I am new to reloading rifle shells and I am reloading some of my once used .257 brass. The Weatherby cartridges in 115 Gn Nosler bullets show an overall length of 3.029 in the Nosler webpage. As I still have some unfired factory cartridges, I measured these and they measure 3.16". Should my reloads match the factory loads or the Nosler figures? I know they are close but wanted to be correct as the factory ammo shoots very accurately, (best group of 3 measured .29 in at 100 yds). Thanks for the advice to this newbie advance!
Differences in overall cartridge length - .257 Wby Mag
- Thread starter Jetjock
- Start date
I'm assuming you have no tools to measure to the ogive , so what you could do is load long and try the first shell gentle on the bolt adjusting shorter UNTILL you feel that the bullet is not contacting the lands , then try 5 and see how they shoot and go from there .All bullets will have a different measurement to the ogive so keep a record and do test on each new bullet you try. Have fun.
You better buy more of that factory Ammo if your after group size . You will have a tough time duplicating without a chrny to test different powders and even then results will vary
You better buy more of that factory Ammo if your after group size . You will have a tough time duplicating without a chrny to test different powders and even then results will vary
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If you're trying to replicate a factory load, by all means use the same OAL as the factory cartridge assuming you're using the same bullets.
You should consider that you might get better accuracy (than factory) by finding a load and OAL customized for your rifle. For most of us, the published OAL is largely irrelevant. We judge max OAL by the dimensions of the chamber of a particular rifle, or by the maximum length that will load in the magazine. Google load development and cartridge overall length.
You should consider that you might get better accuracy (than factory) by finding a load and OAL customized for your rifle. For most of us, the published OAL is largely irrelevant. We judge max OAL by the dimensions of the chamber of a particular rifle, or by the maximum length that will load in the magazine. Google load development and cartridge overall length.
It is a simple question but the answer is complicated. I suggest you read this article on COAL by Bryan Litz from Berger, and then post any follow up question you may have. Great groups by the way... I can see why you want to replicate that.
Correction! I misrakenly used the wrong OAL from the Nosler website. They give the cartridge length as 3.209. Factory Weatherby shells measure 3.167. Sorry for the confusion. Just looking at the bullets, the Nosler 115 gn are more pointed than the ones in the factory box.
If you want to take more meaningful measurements I would suggest you get some Hornady tools to measure from the ogive to the base, not the bullet tip to the base. What you need beside a vernier gauge is:
1. Comparator Body - to hold the caliber specific insert
2. Insert for your bullet size - #4-25 for 0.257"
And while you are at it, you may want to also order the insert required to measure your cartridge length to the shoulder for accurate resizing. It uses the same body as #1 above:
1. Headspace Bushing - For the .257 Weatherby, the 0.400" "D" bushing should be the right one
1. Comparator Body - to hold the caliber specific insert
2. Insert for your bullet size - #4-25 for 0.257"
And while you are at it, you may want to also order the insert required to measure your cartridge length to the shoulder for accurate resizing. It uses the same body as #1 above:
1. Headspace Bushing - For the .257 Weatherby, the 0.400" "D" bushing should be the right one
I wouldn't sweat the details too much, there's not much use trying to
predict what 40 thousandths will do in a rifle/cartridge with 3/8" of free- bore. However you do have to start somewhere, so
I'd either load to the factory length, or magazine length minus enough rattle room for sure function and easy loading. 30-40 thousandths off end-play is great.
If you want to put the Nosler manual to use, read the rest of
it. The tech section or notes from the lab will inevitably mention that they got their best accuracy loading to magazine length with the Weatherby cartridges.
My .257 Weatherby die was set for
The Ballistic tip at 3.333" . I can scientifically prove that it is an easy number to
remember.
predict what 40 thousandths will do in a rifle/cartridge with 3/8" of free- bore. However you do have to start somewhere, so
I'd either load to the factory length, or magazine length minus enough rattle room for sure function and easy loading. 30-40 thousandths off end-play is great.
If you want to put the Nosler manual to use, read the rest of
it. The tech section or notes from the lab will inevitably mention that they got their best accuracy loading to magazine length with the Weatherby cartridges.
My .257 Weatherby die was set for
The Ballistic tip at 3.333" . I can scientifically prove that it is an easy number to
remember.
Funny, I had the same issue about 3 years ago with the identical Bullets. I have a 257 WM Lazerguard. It would shoot the factory 115 NBT to about half to 3/4 inch 3 inch groups consistently. I got a good deal on the Bullets and it was the cheapest way to get brass lol. Anyway, I reloaded to Nosler max published data and the groups doubled in size. I loaded to factory coal and the groups are now 1/2-3/4 inch again). Bottom line is that Norma knows what it is doing and in my opinion, loading close to the lands is over-rated in most factory hunting rifles. I now usually load dummy rounds up and use the marker technique to get the max bullet seating length then I know the max I could go without ending up with a mess at the range. Lol! Enjoy loading for the Weatherby 257, it is a hoot!
). Bottom line is that Norma knows what it is doing and in my opinion, loading close to the lands is over-rated in most factory hunting rifles. I now usually load dummy rounds up and use the marker technique to get the max bullet seating length then I know the max I could go without ending up with a mess at the range. Lol! Enjoy loading for the Weatherby 257, it is a hoot!
