by B.B. Pelletier
Photos and testing by Earl “Mac” McDonald
Beeman R7
You’ve waited a long time for this part of the report. And there’s a good reason that I made you wait. Mac had a problem with the Beeman R7. Instead of shooting like it should, the groups he got were all over the place. But there’s a happy ending, with things working out as they should. Now that we know what was happening, we’re going to turn this test into a tutorial.
For those who are regular readers, this will be easy to solve, although in the weeks that Mac and I worked on it, it didn’t seem easy. That’s because we are separated by half a continent, plus I don’t always trip to things on the first pass. I hope many of you will identify with that.
As I present the report, I’ll give you clues, just as they came to me. Only you won’t have a thousand other things that surrounded the clues, so they’ll jump out at you like billboards. You’ll have to remember that I was puzzling this thing out from the opposite side — the “before”side, if you can understand that.
When Mac first unpacked the box, he exclaimed his pleasure that the scope was already mounted on the gun — just as many of you would like it to be. He also remarked that there was noticeable droop in the barrel on this particular gun. There, those are two huge clues that I didn’t pick up on in the beginning.
Mac was also delighted that the R7 seemed to be sighted in from the start. Unlike a lot of guns, there was no need to zero this one. There’s another clue.
But the groups he reported, once he got around to accuracy testing, went from mediocre to bad! He also noticed that the R7 seemed to diesel long after it should have stopped. Even after hundreds of rounds had been fired, it was still smoking, and Mac could hear a difference between many of the shots. He theorized that the intermittent dieseling was causing the groups to open up.
Let’s look at some of the groups Mac shot. Maybe you can figure out what has happened with just what you’ve learned so far.
JSB Exact 8.4-grain pellet
The JSB Exact 8.4-grain pellet was the most accurate of all pellets in the first accuracy test Mac shot. At 30 yards, 10 pellets went into a group measuring just 1.20 inches across the two farthest centers.
Tightest group of this test was with 10 JSB 8.4-grain Exacts.
Crosman Premier 7.9
Next up were Crosman Premier 7.9-grain pellets. They were not quite as good as the JSB Exacts, grouping into 1.90 inches.
Ten Premier lites are spread out over 1.90 inches. But there is something else about this group.
With the Premiers we begin to get a powerful clue as to what may be happening. Can you tell by looking at the group what may be transpiring?
RWS Superdomes
The next pellets Mac tried were the RWS Superdomes that shot so well in the velocity test. That gave him two interesting groups, one measuring 2.20 inches across and the other measuring 2.40 inches across.
The larger of two groups of 10 RWS Superdomes.
By now, the problem seems obvious. Especially in light of the clues given. But I still didn’t pick up on it. As I told you, there were a thousand other things happening during this time, and I wasn’t paying attention to the details that now seem both bold and obvious.
So Mac and I discussed what could possibly be going wrong. Why was the R7 performing at such a poor level? Had he cleaned the barrel with J-B Non-Embedding Bore Cleaning Compound? Indeed he had. Not once, but three times! That wasn’t it.
Weeks went by and then it hit me. The new R7 has a muzzlebrake. Could some of the pellets be touching that on their way out the muzzle? If so, problem solved. Mac dutifully removed the muzzlebrake but no joy there. The hole was large and untouched. The crown was also untouched and perfect. He shot groups with the brake off that were just as large as with it on. Something else had to be wrong.
Then, I asked him why we were spending so much time looking into the accuracy of this one rifle when others we simply tested and took the results. He said it’s because we know the R7 has a good track record. But there was an even more compelling argument. Look at the Superdome group again. Notice anything, besides how long it is? Yes, it’s not nearly as wide as it is long. And that’s the biggest clue I will give you today. Tomorrow we’ll discover the reasons for all of this.
B.B. you got me thinking 🙂 all pellets went on one side ,but there is no group(except small one at second target) – so it is not a scope (or is it? ) ,my opinion is that gun or scope have had some loose screws much like i do 🙂 sometimes …………my Diana 34 – is notorious with that” loosing screws “habit so i always check tightness before shooting session ,back to R7 there is some groupings going on on the superdome field it seems that that group is shrinking like an arrow shape thingy 🙂 so now i said what i had to say to share my ignorance with world 🙂 now i expect you guys to “open my eyes ” 😉
My bad it is not “except small one in second target” i meant to say third target
Scope adjusted too far to compensate for barrel droop?
AR
I didn’t think of it, but I’m pretty sure you’re right now that I’ve seen it. Which begs the question, why is there so much barrel droop on a gun that won’t accept open sights?
