Today, reader Ian McKee, whose blog handle is 45Bravo, tells us about Benjamin Match pellets. If you’d like to write a guest post for this blog, please email me at blogger@pyramydair.com.
Take it away, Ian
Hello, today we will be shooting the new Benjamin “Bullseye” Match-grade pellets in a standard Crosman Mark I Co2 pistol in .22 caliber. And a Crosman Mark 1 that has been modified into a Mac 1 LD pistol costing more than four times the price of the regular Mark 1 air pistol.
The Pellets
I weighed and measured both the .177 and .22 caliber pellets in this blog back in February 2024. The weight listed on the tin is 14.3 grains. They are clean, well-packed, and sold in single-die lots.
The Pistols
We have covered the Crosman Mark I and Mark II Co2 pistols in this blog many times. They are Co2 target pistols made in .22 caliber (the Mark I) and .177 caliber (the Mark II).
This series of pistols were made from 1966 until 1986. They had adjustable sights, an adjustable trigger, and two power levels to choose from. The earlier models also had an adjustment to add spring preload to the hammer, but that was deleted from the later models.
The Tests
These High/Low tests will be ongoing. A particular pellet will be put through an inexpensive gun and a more expensive gun of the same caliber. These two guns just happen to be the same base gun; only one has had modifications done to it to give it more power and better accuracy.
I will be shooting indoors at 10 yards from a rest. The pistols both have red dot sights mounted to reduce aiming errors as much as possible.
The velocities are recorded with the FX pocket radar chronograph. Each gun was equipped with a fresh Co2 cartridge, and two blank shots were fired to get it up to speed. (Note: Depending on the design, sometimes the first shot or so from a Co2 airgun may be under or overpowered.)
The MAC1 LD pistol, 10 shots went through the radar with a low of 487 fps and a high of 494 fps for an average of 492 fps. The extreme spread was 7 fps, and the standard deviation was 1.8 fps.
The Standard Mark I has no internal aftermarket parts. Only aftermarket wood grips and a 3D-printed picatinny mount were used to mount the red dot for this test.
The Mark I recorded 10 shots with a low of 445 fps and a high of 455 fps, giving an average of 450 fps. The extreme spread was only 10 fps, but as seen in the graph the velocity was steadily climbing throughout the string. The standard deviation was 3.4 fps.
The Groups
The Mac I LD put 10 of the Benjamin .22 caliber Match pellets into a .451 group from a rest at 10 yards.
Not happy with the group size, I reloaded a fresh Co2 cartridge and fired a second group. That group measured .454. As Paul Harrell on YouTube would say, “not enough of a difference to make a difference.” The Benjamin Match pellet may not be a good match for this Lothar Walther barrel.
Crosman Mark I
Ten shots went into a group measuring .624 center to center, which is about what I would expect from a standard Mark I at 10 yards from a rest with an optic.
Grins and Giggles
After shooting the group, I wondered exactly how much the optic was helping me with accuracy. I mean, you only have to line up two points: the red dot and the bullseye.
I removed the red dot and repeated the test.
Taking my time, using a 6 o’clock hold and resting the gun on the bag. 10 shots went into a well-centered group measuring .944 of an inch.
So using the red dot over the iron sights, reduced the group size by half.
Summary
The new Benjamin Match grade pellets are clean, well-packed, and die-sorted for consistency.
I expected better accuracy from the Lothar Walther barrel, but this is apparently not the right pellet for this gun.
The Benjamin Match pellet performed well in the factory Crosman barrel, on par with pellets in the same price range.
What guns would you, the blog readers, like us to test the new Benjamin pellets in?
Shoot safe, have FUN.
Ian
Well, I know I’ve got a couple guns these need tried in. The scoped 362 and the 3622.
OhioPlinker, roger that. 😉
Ian, I would also like to add the Crosman 1322 to that lineup.
