I recently purchased a re-stocked and re-barreled pre 64 model 70 In 300 H&H. My first trip to the range with it I shot some factory Nosler 180 grain partitions with an advertised 2950 FPS. I shot 5 rounds that averaged 2450 FPS. 500 FPS less than the “published” speed.

This past weekend I shot three different hand loads. 180 grain Swift Sciroccos with IMR 7828SSC, 180 grain Accubonds with RL22 and 180 grain Barnes X with RL22.

The Sciroccos with 74 grains of IMR7828SSC gave me an average of 2844 FPS, 125 FPS slower than the reloading manual.

The Accubonds with 71 grains of RL22 gave me 2734 FPS, 266 FPS slower than the reloading manual.

The Barnes with 71 grains of RL22 came in at 2766 FPS, 234 FPS slower than the reloading manual.

With all the hand loads I noticed that the case necks on all the fired rounds were powder burned.

Any ideas why I am not getting published velocities?

This may sound silly, but have you checked the brass after shooting to make sure it hasn't been re-chambered to .300 Weatherby or some other "improved" case?

How's the accuracy? How's the bore? A shot-out bore can reduce velocity.

What is the inside neck diameter of the fired cases?

Every rifle is different. Published velocities should only be used as a guide.

If you are using a folding chronograph like a F1 make sure it has been folded out the whole way.

Low light can also cause under readings as can the chrono not being level.

I'd check those factors first on the basis of it be cheap and easy to fix!

Any pressure signs on brass? How is the rifle chamber- tight or sloppy? I wonder if your chrono is accurate. Try to shoot over another one. If you trust your chronograph, then put more powder in cases until pressure signs.

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Originally posted by Go Dawgs:


The Accubonds with 71 grains of RL22 gave me 2734 FPS, 266 FPS slower than the reloading manual.


?

That´s the load I use in my .300H&H. That does +3000 ft/sec in my 24½" barrel rifle.
So your loadmanual does give you the right info.

Blackened powder is an indication of too mild a low that is not expanding the necks and getting powder blow back...Work up a hotter load, your using the right powder. Looking thru my many handloading books, I see two books with max loads of 76 grs. of RL 22 with a 180 gr. bullet.

71 grs of RL-22 is a max load for 200 gr. bullets in several of the books..

Based on your experience, and if your a proficient handloader of some experience I would up my load a 1/2 grain at a time until I saw at least some pressure signs such as a sticky bolt, cratered primer, black ring around the primer, a crack as opposed to a boom, or something to indicate what my gun was about..smokey soot on the neck is definatly lack of enough powder...The old H&H tends to be under loaded perhaps as Ive been shooting and hunting with it for probably 60 years and have experienced much the same as you speak of..A proper chronograph is needed in every case..I prefer the ProChrony and it costs about 120. bucks..If you feel uncomfortable working up max loads, surly you know some smith or friend that will do that for you.

All my 300s over the years got me and easy 3000 FPS with 180 Noslers and 2900 FPS with 200 gr. Noslers, some a little more and some a tad less. I would expect that with RL-22, it meters well and fills a case real well..

If you have access to a place you can shoot 500 yards, just check the bullet drop. I rarely chrono anymore; I zero at 200, check drop at 500 and 800, and from there can calc my MV.

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I shot 5 rounds that averaged 2450 FPS. 500 FPS less than the “published” speed.

Welcome to real world book velocities hardly ever live up to their life.

Thanks for the feedback. I'll respond to the comments and questions

All the cases were new RP 300 H&H cases. The bore is good, the rifle had been shot very little. Inside diameter of hired cases is .312. Outside diameter is .342.

I was using a Lab Radar chronograph. The same day I shot the 300 H&H I also shot 3 different factory loads of 375 flanged. All the those factory loads showed velocity within 20-30 fps of the published speed. I'm fairly confident the chrono is accurate.

No signs of pressure. I'm sorry to say I do not know how to tell if a rifle chamber is tight or sloppy.

I am using the most current editions of the Nosler, Barnes and Swift reloading manuals. The loads I originally mentioned are all max loads for the powder and bullet I was using. I don't have a problem slowly moving above the max loads although all three were at or very close to 100% load density.

The range I belong to only goes out to 300 yards.

Thanks again for your comments.

Sounds as if you have an overly generous chamber, perhaps with some added freebore. You'll find out when you run some of that fired brass through a sizer die, but before that you can compare the shoulder diameter of fired brass with new brass to see just how large your chamber might be.

You don't mention the length of your barrel, and a shorter barrel could be part of the difference. After all, a .300 H&H bullet starts out closer to the muzzle than many rounds, so the distance it travels in the bore is a bit less.

Some rifles just have "slow" barrels, due to any number of factors. It seems you have one of those.

Book max shows in grains for a 180 71 to 76 grs. as max with RL-22...I shoot 73 and I worked up to 76 and it was a hot load, but accurate and got 3100 plus a tad..I backed off to 73 and got just a bit over 3000 FPS and no pressure...

you could take a chamber cast of your chamber, but I see no need in it..I would just tweek what you have if your an advanced reloader and know we always fly by the seat of our pants in that we have no sufisticated equipment as to pressure..but your velocity is worthy of a 30-06 and more like that of a 30-30..

Check your scale ¿Digital or electronic?. Regards, Hector

I agree with Ray here. With your eyes wide open to all potential pressure signs I would push your loads a little harder, sooty necks are like Ray said a sign of a low pressure load.
Also do not use reloading manual velocity estimates as a hard an fast rule as to what your rifle should be doing velocity wise.
Some rifles are slow, some are fast and a lot are average.
Velocity takes a far second place to an accurate reliable load.

When you full length size your shot cases, do they need to be lubed a lot to size or do they go into the sizer die easy? The tougher the sizing goes, probably the sloppier the chamber is. I would put more powder in my loads and watch for pressure signs. I easily get 2900 with 180 bullets in all my 300 H&H's.

those newfangled chronographs broke a lot of 30 magnum owners hearts back in their day.

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Originally posted by Lamar:
those newfangled chronographs broke a lot of 30 magnum owners hearts back in their day.

Don't forget all the 7mm Rem mag guys too!

Just size the neck of a fired case enough to hold a bullet but allow it to move in the case neck and insert into your chamber push the cartridge into your chamber with the bolt or your finger. Carefully extract the case and see how far the bullet has been seated, Your rifle may have been chambered with a lot of freebore which will drop pressures if excessive. May have been chambered specifically for use of monometal bullets which are longer for weight and are also often set up to jump into the rifling for best results.

If this is the case then you will need to load up to get the velocity.

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Actually eagle27, the 300 H&H has such a long sloping shoulder and long neck you shouldn't seat the bullets out in the chamber like on a 30-06 or whatever as the magnum magazine is fully filled with a rather deep seated bullet. What Im trying to say is the 300 H&H case is not compatible with the long throat theory, a practice I believe in btw, but feel the only way to improve the 300 H&H is to use more powder or blow the shoulder out to a 300 Wby or its ilk.