125g Supersonic, 55g 223REM, 220g Subsonic
300/221
Load Data
HOME
Questions? E-mail the webmaster here.
BRASS TRIAL
Nothing beats the excitement of getting a package in the mail. Especially when you know it’s the Redding 300/221 dies that you ordered from Graf & Sons, Inc. Now, I was ready to begin loading some rounds and exploring the potential of the 300/221.
First, I had a brass issue. I had three different brass sources sitting on my reloading bench: 1) 40, .221 Fireball cases I picked up for a few dollars at a gun show. I ran each of these through the .308 expander on a 30-30 die and I didn’t have any problems with split necks. This was used brass and they formed quite easily with one pass. 2) Brass from loaded Cor-Bon ammo that I bought when the upper first arrived. Even though I’d read notes about neck thickness and pressure problems with cut .223 cases, the Cor-Bon ammo had Lake City head stamps and the box clearly stated it was .223 brass. 3) And, a few IMI .223 cases (TZZ headstamp) that I cut and formed.
Initially I was resigned to buy .221 brass when I bought the upper, but when the CorBon boxes arrived, I thought if they can do it, then I also should be able to it. And, I have a large supply of IMI .223 and this would be my cheapest source if it works. So, to validate that .223 cases would work, my first reloads were a comparison of brass sources. I loaded six of each set with 20.6g H110, a 125g Sierra SP, OAL 2.05”. From my reviews, this seemed to be a max load and should push the 125’s about 2300 f .p.s. I figured if there's any major difference, I might see it in this test.
BRASS TRIAL DATA
BRASS VELOCITY BULLET / OAL POWDER Lake City (Cor-Bon) 2342 125g Sierra SP / 2.050 20.6g H110 RP 221FB 2339 125g Sierra SP / 2.050 20.6g H110 TZZ (IMI) 2297 125g Sierra SP / 2.050 20.6g H110 Cor-Bon Ammo (LC) 2179 125g HP / 2.066 ?
Okay, what did I learn... the LC and RP brass had identical numbers and showed only mild pressure indications around the primer pocket. The TZZ fell short in the velocity category by a solid 40+ f.p.s. with similar, mild pressure indications in the primer. The primers for all three groups retained slightly rounded edges and gave me no cause for concern.
SUBSONIC LOAD TEMPERATURE TRIAL
I wanted to experiment with subsonic, heavy bullet loads. So, I bought some COR-BON Ammunition so I had a reference example of what it's "supposed" to feel, and sound like when I shoot subsonic. The COR-BON arrived and the box claimed a velocity of 1040fps for the 220gr bullets. On my next range day I loaded a mag, point the muzzle over my chronograph and BANG... 957fps.... next round, BANG... 948fps...
Okay, what's the problem? Why so far below the advertised velocity?? I was using a 16" barrel, the chrono was eight feet from the muzzle; none of this should have such a great affect. So, as I stood there and left out a disgusted sigh, I noticed how much my breath showed up and realized just how cold it was that Saturday morning... TA-DA... It's COLD!!!! That's why the speeds are so slow. So, I got this great idea of loading 220gr Sierra HPBT's to 1050fps and tracking what powder charge I require in different temperatures.
I'm working on my first set of loads and hope to find my winner while it's still below freezing. Then, I will shoot another set each month, trying to get a whole range of temperatures for my data.
Stay tuned....
SUBSONIC LOAD TEMPERATURE TRIAL DATA
TEMPERATURE (F) POWDER CHARGE BULLET / OAL VELOCITY MACH 1 24 Hogdon 110 9.4gr 220gr Sierra HPBT / 2.70" 900fps ~1080fps 40 Hogdon 110 ?gr 220gr Sierra HPBT / 2.70" ??fps ~1096fps 60 Hogdon 110 ?gr 220gr Sierra HPBT / 2.70" ??fps ~1118fps 80 Hogdon 110 ?gr 220gr Sierra HPBT / 2.70" ??fps ~1140fps
My Favorite Loads
Powder Velocity OAL Bullet 20.6 H110 2300 2.05 125SP Sierra 8.9 H110 710 2.235 250g Hawk - - - - - - - -
I really like the 125gr Sierra at 2300fps - this gives me a flight path of 1" high @ 50 yards, 1.5" high @ 100 yards, dead on at 150 yards and only 4.1" low at 200. That gives me a "flat" hold for anything out to 200 yards with a large capacity, semiautomatic, 30 caliber rifle... just what the doctor ordered!!
Here's a five shot target at 100 yards.
(L-R) 125gr SP, 220gr HPBT MK
