Diana 34 Easy Modular System (EMS) Synthetic: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Diana 34 EMS
Diana 34 EMS with synthetic stock.

Part 1
Part 2
Part 3

This report covers:

  • Scope
  • The test
  • Pellets
  • Sight-in
  • JSB Exact Heavy domes
  • Crosman Premier Heavy
  • Trigger
  • Heavy pellets
  • H&N Baracuda with 4.50mm head
  • Evaluation so far
  • Summary

Okay. Today is the test many have been waiting for — the Diana 34 EMS at 25 yards. How accurate is it?

Scope

I scoped the rifle with an older  UTG AccuShot 4-16X50AO scope, mounted in BKL 2-piece double-strap one-inch rings. Since the scope was already shimmed in the rings I figured they would adjust to the point of aim relatively easily.

The test

I shot from 25 yards with the artillery hold and my off hand rested on a sandbag. I will note that with the thumbhole stock I’m testing a true artillery hold isn’t possible, but I held the rifle as loosely as possible. My off hand was at the rear of the cocking slot.

I shot 10-shot groups today. I have to say the EMS is easy to cock and you don’t have to slap the muzzle to break it open. This is a very well-behaved air rifle.

Pellets

I selected JSB Exact Heavy domes from the test at 10 meters. In that test we learned that the 34 EMS likes heavier pellets that are also larger. So I also selected two heavier pellets that I hadn’t tried before. When you see the results I think you’ll agree I picked two good ones.

Sight-in

I shot a single JSB Heavy pellet at 12 feet and confirmed that the scope was close enough on for me to back up to 25 yards. Once there it took me three more shots to get on target. Of course I didn’t want to hit the center of the bull and destroy my aim point, so all groups will be at the edge of the black.

JSB Exact Heavy domes

First up was the sight-in pellet. The first shot landed in the top of the bull and I thought it was perfect, but the next several landed high and outside. When all 10 had been shot I had a somewhat vertical group that measures 0.675-inches between centers. It’s a little larger than I would like from this rifle, but there were no shots that were called pulls.

Diana EMS JSB Heavy
The Diana 34 EMS put 10 JSB Exact Heavy pellets into 0.675-inches at 25 yards.

Crosman Premier heavy

The second pellet I tried was the 10.5-grain Crosman Premier heavy. These pellets are sometimes the best of all, and today was one of those days. The 34 EMS put 10 of them into a tight 0.619-inches at 25 yards. 

Diana EMS Premier heavy
Crosman Premier heavys wanted to stay together when shot from the Diana 34 EMS. Ten went into 0.619-inches at 25 yards.

Trigger

You may recall that the 34 EMS has a different trigger that is not crisp like the Diana T05 or T06. This trigger has a second stage through which the trigger blade moves considerably. It’s light enough, but not crisp. I have said that it feels like a single-stage trigger, once you get to stage two. I got used to it in Part 3 and today I was able to do good work with it. I still can’t tell when the rifle is about to fire, but pulling the trigger has no adverse effect on the stability of the crosshairs.

Heavy pellets

I think there is something to this thing about heavy pellets and the EMS. It seems to like them a lot. If you get one of these, try it with heavy pellets first.

H&N Baracuda with 4.50mm head

The third pellet I tested was the H&N Baracuda with a 4.50mm head. I just knew this one was going to shoot well and it did. Ten of them went into 0.634-inches at 10 meters.

Dioana EMS Baracuda
The Diana 34 EMS put 10 H&N Baracudas with 4.50mm heads into a 0.634-inch group at 25 yards.

Evaluation so far

I really like the Diana 34 EMS. It is different than the Diana 34 of the past that we knew, but it is a worthy air rifle in it’s own right. Yes, Diana shouldn’t have touted the barrel shimming and caliber swaps before they worked out the details, but that marketing blunder has no bearing on the rifle’s excellence.

I don’t often select spring rifles to shoot at 50 yards, but I’m choosing this one. With luck I’m thinking we could see ten pellets in less than one inch.

Summary

If you have been waiting to see whether the Diana 34 EMS was a worthy air rifle, I think that point has been proved. I would recommend getting the wooden stock just so you can shoot with the full artillery hold, but if money is an object this synthetic thumbhole stock can also shoot. Today demonstrates that.

I just hope Diana makes the gas pistons, barrel shims and different caliber barrels available soon. I would sure like to try them out!


