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Reloads for 300 H&H Magnum

08 Apr 2024
@ 05:35 am (GMT)

Curt Clark

I have a fondness for pre-64 300 H&H Winchesters.

However, over time they can get roughed up hunting mainly elk in Montana, so a few years ago I bought a Browning X-Bolt Stainless Stalker in the same caliber. The Winchester has a 26" barrel, and the Browning has a 24". I currently have a sliver VX-III Leupold 3X9X40 1" tube on it using Talley mounts. That all works together well.

For reference, we are hunting for meat, so it's mostly cows. Sometimes bulls. The caliber [and load below] doesn't have much trouble putting the game on the ground. I usually shoot 300 yards or less [off some kind of rest] so even a head shot [not recommending] is doable.

My favorite load so far is:

64 grains of IMR 4831
Sierra Pro-Hunter 180 grain Spitzer
Federal 215 Large Magnum Primer

It seems that old calibers like the H&H like old bullets, old power and old primers the best. Maybe old hunters too. I know one. I can group under 1 1/2 inches at 200 yards which is, in my thinking, respectable. 100 yards, less than an inch.

Both the Winchester and the Browning are strikingly similar in accuracy and behavior. Even recoil. I call it a big push, not a kick. I favor the Browning now because of the magazine. In both guns my reloads are a little tight. Factory ammo and new brass reloads are not. Any ideas? Yes, the dies are probably 60 years old but really haven't been used that much. Not a wear problem anyway.

In addition, I would like a load with the same [or better] accuracy in a 150-165 grain bullet if you're playing with one.

Thanks for any help.

Old guy, old caliber.


08 Apr 2024
@ 07:11 am (GMT)

Nathan Foster

Re: Reloads for 300 H&H Magnum
Hi Curt, from what you describe, it sounds like the die is (as usual) narrow (min spec) at the body and is elongating the case by a few thou. Normally, the case is elongated as it goes through an FL die and then pushed down at the shoulder which finally reduces all dimensions.

The dies may have been made with a specific shell holder which has since been lost. The current shell holder may be thicker and therefore not allowing the case to enter far enough into the die to push the shoulder back. In other words, while you think that your die is loose, the opposite is true - it has a very tight body.

Either way, FL sizing causes a great deal of case distortion before finally reducing case size. It is not an ideal situation. This problem has been compounded more recently via various podcasters (i.e people who derive their income from google / youtube) casting criticism toward neck sizing, stating that FL sizing is the only way to go. These statements can ultimately confuse shooters.


1. Read my Reloading book.

2. If the ammo feeds OK and accuracy is acceptable, leave it alone.

3. Try a thinner shell holder.

4. Try neck sizing. This won't make ammo easier to chamber but it will reduce case distortion, extend case life and help you to maintain accuracy.

The rifle doesn't have to feed with zero resistance so don't get caught up in the modern "I bump .002" trend we are now seeing on the internet. Many of the guys posting these statements do not unfortunately understand that their cases are being heavily distorted in order to achieve the so called bump. In order to achieve a true bump (minor reduction of shoulder length) without heavy distortion, the chamber and dies must be very closely matched in tolerances which in reality is very difficult to achieve. This applies doubly regarding magnum chambers.

Don't worry about the belt. This is likely not an issue, even though it tends to get blamed for everything.

Regarding your loads, something not quite right there, perhaps you misquoted, should be up around 74 grains with a 180gr projectile and 75.5 grains with a 165 grain projectile. If you want to have a bit of a play, there are of course a number of 150 to 165gr projectiles to experiment with, the 165gr SST being a good example. Having said this, there are now some very wide wounding, flat shooting heavy weights that can be highly enjoyable to experiment with and open up well (as per a 150 grain), whether hunting small or larger bodied deer. They may start a bit more slowly than a 150 grain pill but energy is much higher downrange. The 200 grain ELD-X is one example of this. For more on this topic, see my cartridges book.

Hope that helps a bit, Nathan.
08 Apr 2024
@ 08:44 am (GMT)

William Badgley

Re: Reloads for 300 H&H Magnum
I'm no expert but for what it's worth I had the same problem with my belted magnums until I bought a special die made by Larry Willis. It is called a
Belted Magnum Collet Resizing Die. After shooting my magnums just a few times the web just above the belt swells to about .513 to.514. Factory is more like .509 to.510. A standard resizing die can't reach that part. I use to bin my brass after only a few reloading's. Now I get up to 20 reloading's. It doesn't resize the case so you still need to do that as you always did. All it does is push that web back where it swells above the belt. It's always my last step before the powder. Larry died last year but I'm pretty sure someone is still running the business ? I found this on-line if anyone wants to look into it. [email protected]
This may not be your problem, but I know for myself and a lot of other folks this has solved the problem you are describing. Good luck !
08 Apr 2024
@ 07:59 pm (GMT)

