Bullet Weight

[D.Hayden]

I know this had to be discussed before but can't find it.

I've been loading and trying a few different bullets and weights..

It seems that most people shoot the medium weight bullets like:

Sierra 69 HPBT MatchKing

Hornady 68 HPBT Match

vs. (heavy)

Sierra 77 HPBT MatchKing

Hornady 75 V-Max

Hornady 75 HPBT Match

vs. (light)

Hornady 55 V-Max

Sierra 52 HPBT MatchKing

and for us cheapskates:

Winchester 55 FMJ

Hornady 55 FMJ

What's the advantage to the heavier bullets? Is it just for less wind deflection?

It seems that a very fast flat shooting bullet like the Sierra 52 should work better.

Is is just which bullet shoots best for your rifle, or do I need the heavier wieghts? Or just shoot the heavier bullets in certani conditions?.. The 55's work well for me (mostly shooting under 200yds) - one day I'll get to shoot at 400yds in practice and see what they're doing.

[davidwiz]

If for USPSA or IMG 3-Gun, the longest range you're going to be shooting is around 300 yards, with most targets being from 0 - ~25 yards.

All else being equal, a heavier .223 bullet w/ a good BC will be deflected less by wind than a lighter bullet, and, also have less drop. However, a heavier bullet will usually cause more felt recoil.

What some people have taken to doing is to use store-bought 55gr .223 ammo for the close stuff, and heavier (69gr or 72 gr) bullets for the long range stuff, either reloaded or purchased already loaded. There are also people who use 55gr bullets exclusively, and don't seem to have a problem with the further out targets.

Basically, it boils down to 1) your budget, 2) what your rifle likes, and 3) what feels comfortable to you.

-David

[Wap wap]

Bullet drop equal time to target, the shorter the time (or lack of) to target the "flatter" the hold on the target regardless of bullet BC. Most 40-60 gr. .224 bullets have BC around .255 a 69 gr. .375. If the 40 gr can be shot at 4200 fps they have the same drop as a 69 gr. at 3200 fps. Problem- difficult to get either out of AR type guns. A 24 in varmit heavy will push a 69 gr to the curve but the same load in a 16 in runs about 2400. problem- which bullet has the best characteristics of both flat traj. and knockdown. Depends on your barrel length and use. Recoil in an AR hold the barrel down with weight, problem - how much --depends on the shooter. The recoil difference between 55 and 69 gr is about the same as between 40 and 50 gr. I think it's amazing someone can tell the difference between 10 grs on a gun that weighs close to 49000grs., that would be a 2.04 -4e weight change in ejecta mass. In any case put a 1/2 oz wheel weight on your hand guard.

[MikeFoley]

There is discussion of this on Matt Burkett's AR15 video. The larger bullets have more energy at 300 and beyond where you need the power to knock down steel or to move targets enough for a visual if it is that type of target. Your rate of twist determines which bullets you should start with in your barrel. Here in KY, in TN, and at Nationals at PASA in 2003, 55 grain is more than enough because of the limited distances we shoot.

[Zak Smith]

On a silhouette, hits were barely perceptible with XM193 at 500 yards. Switching to 75gr made it easier to observe. Switching again to 110gr 6.8SPC was much easier.

FWIW, I shoot 75gr on far stuff because it shoots great in my gun and hits the steel a little harder (which makes spotting hits faster), and then switch over to XM193 for 100 and in.

-z

[George]

I'm with Zak on heavy for far so the flashers react better. I shoot a SMK 77 at 205PF for anything 225+. For under that, I use either a 69 SMK handload (185 PF) at large matches, or a 55gr junk ball handload (165ish PF) at club level matches.

I also use the JP reticle in my ACOG so the 77's are on the button with the hash marks for LD work with no thinking about hold offsets, just pretty much pick a line and shoot.

--

Regards,

[D.Hayden]

Ok, cool.. this is making more sense.

So, if it's a real mixed stage, starting at 25yds... and targets going 200yds plus.

Are you starting with a cheap - load 55FMJ magazine, then changing to a mag with 68/69's or 75/77s?

I was thinking of doing that, wasn't sure if that was my cheapskate side coming out.

[George]

Nah, if there are 2 pieces of steel at just under 200 and 30 rounds at under 50 yards, the 55's will do it all at club matches and the 69's at large matches (for me). But if the stage is mostly steel and has stuff spread out from close to over the horizon and if there are any targets at 250+, then I keep it simple and load 77's across the board.

If it weren't for how well the 77's shoot in my JP 1:8 bbl and the calibrated reticle, I would probably use SMK 69's across the board, they just don't shoot real tight at distance from my CTR like the 77's do and the cost is pretty much the same as the SMK 69's. So there's my rationale ;-)