I am fairly new to reloading, and in working up a load for my 300 Wby, I am getting conflicting information. My book mentions one OAL, then I read to chamber all the way to the rifling, or maximum that will allow the mag to function. If I go all the way to the rifling, the OAL exceeds the book by roughly .1". Is this safe? advantagous?

If it is a Weatherby you're loading for and are loading to Weatherby specs, Weatherby rifles have considerable free bore.
I think I'd load to book OAL and see how that does, then work out a bit at a time to mag length and see if it gives me any improvement. Loading into the lands is not a magic open sez me that some would have you think and can be somewhat dangerous if loading for a hunting rifle. Especially for a newbie.
Wait until you've got your feet firmly on the reloading ground before trying some of the things you will hear in cyberspace.

quote:

Originally posted by wasbeeman:
If it is a Weatherby you're loading for and are loading to Weatherby specs, Weatherby rifles have considerable free bore.
I think I'd load to book OAL and see how that does, then work out a bit at a time to mag length and see if it gives me any improvement. Loading into the lands is not a magic open sez me that some would have you think and can be somewhat dangerous if loading for a hunting rifle. Especially for a newbie.
Wait until you've got your feet firmly on the reloading ground before trying some of the things you will hear in cyberspace.

Best advice you're going to get.

I'm new.., but I have 10,000+ rounds for my pistols, but working up a rifle is much more precise.

I've loaded for three .300 WBY rifles. In all three (2 700s, 1 WBY/Sauer) freebore makes it impossible to seat a 180-200 gr projo such that rounds fit in the box magazine and heads contact lands. Possibly a very long for caliber round nose could get you close to the lands.

IME, best .300 WBY accuracy has always come from seating heads as far out as the box magazine will allow. In my .300s the improvement has been striking. This is a good place to state that I never push any cartridge to flat-out max performance levels - and I always use a chronograph to make sure things are sane.

Frankly, WBY freebore simplifies load development for all but really light Pb core projos. I simply load to just under box magazine length and then try on paper.

Sam

I have loaded for many 300 Bees as well. The 700s and M70s I have loaded for have not had the freebore and shot well with OACL within the magazine. The Wby rifles in most cases, have shot lead core bullets better seated beyond the magazine, but still not to the lands. Most mark Vs have shot most of the Barnes T/TSXs best within the magazine. The only exception I've found to date is my current mark V that needs extra length with the 168gr TTSX. The accuracy diffrence makes it worth while to shoot it as a single shot. (It is still well off the lands, just too long for the magazine.)

So it sounds like exceeding the book OAL is not the deal breaker that I thought it was. I am starting with book and stepping out until I get to the magazine limit. I don't want this as a single shot.--- for the record, it is a Mark V

Out of curiosity, what bullets are you working with?

Quintus,

Not to hijack, but I'm interested about the chambers of your .300s. My 700s are throated with at least some degree of freebore section. I say "some" b/c I have not measured and compared the length of the freebore to that on the WBY rifle. I always assumed the throat was freebored the same distance to rifling. But you know about assumptions.......... Anyway, I am unable to get any projo to touch the rifling on my 700s with a COL that will allow use of the magazine....same as with the WBY MK 5 rifle. One of my 700s dates from the first year RP chambered .300 WBY. The other is much later.

Wouldn't Remington and Winchester be taking a risk by not freeboring the throat as per .300 WBY spec? - especially given Weatherby factory loads are not exactly watered down, and most always deliver close to spec velocity.

So I'm wondering if your 700s differ from mine, ie., can you get a loaded head to touch rifling and still fit the mag box?

Sam

ETA Forgot to mention my 700s work fine (no evidence of pressure issue) with WBY factory loads.

I think SH is definitely onto something. If commercial ammo (especially WBY brand) is loaded for a WBY rifle with lots of freebore, wouldn't it be kinda dicey to have a rifle w/o that free bore?

quote:

Originally posted by Ray17015:
So it sounds like exceeding the book OAL is not the deal breaker that I thought it was. I am starting with book and stepping out until I get to the magazine limit. I don't want this as a single shot.--- for the record, it is a Mark V

Think about it; for every gun you load for, you have to determine what is a safe load. You are never going to be able to exactly all details from primer, to bullet to chamber to barrel that's published in any load book. You have to start low and work up so as long as you do so, small details such as COAL don't matter much in a cartridge as large as a 300 Weatherby Magnum.

For cartridges to be fed through a magazine, your first job is to be sure they're short enough to do so. Provided that condition is met, get the bullet as close to the lands as possible without actually touching them. Finally, irrespective of the afore mentioned, there has to be enough bullet seated in the case to hold it securely which is usually accepted as being a caliber length.

Note: this only pertains to cartridges with moderate to large case volumes. In small volume handgun cases, one must be very aware of the published COAL.

"Frankly, WBY freebore simplifies load development for all but really light Pb core projos. I simply load to just under box magazine length and then try on paper." Samuel Hoggson.

This is generally good advice for a Mark V and what I do with mine.
I will also add, it has been my experience that most factory Weatherbys shot better with flat based bullets than with boattails. Your experience may be different.

quote:

Especially for a newbie.
Wait until you've got your feet firmly on the reloading ground before trying some of the things you will hear in cyberspace.

Outstandng advice.

I load for two 300 Weatherbys. Neither of the ultimate loads nor test loads developed showed enough accuracy (or velocity) increase/decrease from OAL tweaking to make it worthwhile.

quote:

I simply load to just under box magazine length and then try on paper.

The best loads with Cup 'n Core bullets (flat bases) shot the best right at 3.6" which was just a tad under magazine length.

The Barnes'(130 gr. & 180 gr. TTSX's) shot best crimped into the front relief groove making the cartridge pretty stubby by normal Weatherby standards and they are extremely accurate.

Since I can imagine that pretty much most 300 Weatherby loads will be hunting loads; making cartridge reliability paramount.

quote:

Originally posted by Magnum Hunter1:
I will also add, it has been my experience that most factory Weatherbys shot better with flat based bullets than with boattails. Your experience may be different.

Isn't that the truth. The difference can be dramatic. My 700 AS puts 5 180 CLs into 1" @100 consistently. Once...once....I substituted 180 gr Sierra BTs - I thought my scope mount had loosened up. Minute of target frame was about it.

Sam

a 700 classic and an M70 classic sporter both had very short throats for the 300 Bee, and both made me uncomfortable with weatherby ammo. The Rem actually was one of the best and most consistant grouping rifles I have ever owned. The Winchester didn't shoot very well with much effort and many attempts. Both are now long gone. Back then I didn't have a Wby to compare to, and had no idea about freebore. I was baffled when I got my first weatherby rifle - in 257 and tried to find the lands with my first load.

SAAMI spec for a 300 Wby will be .361 freebore. Unless you have a custom chamber it will be done to that spec. Of the bullets I've tried in my Weatherby rifles I've found that mag box length minus enough for everything to function is a good place to start. From there seat them a little deeper until you find the accuracy node of that bullet/powder combination.

Ken....