Sunday GunDay: 6-284 TackDriver for 600-yard Silhouette Game

Editor’s Note: This story was first published many seasons ago. In the interceding years, equipment has evolved — actions, optics, front rests and so on. But this rifle remains very competitive in the 600-yard silhouette game, and it remains a wicked weapon for long-range varminting.

The 6-284 may well be the “ultimate” 6mm cartridge, if speed AND accuracy are considered. While it burns a lot more powder than a 6mmBR or 6 Dasher, it also delivers a lot more velocity. Our friend John Southwick, owner of this week’s featured 6-284, can push 107gr SMKs past 3400 fps — velocities no 6BR, 6BRA, or 6 Dasher can touch. He normally dials that back to 3200 fps or so, but that’s still well beyond the limit of a 6 Dasher even a 6mm Creedmoor. John’s gun is more than a speed demon of course — it’s a hyper-accurate match rifle that has claimed many Varmint Silhouette wins. At his club, when John and the Black Borden come out to play, everyone else is usually competing for second place.

Building the Borden Black Beauty
John tells us: “I chose the 6-284 mainly because it appeared in the winning equipment lists of 1K BR matches, and it was becoming very popular with long-range varminters. Skip Talbot had also used a 6-284 to set an IBS 1000-yard record (subsequently lowered in the last decade). Norma and Lapua offered quality 6.5-284 brass, so case-forming would be easy. I wanted a fairly light-recoiling rifle, and after much research I came to the conclusion that a high-BC 6mm bullet driven at 3200+ fps would meet my needs.

I was looking for a very high performance long-range target/bench rifle, primarily to use in 600-yard matches at my local club (Ojai Valley Gun Club), and possibly 1000-yard bench matches, plus occasional varmint hunting. I wanted to have a rifle that was built by a prominent gunsmith. I chose to work with Jim Borden of Borden Rifles for several reasons: his rifles had set world records, his reputation was excellent, and his rifles often showed up in the winning equipment lists of IBS and NBRSA sanctioned shoots. Also I had decided that I wanted a Nesika-actioned gun. I was impressed that Jim had designed one of the Nesika’s key features – Borden Bumps. Likewise, I liked the Bald Eagle front rest, and found out that Jim contributed to its design as well. This gave me confidence that Jim understood every element that goes into precision rifle performance.

Loading for Accuracy
My match load consists of Norma 6.5-284 brass, 51.0 grains of Alliant Reloder 22, Fed 210m primers, and Sierra moly-coated 107gr MKs, seated about .010″ into the lands. This runs about 3250 fps from the 28″ barrel. Case necks are turned to .0133″ wall thickness for a .270″ loaded neck diameter. I use a .268 or .269 bushing, and bump the shoulders back each time. I set the “bump” so that, with firing pin removed, I can just feel the case in the chamber when closing the bolt. My loaded rounds typically show no more than .0015″ runout on a NECO concentricity gauge. I credit the low run-out in large part to the custom inline seating die and shoulder-bump neck-bushing die Jim made for me.

How the 6-284 Shoots
The rifle has fulfilled all my expectations. It is a superbly precise and accurate rifle, as long as I do my part in steering the gun and feeding it consistent, quality ammo. I haven’t done a lot of 100-yard group shooting, just enough to test loads. Typically the rifle easily puts five shots into half-MOA or less at 600 yards. I’ve logged several 3-shot groups between 1.06″ and 2.2″ at 600 yards. I’ve been told that kind of accuracy would be competitive in a 600-yard BR match. But most importantly, I have confidence the gun will hit where I aim. Our Ojai club uses half-size silhouette targets. This gun’s ability to pick off the relatively small steel targets, even in some of the worst conditions imaginable, is nothing short of amazing. At times it seems I’m launching 107gr silhouette-seeking guided missiles.”

Borden 6mm-284 SPEC SHEET Borden Long-Range Rifle, 16.5 lbs Nesika ‘K’ Action, 1.70″ diam., Right Bolt, Left Port. Hart 28″, 1:9″ twist, .920″ at muzzle, cryo’d with .272″ neck diam. and 1.5° throat. McMillan MBR stock, Borden texture finished, pillar-bedded, with action also glued in. Nightforce 12-42x NXS, NP-R2 reticle, 20 MOA ramped scope base, Leupold Mark IV rings.