Mine has a 12″ (Crosman) barrel; but a stock barrel would be fine; thank you. 🙂
Ian,
Love the graphics! Maybe B.B. could ask Santa for an FX crony for Christmas?
Nice shooting. Shooting a pistol well is hard.
-Y
He tested them when they first came out.
The interface was new and not very user friendly.
That has been improved somewhat, but some things in it have not.
Having to constantly change the gun profile from a high power pcp, to a low powered spring BB gun can be a pain.
You have to know approximately how fast the gun you are testing is shooting before you start chronographing it. .
If you have it set to expect the wrong speed range, it will not record the shot.
Ian
Yogi,
Why on Earth would B.B. need anything more than the LabRadar he already owns? He might need to read the manual/watch the tutorial videos a few more times to understand the how to do its. It give you everything to include multiple downrange velocities to compute BC/Drg Counts and MORE. IT has interface capabilities to computers through the app or direct file downloads!
It is still the most capable Prosummer Doppler RADAR; BAR NONE.
I own one and have no other connection with the supplier or manufacturer.
shootski
I just love the graphics that Ian uses with his FX.
Easier for me to understand that a column of numbers.
-Y
Yogi,
Once the data is in the App and certainly once it is downloaded to the computer you can create almost any kind of graphic you could imagine. The folks on HAM do it all the time with simple output graphics. Much more complex three axis (x, y, z) is possible. Also the number of data points actually recorded is incredible.
Once a template is created/chosen it is EazyPeazy.
I had hoped the LabRadar would have made Tom’s work creating the blog more streamline, informative, and FASTER. IT hasn’t happened that way unfortunately.
shootski
Thanks for the well done report on some interesting tests. I like the format which compares the performances of two guns as well as testing the pellets in those guns. I am trying to reconcile the steadily climbing velocities on the Mark I gun with what I know of the temperature/pressure relationship of the CO2 cartridges. I would have expected steadily declining velocities due to the cooling effect of the CO2 liquid in the cartridge evaporating. I am guessing that the steadily increasing velocities is probably due to the operation of the valve. Maybe it lets more gas through as the pressure in the cartridge is decreased (much like we see in the curve of a graph of the velocities of an unregulated PCP gun). (I think I might have just figured it out as I wrote this!) However before I thought it through I had always assumed that the velocities would be decreasing.
As far as which guns to test the pellets in, I would suggest a couple of mild mannered springers such as the inexpensive Diana Two-Forty ($99) versus a Beeman R7 ($400).
The CO² cart is in the grip of these guns. Maybe the warmth of the hand warmed up the CO² over time if enough time between shots allowed the internal parts of the guns to return to room temperature?
I waited 30 seconds between each shot.
The room temp was 72deg?F.
I guess I should have listed that.
Ian
I suppose I should elaborate on my understanding of the way the valve works. In an unregulated PCP gun, the pressure in the reservoir helps hold the valve closed. As the pressure is reduced after each shot, the force holding the valve shut is reduced. This means that the hammer that opens the valve (momentarily) has less resistance to overcome. The force of the hammer remains constant but (due to the reduced pressure inside the reservoir) encounters less force holding the valve shut. The result is that the valve remains open for a slightly longer time. And more air is released into the barrel. The same idea should apply to a CO2 gun (which is also typically unregulated).
Not quite.
Co2 is different in that when you compress it it turns to a liquid. when you release the pressure it turns to a gas a room temperature.
The Co2 cartridge actually has liquid Co2 inside of it under pressure.
When the cartridge is pierced the liquid expands and boils off to a gas.
the typical Co2 pressure is about 800 psi to 1100 psi depending on the temperature.
Co2 is temperature dependent, at warmer temps you get more velocity, at lower temps you get less.
The guns are designed to run on the gas , as you use the gas, more liquid changes to gas.
Until you run out of liquid, then the pressure starts to drop like a rock,
Your BBQ grill works on the same principal, you have a tank with 20 lbs of liquid propane.
You use the gas, not the liquid.
