Home Forums Hunting & Shooting Ask The Gunwriters 30/06 Long Throat

Many moons ago Mr Timm wrote an article for, I believe, Guns & Ammo about his testing of a long throated 30/06. He reported pretty substantial velocities.

I assume he increased the pressures to those approved for the 270 Winchester.

There are new powders since those days.

Does anyone have any experience with a longer throated 30/06 using 64,000psi and modern powders?

First, new powders do not do much for the 30-06. The case capacity is too small to hold enough of a slower powder to gain velocity over what can be done with grand old H4831, or if you want to push things a bit IMR 4831.

You know, there might be a couple exceptions here with Magnum or one of the other high density powders which you could actually get more weight into the case.

Second, I rebarreled a 98 Mauser to 30-06AI many, many years ago, and had the mag well and throat lengthened to accept a 165 NBT seated about 1/3 of the way into the neck of the case. I was thinking just as you are, long before the age of internet message boards and the free exchange of load information among peers.

All an exercise in futility. I later learned that I could vibrate as much as 63 gr of H 4831 or IMR 4831 into a Lake City 30-06 Springfield case, so that it filled the case level full, and still seat my 165 NBT to SAAMI COAL. The powder crunched as the bullet was seated. But I never had one push back out.

Then I did the same thing with the Hornady 190 spbt. There was a bit more crunching with the 190.

Remember the Barsness 4:1 rule. Four percent more powder capacity yields one percent increase in velocity.

If you gain room for two gr of powder by extending the mag and throat, on a load of....say...60 gr H4831, that is a 3.3% increase in capacity. If your beginning load produced 2900 fps, you can gain 24 fps without increasing pressure levels.

Actually, you have not gained any case volume. You are just compressing the load less as you seat the bullet.

Sure it is easy to gain velocity with higher pressures. Many of us have gone there and have the expanded primer pockets to prove it. But it is a whole lot easier (and safer) to just use a barrel chambered for a higher capacity cartridge. If you really want 300 WSM velocities, get a 300 WSM. If you want 300 Wea mag velocities, get a 300 Wea.

You see where this is going. BTDT. It is a great exercise in education. Or you can read about what others have done and learn that way.

Don't think I would say new powders are no advantage. Some guys here are running 200 + grain bullets at or over 2700 fps. Myself I like 24 and 26" barrels for extra velocity...mb

It's now number of years back but someone posted his results of a sensor wired 30-06 and 180gr bullets trying to keep them below 60,000psi and achieving that magic 2800fps. RL-22 was the only one then that did it. I use N-560 in a couple of my 30-06s, it was a little over 60,000psi in his tests, 61 or 62 I think. I get 2745 ish, 22", both rifles are within a single digit velocity . That likely why they both can shoot that load. The limiting factor here on COAL is the box on the Winchester. That's not an issue with the Remington.

Hodgdon's listed max for H4831SC gets just about 2700 fps with 200-grain Nosler Partitions from the 24" barrel of my Ultra Light Arms .30-06.

To get more velocity from the -06 I have gone to lighter bullets. Primarily Barnes TTSX. 165's for elk size, 130's or 150's for deer. Used to run 180's at 2800 with IMR4831 but no longer see a need. YMMV.

22 inch Winchester 670 in 30-06 LC 67 brass

11/20/95............165 Sierra SPBT ....62.5 gr IMR 4831.........2906 fps
11/20/95............180 Sierra SPBT.....61.0 gr IMR 4831.........2867 fps
11/20/95 ...........180 Barnes X........62.0 gr IMR 4831.........2949 fps
11/21/95............180 Barnes X........63.o gr IMR 4831.........3011 fps
11/21/95............180 Barnes X........63.0 gr ....H4831.........2745 fps
11/21/95............180 Barnes X........64.0 gr ....H4831.........2766 fps
11/21/95............180 Barnes X........65.0 gr ....H4831.........2819 fps....very slight crater and slight loss of radius on primer
11/21/95............150 Speer SPBT.....64.0 gr IMR 4831.........3022 fps
11/21/95............165 Sierra SPBT.....62.5 gr IMR 4831........2844 fps
11/21/95............165 Sierra SPBT.....64.0 hr IMR 4831........2932 fps

Remington Nickle brass
11/21/95............190 Hornady btsp..60.5 gr IMR4831.........2852 fps ....very slight crater
11/21/95............190 Hornady btsp..62.0 gr.... H4831.........2681 fps
11/21/95............190 Hornady btsp..63.0 gr ....H4831.........2719 fps
11/21/95............190 Hornady btsp..64.0 gr ....H4831.........2775 fps
11/21/95............220 Sierra MKHP....57.0 gr ....H4831.........2336 fps
11/21/95............220 Sierra MKHP....59.0 gr ...H4831..........2500 fps
11/21/95............220 Sierra MKHP....55.0 gr IMR4831..........2477 fps
11/21/95............220 Sierra MKHP....57.0 gr IMR4831..........2534 fps

I never lost a primer pocket with this '06. Much of my brass was loaded up to ten times. It has been quoted by knowledgeable handloaders for fifty years that you can not get enough H4831 into the 30-06 to create an over pressure situation,

Retumbo, H1000, IMR 7828, and RL25 are suited well for magnum cases. I use them in the 264 and 7RM. But you can not get enough weight into the 30-06 case to achieve pressure. Perhaps with a two inch throat and a 250 gr bullet?

