i am new to reloading. was wondering if load data is different because of bullet diminsions, as to why you cant load the same powder charge for different bulletts. like 180 hornady SST's and Nosler 180 Ballistic tip bullets. i figure the shape and length is where the difference is. if someone knows could you confirm this for me . i am trying to find a good elk and deer load for my 300 win mag. the over the counter accubonds and silver tips are great but wanted to do it my self and save some money.
bullet laoding comparrison
- Thread starter bear71
- Start date
- Nov 4, 2004
- 25,559
- 9,657
bear71
Welcome to the forum, glad to have you here with us.
Every bullet manufacture uses their own lab to test their bullets. Having different test rifles or barrels (chamber dimensions with in SAAMI spec) along with various components, different powder lots, etc. causes different pressures.
What you will find is the same make, model, and caliber may shoot the same load differently and have a preference for certain bullets, powders, etc. This is why you always want to start low and work up to Max loads. Your rifle may even reach MAX before you get to the published MAX in your loading books.
Take a look at the 180 gr AB for your 300 Win Mag. Try RL 22 and work up to 75.0 grs. This load has shot well under MOA for me in three different rifles and there are several others here that have had excellent accuracy in their rifles as well.
JD338
Welcome to the forum, glad to have you here with us.
Every bullet manufacture uses their own lab to test their bullets. Having different test rifles or barrels (chamber dimensions with in SAAMI spec) along with various components, different powder lots, etc. causes different pressures.
What you will find is the same make, model, and caliber may shoot the same load differently and have a preference for certain bullets, powders, etc. This is why you always want to start low and work up to Max loads. Your rifle may even reach MAX before you get to the published MAX in your loading books.
Take a look at the 180 gr AB for your 300 Win Mag. Try RL 22 and work up to 75.0 grs. This load has shot well under MOA for me in three different rifles and there are several others here that have had excellent accuracy in their rifles as well.
JD338
6mm Remington
Ammo Smith
- Feb 27, 2006
- 5,276
- 708
bear71,
As JD338 said, even barrels from the same manufacturer in the same make, model, and chambering will have various differences. One might have a tighter chamber, a rougher or smoother bore, and many other slight differences that make a difference on how a loaded cartridge of the exact same standards will perform differently, and possibly have different pressures resulting as a result of those differences. We did a test on some Remington 700 Varmint rifles chambered in .308 Winchester. We shot the same load from the same lot of powder in each. Most had 24" barrels but one had a 22" barrel and one had a 26" barrel. You are supposed to get more velocity with the longer barrel, but in some cases the 22" would be faster than the 24" barreled rifles and on par with the 26" tube. Even the same rifles with the same 24" length barrels showed differences in velocity while fireing the exact same load. Some of the differences between 4 rifles with 24" barrels that we tested was more than 100 fps between the high and the low barrel, or even more in some cases!
Each bullet from different makers also have different components of metals that effect how hard the metal is, the shapes are not the same from one maker to the next, and a variety of other very small differences can make a huge change in how much pressure is created by a load that is exactly the same except for the bullet loaded in the cartridge. That's why for example when I started loading some 165 gr. Accubonds in my 30-06 using IMR4350 powder, I dropped down a couple of grains from my load that I had been using for the Partition bullets from Nosler just to be on the safe side and go from there. Hope this helps.
As JD338 said, even barrels from the same manufacturer in the same make, model, and chambering will have various differences. One might have a tighter chamber, a rougher or smoother bore, and many other slight differences that make a difference on how a loaded cartridge of the exact same standards will perform differently, and possibly have different pressures resulting as a result of those differences. We did a test on some Remington 700 Varmint rifles chambered in .308 Winchester. We shot the same load from the same lot of powder in each. Most had 24" barrels but one had a 22" barrel and one had a 26" barrel. You are supposed to get more velocity with the longer barrel, but in some cases the 22" would be faster than the 24" barreled rifles and on par with the 26" tube. Even the same rifles with the same 24" length barrels showed differences in velocity while fireing the exact same load. Some of the differences between 4 rifles with 24" barrels that we tested was more than 100 fps between the high and the low barrel, or even more in some cases!
Each bullet from different makers also have different components of metals that effect how hard the metal is, the shapes are not the same from one maker to the next, and a variety of other very small differences can make a huge change in how much pressure is created by a load that is exactly the same except for the bullet loaded in the cartridge. That's why for example when I started loading some 165 gr. Accubonds in my 30-06 using IMR4350 powder, I dropped down a couple of grains from my load that I had been using for the Partition bullets from Nosler just to be on the safe side and go from there. Hope this helps.
Reloading guides are just that... guides. Every rifle is it's own critter, and what shows pressure in one may not show pressure in another... and my lock the bolt on yet another. Every reloader should have a chronograph... and use it in load development. If you're seeing something odd... then something IS odd. If you're using a load that's 3 grains below book... but getting max book velocities... then you're at about max. Same is true with running a book max load and seeing 200 fps less than listed... add a little powder at a time untill you get 100fps or so from the max velocity... and call it good. Also, the Nosler #5 and #6 have excellent articles about reading pressure signs... I suggest you give it a look.
Reloading ain't rocket surgery... but it can be frustrating. Just remember the old addage "there is no free lunch"... and you'll be fine.
Reloading ain't rocket surgery... but it can be frustrating. Just remember the old addage "there is no free lunch"... and you'll be fine.
DrMike
Ballistician
- Nov 8, 2006
- 37,522
- 6,565
bear71,
As has already been stated, differences in bearing surface (the surface of the bullet in contact with the rifling), differing metallurgy and differences in tolerances in the barrel all contribute to differences noted in the manuals and guides. It is a good practise to stay with the recipes that you know are tested, at least until you are comfortable with reading pressure signs and knowing how to avoid trouble. Hand loading is a delightful and profitable hobby for shooters. Best of luck in developing a load for your 300 Win Mag. Few events are more satisfying than taking game with a cartridge you developed and loaded for yourself.
As has already been stated, differences in bearing surface (the surface of the bullet in contact with the rifling), differing metallurgy and differences in tolerances in the barrel all contribute to differences noted in the manuals and guides. It is a good practise to stay with the recipes that you know are tested, at least until you are comfortable with reading pressure signs and knowing how to avoid trouble. Hand loading is a delightful and profitable hobby for shooters. Best of luck in developing a load for your 300 Win Mag. Few events are more satisfying than taking game with a cartridge you developed and loaded for yourself.
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