BG_Farmer,
The R7 was “designed” by people of the old Beeman company. Those were people who have no idea what it best on a pellet rifle. Weihrauch designs the basic HW 30 and it for sure accepts open sights. It was a mistake to eliminate open sights as at least an option from the R7, in my opinion.
B.B.
R7 and HW 50 are accurate out to 30 yards as these 5 shot groups show.
[URL=http://s75.photobucket.com/user/jtlittle5295/media/DSCF1497.jpg.html][IMG]http://i75.photobucket.com/albums/i312/jtlittle5295/DSCF1497.jpg[/IMG][/URL]
BB:
Oh dear,a test.
Ok the groups are almost as broad as they are long.
Like Milan said,this suggests something could be loose and on the move.
Here is my shot in the dark putting together your clues.
The scope was fitted with rings slightly too large or not tightened correctly?
By the way I may have found a fundamental difference between the HW50s and the HW99s.
The 50s has a slit in the front sight shroud so as to change sight blades.The 99s doesn’t,and though it has a knurled ring in the shroud, it wont unscrew and the sight blade appears fixed.
Mike:
Although I can’t make it to South Dakota,I wish you all well come Saturday.
Happy Hunting.
DaveUK
Dave,
I urge you and everyone else to concentrate on the last group as your guide.
B.B.
Thanks DaveUK; Good Shooting to you.
Mike
were is the gun located I’m located in Columbia la.
were is the gun located I’m located in Columbia la.
Austin,
I don’t understand your question. Are you asking where the gun in this report os located? This report was written three years ago, and at that time the gun was located in Maryland. It was returned to Pyramyd AIR after this test.
B.B.
B.B.,
This is what I think transpired:
Austin was asking Mike where his gun was located (he was replying to Mike’s comment, which was a reply to DaveUK’s comment). Mike’s in South Dakota (according to DaveUK’s comment), and Austin was asking where in SD Mike’s gun was located since Austin is located in Columbia, IA, and probably wanted to get together with Mike if his SD location wasn’t on the other side of the state.
Edith
Double diagonal stringing. Erratic firing behavior. Too much smoke. Massive droop. Scope already mounted.
Let’s see now…
I smell several rats !!!
I would start…..no, I will wait and see what you and Mac came up with to see if I am right.
I would look at two different things first, then see If I had to go any farther. The two that I would start with are interrelated.
twotalon
Obviously it’s being caused by the
I would also say that it must be …. 😉 🙂
Checking all the stock screws and scope mount screws would be the first step. But, from what you reported I think the rifle may not be locking up properly. That would cause excessive barrel droop, vertical stringing, and may have something to do with excessive dieseling. Another thing we just talked about here was that if the scope adjusters are too loose they will not hold the erector tube in place. With that much scope droop, the adjuster may have had to be loosened to much to try to compensate for the droop.
David Enoch
Without question, it is the _____________ and the relationship of the ____________ to the _________!
Without question, it is the __________ as it relates to the __________ which affects the _________ directly.
Morning B.B.,
If you didn’t let twotalon touch this scope, I’d have to say that it might be a problem that is fixable with some Viagra.
Bruce
I think you have found the solution ! Rub the gun down with Viagra. That will straighten it out.
If you want a larger gun, rub it down with Enzyte. It works for ‘Bob’.
twotalon.
If you want gun to work for entire week use cialis 🙂 kidding
Too many clues.
Vertical stringing, noticeable barrel droop and a cheap “package deal” scope already installed by the factory. Final clue, those are terrible groups for an R7 at 30 yards.
I’m with AR Tinkerer on this one. The person that adjusted the scope at the factory cranked the elevation too far to compensate for barrel droop and the erector tube was floating.
kevin
AR Tinkerer and Kevin get my .02 as well. If so, the Crosman Premier groups may tell the tale better? two pretty much parallel diagonal lines. Or maybe, BB is telling us we’re off base by directing us to the Superdomes group which still has a long diagonal line, but a little more scattered than the Premiers…
The heavier pellet grouped the best so my guess is that the dieseling is causing the light pellets to go supersonic and tumble.(elongated holes on the paper target is the result). The bad groups with the heavier pellet could be caused by loose stock screws and or scope problems. I would check the screws first before fiddling with the scope.???????
I am with Brian in Idaho with this one ! 😉
Barrel droop and scope already mounted?!
What are the chances the gun was a defective that had been returned and somehow got back into the sales system?
That could explain why the scope was mounted…by the previous owner.