The Daisy 35: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Daisy 35
Daisy 35 multi-pump pneumatic

Part 1
Part 2
Part 3

This report covers:

  • The test
  • Sight-in
  • RWS Superdomes
  • JSB Exact RS
  • RWS Hobby
  • Discussion
  • Summary

Today I test the Daisy 35 multi-pump with a dot sight. Will that sight make the airgun any more accurate? That’s the test. I mounted the UTG Reflex Micro green dot sight.

The test

I shot from the same 10 meters, rested. I used 8 pumps per shot, just as before. I tried to use the same pellets but I couldn’t find the tin of Norma Golden Trophy pellets, so I substituted RWS Superdomes in their place. I have been told that these Norma pellets are equivalent to the RWS line.

I shot 10-shot groups, just as before. The only difference today, other than the pellet substitution was the sight. And I wore my regular glasses — not the reading glasses I wear when  I shoot with open sights.

Sight-in

It was difficult to sight-in the 35. Any airgun that makes 2-inch groups at 10 meters is going to be difficult to sight in. I started at 10 feet and had to adjust the dot down and to the left a lot. When I got two shots that went to the same place I backed up to 20 feet and kept sighting-in. After two shots were good at that distance I backed up to 10 meters and continued the sight-in. 

All things considered, it took about 12 shots to get the gun sighted-in. Then I shot the first group of RWS Superdomes.

RWS Superdomes

It was a fortunate thing that I shot Superdomes today because they gave me the best group of the test. Ten of them went into 1.963-inches at 10 meters. The group is fairly well centered on the bull. It’s just off to the left a little.

Daisy 35 Superdome group
Ten RWS Superdomes went into 1.963-inches at 10 meters. This is the best group of today’s test.

JSB Exact RS

The next pellet I tested was the JSB Exact RS dome. In Part 3 ten of these made a 2.591-inch group. Today with the dot sight ten went into 3.326-inches. Well — that’s no better, is it? Apparently I can shoot just as well with open sights as with a dot — at least this time!

Daisy 35 JSB RS group
Ten JSB RS domes made this 3.326-inch group at 10 meters. The first shot was in the black near the center, which is why I continued with the group without adjusting the sight. Shot two is that large round hole at the upper left. It looks like it was shot with a wadcutter but I saw it form as I shot. This is why a gun that shoots wide is so hard to sight in.

RWS Hobby

The last pellet I shot was the RWS Hobby wadcutter. In Part 3 ten Hobbys made a 2.205-inch group. Today using the dot sight the 35 put ten Hobbys into 2.29-inches at 10 meters. It’s pretty much the same as the last time with open sights.

One thing about this group. It is so spread out that there are two sight-in shots that look like they are in the group. Well, they aren’t. If you look at the edges of their hole you can tell that they were shot with Superdomes that didn’t cut round holes. This group is similar to the group Hobbys made when I shot with open sights.

Daisy 35 Hobby group
Ten RWS Hobbys made a 2.29-inch group at 10 meters. The arrows point to two holes made by Superdomes during the sight-in. They aren’t part of this group.

Discussion

The tightest group shot with open sights in Part 3 of this test measures 2.181-inches between centers. The tightest group of today’s testing measures 1.963-inches between centers. Clearly the Daisy 35 does not become more accurate at 10 meters with a dot sight.

This may look like a short little test, but please remember that each one of those 30 pellet holes was preceeded by 8 pump strokes. Add to that the 12 sight-in shots and I had to pump this airgun 336 times for today’s test. It wasn’t short on my end! But thankfully the Daisy 35 is an easy airgun to pump.

Looking at the groups I see that this Daisy 35 will hit a tin can most of the time out to 30 feet, or so. That’s its strength. It sure isn’t a paper puncher!

Summary

There is one last thing to test and that is the accuracy of the airgun with BBs. Given that it is set to feed BBs with the magnetic bolt tip I don’t see any reason to test it with lead BBs. You can try to talk me out of that, but think about it. Is someone shooting a $35-40 airgun really going to spend $25 for 1,500 BBs?


Crosman Vigilante CO2 Revolver: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Vigilante dot sight
Crosman Vigilante.

Part 1
Part 2
Part 3 
Part 4

This report covers:

  • BB cylinder
  • The test
  • Crosman Black Widow
  • Air Venturi Smart Shot
  • The trigger
  • Marksman BBs
  • Beeman Perfect Rounds
  • Daisy Match Grade Avanti Precision shot
  • Get a good dot sight
  • Summary

Today we shoot the Crosman Vigilante CO2 Revolver with BBs. Some real surprizes are in store!

