so much. Don't ask me how I know this.