As the gas is used, the liquid changes to gas and the pressure stays pretty constant.
Until there is no more liquid. Then the backyard party is over…
Ian
Yes, the pressure is related to the temperature. And if the temperature of the components remained constant, the pressure would also remain constant (as long as there was liquid CO2 in the container). However, as the gas CO2 is used (and more liquid is evaporated to replace the lost gas) the evaporation process requires energy (heat). The result is that the components (remaining liquid CO2, the cartridge, etc all are loosing whatever heat they have stored up to evaporate the liquid CO2. Therefore the temperature and the pressure is reduced. I spent a career in the commercial HVAC world and have plenty of hands-on experience with refrigerants. The same basic principles apply when charging an A/C system with a 30-lb drum of refrigerant. The drum and its contents get colder as the liquid evaporates and the rate of charging is reduced accordingly. This is why I initially thought the pellet velocities should decrease. But, if I understand things correctly, the way the valve is designed to be held closed by the pressure and momentarily opened by the hammer, the reduced temperature/pressure in the reservoir lets the valve stay open slightly longer resulting in the steadily increasing velocities.
45Bravo,
Great try and spot on facts.
CO² is really hard for most folks to comprehend how the Triplepoint actually works in a pellet gun.
Elmer needs to see the graphics and understand the heat budget required to make it work.
PCP valves and CO² just don’t play well as any number of dual-fuel proponents have found out.
Pressure Regulators don’t work with CO² at all!
Ian…again great reporting!
shootski
Shootski, I am not familiar with the term Triplepoint for air guns. But I will search for something. What I am trying to convey is that it dawned on me while I was writing my first post in this report that the valve’s operational behavior would be similar to the valve’s operational behavior in a PCP gun. Here is a graph that I copied that demonstrates the constant increase in velocity (for about the first 20-shots or so) in a PCP gun despite the obvious decrease in reservoir pressure due to using up twenty shots worth of the compressed air.
Elmer Fudd,
Yes you have got the UNregulated PCP valve profile down. The but is that the LIQUID CO² acts like a regulator and only delivers a very steady pressure to the valve. The problem with CO² powerplants is that the pressure is directly dependent on the rate of CO² flashing to gas…which is determined by the LIQUID CO² temperature. The fact that 45Bravo (Ian) waited 30 seconds between shots allows for enough time to have stable CO²LIQUID temperature.
https://www.linkedin.com/pulse/what-triple-point-co2-refrigeration-mentor#:~:text=The triple point of carbon,at 5.17 bar%2F75 psi.
shootski
Shootski, I respectfully disagree. I don’t think that 30-seconds is anywhere near long enough for that much heat to transfer into the liquid CO2 while in a cartridge inside the gun. If the pressure delivered to the valve from the CO2 cartridge is a stable pressure (due to stable liquid CO2 temperature), then how do you explain the constantly increasing velocities that Ian measured?
EF
Magic???
Ed
😉
Maybe Ian has warm hands, and he’s warming up the CO²? TMI alert! (Hihihi: TMI = too much information). The human body’s internal temperature is 98.6°, higher than room temperature.
I also had to reply to one of your earlier comments due to the situation with running out of room to reply. Thanks for spelling out your theory. I agree that it is an interesting and reasonable theory. I think it would be relatively easy to test by simply placing some insulation between the hand and the grip and comparing the velocity results of with and without the insulation. I don’t have one of the Mark I or II pistols or a chronometer that gets along with CO2 gas. Hopefully there will be someone else willing to test the theory?