BB cylinder

To shoot BBs we have to use the BB cylinder that holds 6 BBs, instead of the ten pellets we have been used to. So the groups today will be 6 shots.

The BB cylinder is loaded outside the gun from the front. The rear of the cylinder is too small to accept a BB of any size.

Vigilante BB cylinder
The Vigilante’s BB cylinder is loaded from the front. Three plastic “fingers” apply tension to hold the BB in place. These are 6 Marksman BBs.

The test

I loaded a fresh CO2 cartridge for this test because I plan to shoot a lot. I shot at 5 meters seated with the revolver rested on the UTG Unipod. I shot 6-shot groups so I could test more BBs.

The Vigilante has the UTG Reflex Micro Dot sight mounted, because it did so well in the pellet accuracy test.

Crosman Black Widow

First up were Crosman Black Widow BBs because the Vigilante is a Crosman airgun, after all. And we have learned through testing that Black Widows are premium BBs that usually test among the best in any gun.

Six Black Widow went into a group that measures 0.923-inches between centers. I watched the group grow and I knew this test was going to turn out well.

Vigilante Black Widow group
Six Crosman Black Widows went into 0.923-inches at 5 meters when shot from the Crosman Vigilante.

After shooting this group I adjusted the dot both up and to the left. 

Air Venturi Smart Shot

Next up were six Smart Shot copper-plated lead BBs from Air Venturi. We know that these are on the large side for BBs, measuring about 0.173-0.1735-inches in diameter. And they are lead, so we are safer from rebounds than we would be from steel BBs.

Six Smart Shot went into 1.496-inches at 5 meters. Three of them went into the same hole that looks like two BBs instead of three.

Vigilante Smart Shot group
The Vigilante put 6 Smart Shot lead BBs in 1.496-inches at 5 meters.

The trigger

The Vigilante trigger breaks at 5.5 lbs. in the single-action mode. This is a bit too heavy for such a light revolver. Even though I was steadied by the monopod, the dot was dancing all around the bull, and sometimes it was outside.

Marksman BBs

The Marksman BB is a steel BB that we don’t know what to do with. They measure 0.176-inches in diameter, which is super-large for a steel BB. I tried them because the Vigilante has a rifled barrel for lead pellets, so it should be fine with these. And, it is! Six of them went into 0.841-inches at 5 meters. I was impressed!

Vigilante Marksman group
Six Marksman steel BBs went into a group measuring 0.841-inches between centers.

Beeman Perfect Rounds

The next “BB” I tested isn’t really a BB. It was supposed to be shot in rifled pellet guns and H&N made them for Beeman. Perfect Rounds measure 0.176-inches in diameter, like the steel Marksman BBs, but these can take the rifling of the barrel. The Vigilante put them into a group that measures 1.04-inches between centers at 5 meters.

Vigilante Perfect Round group
Six Beeman Perfect Rounds went into 1.04-inches between centers at 5 meters.

After the Perfect Rounds I adjusted the dot up another three or four clicks. The Perfect Rounds landed lower because of their weight, but the Marksman steel BBs had also landed low on the target.

Daisy Match Grade Avanti Precision shot

The last different BB I tried was the Daisy Match Grade Avanti Precision shot. The Vigilante is shooting so well that you guys would have been after me to try it if I hadn’t. And they were great! Six of them went into 0.907-inches at 5 meters.

Vigilante Avanti Match BBs group
The Vigilante put 6 Daisy Avanti Match Grade Precision BBs into this 0.907-inch group at 5 meters.

This revolver can really shoot — BBs. And that’s my recommendation. Buy the Vigilante for BBs and be pleased that it can also shoot pellets. But it’s perfect for BBs.

Get a good dot sight

And get a dot sight that works! This Reflex Micro Dot is expensive; I understand that. But ASG, Crosman (Centerpoint) and UTG all make less expensive reflex dot sights that should work as well. They may not be as small as the UTG Reflex, which is one of its chief selling points, but these don’t cost more than the Vigilante.

One more time

The Markman BBs were the best thus far, so I fired a second group of them. Now that the sight was adjusted they should go into the bull, or close. Six BBs went into 0.693-inches at 5 meters. It is the smallest group of the test!

Vigilante Marksman BBs group2
The last group of 6 Marksman BBs was the smallest of the test. Group size is 0.693-inches between centers.

