Ruger’s Mini Thirty Tactical Rifle Part II

To be honest, my intention was to post handload data and move to the next project, but the Mini Thirty proved to be too much fun to put aside without exploring some of its live fire related features. The Mini is supplied with 1″ scope mounts that are low, but clear the rear sight and ejecting empties. A scope can be mounted easily, as shown above, but it can also be removed in an instant if the use of the ghost sight or alternative sighting system is desired.

Built for speed… shooting

I picked up a Warne Weaver rail mount that fits the Ruger Mini Thirty series. Brownells# 947-010-000 $34. The mount is matte black, hard anodized aluminum body with steel clamping and fastener hardware. The base’s is tab locked to prevent it from lifting or moving fore and aft after installation and it is high enough to clear the rear sight and ejecting empties..

With the Warne mount in place I was able to move a Burris FastFire II red dot sight from a 12 Gauge slug gun to the Ruger in just a few seconds and it proved to be an excellent combination. Bouncing empty cans or shooting at longer range bullseyes, the FastFire II is very fast to get on target. Of course, with the rail in place, scope rings and other sighting accessories can also be mounted.

The 7.62x39mm in context…

Cartridge	Case Length”	COL”	Max Body Diameter	Rim Diameter”	Capacity Grains	Max PSI (000)
.223 Remington	1.760	2.260	0.377	0.378	28.8	55
7.62×39 Russian	1.528	2.220	0.447	0.447	35.6	51
.30-30 WCF	2.039	2.550	0.422	0.506	44.0	42
.308 Winchester	2.015	2.810	0.471	0.473	56.0	60

The 7.62x39mm’s redeeming value is in what its short length and modest case diameter can do for a compact autoloader like the Mini Thirty or similar size military autoloaders. It can elevate these guns from the pop gun status of the .223 Remington to the ballistic equivalent of the .30-30 WCF, a cartridge that has killed more elk, deer, black bear and similar size game than any other modern cartridge.

In the case of the 6 lb and 37½” Ruger Mini Thirty, the 7.62x39mm chamber makes it a very compact and competent medium size game rifle that will shoot farther than the eye can see in hilly woodland and do so with low recoil and report, the 7.62x39mm Russian is inexpensive to handload and quality factory ammunition costs less than fifty cents per loaded round.

7.62x39mm Russian 150 grain bullet Performance
Range -yds	0	50	100	150	200	250
Velocity – ft./sec.	2200	2085	1974	1866	1762	1661
Energy – ft.-lbs.	1612	1448	1297	1159	1033	919
Path – in.	-1.5	2.1	3.7	3.1	0.0	-5.9

When is 0.311″ not 0.311″? When it is 0.308″.. No, wait, scratch that

The 7.62x39mm M43 Russian specification, the SAAMI drawing, European firearms, and virtually all loaded ammunition, regardless points of origin are barreled reflect a bullet diameter of 0.311″. Some older American firearms chambered for the 7.62×39 have a long leade and groove diameter of 0.308″ to facilitate the use of 0.308″ or 0.311″ bullets. Reloading dies sets, like the Lee Precision set pictured, include two expanders, both 0.307″ and 0.310″ to facilitate reloading bullets of either standard. The Ruger Mini Thirty has a 0.3105″ groove diameter, 6 grooves 1:10 twist.

It has become popular folklore for folks to cite the pre 1992 Ruger Thirty as having a 0.308″ groove diameter and post 1992 as having a 0.3105″ groove diameter. I know because I’ve even perpetuated the myth. The origin of the 0.308″ Mini Thirty appears to be an independent book written about this rife. Ruger senior, long term personnel insist this was never the case and that the Ruger Mini Thirty was ONLY produced with a 0.3105″ barrel. Specifically the comment was, “We would very much like to see an actual Mini Thirty factory was a factory installed 0.308″ barrel, not a report of someone knowing someone who had one, or someone who claims they once owned one, but an actual Ruger firearm with a factory 0.308″ barrel”.

