Mini 14 Accuracy

Discussion in 'The Powder Keg' started by D. LIVINGSTONE, Mar 15, 2002.



    I'll start the ball rolling with something that has been bothering me about my Mini 14. When I switch ammo brands I get alot of horizontal stringing. Meaning my rifle is dialed in with my reloads at 100 yards.(winchester748 55gr soft points) If I shoot UMC 55gr ball it shoots about 6 inches right of the target. If I shoot winchester USA brand (55gr) it shoots more than 12 inches. I have shot some miltary surplus ball ammo made in Malayisa that shoots more than foot to the right. Each ammo shoots fair to good groups, just to a different point of aim. I have a friend with a Mini 14 and he gets the same results. I could understand vertical strings if one ammo was hotter, but not the horizontal. I also suspect this is why some people think the Mini 14 has bad accuracy. If I switch ammo without changing the point of aim of my scope, sometimes I can't even hit the paper.
  2. squirrelsniper

    squirrelsniper Guest

    The difference in point of impact isn't actually relative to whether one brand of ammo is "hotter" than the other, the difference is due to differences in barrel vibration or "harmonics." The different bullet weights, styles, powder charges, types of powder, and other variables is what changes the point of impact due to the different ways they make the barrel vibrate. Although the Mini-14 may be more picky about changing ammo than other types of rifles, all firearms whether it be rimfire, centerfire, rifle, pistol, muzzleloader, or even a shotgun will experience this change of impact to some degree.

  3. shooter

    shooter Guest

    accuracy problems with mini

    I had my mini accurized by ARS in Odessa, TX. When I test fired it , it too had horizontal stringing. They had me send it back and worked on the bedding and free floating. Tim, at ARS (Accuracy Rifle Systems) could explain better than I. However, the stringing stopped. Call: 915 362 6840 (w) and ask for Tim.
  4. Logansdad

    Logansdad Guest

    TUNE YOUR MINI-14 by James Mason
    From Guns & Ammo/March 1987

    With the introduction of the Mini-14 rifle, Sturm, Ruger wrought a major coup in the field of firearms. This lightweight .233 caliber rifle displaced the M1 Carbine in the hearts and minds of many American shooters.

    The scale, weight, and military presence of the Mini-14 made it an instant hit... the .223 cartridge being vastly superior to .30 caliber M1 Carbine ammo. Few firearms have so instantly filled a market niche as the Mini-14.

    Over the years, shooters have come to realize a few shortcomings in the Mini-14. The factory corrected one of these when it brought out the Ranch Rifle by equipping it with scope blocks and low side ejection of fired cases. The other concern has to do with accuracy. The Mini-14 was never designed for match shooting and delivers 3 to 4 inch groups at 100 yards; throw in the usual "human factor" and that score reads 4 to 6 inch inconsistent groups.

    The average Mini-14 owner is not necessarily an accuracy buff, but the latterday generation has come to expect smaller groups from all rifles. Many shooters are adept at doing minor repairs on their own guns, and tuning the Mini-14 for its performance potential makes a good weekend project for the off-season.

    With appropriate references to "kitchen table" gunsmithing, there are three areas where work on the Mini-14 will pay off in tighter groups. This is a serious project that, while not overly difficult to perform, requires attention to detail from the amateur gunsmith.

    Stock bedding, Trigger group modifications, and sights are the areas that best reward diligent attention. Tailored handloads can also contribute toward accuracy and will be discussed, but this is outside the reaim of a gunsmithing activity. Besides, a lot of Mini-14 shooters do not reload, and depend upon commercial or remanufactured ammunition and foreign military fodder.

    A discussion of some Mini-14 design realities helps put this project in perspective. As was mentioned above, the Mini-14 was not designed as a match gun. It has a thin, low-mass barrel with gas-impulse actuation. The barrel will vibrate from firing alone, but gas impulses against the relatively heavy inertia operating slide cause further disturbances to barrel nodal movement.

    The Mini-14 gas system uses a hollow, fixed piston though which propellant gases impinge on the operating slide. There is no contained, modulated piston stroke. So, the reaction to the gas pulse induces a slight bending movement on the mid-barrel section-enough to disturb normal barrel vibrational rhythms.

    The Mini-14 has a good quality birch stock, which is quite stable, but not overly stiff, due to the thin wall sections around the receiver and fore-end. New guns are factory fitted to provide some stiffness, but after shooting a couple of thousand rounds, setting of parts makes the stock fit a fairly loose proposition. Rebedding can restore that stiffness and assure support for the Mini-14's operating elements.

