The Mac1 Benjamin-Sheridan Steroid Conversion

Mac1 Airguns makes several unique custom airguns and accessories; I’ve had experience with two. The first was his customization of my Crosman Mark 1 CO2 pistol, one of many airguns I wish I’d kept. The other is his “steroid” conversion kit for Benjamin and Sheridan pump rifles. It consists of a stronger cocking lever and link, an improved valve, an adjustable pistol, and a few other parts, and makes the converted rifle capable of something like 50% more muzzle energy.

In the photo above, taken around 1998, I’m shooting a .22 caliber Benjamin converted by Mac1. This was a review loaner for an article in U.S. Airgun magazine. The gun also had a forward scope mount to which was attached a Burris pistol scope, creating a sort of pneumatic Scout rifle. I wrote that it was an excellent gun, and maybe the ideal survival air gun: Rugged, easy to maintain with a few hand tools, and entirely self contained.

I still agree with what I wrote back then. It may take a while to pump up, but you rarely get a second shot hunting small game. The gun was capable of over 25 foot-pounds of muzzle energy with ten pumps. A conversion kit will cost you around $100 today, which is not much considering how much it improves the gun.

The RWS/Diana Model 34, part 1

The Diana 34 has been one of the most popular European spring-piston air rifles of the past 40 or 50 years. It’s often been touted as a sort of entry-level “magnum” gun, that is, one capable of generating over 12 foot-pounds of muzzle energy. I’ve owned around 30 or 40 quality airguns- that is, modern pellet firing guns with rifled steel barrels- but I’ve never owned a Diana Model 34, or any Diana spring-piston gun. That changed recently when I purchased a new Model 34 in .22 caliber.

There were three reasons for this purchase. First, I was looking for a lightweight break barrel gun for use afield. Something more powerful than my R7/HW30, and lighter and handier than my TX200 and ProSport. Second, I didn’t own any airguns in .22, and last, I was curious about the performance of this very popular gun. Did its performance justify its popularity? It arrived today and I spent a few hours getting some initial impressions.

It’s not terribly different in appearance or construction from the typical German break barrel air rifles of the 1970s, when I first became interested in what were then called “Adult Air Rifles.” About the only concession to modern technology is the increased use of plastic parts, and the light-pipe open sights.

The sights are very visible, but the shape of the stock makes it impossible for me to get good sight alignment, and the front sight makes it impossible to grip the end of the barrel to get good cocking leverage. I removed the rear sight- I’ll put some short Allen screws in the screw holes to fill them- and removed the front sight blade and hood, leaving the plastic sleeve in place as a muzzle protector. (I’ll eventually replace that with a steel or aluminum “muzzle brake” cocking handle to protect the muzzle and get a bit more cocking leverage. )

To replace the open sights I installed a 2.5×20 Barska scope I happened to have on hand. (It was previously used on a break-barrel .357 Magnum carbine I owned some years ago that I had built up as a woods gun.) The front lens element on this scope appears to be held between two threaded rings, so it should hold up well to spring piston gun recoil.

Cocking this gun generated a lot of noise from the spring, and the first few shots from this gun produced a significant amount of smoke and the smell of burning oil, something that put me in mind of the guns I bought back in the 70s and 80s. Newer and more modern guns, like my TX 200 and Pro Sport, and my Theoben, shot quietly and smoothly from the day they arrived. No smoke, either. Shooting the 34 is a trip back to the 70s or 80s, when it was assumed that the first thing you needed to do with any spring gun was to give it a proper tune-up. Strip it down, remove the excess lube, polish and de-burr the cylinder, etc.

After zeroing it in, in my basement 10m range, I shot a 5-shot test group:

As you can see from the vertical shot dispersion the gun was still dieseling. I suspect it’ll settle down some as the excess oil burns off, but what it really needs is a better spring, a spring guide to quiet it and reduce internal friction and wear, and maybe an improved piston seal. I’ve often heard that the gun is over-sprung, and that going to a weaker spring can actually improve velocity as well as accuracy. I’ll probably rebuild it this winter, when I’m stuck indoors, using a Jim Maccari or Vortek kit. I’ve had good experience with both. My TX 200 was purchased direct from Maccari back when he was tuning rifles, and I installed a Vortek kit in my R7/HW 30 several years ago. Both are very smooth, quiet, and accurate shooters.