Out of curiosity I just conducted a test using my Crosman 2240 pistol. The new CO2 cartridge fits snugly inside a metal tube. I assume that there is some reasonable amount of contact between the inside of the tube and the CO2 cartridge. In the conditioned basement the thermostat is set on 68-degrees. The gun had been in its box on the somewhat cooler tile floor. Before I started I measured the temperature of the outside of the tube at 66.4-degrees with an instant-read meat thermometer. I shot 10 pellets waiting 30-seconds between shots (total elapsed time by stopwatch was 4 minutes and 30 seconds). I measured the temperature of the outside of the tube as 64.2-degrees. I double checked this with an infrared thermometer and got a similar 2-degrees difference. Heat energy flows from warmer objects to colder objects. The liquid CO2 inside the cartridge must have been even cooler in order to absorb heat energy from the cartridge and the metal tube that surrounds the cartridge. Areas of the gun not in contact with the cartridge (further back on the tube for instance) stayed about two degrees warmer than the part of the tube in contact with the cartridge. If the temperature of the CO2 is lower than when I started, then the corresponding pressure will also be lower.
Here is a photo I forgot to attach:
EF, just an fyi, the Co2 from the 2240 goes directly from the cartridge into the valve, the valve seals against a seal on the front of the valve. .
The MKI piercing device is at the base of the grip,
The inverted cartridge releases its liquid contents into the sealed area surrounding the cartridge.
The gas is let into the valve at the top of the grip.
Unless you turn the MKI on its side or upside down the valve always sees gas. Not liquid.
Ian
WordPress ran out of reply space so I went up to Elmer’s last comment.
Elmer, I too am interested in the question of why velocity seemed to initially increase, but just in case I am being misunderstood, please forgive me, I want to reply to the part of your comment, “But I submit that it still isn’t a quick enough heat transfer rate to keep a constant pressure with only 30-seconds between shots.” I am proposing that the pressure is NOT constant for those first few shots due to the CO² warming up from the heat of Ian’s hand, that the pressure is increasing until it reaches a new temperature, somewhat above the original temperature of the gun when first charged with CO². Then the cooling effect may occur but subside after the 30 second interval. Eventually, the velocity and therefore the pressure of the CO² and by extension the temperature of the CO² stabilizes.
That’s my theory anyway. I notice that when I shoot my Mark I or IIs my hand gets colder, which means heat is leaving my hand into the exposed metal parts of the grip.
Elmer Fudd,
I don’t doubt your testing results.
They just provide a snapshot of why the Crosman 17XX/22XX CO² powerplant would never be Match Grade.
CO² was only briefly used and quickly replaced by PCPs in Match/Olympic Grade shooting irons because it was difficult to handle and use. If you didn’t get the (BULK) fill right you might not make it to the end of the Match/Stage; capsules/bottles, and powerlets were not used.
Most of the plinker CO² guns were converted to bulk fill, Hpa, or sat on shelves in my early years of Adult Airguns.
I provided the facts for the Readership with no intent to be argumentative.
shootski
Interesting. Shootski could probably calculate the difference in pressure at that small temperature difference, but I stand by my theory of the Mark I or II, which stores the CO² in the metal grip, warming up from the shooter’s hand, transmitted from the metal parts in direct contact with the skin.
Yes, I agree that the design of the Mark I or II does provide for some heat transfer from the hand of the shooter to help warm up the CO2. But I submit that it still isn’t a quick enough heat transfer rate to keep a constant pressure with only 30-seconds between shots. Otherwise I don’t think we would have seen the consistently rising velocities that Ian measured. Metal grips instead of wooden grips might increase the rate of the heat transfer from the hand. I wonder if Ian felt any temperature drop of the grips as he was shooting. I am trying not to be argumentative either. I have a theory that seems logical to me. If anyone else has a reasonable theory or explanation for the steadily increasing velocities measured by Ian, please let us know.
Since you asked, Ian and since you are testing these pellets in CO2 pistols, why not test them in CO2 rifles like the gas version of the Ruger 10/22? That is just a minor suggestion, not one meant to send you down countless rabbit holes or climbing infinitely growing branches of decision trees.
I would like you to test these in the same guns as you are testing the JTS pellets in.
Since these pellets are toward the top of the price range, I would think guns that could bring out the best. It’s easy to recommend a few guns, but I don’t know what options are available to you. I would like to see a good pcp and a high end springer in the mix.