    Trigger pull characteristics on all military rifles leave a lot to be desired. The safety aspects of two stage pulls need not be sacrificed, but a properly regulated trigger job can produce a 4 to 4 1/2 pound letoff that will do more to reduce the effect of the human factor than anything else, with the exception of a better sight system.

    The coarse-adjusted military sight on the factory Mini-14 is suited to the original design objectives of the rifle. It is okay for a rifle designed to shoot 3 to 4-inch groups. But, adjustment stops and aperture design limit it for more demanding shooting. Millett Sights (16131 Gothard Street, Dept. GA, Huntington Beach, California 92647) understands the needs of more demanding Mini-14 shooters, and have adopted their Series 100 Sight to the Mini-14 and other assault-type rifles. The result is a first-rate replacement peep sight that meets the needs for realizing the performance potential of the Mini-14.

    Positive, 1/3-minute click-adjustments on the Millett sight allow for both windage and elevation. A large match-style eyepiece shields the eye from glare. The standard .080-inch aperature (.050-inch is optional) provides a crisp, clean sight picture; the aperature hole is reverse tapered, like top-grade match sights, so no "tunnel effect" distort aperture edges. The Millett sight base fits directly into the Mini-14 receiver and is secured by a single throughpin-a simple, easy installation once the factory sight is removed. The installation makes a handsome complement to the Mini-14 receiver.

    The factory Mini-14 front sight blade is an exposed, serrated ramp with a slightly tapered silhouette. There are several possible replacements available for this front sight unit. The Choate front sight and flash hider unit makes a good replacement choice and was installed on our conversion. The Choate front sight blade is a military post with "ears". The flash hider is of the bird cage type, and is solid on the bottom, providing muzzle stability during firing.
  5. Logansdad

    Logansdad Guest

    A well-bedded stock adds to stiffness and support of the operating elements. While new Mini-14's may fit well, continued firing will loosen up the stock and receiver union. By using a non- shrinking stock bedding compound such as Accraglas glas, support for receiver legs, the operating rod guide channel and the stock ferrule can be reinforced. Dismantling the stock allows removal of the stamped sheet metal recoil stop that fits inside the receiver magazine opening A thin coat of bedding compound under these supporting structures adds to the stiffness of the midsection of the stock and assures minimal creep of the recoil stops. After treating metal parts with parting compound, lightly apply epoxy to the wood then replace the recoil stop in the stock and tighten the side screws. Let this piece cure overnight.

    Next, remove the stock ferrule and the sheet metal action slide guide. Butter the stock seating area for these parts and replace the metal. Again, be sure to coat the metal with parting compound before contacting the bedding compound.

    Using silicone parting agent, spray the inside surfaces of the gas piston collar assembly and butter the outer surface of the stock ferrule with compound. At the same time, spray the receiver legs and bottom of the receiver with parting agent. Butter the receiver leg channels in the stock to fill in the area below, in front and to the sides of the receiver legs where they seat in the stock. Assemble the barrel/receiver group in the stock using a large rubber band to hold the stock and receiver together. Let this work cure overnight after wiping off any excess bedding compound that oozes out of joints. A little oozing shows a proper amount of compound; don't overapply, but use enough to fill all the voids. Failure to use parting agent can result in embarrassment. You might permanently bond the stock and the receiver together!

    Separate the stock the next day, then carefully chisel out any excess ridges on the inside of the stock. Small bubbles in the work may be refilled. Reassemble the stock and insert and secure the trigger assembly. Observe any looseness of the trigger assembly. This may require additional bedding under the flat contact pad on the bottom outside edge near the middle of the receiver.

    Use parting agent on the receiver bottom, then apply bedding compound on the stock surfaces adjacent to the receiver pad. Reassemble the rifle, insert the trigger group, but close the trigger guard down only to about 1/2 inch away from its hooking point. Let the epoxy cure, then clamp the triggerguard shut. This technique assured a very solid stock-to-barrel/receiver fit, necessary for consistent shooting accuracy.

    Trigger work calls for smoothing burrs and surface roughness off of sear/hammerhook engagement surfaces. First disassemble the trigger group and arrange the parts so hard stoning of the contact areas can be done without altering engagement angles. Dressing hammerhooks and sear surfaces amounts to a few deft strokes only. As a rule, when people feel they have done enough, too much stoning has been accomplished. Overstoning will reduce trigger pull letoff weight to below 3 1/2 pounds, making trigger release unpredictable in an autoloading rifle. Too light a pull can cause the gun to "double" or "triple" due to the rocking motion of recoil and return-to-battery of the enertia slide. A 4 to 4 1/2 pound pull is ideal with little or no sensation of cheep. The classic two-stage military pull characteristic should definitely be maintained.