Craig Sanford

Re: Reloads for 300 H&H Magnum
I’m glad I found this topic as there is a lot of good info here. I recently acquired a pre 64 .300 H&H and have been trying to figure out how to move forward with it. I have had the rifle for months and been unable to shoot it and this is keeping me awake at night! I live in Alaska and it is extremely difficult to find this ammunition here and practically impossible to get it shipped up. I have access to reloading gear but components are still difficult to obtain. Brass is available online and can be shipped up but the prices are obscene. I can literally buy factory loaded .300 Weatherby ammunition locally for little more than the price of shipping up .300 H&H empty brass. The stores here regularly stock .300 Weatherby ammunition and I have been considering having the rifle rechambered for it. I am not worried about the collectibility of the rifle as previous owners refinished and modified it to the point any collectors value is not a concern and moreover I want rifle to hunt with as I very much like the features these older models had to offer.. I would very much appreciate any opinions from you H&H aficionados.
By the way I strongly recommend the book series. I got the full set last year and it is the best collection of information I’ve ever seen.
09 Apr 2024
@ 07:33 am (GMT)

Nathan Foster

Re: Reloads for 300 H&H Magnum
Hi guys, OK will do this one at a time.

Hi Bill, regarding the belt sizing die - If the chamber is very tight and right on min spec, then it can make sizing difficult. The key to alleviating this in the first instance, is to not cut the chamber to min head space. But in addition to this and to make life easier all around, rather than cut to mid spec, the belted mags go very well when cut to max head space so that the no-go gauge allows the bolt lugs to begin engagement with the rebates. After assembling the rifle, barrel at full torque, the bolt may close to about 1:30 or 2 O'clock. This head spacing may seem loose to some smiths, but the rifle will be accurate after fire forming to the shoulder and easy to load without any case head issues. These are the instructions I provide for 7mm practical chambering - a very accurate cartridge.

Hi Craig, yes you could likely ream to the Weatherby. The throat of the Wby is very long and the neck diameters are near enough the same. The smith might however want to (best if he did) turn the barrel in just a touch so that he gets a fresh reading off his belt gauges and to clean up the case mouth transition.

The downside of chambering to the Weatherby is 1. Your barrel is already very old and may have unseen corrosion that will limit results and 2. the M70 was never really long enough for these full lengths magnums, even though the receiver was milled larger than its kin. In actuality, the receiver really only just fits the .300 Win Mag if using modern hand loads. The mag box does not allow any flexibility if you ever wish to hand load the Weatherby, but it will house the Win Mag. Although it may seem unsightly to you, you might want to consider a new stainless barrel chambered in .300 Win Mag or the shorter .338 Win Mag. Something to think about anyway.
09 Apr 2024
@ 05:45 pm (GMT)

Craig Sanford

Re: Reloads for 300 H&H Magnum
Hi Nathan, thank you for the reply. The point regarding the mag box is well taken, and I do recall from your rifles book that the magazine length of these old Winchesters was not all that generous. A new stainless barrel in .300 Win Mag may indeed be the way to go. The original stock is long gone and since replaced with a new laminated wood stock, so a new stainless barrel would actually look right at home. The existing barrel is the original, all the way from the year 1949. The bore and crown seem to be in decent condition although the exterior was refinished at some time, but as you said there could be some unseen corrosion... I certainly have some options to consider with this one. I had really hoped to explore the potential of the original H&H chambering but ultimately it may prove more realistic for me to rebuild as a Win Mag. I have an affinity for pre 64 model 70 rifles.. Alaska made them the official state gun about ten years ago. Thanks again for sharing your knowledge!
25 Apr 2024
@ 05:55 pm (GMT)

Craig Sanford

Re: Reloads for 300 H&H Magnum
How quickly things can change! I was ready to take the rifle to a gunsmith and have a talk about a new barrel, when I found a deal locally on a good quantity of .300 H&H ammunition and brass. A few boxes of factory ammunition and a couple hundred reloads plus some fired brass. I have, of course, been of the mind to pull the bullets from the reloads and refill them with new powder. I’ve never been one to trust other peoples reloads. The problem here is these are some of the best looking reloads I’ve ever seen. Honestly these look great. They actually look better than most factory ammo. All the load data is included and it seems clear that the gentleman who loaded these was keen on precision. All of the reloads have Sierra Match King or Hornady A Max bullets. I have no doubt they were loaded with long range accuracy in mind. So now I’m kind of undecided between tearing down these beautiful cartridges or taking the risk of shooting them. I am going to consult with an older, more experienced hand loader to get his take on this. In the meantime, I can try out this old rifle with some hard to find factory ammo!
25 Apr 2024
@ 06:47 pm (GMT)

Magnus Vassbotn

Re: Reloads for 300 H&H Magnum
Hi Craig.