4350 burn rate hits over pressure before it can make the velocity available with 4831.(with bullets over 165 gr)

RL 22 is very similar burn rate as 4831. RL22 does have an advantage that it is easier to fit 63 to 65 gr into 30-06 brass.

Magnum and Magpro are a bit slower than H4831, and they are a bit denser. You might be able to beat the velocities I have provided with them or with another similar powder which I am unaware of.

I've done that frequently as well. The latest load tried--which has worked very well, is the 175-grain Barnes LRX with Hodgdon's listed max charge of IMR4451, for around 2850 fps.

But before Barnes and other monolithics appeared, the 200-grain Partition was the deepest penetrating bullet generally available, which is why I experimented with it quite a bit, both for elk and the slim chance of running into an aggressive grizzly while elk hunting--which is possible about anywhere in the western half of the state. Still trust the 200 Partition as much for that purpose just about as much as any other bullet, and at 2700 fps it flies a lot flatter than most hunters would believe.

Ran into several in one drainage near Idaho/Montana border and read about your 30-06 nosler use/rationale. Yeah, parts of that area are thick and close in ranges and it's why I own a 30-06. Before that when on horseback I had an old 348win but it's hard to keep fed

Yeah, I had a .348 for a while, but the bullet problem tends to keep getting worse! Especially in these days when primarily the most popular-caliber bullets and cartridge cases tend to be produced relatively regularly.

Have encountered grizzlies, and their fresh sign, in several parts of western Montana. Can't remember exactly how many I've seen over the years, or the instances of, say, fresh tracks still filling with water on a wet day. One instance occurred while pheasant hunting in the thick valley-bottom brush near St. Ignatius, when I was living in Missoula in the 1980s, where more than one bird hunter has been mauled. My Lab went into the nearby brush on a hot pheasant scent, and I got ready to shoot--but then he came running back with his tail low. I went a few feet further, and found mid-sized grizzly tracks in the damp earth. So we turned around and hunted elsewhere.

Have never been threatened by a Montana grizzly, but the odds tend to increase the more you encounter them. Have hunted in other grizzly country up through western Canada to Alaska, but the only two threatening incidents occurred within less than an hour on Kodiak Island, where two females with cubs bluff-charged the small group of salmon anglers Eileen and I were part of. We were hiking along the edge of Zachar Bay toward the mouth of the Zachar River, where we'd start fishing. Luckily, both sets of cubs soon obeyed their mothers and ran uphill away from us, and their moms followed....

I think many reloaders already encroach upon that 65,000 PSI area which modern rifles and barrel steels easily contain, but if a .30/06 was throated to permit utilizing a 3.6" magazine, it opens a door to a world that threatens a lot of cartridges by also allowing greater utilization of 200 grain bullets especially if a freebored section is included within that OAL.

How much of an increase is a guess, but I would expect something closer to WSM velocities with a 24" or 26" barrel. Of course the greater practical value would still be the 5 down and 1 up the spout which is a value to many.

The other interesting fact is that the action would not need to be opened up as the standard case is still handled by OEM design spec's and a full loaded round will extract from the basic '06 length opening.

I have a cool video on my phone of a fairly close encounter with a good sized Grizzly while duck hunting the Flathead River near my home in Bigfork, MT. This was last November.😊

Interesting! Would love to see the video.

As I noted, have never had any trouble with Montana grizzlies--even when encountered at pretty close quarters. The closest was when hunting spring black bears in the northern end of the Bob Marshall, maybe 5 miles south of Glacier Park, 30+ years ago. Was following a trail through some semi-thick brush, and suddenly at the other end of a clearing around 20 yards away was a mature but not huge grizzly. He raised his head and looked at me, and I looked at him--and within a few seconds he turned around and walked in the brush on his side--and after I heard him moving away for at least 10 seconds, I turned around and went back along the trail the way I'd come....

According to my 4-to-1 Rule (which was derived from crunching pressure-tested numbers) any increase in powder capacity results in about a 25% increase of that capacity in muzzle velocity at the same pressure. This is with the "best" powders for each load, not the same powders.