Summary

I always wanted to shoot a Crosman 357, and with the Vigilante I feel I have done it. The revolver is red-hot with most BBs and okay with pellets. If a lookalike CO2 revolver is what you want, this is one I recommend.


Let’s have fun!

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • Background
  • A powerful breakbarrel rifle
  • A new multi-pumpA hunting pellet
  • Youth target pellet rifle
  • You’re cookin’
  • What’s this?
  • Seen it all before
  • Summary

How about a weekend of fun? I have a game for everyone. It came to me yesterday as I was writing the report about the Norma S-Target Match pellet. It occurred to me that was a long name for a pellet. So, what name would be better?

Background

There is a back story to today’s report. When I went to Fort Lewis, Washington, for ROTC Summer Camp in 1968, I spent several days in Vancouver, British Columbia, before reporting to camp. I was traveling with a buddy and we just wanted to see the sights up there. I remember seeing my first Canadian car — an Acadian Invader! It looked like a Pontiac to me, and when we saw a Beaumont, which was an upscale model, we knew that’s what it was. I have since learned that GM Canada used both Pontiac and Chevrolet platforms for what they made and sold to our northern cousins — eh!

That experience started me on a lifetime of pondering product names, and today I’d like us to generate some product names for airguns and related products. I’ll get you started.

A powerful breakbarrel rifle

Let’s pretend that we are the marketing team responsible to come up with a name for a new .25-caliber breakbarrel hunting rifle our company is about to bring out. It’s large, very powerful and extremely hard to cock. Here are the names the team has come up with so far.

Harvester 30 (for 30 foot-pounds in .25 caliber — from the president of the company)
Super Schuetzen (from old Dan the engineer, who’s been with the company 35 years)
YZP25 (from Carl, who thinks letters and numbers are better than words)
Ulysses 25 (from Donna, who thinks the rifle is too hard to cock)

Can you do better?

A new multi-pump

We have just sourced a new multi-pump air pistol from Taiwan. It’s .177 only and very accurate. It has a good 3-pound trigger and crisp adjustable sights. The manufacturer calls it the Brilliant Light. What should we call it?

A hunting pellet

We just struck a deal with a Brazilian pellet manufacturer. They have a high-tech .22-caliber hollowpoint hunting pellet that expands to twice its diameter at just 500 f.p.s. We have seen it demonstrated and it does work, so we will be selling it in the U.S. It is a domed pellet that has cuts in the hollow dome that open immediately when meeting resistance. It flies like a dome and opens like a hollowpoint. In Brazil they call it the Mako Shark. Here are the team’s suggestions.

Donna wants to call it the Lotus22 because it opens like a flower.
Carl wants to call it the DQP22
The president wants to call it the Meg22
Dan wants to call it the 22 Expander

Oh, on this one the art department is limiting the number of characters in the name to 12, including spaces. That’s because the name has to fit on a label on the tin and be recognizable on a storeroom shelf.

Youth target pellet rifle

The company has just struck a deal to purchase the rights to the Air Venturi Bronco from Mendoza. We want to make the rifle easier to cock (by lengthening the barrel jacket), to slim down the stock considerably and install target-style sights — with a peep sight in the rear and a hooded front sight that takes replaceable inserts. The president of the company likes the Bronco’s two-blade trigger for both its safety and for its smooth release. The straight Bronco would sell to us for $95 if we commit to purchase 1,000. With a Mendoza peep sight, a hooded front sight and an adjustable trigger stop (just a screw through the triggerguard) that we will install until the Mendoza factory gets up to speed, our cost rises to $119.00. We have to add $40 to that cost for modifying the trigger stops in-house on the first 100 rifles, to give Mendoza time to gear up for it, but the decision has been made to amortize that expense across the first 1,000 sales.

The president has told our team that he sees this rifle as an upscale youth target rifle that can compete in the Student Air Rifle program (SAR). He plans on charging $175 to SAR competitors and clubs and $225 to the general public.

He wants a name that conveys quality, excellence and value. What do we call it?

The president also wants a name for the trigger.

You’re cookin’

Okay, that should get your creative juices flowing. Now, name the following products.

A 10-40X60 scope with a 34mm tube that has a mil-dot reticle with illuminated dots that the shooter controls. The shooter determines which dot gets illuminated. This scope is no longer than a 4-16, and just as bright at 40X as the 4-16 is at 16X.