Here's how I see it regarding those hand loads:

From what I gather, this is to be an Alaska hunting rifle. Unless you plan on using those bullets for hunting, I would not waste case life or barrel life on shooting the hand loads. If you're gonna use them for hunting (and deem them safe), all good. Alternatively they could serve as practice rounds for steel etc, provided the have similar velocity and BC to the hunting load you're gonna use. However, even though they look good and are probably loaded with accuracy in mind, there's no guarantee they'll shoot well in your rifle. You could shoot a few groups and see, and then use the then fire formed brass to start load development with your preferred hunting bullet. In order to feel safe, I would disasemble a couple of them and check the charge weight up against book max. You'd just have to trust that the powder type on the provided data is the same as in the actual cartridges. Then I would make sure there is at least a little bit of jump, and that the bullets are not jammed in the lands. Your reloading buddy can probably help you. For the first couple of shots I would put on goggles, double hearing protection, and hold the rifle behind a house corner with one hand, so there is no way any potential shgapnel can hit anything other than your hand.

But I would not mess around, and rather just disassemble all of them and put all my time and energy into my actual hunting loads from the get go.

26 Apr 2024
@ 08:14 am (GMT)

Craig Sanford

Re: Reloads for 300 H&H Magnum
Hi Magnus,
Thanks for the reply. Those are pretty much my thoughts as well. I’m still inclined to pull these apart and reload as my own. It just gives me pause to think how much effort the last fellow must have put into making these. At the end of the day it’s probably not worth the risk to try someone else’s reloads no matter how good they may be. Brass life, as you mentioned, is a big concern here… I looked long and hard to find this stuff! Thinking about the 208gr ELD-M bullets for my purposes. I’m just excited to give it a go. While I have a great deal of experience with handguns and semiautomatic rifles, I consider myself a relative novice in the areas of long range precision shooting, bolt action rifle accurizing and hand loading. Finding this website really got me interested in these things, and after getting the book series last year and reading it all, I’m ready to go for it. I’m hoping to get this .300 H&H project together in time for spring black bear hunting. I will try to post updates as I go along. Thanks again to all who have contributed to this topic.
29 Apr 2024
@ 11:33 am (GMT)

Mike Davis

Re: Reloads for 300 H&H Magnum
Having been caught out advice
pull the reloads...and write down what you believe is in them..take careful note of overall length....
IF AND ONLY IF what you get on the scales tallies up with what the given recipe is AND you can find book data that says its ok..put loads back together and use them...but it will only take one load to be off and it can ruin a heck of a lot more than your day...far better and safer to pull them,dump powder if cant 100% be sure its what its said to be (by comparing to new stuff out of tin) and reload with fresh powder and primer..too easy to fire off primers and start again.
I chucked $4-500 worth of powder on my back lawn as couldnt guarantee it was correct..... it hurts but sometimes its just safest thing to do
believe me when I say blowing up your favorite rifle is not a good experience.
06 May 2024
@ 04:39 pm (GMT)

Craig Sanford

Re: Reloads for 300 H&H Magnum
Hi Mike,
Thanks for the reply. I had the reloads checked over by a more experienced hand loader and he said they should be good to go. I will still plan to pull them and reload myself to save the longevity of the brass if nothing else. The currently loaded projectiles are not really what I would select for my hunting needs. The dilemma now is finding a proper base to mount a scope. The rifle had 2-piece Weaver bases when I got it. I noticed the rear base had only 1 screw so thought 1 was missing, then realized the bridge was only drilled and tapped for 1 screw! Not sure what the previous owner was thinking there. So off to the internet to buy a 1-piece Redfield base. I found a base for the correct make/model and serial number range. Not even close. Measured hole spacing and ordered a different base with matching measurements, although a different serial number range. Very close but not quite. Seems like it must’ve been a 1949 custom job, and will need to be in 2024 too.
12 May 2024
@ 12:16 am (GMT)

Craig Sanford

Re: Reloads for 300 H&H Magnum
At long last I was able to try out this old rifle, albeit with iron sights only. I found an old box of 220-grain Winchester Silvertip ammunition that looked like it had been on the store shelf for half a century (or more) waiting for someone to use it. Gave her all 20 rounds… Worked great! My first impression is the rifle is true to the reputation for H&H smooth feeding - and of course the expected Model 70 reliability. Accuracy was as good as could be expected with iron sights and old ammo, fair groups but printing high at 50 yard with the fiber optic sight the previous owner installed. A taller front sight is now on the to do list, along with a custom base, cera-kote, glass bedding, and of course a thorough work up of reloads. Suffice to say this project is going to take a while before completion. I will use the trusty old .35 Whelen for my spring bear hunt later this month, arguably a better tool for the job anyway as our bear hunting is typically a closer range affair. I will aim to have the .300 H&H ready for her tryouts with caribou and moose in a few months, thus allowing for some true long range practice in the meantime.


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