Appreciated the Paul Harrell reference.
CB
The High/Low concept is mine, I like to see an underdog do well.
And it gives both ends of the spectrum for the buyer.
But every gun is unique, and while it MAY shoot well out of many guns of that model, somewhere out there are guns that it does not shoot well in.
Ian
I am not sure that I follow you exactly on the High/Low. Does that mean a high end and low end as far as cost of the gun? If so, that is why I said a ‘good pcp’. If memory serves, I believe BB’s Avenger is one of, if not the most accurate pcps that he has. And it would certainly be on the low end of the price spectrum.
But I personally am not aware of a low priced springer that is considered exceptionally accurate, though I would love to be proven wrong.
CB
Yes, retail price against retail price.
The owner of the less expensive gun can see how that gun groups against a more expensive one without any tuning on either gun.
Likewise for the owner of the expensive gun.
Ian
Ian,
got it. And I like it. Most of my guns are on the low end of the cost spectrum, but I still want to get everything I can out of them.
CB
Esteemed Readership and esteemed Elmer Fudd too,
https://www.pyramydair.com/blog/2023/06/why-not-co2/
shootski
PS: I will offer an alternative to the “theories” already presented.
Given the number of shots in the “climbing” group Ian’s Mark 1 valve is not balanced for that high of CO² pressure achieved on the shoots shown and liquid CO² temperatures . As the CO² cools from his (45Bravo’s) “rapid” shooting lowering CO² gas pressure is allowing the valve to operate “better” and increase MV (Muzzle Velocity) in an apparent incremental fashion.
Do i believe what i just wrote to be fact? NO!
It isn’t even a working theory it is SIMPLE Hypothesis.
Thank you Shootski. I read the report by BB that you linked to. I had read it a while back but this was a refresh my memory read. Here is a quote from BB’s report:
“ Also, as you shoot some guns are cooled by the expanding CO2 rapidly. This changes the velocity for the next shot. Some guns can lose 100 and even 150 f.p.s. when firing rapidly. Other guns are affected much less. This is a case when a chronograph comes in handy.”
And that is what I initially thought the velocities should have done (decrease). Instead, Ian reported steadily increasing velocities. And as I was trying to ask why we were seeing increasing velocities, I remembered and realized that unregulated PCP guns also increase in velocities as the air is used and the pressure in the reservoir reduces. This is counter-intuitive but when we understand how the valve works we can comprehend how the increased velocities happen. Your hypothesis appears to be, for all practical purposes, the same thing that I have been trying to express all along. I think that my experiment with the 2240 and RG’s grip getting cooler as he shoots show that the temperature of the liquid CO2 and consequently the pressure of the CO2 gas is being lowered from the “rapid” shooting. The valve then operating “more efficiently” as a result of the lowering pressure is apparently the reason for the increased velocities. I really think that we may be “on the same page” now. Thanks for “listening” and responding to me.
Hello everyone,
I don’t own one of these pistols and have passed on them because I own some fine spring pistols and have never owned a CO2 one. Never felt the need for one.
Curiosity kill the cat. I am tempted. Have read the blogs relating to rebuilding the seals on one of these pistols.
My laundry washer has sprung a leak and need to replace the drain water hose.
Air pistol or washer?
I was looking to stock up on these new pellets but suddenly prices went up from $19.99 to $29.99 at my regular online shop. Last time I checked, Israelis and Ukrainians were not using these.
Capitalism and Democracy, America’s greatest export. mmmm?
I still have a bit over ten years to retire. I am tired or working 12 and 16 hours shifts.Tired of the politics in the USA. Tired of the rat race. I am of Mexican ancestry and thinking of retirement there. However, my brother in law is Salvadorian and I am contemplating retiring there. Any thoughts.
My thoughts sprung from my sister visiting me from Texas this weekend. I live in California. Blame the weather. We have some beautiful downpours here in Los Angeles.