John’s rifle is a purpose-built gun, optimized for one task — hitting little half-size silhouettes at very long distances, at a shooting venue that demands serious wind wizardry. At Ojai, even though matches commence early in the morning, it’s not unusual to have a 10 mph wind blowing left to right at the firing line, no wind at the mid-course flag, and a swirling variable wind at the targets. To make matters worse, the little critters sit on top a ramped berm. When the wind switches to 6 o’clock, it can rise right in front of the target, sending shots high. Despite the often-wicked conditions, John and his Black Borden have excelled at the varmint matches — he’s the “smart-money” bet to win on any given weekend.

John reports: “The rifle has really proven itself at the 600-yard silhouette match at my local club. We shoot ten targets per match, usually three “matches” or relays per day. Targets are half-size NRA Hunter Pistol metallic silhouettes: 1 Ram, 2 Turkeys, 3 Pigs, and 4 Chickens (note, these are larger than the mini-silhouettes in the above photo). The Ram counts one point, Turkey two points, Pig three points and the Chicken counts four points. The Chickens have a “hit zone” roughly .6 MOA at 600 yards–about 3.6″. Trust me, that can be challenging, particularly in shifting winds. Unlike conventional silhouette matches, we shoot F-class fashion from the ground, using bipods or pedestal rests. That’s easier than shooting off your hind legs of course, but our targets are much smaller than standard high-power silhouettes.”

The Black Borden was the rifle to beat at Ojai for many years. John held the record for the most “cleans” (no misses) for the event, and he was the annual Champion for many years, including five years in a row. One year he won the championship in the very last match. John noted: “Thankfully, the gun was humming and I made the right wind calls. I picked up enough points in the final shoot to win the series for the year.” Yes, John’s flat-shooting Borden 6-284 had done its job once again.

Long-Range Silhouette Match Strategy and Techniques
In competition, John says watching the conditions, and minimizing mental mistakes is key: “I keep things pretty basic. Our varmint silhouette matches allow 20 minutes for sighters and 10 shots on target (one per animal). We usually get in three “matches” or relays per event. I try to wait for a favorable condition, then take a few sighters and adjust the scope as needed. If the condition holds steady, I’ll try to run my targets before the wind changes.

At the Ojai range, it is vital to watch the wind flags and heed your spotters’ calls. I’ve seen the wind go from 7mph right to 10mph left from one target to the next. That’s nearly a foot and a half of horizontal change for my gun. If there is a major change, I will try to wait it out. If the shift is small, I may hold off a bit. Scope corrections are a last resort; while you’re dialing, the wind may switch again.”

Technical Report from Jim Borden, Gunsmith

We set up John’s 6-284 as we would for 1000-yard Light Gun competition. We’ve also built some of these rifles in 6MM BR for use in 600-yard competition. For John, we used a Borden/Nesika Model K 1.70″ diameter action as the beginning basis of the rifle. The timing and cocking-piece system for this rifle has the Borden improvements to improve firing pin energy and lock time. The action was pillar-bedded and glued into a McMillan Tooley MBR pattern stock. The stock blank was gel-coated and then epoxy-finished with a texture.

About the Muzzle Brake — We normally blend the brakes into the barrel to make the transition smooth and unseen. John preferred to have the brake larger than the barrel so that it could also be used on future barrels.

9-Twist Barrel — The barrel is a 1:9″-twist Hart HV pattern 28 7/8 inches long. Our 6×284 reamer has a .272″ neck diameter. It is throated with a tight cylindrical section followed by the 1 ½ degree throat. Chambering of the barrel was done utilizing our proven Benchrest chambering techniques. The method of chambering ensures that the body, neck and throat of the chamber align concentrically with the bore and grooves of the barrel. [Editor: With a 6BR or 6 Dasher, we’d definitely recommend an 8-twist barrel to shoot 105-107 grain match bullets. However, with the extra velocity of the 6-284, the 9-twist Hart worked great for John.]

NOTE: Borden Accuracy (BordenRifles.com) now produces its own excellent Borden Custom Actions, which have won National Championships and set World Records. Borden offers precision bolt action receivers for competition, ELR, hunting, varmint, PRS, and other shooting applications.

Situated in the Coastal Mountains behind Ventura, California, the Ojai Valley Gun Club is a
beautiful place to shoot. And the Hwy 33 route up to the range offers stunning views.