This article is presented to you courtesy of Clark Custom Guns,
with permission from Accurate Rifle Magazine.
By John Dustin
When the Mini-14 by Sturm, Ruger & Co. came out, I thought "what an interesting concept ". When they introduced it in stainless. I knew had to have one...I mean here was a rugged, light, low-maintenance, easily handled semi-auto based on a proven military design, shooting mild-kicking ammo which was in abundant supply. It was everything you could want in a utilitarian - "pickup truck" rifle.
Except accurate. The Mini-14 soon earned a variety of unflattering sobriquets, such as "world's most expensive plinker" and "pebble chucker". I did everything I could think of to mine, including bedding work, increasing lock speed, performing a match-grade trigger job on it, building a variety of meticulously assembled hand-loads, and machining a combination muzzle brake/barrel tuner for it, all to little avail. On a good day using the best ammunition I could conjure up. I might get a 4 inch 5 shot group at 100. I banished the Mini-14 to the dustiest corner of my shop, and devoted my energies to more tractable problems.
Anyone who has had one of these rifles apart might quickly form an opinion as to why this might be so. The barrel resembles a half-scale featherweight tube off a typical mountain rifle, weighing in at a scant 21 ounces.
Of necessity, this must carry the gas block, which itself is in contact with the stock and thus every other piece of the rifle. One day, in a moment of supreme confidence, I began cogitating about rebarreling mine with a heavier match-grade tube in an effort to bring the accuracy up to acceptable standards. Mind you, it wouldn't be possible to fit a genuinely heavy barrel, but some judicious machining of the gas block and action rod would carve out enough space to fit a modified #1 tube, which would provide some significant help in the stiffness department.
Before I could embark on this Quixote-like journey, I had the good fortune to discuss it at length with Jim Clark Jr., President of Clark Custom Guns, at the 1999 Steel Safari match. Jim is one of the best 3-gun and tactical shooters around, and is widely known for his superlative .45 work, as well as his match-grade 10/22's. He has also done considerable accurizing work on the Mini-14, concentrating initially on precisely the type of re-engineering job I had in mind. It was effective, but needless to say the amount of precision machining involved mandated a breathtaking price tag which took a lot of the fun out of the whole exercise.
Enter engineer / Palma shooter David Crandall from up in Idaho Falls, who had seen Jim's periodic ads on the Mini-14. David had been working on a different approach to the accuracy problem, and figured he had a better mousetrap on his hands. Inspired by Randolph Constantineís earlier treatise, which appeared In Precision Shooting during September 1995, it amounted to a rather substantial bloop-tube type barrel stabilizer, with one important distinction ---- it cantilevered backwards from its muzzle attachment point, contacting the rifle only at its forward mounting sleeve. Would Jim be interested in evaluating one, and maybe making an offer?
What followed was a period of R & D on the original all-steel unit, which saw the weight pared down to a more manageable 20 ounces total, and the addition of a wrapped carbon fiber section at the unitís forward end, surrounding an aluminum bushing which is closely fitted to the mounting sleeve. The eventual product seemed both effective and practical, so a deal was struck and Clark's entered into production.
David theorizes that this unit works as a "stabilizer"' rather than a ''tuner''. The latter traditionally is adjustable, and changes barrel harmonics to optimize them to a particular load. Thus, a setting that is good for, say, 155 grain loads will likely not work for 175ís (and vice-versa). By contrast, a "stabilizer'' should provide a beneficial effect on all loads. It accomplishes this by using mass and stiffness to straighten out the tip of the barrel during firing. Even though the barrel is still vibrating (albeit with reduced amplitude resulting from the increase in overall mass), the weight of the stabilizer aided by its comparatively high polar movement of inertia works directly against the muzzle's natural inclination to point in different directions, much as the tip of a fishing rod does if you whip it side to side. By reducing the angular excursions of the barrel tip during firing, greater accuracy should result with all suitable bullets.
Now I love a good theory as much as the next rifle crank, but I'm an absolute sucker for empirical evidence. It seemed there was only one thing to do. My next visit with Jim came at the 2000 SHOT Show, and I asked him to stick one of these in the mail when he had the chance. My new shop was not yet operative, so some months passed before I was able to get on it, but the happy day finally arrived.
Installation of the unit is straight forward and not excessively time consuming.
The stabilizer itself consists of 3 pieces. The first of these is a threaded
tubular barrel adapter, designed to form a friction fit with the muzzle. The
front sight is removed, and the barrel adapter fit is checked. With the barrel
I was using, it was necessary to do a bit of judicious polishing, being careful
not to lose a genuinely tight friction fit. This is best accomplished in a
lathe with the barrel off the receiver. When the right fit has been obtained,
the adapter sleeve is semi-permanently installed using the included Loctite
RC 680 This joint is allowed to cure for a day before the remaining assembly
takes place. The stabilizer body is slipped over the adapter tube, where it
encounters a small 45 degree cone as it comes to rest. At this point, clearance
between the stabilizer and the gas block is checked, being sure to maintain
at least .020 inch clearance throughout. My unit exhibited a very satisfactory
fit, with sufficient clearance but no obvious "gaposis". Finally, a precision-machined
locking ring having female threads corresponding to the adapter is screwed
in place and torqued to the desired setting using the supplied spanner, thus
locking the entire assembly together quite rigidly. PHOTO
The finished rifle looks like a Mini-14 that has gotten a good scare from a heavy varmint rig. Closer inspection reveals the true nature of that fat thing out at the end. The new appearance is quite easily, gotten used to, as the essential lines of a typical carbine remain intact, and the good craftsmanship of the unit coupled with the intriguing section of carbon fiber create a very businesslike impression. The rifle is a pound and a quarter heavier than before, but maintains its handy size. The added mass (with its forward center of gravity) actually improve the rifleís offhand stability. Strike the stabilizer with a modest blow and it gives off a pleasing resonance, just like a tuning fork. PHOTO 2
I took myself and my new/old shooting iron to the local range with three types of factory ammo, including Black Hills "blue box" (remanufactured) with moly-plated 52 grain hollow points, some "red box"(all new) loads with plated 50 grain V-Max bullets, and some unplated 55 grain ball by HSM. Groups were fired with all three. 5 shots apiece at 100 yards both with and without the stabilizer. I can only describe the results in superlative terms. "Before" groups exhibited the usual Mini-14 behavior which is to say groups in the 4 to 6 inch category. Installing the stabilizer yielded immediate improvements in group size, throughout all loadings tested, of 300% to 400%, consistently producing groups in the 1 to 2 inch category. The Black Hills offerings with good varmint bullets showed groups in the 1 to 1.5 MOA category (see attached photos). These bullets are rather deeply seated, with considerable jump to the lands, so my belief is that a careful program of load development will reduce these groups even further.
Summary: This well-thought-out and superior-quality device
produces wholesale improvement in the most serious shortcoming of an otherwise
worthy offering. The price paid (in terms of cost and extra weight) is well
worth it to any proponent of superior rifle accuracy. It transforms a rifle
of extremely limited utility into a genuinely worthy moderate-range varmint
buster. It should also find favor in the corrections field, where it may have
to be fired with considerable precision into tight groups of combatants.
Oh yes: about the Shootout Lane part...thatís the address of Clark Custom Guns in the town of Princeton, Louisiana. Iíd sure enjoy meeting those city fathers, and shaking their hands!
Clark Custom Guns, Inc.
336 Shootout Lane
Princeton, LA 71067
Call 318-949-9884 M-F 8 am - 4 pm CST to get yours today.
From the DECEMBER 2000 issue of Accurate Rifle Magazine pages 48-50.