Bullet weight vs style

[Pasco]

I suppose I could apply this question to rifle bullets as well, but my interest now is for handgun reloading.

Next week I am reloading my .357 for the first time, I have some 158 grain JHP-XTPs coming. I will probably be using Hodgdon Universal this time around (published data). I was wondering if, for example, a 158 grain JSP or FMJ from another manufacturer could be substituted for the XTP bullet without changing other components, even though I cannot find that bullet/powder combination published. Is it the weight of the bullet, or the style, that is most important to keeping pressures in line with the book (or both)?

For rifle shooters, can a 50 gr V-MAX be inserted directly into a 50 gr NOS BT load(i.e. .223 load)? Can you explain why or why not? I would think that length of contact with the lands would enter into it.

How ‘bout 130 gr Sierra Gameking Boat Tail Spitzer (for example) swapped for 130 gr Nos Partition Boat Tail Spitzer?

Any thoughts? Hey, I’m just asking, so hold the lectures to a minimum, if you please. :big grin santa hat:

[tmoniz]

Weight is the most critical. I have seen differences in accuracy between say a 165 speer boattail in a 3006 and a 165 nosler ballistic tip, but no real detectable pressure changes using the same case primer and powder charge. As an example my pet 06 load is nickel rem brass, 165 nosler partition, fed 215 primers and 59 grains of h4831sc. That load will put up 5/8's inch one hole groups. But when you change to a Barnes 165 it sucks. 2 inches at 100 yards at best.

[ricciardelli]

You can substitute bullets of the same weight, using the saem components...HOWEVER...the first law of reloading is always to reduce your load when using any new component...even when using bullets of the same make and type, but a different lot number.

[Pasco]

Thanks gents. I thought swapping bullets without seeing the identical combination published was a NO-NO. Glad I asked

[MarinePMI]

Hmmmm....

When using the same weight round, you can substitute load data...Just not the same ballistic data. Load bearing surface and ballistic coefficient are going to have different effects however (and ballistic coefficient applies to rifle rounds at significant ranges).

Always check your zero, as these minute changes may affect how the round leaves the barrel. For example, two rounds may hit the paprer at 100 yds in roughly the same area, but one round may be low and to the right. Bearing surface and how it seats/fills the lands and grooves will determine what EXACT pressure (you know, the thing that sets/determines the actual velocity of the round) and this will effect how it leaves the barrel. An interesting test would be to take a load and run in through one barrel with a right hand twist and another with a left hand twist. Try it. The rounds won't be (all things being equal) on the same spot on the paper. Mainly because of the imparted spin and how it affects the round as it travels through the air at long ranges (for that cartridge). This is merely an example of the practice of reloading and how CONSISTENCY is the key to achieving the utmost in accuracy out of a load. Much like shooting itself,duplication is the key to making a rounddrop in the same hole every time (if the rig/weapon is consistent).

By all means play around with different rounds, but remember...a zero is only good if the same components are used in ALL the rounds used against that zero. Heck, I've seen differences (though subtle) even with the same components, but loaded on a different days. Anal? Maybe. But if you spend the time working up loads, why not follow through and load up A LOT of the same loads at one time. If you're hunting, sitting down and reloading 200 rds in a night will last you for quite some time.

Just my centavos worth...

BTW, with pistol...you're shooting at 25yds (maybe 50 if you're into harball/bullseye). Can you really, or do you have a pistol, that's accurate enough to tell the difference? Then again, I was never much of a pistol shot...