I was speaking with a group of very advanced airgunners recently and found myself amazed by what we all took for granted. The subject was airgun accuracy and topics like distance, powerplants and pellet shapes came up, but no one in the group seemed to remember the time when none of those things made any difference. They didn’t because there weren’t any pellets on the market that took advantage of them. Until around the 1960s, accuracy with airguns was iffy, at best. The problem was not the guns — it was the ammunition!
Crosman 160 opened my eyes!
I remember buying a new-old-stock Crosman 160 target rifle that had been produced and sold to the U.S. Air Force. The rifle hadn’t been fired since Crosman tested it with CO2 at the factory some time in the 1970s. The Air Force bought an unknown number of 160s that came with slings and the Crosman S331 rear peep sight. Presumedly there was a plan to use these rifle for some type of training, but that must never have happened, because hundreds of them were found in a military warehouse in the 1990s in unused condition. When I opened the gas reservoir to install 2 fresh CO2 cartridges, I found the original cartridges Crosman had used to test the gun before packaging in the 1970s! The rifle was brand new, as were hundreds of others just like it!
Today I present to you one of the most important reports I have ever written. It doesn’t turn out the way I imagined; it turns out far better! Please enjoy what I feel is the most significant work I have done in a very long time.
Today is accuracy day for the Swedish Excellent multi-pump pneumatic. In Part 2 we determined the velocity for both the Swedish Excellent round lead balls and also for some lead balls called Lobo from Argentina. The Swedish balls were about 100 f.p.s. faster than the Lobo brand balls, and we discovered that the Lobo balls are about one-thousandth of an inch larger than the Excellent balls. I think the size and perhaps even the uniformity of the ball sizes will play a big role in what happens today.
Today we look at the power of the Swedish Excellent multi-pump rifle I recently acquired. Remember that this rifle is an oddball caliber that shoots lead balls measuring 0.213-inches in diameter. I discovered that Argentinian lead balls branded Lobo measure 0.214-inches and will work in the rifle, too. Today I will test them both at differing numbers of pump strokes.
6 strokes are minimum
Right away I discovered that 6 pump strokes are the minimum necessary to shoot this rifle reliably. I stuck several balls on 4 pump strokes. But that was not the only discovery I made.
I’m writing this from my hospital bed on Saturday, though I hope to be discharged later today. I would like to thank Val Gamerman for covering the blog for me last week. I was unable to do much of anything, and my thanks to all of you for keeping things going. This will be short, because of my situation. Let’s talk about airgun projectile stability today.
When I shot the Benjamin Pioneer airbow at the SHOT Show this year I was amazed by the accuracy it gave. Not just when I shot it, but also there were two cases where one arrow went inside another one at 30 yards. Television’s Mythbusters proved that a regular longbow cannot do that because the arrow is constantly flexing as it flies, but the Pioneer pushes the arrow from the tip (it’s hollow inside) rather than from the back end and it doesn’t flex in flight. That got me thinking about what has been done about airgun projectile stability and what remains to be done.
Today is the day we check the velocity of the Dan Wesson 715 6mm airsoft revolver, but I’m going to add some things to this report. I said in Part 1 that I would tell you how the Hop Up adjustment works and show you how to adjust it, so we’ll look at that, as well.
I usually try several different types of ammunition in a velocity test to give you a good idea of how powerful the airgun is. In the case of an airsoft gun, however, I have to constrain my test to a specific weight BB of the three most common weights — 0.12-gram, 0.20-gram and 0.25-gram. I do that because airsoft guns are designed to work best with one specific weight of ammunition and no other. In the past I have experimented with other weight BBs in some airsoft guns, but all that did was prove that the weight recommended was the best one.
Before I get into today’s report I want to give you an update on the Hammerli trainer for the Swiss K31 rifle. I am having trouble getting it to work after disassembly and cleaning. There is a small ball bearing that connects the trainer’s sear with the piston, and that ball has to be assembled in exactly the correct fashion (I believe) before the gun will remain cocked and fire. It has to travel in two raceways — one on the sear bar and the other on the piston, and there are holes it must be forced through at critical times in order to provide clearance for the parts to move against each other. My gun buddy, Otho, looked at it with me, and after two hours of working with it he decided that the man who invented such a complex system was probably on the verge of insanity.
A few new IZH 61′s!
Before we begin I want to tell you that Pyramyd Air just got a small shipment of new IZH-61 rifles from another dealer. These won’t last long, so now is the time to act!
Today is accuracy day for the Haenel 310. I was not able to locate the unplated 4.4mm lead balls I have, so I will only be shooting two types of ammo today. The distance will be 5 meters and the target will be an NRA 15-foot air rifle target – which is to say a BB-gun target. While the 310 is rifled, it is not quite as accurate as the Daisy 499 Challenger, so 5 meters is a good distance to shoot. I shot off the UTG Monopod, and before anyone asks — yes, that is just as stable as shooting from a sandbag rest. The magazine only holds 6 shots, so I loaded 5 balls at a time and shot two magazines of each type of ammo at a target.