A precharged pneumatic that has a huge air reservoir and a max fill pressure of 1,800 psi. In .177 caliber it fires JSB 10.34-grain domes at 950 f.p.s. and gets 60 shots per fill. The rifle weighs 8 lbs. without a scope, due to a type IV carbon fiber reservoir. There is no regulator but the balanced valve gives all 60 shots with a maximum 18 f.p.s. spread. Twenty-two and twenty-five calibers will follow if the .177 is successful. The projected price will be $1,200.

A new wadcutter pellet with a thin ring of lead around the edge of the nose. Testing has shown it to be hyper accurate in target air rifles that need pellets with heads sized 4.49mm to 4.52mm. It costs about double to produce, so they will be sold in trays of 200.

new pellet
The new pellet with adaptable head sizes.

A bipod whose left leg holds up to 30 pellets and whose right leg detaches and contains a folding knife, Torx wrenches in sizes T6, T7 and T8, a ballpoint pen and scissors.

What’s this?

Now tell us what the following product names apply to.

  • Eagle Claw
  • Civet
  • Torque release
  • Restraint
  • Bombard
  • Momentum
  • Hyperion

Seen it all before

In the late 1990s I became incensed when Crosman applied the name Blue Streak to a breakbarrel rifle in the Benjamin line. In fact today the name is so confused there are people selling Benjamin-Sheridan 397 rifles on eBay. Tell me that isn’t wrong!

Dennis Quackenbush called his kit to make an outside lock air rifle the Amaranth. That one fooled everyone. 

And Walther used the name LGV for their new line of breakbarrel sporting rifles a few years ago when most of us silverbacks knew it as a breakbarrel target rifle from the ’70s.

Summary

I know some of you will enjoy doing this exercise, the point of which is to demonstrate that it isn’t easy coming up with product names that convey a sense of the product. Let’s see what you can do.


Crosman Vigilante CO2 Revolver: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Vigilante dot sight
Crosman Vigilante with the UTG Micro dot sight mounted.

Part 1
Part 2
Part 3 

This report covers:

  • What has changed?
  • The test
  • Sight-in
  • RWS Meisterkugeln Rifle
  • What does this prove?
  • Crosman Premier Light
  • Sig Match Ballistic Alloy
  • Norma S-Target Match
  • Is it me or the pellets?
  • Summary

Today I believe you will be surprised. I sure was! This is the second accuracy test of the Crosman Vigilante CO2 revolver.

What has changed?

Today I mounted the UTG Reflex Micro dot sight on the revolver, to see if a better sight would improve my accuracy. I tried the Sig Match Ballistic Alloy target pellet and I also introduce a new pellet that I will begin testing for you today, plus the two best pellets from the last test were chosen for today’s test. Those are the only things I did differently in today’s test.

The test

I shot 5-shot groups at 10 meters with my arms rested on a sandbag. I have to tell you, that dot sure jumps around when the revolver is held in the hands!

Sight-in

The dot sight was not on target to begin with, so I moved forward to 10 feet and started the sight-in. I shot 4 pellets before getting them where I wanted. Then I backed up to 10 meters and refined the sight picture with 4 more pellets. Now I was ready to shoot.

RWS Meisterkugeln Rifle

The first pellet to be tested and also used for the sight-in was the RWS Meisterkugeln Rifle wadcutter.  The Vigilante put five of them into a 0.684-inch group at 10 meters. I was astonished! In the last test using open sights I was able to put five of these same pellets into 1.828-inches at the same 10 meters, with everything else being exactly the same. 

Vigilante dot Meisterkugeln rifle group 1
The Crosman Vigilante revolver , with the UTG Reflex Micro dot sight mounted, five RWS Meisterkugeln Rifle pellets into a 0.684-inch group at 10 meters.

Take me home, mother, and put me to bed! I have seen enough to know that I have seen too much. That group, my friends, is a result! The Godfather of Airguns may say that sights don’t improve the accuracy of an airgun, but in this case — they do! That little green dot may have been wobbling around the bullseye as I watched it, but apparently the pellets all knew right where I wanted them to go. After this group I didn’t adjust the dot sight again for the remainder of the test.

What does this prove?

What this proves is this pistol can be just as accurate as its owners claim. I don’t doubt that goes for the Crosman 357 that preceded it, as well. It isn’t a precision target pistol, but for what little you pay, you get a whole lot of value!

Crosman Premier Light

The next pellet I tried was the Crosman Premier Light dome. Five of them went into 1.853-inches at 10 meters, with four of them in 0.867-inches. I didn’t call that lowest shot a pull, but it’s directly below the other four pellets and you have to remember that this revolver has a very heavy trigger pull.