Plastic trigger guard and possible replacement

Other plans are to replace the plastic trigger guard with a metal one (I have what I believe is an HW or possibly FWB on hand that looks as if it’ll fit) and if possible, find a better stock for it. Back in the 90s Maccari was making excellent unfinished custom stocks at very reasonable prices, and I purchased one for my HW77. Today all I’ve been able to find are complete custom stocks for over $1,000, which is overkill for a $300 rifle. It could also use a scope with higher magnification. 2.5x is fine for deer at 40 yards, but rodents are much tinier targets.

I’ve only put around three dozen pellets of various types through it, and while it’s still noisy and rough shooting it has quieted down somewhat. I may try adding some heavy silicone grease to the spring and see if that quiets things a bit.

The Umarex TR50 (and HDR 50)

Umarex TR50

Umarex has a line of paintball-type guns they call “T4E” or “Training for Engagement.” The line includes .43, .50, and .68 caliber CO2 guns intended for law enforcement and military training, firing rubber balls, chalk-filled “dust balls,” and paintballs. Two are also available in higher power versions for use as non-lethal defensive weapons in countries that prohibit the use of weapons for that purpose.

Not long ago I purchased their TR50, a CO2 powered revolver that uses 12gram CO2 cartridges and replaceable cassettes, each of which can hold 6 rounds. It has a nominal muzzle energy of 7 joules, which translates to about 6 foot pounds. The HDR is the self-defense version, which produces 11 joules, or around 8 foot-pounds, of muzzle energy. It’s not available in the US but, curiously, can be purchased in the UK and some European countries. I’m not particularly interested in the TR50 as a self-defense weapon, although loaded with rubber or pepper balls I think it would be a good defense against aggressive dogs while bicycling or hiking.


One interesting feature of the TR50 is how the CO2 loads. 12gram cylinders are loaded in the grip, after which a plug is screwed in, but this doesn’t pierce the cartridge. To do that, the user has to give the plug a sharp rap with the palm or a nearby firm surface, the idea being that the gun can be loaded and ready for use with the risk of gas leaking out. (An Allen wrench is provided to help seat the plug, though after a few loading cycles it becomes easier to tighten the plug by hand.) Once pressurized, a metal peg pops up above the grip, giving both a visual and tactile indication that the gun is ready to shoot.

TR50 cylinder loaded with rubber balls

The TR50 and HDR are much more popular in Europe than in the US, largely because there aren’t very many legal self-defense options available in many countries. The result is a number of products designed to improve the terminal effectiveness of the gun- better projectiles, longer barrels, and molds for making your own projectiles. The simplest way to improve power downrange is via heavier projectiles, which do a better job of extracting the energy available in each shot. You can buy hard plastic balls with a steel center, balls made from rubber mixes with powdered iron, and molds to make your own projectiles. It was this last option that most interested me, but high shipping costs make this an unattractive option, as they almost double the price from around $40-50 to $80-90.

What I’ve decided to do instead is to make my own molds, either from a chunk of aluminum or from a piece of UHMW polyethylene I have on hand. European experimenters typically make their projectiles from hot melt glue, which has several advantages: It’s hard enough to hold its shape when fired, soft enough to not damage the gun and barrel, and cools and hardens rapidly, which speeds up the production of multiple rounds. I do intend to try that, but I’m also considering paraffin wax, silicone caulk, and other materials. More on that after I get around to making the molds.

While I’m not planning on using this as a defensive weapon, I did install a rail-mounted flashlight I received for review:

Looks totally tacticool, doesn’t it? This inexpensive light uses CR123A lithium batteries and produces a very bright and wide illuminated region. It might actually be a good tool for investigating noises in the backyard after dark- especially when loaded with a full cylinder of pepper balls.




What Happened to Crosman Premier Pellets?

Old 10.5gr Premier on the left, new one on the right

Crosman has been bringing out a lot of exciting and innovative guns in recent years, but I’ve been hearing complaints about their pellets. The bulk-packed Premier 7.9 and 10.5s have long been my go-to pellets for FT and hunting, and recently, thinking I was down it only half a box, I ordered a new box of the 10.5s.

What I received was downright depressing, starting with the box they were packed in. It was made of cheaper, lighter weight cardboard, it leaked pellets, and the familiar die number stamps was missing from the back. The pellets themselves were nice and shiny, but each one had a distinct mold line running around it, and the surfaces were much rougher than that of my old pellets. Inside the box I found lead flashing, distorted pellets, and other signs of poor quality control.

Has Crosman given upon producing quality pellets? Have they outsourced these to China? I don’t know. Luckily I discovered two full boxes of both the 10.5s and the 7.9s, which should last me quite a while. But unless something changes at Crosman, after those run out I’m switching to JSB.