The 300 HAM’R® was developed with one thing in mind, OPTIMAL TERMINAL PERFORMANCE. It offers near .308 Winchester effectiveness on game animals with amazing accuracy and low recoil in the lightweight and compact WC15 platform. Terminal performance testing on over 2000 Texas feral hogs and various game animals as large as 800 pounds has proven it to kill much more effectively than the 6.5 Grendel, 6.8 SPC, 7.62×39 or 300 Blackout. Due to the optimization of bullet weight to barrel twist, accuracy has proven to be outstanding. Sub one-inch groups are the norm with multiple bullet choices for varying applications such as hunting, target shooting and tactical use. Undoubtedly the 300 HAM’R will be compared to the popular 300 BLACKOUT or 7.62×39 and as the comparison charts below indicate, ballistics of the 300 HAM’R far exceeds the 300 BLACKOUT and 7.62×39 in both velocity and energy when utilizing 95-150gr bullets.

The 300 HAM'R is now SAAMI approved

Click Here for new Cartridge & Chamber drawings

I guess you could say the project originally started way back in 2005 when J D Jones sent me one of his 300 Whisper uppers and a set of dies. This cartridge seemed like a good idea to me other than in order for it to fire heavy subsonic bullets a short case with minimal powder capacity was required. Being an avid hunter my primary interest was terminal performance and the 300 Whisper just didn’t get the job done for me. So, at that point I moved on to the 6.8 SPC and did a lot of work with it and killed a LOT of hogs and deer.

I’ve always been a bigger bullet is better guy and a .277” diameter bullet just wasn’t exactly what I wanted. Then, in 2008, Remington came out with the .30 Rem AR and I started getting the terminal performance on game that I was after. However, that caliber has its share of issues such as a proprietary upper receiver, bolt carrier group and magazine, and then you add on the fact that shortly after Remington brought this caliber to market they quit supporting it. I never did understand this.

Along came the 300 Blackout that Robert Silvers sent me early on for testing. I didn’t see any terminal performance improvement over the 6.8SPC with 110-125gr bullets and it didn’t shoot nearly as flat. I briefly tried shooting hogs with heavy subsonic bullets, but the rainbow trajectory and poor bullet performance on game turned me off quickly.

This brings us up to the 7.62×40 originally the brainchild of Kurt Buchert. Kurt’s cartridge that Wilson Combat brought to market as the 7.62x40WT, is a well-balanced cartridge that met Kurt’s requirement for it to accept virtually every .30 caliber bullet in the 110-135gr weight range. However, to achieve this with the long-pointed bullets the case length had to be limited to 1.565” (40mm). Don’t get me wrong, I really like the 7.62×40 and have done a lot of successful hunting with it. But I always wanted more; to at least equal the legendary and time proven .30-30 Winchester in terminal performance.

So, I came up with this quest to create a .30 caliber cartridge that could be fired from an AR15 platform utilizing the original 5.56 bolt, and I was going to call it the .30-30AR. Obviously the logical place to start was with Kurt’s 7.62×40. As I mentioned above, the problem was a lack of powder capacity so the first thing I did was to lengthen the throat by .060” to allow for the bullets to be seated out longer. This didn’t gain anything with the long nose pointed bullets that were already being seated out to maximum magazine length. It did allow for me to seat bullets designed for the .30-30 out an additional .060” giving me an additional grain of powder and reducing pressure due to the larger case volume. The result is I gained about 50fps with the Speer 130gr HC which proved to be a VERY terminally effective projectile.

Now, I have a problem, we can’t just start chambering the 7.62x40WT with a different chamber! Also, in my opinion, the two main factors that prevented the 7.62x40WT from being more successful in the marketplace was the name and the other was bad timing. When Wilson Combat releases a new and similar cartridge at basically the same time as the SAAMI approved 300 Blackout with Remington Arms behind it, let’s face it, who’s going to win? Therefore, a minor facelift of the 7.62x40WT wasn’t going to meet my goals for this project even if I could get close to the .30-30 in performance. So here I am back to powder capacity, or the lack of and the first step is to determine which bullets the cartridge must be compatible with and decide if this selection is adequate to meet all of the goals for the intended use of the cartridge (hunting, target and tactical).