A 3.6" .30-06 magazine and a similarly longer throat (about 1/4" longer than standard) results in about a 15% increase in powder capacity--which means about a 4% potential increase in velocity--again, at the same pressure, in the same barrel length. This means about a 100 fps increase in potential velocity with, say, a 200-grain bullet at 2700 fps in the "standard" .30-06 in a 24" barrel.

The question might be, however, how much this means in both "killing power" and trajectory. That 100 fps is about as much velocity as a 200-grain spitzer loses in the first 50 yards--and less at longer ranges.

The .300 WSM gets about 6-7% more muzzle velocity than the .30-06 when loaded to the same pressures, in the same barrel length. This means about 2875 fps with 200-grain bullets, which is around what I've gotten with various powders in 24" .300 WSMs. So the "long magazine/throat" .30-06 would be halfway between those two extremes.

Have owned and hunted with a bunch of .30-06s and several .300 WSMs, and have never been able to tell any difference in "killing power" with a variety of bullets at ranges out to 400+ yards. If the bullet landed in the right place, and expanded and penetrated sufficiently (so far all have) the animal died pretty quickly.

Now, the .300 WSM does have a little flatter trajectory at 400, but that ain't much of a problem with laser rangefinders--or even using a scope reticle to estimate range.

Have also found (contrary to what some have claimed on this thread) that "modern powders" can make a difference in the .30-06. An example is the 175-grain LRX load with IMR4451 mentioned earlier, which gets 2850 fps from the 24" barrel of my Ultra Light Arms Model 24. I'm using the maximum charge listed in Hodgdon's data for the 175-grain Sierra--which probably produces more pressure than with the 175 LRX.

All of which is why I sold my last .300 WSM a few years ago, and haven't missed it.

I wrote what I thought was semi-informative post, but was told I couldn't post here. Let's see if this one goes. GD

I tried to make the point above, the longer mag does not actually increase the powder capacity of the cartridge at all, with the extruded powders I am familiar with, and builet weights of 190 gr or less. One can only fit so much powder into the empty brass. When it is full, it is full. A longer mag or throat does not change volume of the brass measured to the end of the case.

A longer mag, and throat does decrease compression of that powder as the bullet is seated.

I held my brass against the spindle of a running vibratory tumbler as I added powder, so that the charges would fit. Then I seated the bullets to SAAMI COAL.


I have no experience with the Enduron powders.

I easily got 2850 fps from the Sierra 180 spbt and IMR 4831, with a 22 inch barrel.

That speed was not available with either of the 4831 powders on hand with the original (ungrooved) 180 Barnes X (high friction version) which was available at that time.

Just my observations, from the days when I made velocity/charge weight graphs for everything I could get my hands on.

Admittedly, these loads were a labor of love. A slower, denser powder, which would fit into the case without vibratory assistance would do much to stream line the loading operation.

An apples to Buicks comparison; but I built a long throated 300 Savage on a 95 Mauser. I was hoping for 308 vels with 150gr and 165 gr bullets. I got them but, newer powders have made the 308 vels unobtainable for the primitive 95 action. I didn't/can't get top dog 308 vels, but can get to the middle of the pack. The drawback is it will only shoot those bullets at that length accurately. If I run short 125/130gr bullets, I'm .1"+ off the lands or the bullet will fall out of the case. Running factory ammo gives me .2" of freebore and shotgun sized patterns.

Idaho Shooter,

IMR4451 is essentially a double-based version of H4350--with a decoppering agent. So it contains more energy than single-based powders like H4350 or H4831SC. The charge I use with the 175 LRX is 57.0 grains, due to the length of the bullet is slightly compressed--but not "crunched."

The IMR Endurons (4451 is one) were temporarily discontinued due to the plant in Canada where they're made having to fulfill military contracts. Apparently the Endurons will be made again once that's done. They're some of the finest powders I've ever used, with 4451 my favorite. Am glad I stocked up on it!

I love the 4451 as well. Great in the 22/250 (80 gr. bullets), the 06, and the 338wm. I'm hoping they get back to supplying it soon. GD

For many years I owned and hunted with the rarest of Mannlicher Schoenauer's, the 1924 High Velocity Sporting Rifle, with the longest throat of any rifle I've ever owned. Factory shells got dismally low velocity, all published loads got well below book velocity. Being young, and thinking it mattered, I started stoking it with faster powders, to get the magic killing velocity of 2800, not 2750 which is useless, grin, with a 180 flat base. Before I was done I was burning a nearly 100% volume load of Win 760. Strangely enough, although way over any published load, I also got good hunting accuracy (4x Pecar in claw mounts), liveable recoil, and very good brass life. Thinking about it in later years, I'd guess very long freebore changes the pressure/velocity graph so radically, that most published data does not apply. My load, when fired in a SAAMI chamber of a Remington model 30S would shake your fillings loose and the primer would fall out at one firing. 70,000 plus maybe. All this for a little more velocity to gain 40 yards of point blank hold. Ah, the folly of youth.