    A word of warning is in order here. Trigger adjustments demand experience and a definite "feel" for the job. A poor trigger job can ruin an otherwise good rifle. It is possible to make the piece unsafe if the adjustment is botched. Amateurs who may do other gunsmithing perfectly well may have no particular skill at trigger adjustment. Unless individuals are experienced at regulating a trigger pull, the job is best done by a trusted professional. The rewards of a well regulated trigger are essential for rifle accuracy, so take your Mini-14 trigger group to a competent local gunsmith or put it in a padded mailing envelope along with a check or money order for $35.00 and send it to: Poway Gun Works, 13168 Poway Road, Dept GA, Poway, California 92064 to have it done right.

    Field testing comes after the bedding, trigger regulation and sight installation. The test rifle was first fired with some surplus Lake City Arsenal '67 vintage ammunition. Center zero was established at 25 yards with intermediate (50 yards) firing and later 100-yard groups fired off the bench. Shooting was done in early morning with very little of no crosswind.

    Our early groups were erratic and disappointing, but, as firing continued, the rifle settled into its bedding and groups converged on zero. Early cold-barrel groups were respectable in the 2-3 inch size. But groups "walked" with a vertical string as the barrel heated up. Once the bedding was seated and the gun heated uniformly, the best groups appeared.

    After things settled down and became consistent, a switch to Remington .223 commercial ammunition produced groups up to the full potential of the gun. The best six-round group measured 1.6 inches at 100 yards. It would be good to try Winchester and Federal Commercial loads in individual guns to observe the result. None of these brands were available on our test day, however. Nobody can complain about 1 1/2 minutes of angle with a Mini-14!

    The Choate front sight is investment cast and the top post corners are very slightly rounded. Flat filing squares up the post. Millett's sight base with the Choate post combination made the gun shoot high-about 12 inches high at 100 yards. Millett has since modified their base to correct for this.

    Bedding effects are intrinsic to such good groups. But the trigger job and crisp, effective Millett sights were appreciated as aids to practical accuracy. Shooter confidence imparted by this tuning was evident shortly after firing began.

    Custom handloads would probably shrink groups further, but the effects would not necessarily contribute as much as if the loads were fired in a bolt-action rifle. The need for cannelured bullets and crimping with self-loading ammunition, along with loose chamber dimensions of self-loader, limits accuracy contributions of carefully assembled custom loads in the Mini-14.

    So, there it is! An attainable project for the Mini-14 owner who wants to get the most out of his rifle. For just a couple of evenings' time and the price of materials, you can upgrade the rifle's handling characteristics as well as accuracy and performance. And, for riflemen who care, there is the self-satisfaction of having made their Mini-14 perform.
  6. mark8252

    mark8252 G&G Newbie

    I really like my Series 181.
    The pop cans I shoot at do not care if I miss.
    The fun is in the shootin.
  7. parkerlarry1

    parkerlarry1 Guest

    reload f MOA 500 Yards [YUR Ranch rifle/box stock...]