I too think it is a returned rifle. In the superdome pic, are they tumbling?? Some of those holes look big for one pellet hole.
BB,
Posted this before I read any comments so no idea what others have said.
Sounds to me like the scope is adjusted to the point is it out of it’s adjustment range and the erector tube no longer has enough spring tension so it is “floating”. Seems the vertical stringing would possibly indicate that. Also the barrel droop hint means that in order to get the gun on target it would take a LOT of adjustment.
Not sure what effect the “smoking gun” would have on groups but sounds like some one oiled the heck out of the compression chamber, spring, and piston? That may be a factor but I feel it is not the main cause.
BB,
I also checked the velocity results from part 2 and the spreads don’t seem too large. So I am betting the dieseling is at best only a small part of the problem if at all. But your statement that he could hear a difference between shots raises alarm bells.
Could this gun possibly have a broken or damaged mainspring? Or the spring is dragging on something?
Just my 2 cents.
Yep, that covers it all. I would personally start with the scope. Optically zero it or at least get close and then see what groups the rifle shoots. Probably a”so re-mount scope. If the rifle is still dieseling, a takedown might be called for.
I join everyone else on the scope issue. Someone has over adjusted the scope to compensate for the barrel group. Previous recent articles stated this as the classic reason for vertical stringing. Actually I only needed the first target to make that decision. I’ll tell you something else I believe, too, someone else owned this rifle before you. It has an improperly mounted scope (how many times do you get a combo with the scope mounted) and it has been over oiled, hence the dieseling. If I were you I’d check the barrel carefully for crown nicks, too. I think the supplier slipped you a Mickey.
-CJr
Uh… make that barrel DROOP! not Group!
-CJr
BB
It appears Beeman has proved to us all exactly how stupid it was to remove the iron sights on this rifle, and not even offer them as an option. You could easily determine if the scope was to blame by shooting without it. Even if you shoot poorly with open sights, as I do, you would most likely shoot better groups than this at 30 yards.
Others have hit the nail on the head, in my opinion, so I will not beat a dead horse. I will add that the back ring is likely to be shimmed with tape that can allow the scope to shift around.
I don’t see lockup problems as being the likely culprit. Even if Beeman is now the Chevy to Weihrauchs’ Cadillac, HW breakbarrels have very tight lockups in my experience. (I now own 3.) I was quite surprised that my newer R7 diesels still. I can’t hear it, but I can smell it.
I am reminded that you are quickly on the mend, and could easily cock this rifle now. I would love to see a part 5 or 6 where you test it for yourself and compare it to R7s you have owned or own.
I’m going to go out on a limb and say that I don’t think the gun is defective (a returned gun, slipped a Mickey)
just because the scope was already mounted or even because it’s shooting this way.
I think Mac is testing the Beeman R7 Elite Combo package (gun, mounts and scope sold together):
/product/beeman-r7-elite-series-combo?m=1561
Since Pyramyd AIR offers the option of mounting your scope and test firing the rifle I think this is what happened.
I’ve been wrong before. Earlier this morning in fact.
kevin
I thought it was mentioned either in a previous R7 blog or a comment that the scope was mounted by Pyramyd Air’s tech team.
Edith
I didn’t remember that PA mounted the scope. I will trust their expertise and that the scope is indeed mounted and zeroed correctly. Therefore, I will rule out that part of my diagnosis. The only other thing I can think of that would cause vertical stringing is a gradual loss of power. Since the gun is dieseling so much maybe it is over oiled and the seal is bad. Nah…it’s gotta be the scope somehow. Yet, I do want to trust that PA knows their stuff. If it was mounted by them and the gun was tested by them (the testing part is an unknown) it must have been in good working condition prior to shipping.
I’m thinking now the shipper broke the scope when he threw it on BB’s front porch.
-CJr
Mrs. Gaylord,
I’m sure you’re correct. I hope when you reach my age your memory is better than mine. 🙂
kevin
Kevin,
I believe I’m way past your age. I’m 62. I believe you have young children. I assume you’re 15-20 years younger than me.
Edith
Mrs. Gaylord,
Yes, I have a young daughter. Clint Eastwood had his last daughter when he was 56 years old. I wasn’t quite that old but…………you’ve missed guessing my age by a long shot. I do owe you a gift though.
kevin
BB:
Dang.I fell at the first hurdle not identifying a vertical string 🙂
This topic of ‘barrel droop’ coming up got me thinking,I did a rudimentary test on my HW by using a laser spirit level.
After setting a straight vertical line up a wall with the laser.I offered up the rifle using the spring housing as the straight line on the rifle.