Once I determined the answer was yes, measurements were made to determine how long the case can be and still work with the bullets I had selected. This turned out to be .040” longer than the 7.62×40 or .260” longer than the 300 Blackout. At this point I called Pacific Tool and Gage and worked with Dave Kiff to finalize a chamber reamer. The reamer arrived in early January 2018 and my testing began.

It was immediately apparent that there was potential and that we could probably gain 100fps over the 7.62×40 and lot more over the 300 Blackout. My good friend Terrill Hoffman and I shot thousands of rounds testing loads and barrel twist rates since I also wanted this cartridge to be optimized for accuracy.

Then one day I was corresponding with Ron Reiber of Hodgdon Powder Company and he strongly suggested that we try their new CFEBLK powder. To make this long story shorter, this ended up being a game changer and the final piece to the puzzle. It gave us improved accuracy and more velocity with less pressure allowing me to exceed my original velocity goals. Once I decided on a 1-15 twist rate for the barrels and we were good on ballistic performance and accuracy, all that was left was to decide on a name and test real world terminal performance.

During the early testing we were calling it the .30-30AR. That was the name on the original chamber reamer print and what we engraved on early test barrels. My buddy Terrill said something to the effect of “only us old guys know and care much about the old thuty-thuty”. So we came up with a bunch of potential names and my son Ryan said “we just came out with the 458 HAM’R and we have a trademark on HAM’R so let’s call it the 300 HAM’R”! Now 13 years later, THOUSANDS and THOUSANDS of rounds downrange, several scrap barrels, one upper blown up and thousands of dead TX feral hogs we have the 300 HAM’R that not only meets all of my original goals, but EXCEEDS them!

– Bill Wilson

300 HAM’R
16.25” Barrel
Sierra 110gr HP 2600FPS MV, 1651FP ME
Sierra 125gr SBT 2520FPS MV, 1763FP ME
Sierra 135gr HP Varminter 2400FPS MV, 1727FP ME
Hornady 150gr SST 2290FPS MV, 1747FP ME

16.25” Barrel
Hornady Black 110gr V-MAX  2395FPS MV, 1401FP ME
Hornady 125gr HP American Gunner 2175FPS MV, 1313FP ME
Hornady 135gr FTX 2055FPS MV, 1266FP ME
Federal 150gr Fusion 1900FPS MV, 1202FP ME



300 HAM’R
16.25” Barrel
Sierra 125gr SBT 2520FPS MV, 1763FP ME
Hornady 150gr SST 2290FPS MV, 1747FP ME

16.25” Barrel
Remington 125gr Cor-Lokt 2365FPS MV, 1552FP ME
Winchester 150gr Razorback XT 2056FPS MV, 1408FP ME


The 300 HAM’R is capable of duplicating the proven ballistics of the legendary .30-30 Winchester from a comparable barrel length. However it does this with much more efficiency taking only 25-28 grains of powder compared to the 34-38 grains the .30-30 requires. No other caliber that can be fired in an AR15 platform rifle utilizing a 5.56/.223 bolt can come close to this ballistic performance!


The above chart shows the large advantage the 300 HAM’R has over the 300 BLACKOUT or 7.62×39 at common hunting ranges. The 300 HAM’R has 18% more retained velocity, 40% more energy and a 56% flatter trajectory than the 300 BLACKOUT at 200 yards!


Tactical/Home Protection: The 300 HAM’Rs performance in the hunting fields prove the cartridge’s increased terminal performance over it’s 5.56, 6.5 or 6.8 rivals and make it an optimal choice for home-defense. It’s terminal performance and magazine capacity make it a smart choice for tactical use or protecting your family.