    Believe my M 14 trigger is 7 lns plus/so what. Yep, all my firearms are box stock [my Russian SKS I shimmed the recoil lug with several .012 beer can shims/like that], but I shoot reloaded ammo and ++tweak that considerably++ since my first lee cast 113 gr flat nose bullet and IMR 4227 powder back in 81...chopped argentine 1909 mauser rechambered to 30 06 @ 70 dollars lay a way fresno ca Kmart. Like that quality/German/1909. Yea. I got 16 lbs of W680 back in 2000 from I believe it was BartletT in Ohio for the 7.62X39/155 gr lee cast [Harris designed bulletGC] and the 223 55 gr FMJBT military vietnam surpluss bullets/ 8$ a lb. Oh there is a limit to how much y o u can buy/ not exceed. Any way, last Sunday, Sept 07, using my improvised 20 inch high X 36 inch long X 10 wide [carpenter/sometimes] saw horse and 8 inch rolled up carpet I go 2 shots spaced 5 inches apart/55 gr and say 9 inches lower and 2 inches right ditto for 62 gr. The cases were mixed military lake city winchester mfg 85 thru 90,s mfg. The big deal here was the rest used [I have used over the backpack prone type shooting/similar results] pull rifle into shoulder/bedding down [firmly] into the pack and fire at will... Oh, your 17 gr W680 power scoop [lee says shake level once for theirs] is 38 super case, unsized and trimmed to say .845 " . Thats with a simple twisted tight at the case's extractor groove stainless linemans wire for a handle [what is that diameter , about 1/32 inch?] Figure 2800 fps for 55 gr, good case extraction [not if your rifle is brand new, drops em at your feet or fails to eject first round cold barrel], rounded primer edges and say 2650 fps plus for 62 gr [don t go outa your way to get these 'better ballistics' morebetter/more expensive mil surplus bullets unless your felling really mean], flattented primer/significatly high pressure loading. Reason is in a later 10 to gusting 15 mph cross wind both bullets got blown astoundingly right 15 to 22 inches of the 30 gallon metal trash can with the blaze orange 1 fot square duct tapped across the front. I confess I did hold level with the top of the can with the trusty ebayed 3X9 Bushnel sportview/23$/Mini 14 ranch rifle [stainless steel] and the bullets landed 20 inches below the bottom and 4 inches right of center/Ah thats looking back at the ridge from the center of can and cutting down with knife to bullet impacts in the slope I was on. Is that bright at 500 yards? 3 clicks left [1/4 " at 100 yrds] and 10 clicks up. Thats doable. So is the 4X4 on string with the 7 lb tomato can nailed to the bottom [I like that/don t blow all yur ammo off/got 22 ruger auto? a B l a s t/40 yartds with 38 special...125 gr 6 gr unique] More stuff on Hunting:
    FMJ Grey Squirrels/Weaverville Basin Bloody red pancaked once across the autumn forested slope. Seconds before the stainless Ruger held the Grey Squirrel fatally suspended 40 feet up on the digger pine branch facing my position, the Bushnell’s (Ebay, 20$, sighted in with boiled linseed oil on all mounting surfaces/absolute necessity/dries gummy) 6x sportview centered on the crouching center of mass across the steep gully between us. His sporadic barking outbursts silenced as the left hand pulled the loop of the leather military slinged 223’s rifle butt into my shoulder while the right hand perceptibly tightened on the pistol griped stock. Momentarily concious of my trigger finger nearly pulling the full weight of the 7 1/2 lb rifle, our eyes now locked in mortal ernest for what could have been eternity, I am abruptly stunned with the arrival of the semi autos recoil and muzzle blast of the 55 gr. projectile’s launch (win 680 surplus 18 gr.) at 2800 feet per second, with only one unbeleavably swift after image retaining the instantanious explosion some 45 yards distant, or is it just my imagination... Head up, I Immediately glimpse the vacant limbed perch and pine tree and then frantically capture the questionable win of the dramatically crimsoned forms' midair tumble just above ground. No finishing shot here, game over. The continuing midmorning sun warmes all and forested quiet moved only by acorns and leaves falling resumed its progression as I recovered the final seen. Absolutely lethal. I had read that the bullet breaks into 2 pieces up to 200 yards distant. Pulled the safety back into the trigger guard and rose up to recover the Lake City brass case resting brightly several feet down slope, habitually examining the CCI primer for pressure. The 12$ 10 round clip had not jammed. Good.
  8. Steve Blickley

    Steve Blickley Guest

    about small groups with mini14: Solved

    I found the solution to my poor range performance with my old [12years] mini14.
    In one fell swoop I picked up a parcel at my gunsmith. He had put a reddot on
    my new mini14 rifle and said he had so much fun sighting it in on the range,
    then he told me why. He zeroed it in and proceded to use up my box of heavy
    Hornady ammo and got 2 sub moa groups... got out his cell phone at the range and ordered a mini14 NRA from his supplier. We were at the range a month laiter and had a little shoot out, his was just over moa mine under again. After taking so much ribbing at the range about my old mini14 it is nice
    to see the same guys stop shooting to watch my rifle perform. It must be just
    a 1 in a thousand rifle, but it sure enjoy the quiet as my group gets posted.
    Ruger is better than ever and I got lucky.
  9. blaster

    blaster G&G Evangelist

    while not a tack driving rifle, I never knew Mini 14 s were considered "inaccurate" before joining this forum. I bought my first one in 1980. I have always liked the feel of the rifle with a M-14 style flash hider, so that was the first thing I did to a new one. once I was shooting my newer stainless mini and the roll pin that holds the flash hider & front sight broke and they flew off. I was shooting through a scope so I continued shooting. the groups really opened up! I think the extra weight and mass on the end of the bbl helps tone down the vibrations.
  10. Clem321

    Clem321 G&G Newbie

    My Mini is a 20 yr. old 187 series. I wasn’t satisfied with the accuracy, so I sent it to Texas for a new barrel. With the original stock, it would seem to shoot 1.5” to 2” groups with M193 ball and right around 1” with handloads with Sierra 55 gr. bullets. I am currently waiting to pick up a new Mini.