Allowing for the fact the barrel may sit lower in relation to the spring housing,it still did appear to fall away(droop)from the laser line by about 5mm.Not a precise enough test to measure accurately though.
DaveUK
How about laser level mounted on the scope rail and a laser bore-sighter in the barrel? Measure the vertical distance at 10m between the laser dots?
Dave,
This rifle droops by more like 20 mm. It is major. And that is why the vertical string is such a huge clue as to what is happening.
B.B.
That sounds like my storm xt when I first got it. But the Storm has a much longer barrel. That much droop would be hideous on a longer barrel if you compared droop inch for inch of barrel.
twotalon
I went back and re-read the previous articles. The gun came with a 10 for $10 test crono ticket. I don’t know if this also comes with a target showing better groupings but I would hope so. Therefore, I’m still inclined to say the gun left PA in good order and what ever happened to it happend after it left the store. Now, dieseling has not been ruled out as the culpret but I’d still put money on a damaged scope. I just can’t wait to be stuffed back under my rock as BB reveals the correct answer.
-CJr
The 10 for $10 services does not include accuracy testing. It would be impossible to test a variety of pellets for each gun to find the most accurate for each caliber. Then, you’d have to depend on the shooting ability of the tester. Gun prices would have be increased a lot to accommodate that kind of testing. Here’s what the service includes:
Remove your gun from its box and fire 10 shots.
Ensure that the gun cocks reliably for all shots.
Verify that the trigger functioned reliably for all shots.
Enclose chronograph tape.
Make sure your gun doesn’t leak (PCPs only).
List the air pressure used to shoot your gun (PCPs only).
Sign & date a certificate stating when the test was performed.
List the name and serial number of the tested gun on the certificate.
Edith
Oh, and I have visions of BB putting that barrel across Edith’s knee and un-bending the barrel droop.
-CJr
CJr,
BB’s not that strong…and neither is my knee!
Edith
CJR,
One more thing. Did you forget that Mac was testing the gun? He lives in Maryland. We live in Texas.
Edith
You two are loving this, aren’t ya?? lol
Ok, since Maryland is on the RIGHT coast, and closer to sea level, thus closer to the center of the Earth…. nevermind.
Yeah, I knew Mac was doing the testing. So, it looks like you’re still outsourcing. BTW, you don’t think Mac is outsourcing HIS testing to China, do you? That would explain a lack of quality in testing. Then, there is really nothing wrong with the rifle or scope it’s just cheap Chinese testing? 🙂
-CJr
Chuck,
Here is the ironic thing. If Columbus had been right about his navigation, there would be no one to outsource to.
B.B.
BB:
After many hints and tips from your good self and other comments on the subject by the learned gentlemen of this forum.
I could still say, “I am buggered if I know” lol, but I wont.
Is it to do with the breach seal?
Causing the barrel to droop and possibly bounce vertically on firing?
Forgive me BB if you are currently sat with your head in your hands in disbelief 🙂
I will see you all tomorrow.
DaveUK
way off topic…. y’all see this pistol yet?? .60 cal, 7591 ft/lbs. ….
Google “Pfeifer-Zeliska .600 Nitro Express Magnum. ”
Gene
wonder if its available in .177 ??
First the R1, and now the R7 delivering dubious accuracy in both your tests. It sounds like quality control at Weihrauch is in question. The have been several rantings on the UK airgun forums regarding the decline of Weihrauch quality-it appears they may be true. This is a shame because people pay good money for their products and they need to start delivering instead of slipping down the slope of mediocrity.
I would have said scope wandering for some unknown reason. The fact that PA installed it seems to hurt my case, but I can’t imagine what else could be the problem.
Stingray, the other day when I said large POI, I meant to say change in POI. Your groups are good, and they also confirm our rough estimate that standing groups are about three times larger than rested groups although I believe the ratio gets larger as you move farther out.
B.B. and CowBoyStar Dad, I didn’t even know about the HK MP 7, just it’s more famous relation the MP 5. But the MP 7 looks very impressive and a nice gun to model.
Say, I had the most outstanding shooting experience the other day. After indifferent performances from my Crosman 1077 and IZH 61, I shot two 10 shot groups with my B30 through the same hole each. These weren’t continuous openings; they were really pellet-sized holes. I attribute this to my mental state. I focused totally on process and coldly ignored all impulses to snipe and all misgivings. I now know what it is like to be utterly and truly merciless!
Matt61
Matt,
Congratulations! When I wrote about shooting 10-meter pistols I talked about a place or metal state where you were completely focused on the front sight. Your scores will go up when that happens.