During the course of reloading, the Lee Precision dies worked without qualification with the exception of light weight round nose bullets and bullets with sharply angled ogives. The problem was caused by the die set’s deep seater plug recess and the plug’s short length. The result was that the seater die bottomed out on the case mouth and the seater plug ran out of adjustment travel before these bullets could be seated to an appropriate 2.000″ COL. I am sure, on request, Lee Precision could provide differently dimensioned or contoured plugs to address this issue. In this instance we just cranked up the lathe and made a plug that was appropriate for the application.

Handloading a favorite five…

Handloads appearing in this section are all based on 0.308″ bullets. Why? Because they are widely available and there was a better selection to choose from. Additionally, they all performed well.

One hundred ten grain marks the lightest practical 0.308″ bullet for this round. I had some round nose type in stock and these were used to work up that bullet weight potential, however, I would have preferred Hornady’s V-Max or another spire point for actual field use.

The cut off for the upper end of bullet weight was set at 150 grains, as this was about the limit for the cartridge based on predicted muzzle velocity and the cartridge’s modest case capacity.

L-R: Hornady 110 grain, Remington 125 grain, Sierra 135 Grain, Hornady 150 grain, and Winchester 150 grain seemed appropriate for this application and all have construction and an intended impact velocity consistent with this cartridge. After some further assessment, the 160 grain FTX, a soft plastic tipped bullet intended for the 30-30 WCF, was added to the list.

The outer limit for cartridge overall length really is 2.220″. Anything greater resulted in insufficient magazine clearance to facilitate easy loading and reliable feed and to allow for a reasonable amount of safety margin for the same. Long bullets, of course, result in less powder capacity due to bullet protrusion into the case, but even seated out significantly farther that mechanical fit allows, there is not enough capacity pick up to permit movement up to a slower powder type.

IMR 4198 and Re 7, for the most part, yielded optimal results across the bullet weight range. I could not get 3031 to work for me, accuracy and/or velocity and other powders left cases only partially full which is not something I look for in a handload. The Mini Thirty digested everything it was fed, always locked on empty and always fed and ejected cleanly. Velocity with the short 16.12″ barrel was higher than I anticipated. There was a slight issue with case dinging with the heavier cases and a little primer swelling with all loads.

Dimensions and Capacities				Handload Data
Bullet	Weight Grains	Bullet Length	COL	Powder Type	Charge Grains	Primer	Velocity FPS	Energy Ft/Lbs
Hornady RN	110	0.675	2.000	Lil’ Gun	25.5	CCI 200	2547	1585
Hornady RN	110	0.675	2.000	Re 7	29.5	CCI 200	2529	1563
Remington PSP	125	0.810	2.033	RE 7	27.5	CCI 200	2395	1592
Sierra HPBT *	135	1.054	2.220	Re 7	27.0	CCI 200	2404	1733
Hornady BTSP	150	1.100	2.220	IMR 4198	24.5	CCI 200	2201	1614
Winchester PP	150	1.047	2.220	Re 7	25.5	CCI 200	2178	1580
Winchester PP	150	1.047	2.220	Re 7	25.0	CCI 200	2154	1546
Hornady FTX	160	1.025	2.220	IMR 4198	24.0	CCI 200	2177	1579
*Most Accurate

The 135 grain Sierra Match King bullets, noted in load data, shot quarter-size fifty yard groups and just over/under an inch at one hundred yards. The Hornady shot nearly as well with 1″ – 1½ one hundred yard three shot groups. The rest shot sub 1¼” – 1¾”, more typically toward the 1¾” end of the spectrum when the gun was warmed up. The Mini did heat up a bit. I could shoot perhaps eight – twelve rounds before the gun would heat up and a pause in shooting was reasonable.

Oh… one more thing

The Ruger Mini Thirty is an excellent utility rifle… yes, a real ranch rifle. In this configuration, it addresses the .223 Remington’s lack of power and moves the gun up to a competent deer rifle. It also solves the problem of the AR’s weight and the AR having more protruding points and angles than a Swiss Army knife. The Mini Thirty is an attractive and well made rifle, made of durable materials, and it will provide years of reliable service. Excellent gun for an experienced hunter who doesn’t need to carry his ego’s weight in smokeless powder and an excellent choice for the novice hunter who needs to concentrate on building hunting skills and not worry about being over gunned, battered by recoil and/or deafened with each discharge. Nice gun.

Ruger's Mini Thirty Tactical Rifle Part II

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