    I have come to believe that one problem with accuracy of the Mini is the excessively powerful piston stroke caused by excessive gas bleed to the gas cylinder. The resulting load on the op rod not only beats up the receiver and scope, but causes bending of the light factory barrel. One cure for this is to replace the gas bushing with a smaller bushing to restrict gas flow to the gas cylinder. I have recently replaced my stock bushing with a .046” bushing. The cases still eject something like 15’ to 20’, so there is still plenty of energy in the op system, but things are not as violent. I may try a smaller bushing. I tried .042”, but I was getting stove pipes. I may try a .045”. I also put in a 1911 recoil buffer. The op rod is hitting the buffer, but it isn’t battering it. I also changed out the stock for a Hogue Overmolded stock. It feels much better than my wood stock. Accuracy seems to be ok, but I haven’t benched it yet.
  11. Kcoyboy

    Kcoyboy G&G Newbie

    The new minis have the gas block screws staked. How do you get them out to put in a new bushing?
  12. Clem321

    Clem321 G&G Newbie


    With an 9/64" allen wrench. Just have a new set of screws to replace them with in case the ones you removed are too damaged. You can get screws in blued or stainless when you get the bushings and allen wrench. The 9/64" allen wrench wasn't in my allen wrench sets, so I got one when I got the bushings and got a few more spares from a machine tool company I deal with. Mine were staked, and they came right out. I reused them, but if I keep changing out the bushings I may have to use new screws at some point.

    There are several sources for the bushings. Here is the one I used:
    Richard Glab
    [email protected]
  13. Clem321

    Clem321 G&G Newbie

    I made a couple of errors. I took a look at a new Mini this morning. The screws were a little longer than on my 20 yr. old one and were themselves staked. They appeared to be more difficult to remove. Recommend a replacement set of screws prior to pulling the gas block.

    The 9/64ths allen wrench was in my allen wrench set. Sure didn't see it when I looked. Anyway, I now have several spares that I can bring with me to endure that the gas block screws remain tight.
  14. Kcoyboy

    Kcoyboy G&G Newbie

    Clem Ive got a good 9 64 allen tried it a couple of months ago and the screws wouldnt budge. I figured I would break the head off the screws and that wouldnt be good at all!! the only other option would be trying to cut off the block with a dremel but that would be risky. Those folks at ruger screwed up on this one they could have red locktited it at least with heat it could be removed. Ive got an older mini which I had no problem changing the gas bushing to stainless as the old ones werent!!
  15. Clem321

    Clem321 G&G Newbie

    When I pulled my gas block the first time, it was tight but doable. When I replaced the gas bushing the first time, I also replaced the alloy steel gas tube with a stainless gas tube. I think my 20 yr. old gun was staked and not locktited. I got some extra long allen wrenches in 9/64. They helped me to get the screws out and still not break anything. I am hamfisted enough that I have broken plenty of screws doing things like this.
  16. Kcoyboy

    Kcoyboy G&G Newbie

    Like I said my older one was easy . I want to know if anyone has gotten the screws loose on the newer ones with the fatter barrel.:feedback:
  17. Clem321

    Clem321 G&G Newbie

    I am picking up my new one today. I will find out. I need to take apart the gas block and measure the gas bushing. I anticipate getting several bushings of appropriately smaller size to optimize the op rod stroke.
  18. Kcoyboy

    Kcoyboy G&G Newbie

    Thanks for the info Clem let me know.
  19. Clem321

    Clem321 G&G Newbie

    I took my old and new Minis to the range today. The old one originally came with a .088” bushing. I tried a .042” and it stovepiped. I then put in a .0465” bushing. It is a little more than I think I need, but I left the .0465” bushing in the old one, but had a .045” bushing to replace it with if it still seemed too vigorous. The new came with a .102” bushing. I took the .042” bushing and drilled it out with the smallest drill I had, a .052”. I put this in the new one. When I shot it today, it seemed about perfect, pitching brass about 10’ to 15’, actually less than the old one with the .0465”. I changed out the bushing on the old one and put in the .045” bushing. Better. Now the old one and new one are running about alike. The old one with .045” and the new one with .052”.

    I also tried a couple of other brands of ammo. The IMI ammo I was using was definitely has a higher port pressure than some of the other stuff I tried.

    The screws on the new one were staked. I probably damaged them and the gas block when I pulled them. They really weren’t that tight. I replaced the screws with new ones just to be on the safe side. I will probably try to clean up the old screws to eliminate the staking so I can reuse them if necessary.

    I haven't had time to shoot them for accuracy yet.