300 HAM’R compared to a 5.56/.223

.308cal vs .224cal bullet diameter
95-150gr vs 45-77gr bullet weight
Same ammo capacity

300 HAM’R compared to a 6.8SPC

.308cal vs .277cal bullet diameter
95gr-150gr vs 85-120gr bullet weight
20rds vs 15rds/30rds vs 25rds or 17% more ammunition capacity

Hunting: Think of the 300 HAM’R as a 300 Blackout on steroids, in the hunting field the HAM’R will substantially out perform the BLACKOUT or 7.62×39 in all relevant areas: velocity, energy, trajectory and terminal performance. The light recoiling 300 HAM’R is an ideal choice for young hunters or anyone sensitive to heavy recoil.

Target/Range: With its stellar accuracy and low recoil the 300 HAM’R is a natural for the range. During our extensive testing groups as small as .2” were recorded and sub .75” 100 yard groups were very common.


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Accurate/Western Powder Load Data for A1680


300 HAM’R Load Data



95gr Lehigh CC
110gr Sierra HP Varminter #2110 (extremely accurate)
110gr Hornady V-MAX #23010
110 Hornady SP #3010
110gr Nosler Varmageddon #34057
110gr Barnes TSX #30341 or TAC-X #30336
110gr Lehigh CC #05-308-110-CUSP (our partners at Lehigh Defense designed this bullet specifically for the 300 HAM’R to provide extreme accuracy and deadly terminal performance)
125gr Hornady FMJ #30196 (range and target)
125gr Sierra SBT PH #2120
125gr Speer TNT #1986
130gr Speer FNHC #2007
130gr HAM’R HOT-COR (proven terminal performance)
130gr Speer HP #2005 (inexpensive and super accurate)
135gr HAM’R BONDED (great all around bullet)
135gr Hornady FTX
135gr Sierra HP Varminter #2124
150gr Hornady SST #30303 (for the largest game the cartridge is suitable for)
150gr Speer HAM’R BONDED
150gr Speer BTSP #2022 (great all around bullet with a high BC)
150gr Speer Gold Dot #308150BLKGDB
150gr Federal Fusion #FB308F1


The following are available from

Lee Reloading Dies
RCBS Reloading Dies
Wilson Combat headspace/bullet seating gage
WC 300 HAM’R Headstamped Cases

Accurate/Western Powder Load Data for A1680


Lee and RCBS Reloading Dies

Wilson Combat Min/Max Headspace Gauge

Wilson Combat Bullet Seating Depth Gauge

Cartridge Cases with 300 HAM’R Headstamp (SIG and Starline Mfg.)

Barrels in 8, 11.3, 14.7, 16.25, 18 and 20 inch lengths, round or fluted, crowned or threaded

Complete Forged, Billet or Lightweight Billet Uppers

  • The 300 HAM’R has 18% more retained velocity, 40% more energy and a 56% flatter trajectory than the 300 BLACKOUT at 200 yards!
  • Enhanced reliability due to the longer gas systems, 16.25” is mid-gas and the 18”/20” are intermediate gas system.
  • Any AR15 platform rifle can be converted to 300 HAM’R with a simple barrel change and the use of 300 Blackout magazines.
  • The 300 HAM’R  1-11.25, 1-13, or 1-15 twist match grade barrels are optimized for accuracy with 95gr to 150gr bullets from 8″ to 20″ barrel lengths.
  • Factory Starline and SIG produced 300 HAM’R cases are available, but cases can be made from common and available 5.56/.223 cases.
  • The 300 HAM’R has a 300 FPS velocity and 400 FP energy advantage over the 300 BLACKOUT at the muzzle.
  • 300 HAM’R rifle and pistol barrels are available in 8″, 11.3″, 14.7″, 16.25”, 18” and 20” lengths with different profiles.