You have arrived at that state.
B.B.
Hmmm… i love a good mystery!
I am such a newbie to this that i shouldn’t even take a guess, but i will anyway.
On Oct 6 in BB’s article: “A shrine built for a Feinwerkbau 124 – Part 10” he states: “Vertical stringing is a sign that a scope has been adjusted too high.” and goes on to explain the problem. I’m gonna go with that as my guess 🙂
–Steve
Steve your guess sounds good to me. I had a similar problem with my RWS 48. I put a scope on it and had to adjust the elevation to the end of the adjustment travel just to get it close. The rifle would shoot the verticle pattern. I pulled the scope off and purchased a UTG scope mount base for it, hoping the droop compensating base would give me better elevation adjustment. After remounting and adjusting the scope, problem(s ) solved. All I had hoped to gain from the mount was the ability to sight in the scope, without maxing out the adjustment.
Crushing the erector tube by any chance?
B.B.,
Excellent blog. I can’t wait to get back home and read some more of it.
Bruce
Hello all. I am fairly new fan of this blog. I enjoy reading the blog and the comments posted by others.
Could someone please explain to me precisely what “dieseling” is in an air rifle?
The R7 was my first “high end” pellet rifle. I bought it from my uncle almost twenty years ago and it still shoots sweet. The only thing I have ever had to do to it is replace the breech seal in all that time.
Regards,
Owen
Owen,
When a spring-piston gun like the R7 compresses the air in front of the piston, there are micr particles of oil in the air. Under the heat of compression, these oil particles burn, just like the fuel in a diesel engine. That is dieseling. It is present in all spring piston guns that shoot faster than 500 f.p.s., but when you start smelling the burning oil, airgunners are concerned that the diesel event will change the velocity of the pellet.
B.B.
Thanks for the explanation, B.B.
Owen -one more thing about dieseling -it can cause spring to break ….. when oil explode inside gun chamber spring is under enormous pressure(detonation ) , now the only way to release that pressure is spring to crack (usually at the beginning and at the end of the spring)i know because i have learned this at a hard way ,before “spring breakage”you may hear explosion or your air rifle may sound like a fire weapon and that is that ominous sign ,so you dont really want any oil (some ointment are ok but i am not for or against couse some guns have self-lubricating piston seals exp. RWS Diana airguns )in the camber of guns with syntetic piston seal ,leather seal is another story thou…
BB,
What you say is true, but looking at the velocity and spread of the strings I wouldn’t think dieseling was the problem here.
However, the fact that the shots sound different is another story. That simply is not right and points to some other kind of problem.
What Milan says is also a possibility. Spring could be broken or bent.
Piston seals could be chewed up. A number of other possibilities.
Also possible that when the scope was adjusted to compensate for the barrel droop someone applied too much pressure at the limit and broke the scope internally?
Wish you weren’t dragging this out so we could get the full answer.
pcp4me,
“Wish you weren’t dragging this out so we could get the full answer.”
Well, isn’t that true of all of life? We don’t have the “full answer” yet. What I’m doing is giving you insight into solving this problem as we encounter it. By watching us struggle through this problem, you will hopefully get some insight into how to solve these problems for yourself when they arise.
I’m not picking on you, I’m using the term “you” to address all readers. I was fooled by this problem for several weeks before now, and only when the FWB 124 scope issue reminded me of what could be wrong did I click to this one. I would like to get the “full answer” myself, but it’s going to take some time.
Because of the upcoming Roanoke show, Mac and I will be on the road for close to two weeks, so we can’t finish this series right now, but we will get to it. We are just as excited to learn what’s going on as anyone.
B.B.
Scope is your first test. Too much droop may indicate the scope is adjusted too low and possibly too far to the right —- the erector tube it resting against the scope tube and is moving on each shot and fixing to a new zero when the vibration ends.
Shoot open sight until you know it works and go from there.
Sad to see the R-7 is not shooting to spec, they are such sweet little rifles and easy to shoot well that this almost seems a disservice.
Certainly some will quickly peruse the information and not realize there is an underlying issue with this particular rig.
Page all the way down to see how those babies usually shoot.
http://namericanairguns.blogspot.com/2010/05/airgun-gizmos.html
Someday I’ll have to shoot for groupings instead of just plinking. Afraid I may hurt my “ego” though. 🙂
rikib
I purchased a Beeman R7 for my daughter for Christmas. Had the exact same problem! In the process of getting a new scope from Straight Shooters. Hopefully this fixes the problem with inaccuracy.