Vigilante dot Premier Light group
The Vigilante put five Crosman Premier Light pellets into 1.853-inches at 10 meters. The upper four pellets are in 0.867-inches.

Sig Match Ballistic Alloy

Next to be tested was the Sig Match Ballistic Alloy pellet. I just wanted to see what they could do, because in many airguns they are so accurate. The Vigilante put five of them into 1.982-inches at 10 meters. There is nothing in this group that gives me any hope that the Vigilante likes it, so this one is out.

Vigilante dot Sig Match Alloy group
Five Sig Match Ballistic Alloy pellets went into 1.982-inches at 10 meters.

Norma S-Target Match

The final pellet I tried is one you haven’t seen before — the S-Target Match from Norma. It’s an 8.2-grain wadcutter, which puts it into the target rifle pellet class — along with the Meisterkugeln Rifle. The Vigilante put five into a 1.892-inch group. I will be testing this new pellet more very soon, but from these results and the open group I can tell it isn’t the one for the Vigilante.

Vigilante dot Norma target group
The Vigilante put five Norma S-Target Match pellets into 1.892-inches at 10 meters.

Is it me or the pellets?

At this point in the test I was getting tired. Concentrating on the dot with that heavy trigger pull was making me very tired and I wondered if the last few larger groups were the pellets or me. So I shot another group of five Meisterkugeln Rifle pellets that had opened this test. This time the group was larger than the first time, at 1.309-inches between centers. Four of the five pellets are in 0.932-inches and they landed in the same place they did in the first group. This is the second-smallest 5-shot group of the test and it was shot at the end.

Vigilante dot-Meisterkugeln Rifle group 2
The second group of Meisterkugeln Rifle pellets measures 1.309-inches between centers, with 4 in 0.932-inches. The second smallest group of today’s test.

I think the Meisterkugeln Rifle pellet is a good one for the Vigilante and I also think I was partly responsible for the openness of the last few groups. The bottom line is — the Vigilante can shoot!

Summary

In my experience this is one of the very rare times that a different sight has significantly improved the accuracy of a pellet gun. I will still say that different sights don’t usually matter that much, but clearly they can, and sometimes they do.

Next I will test the Vigilante with BBs, and I think I will leave the dot sight installed.


Lapping scope rings

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • Definition of lapping?
  • Scope ring alignment
  • Potential misalignment problems
  • The holes in the scope rings don’t line up
  • The inside of the scope rings are out of round or not finished smooth
  • Lapping scope rings
  • Check scope ring alignment
  • How are scope rings lapped?
  • Finish the job
  • Want to do it?
  • The big deal
  • Summary

This report comes by request of Pyramyd Air. It’s a subject that is not that familiar to airgunners for reasons I will explain at the end.

Definition of lapping?

Lapping is the polishing of surfaces to knock down the high spots and even-out the surface. I have addressed lapping the inner surface of a rifled barrel in the past, though I haven’t gone into it in depth. Today will be the first time I have addressed lapping scope rings.

Scope ring alignment

Scope rings are supposed to align with each other so the thin scope tube is held tight by the rings without any undue pressure resulting from misalignment. If the scope tube is perfectly round and also perfectly true (in a straight line along its entire outer surface), the holes in the scope rings need to be the same. If they are not true and also in alignment with each other, they will put uneven pressure on the scope tube when the rings are tightened.

Potential misalignment problems

There is a long list of potential scope ring misalignment issues. I will address a couple of the biggest ones.

The holes in the scope rings don’t line up

This happens more with 2-piece scope rings because their positioning on the gun is independent of each other. We presume the makers of one-piece rings take care to align them during manufacture. But two-piece rings can be out of alignment because of the scope bases they are mounted on. They can be off side to side and even up and down. It only takes a small alignment offset to create a problem.

The inside of the scope rings are out of round or not finished smooth

Cheap scope rings can have burrs and rough edges inside them that causes the scope to not fit the ring tightly. On really cheap rings it is even possible for the hole in the ring to not be round. Some are so bad they are not worth trying to fix.

Lapping scope rings

For these reasons and more many shooters have lapped the inside of their scope rings. Lapping corrects most of these problem, though if the base the rings are mounted on is the problem, lapping may not be enough. Some gunsmiths fail to take the care required to attach the scope bases to the rifle and create a problem that costs a lot more money and effort to be expended. This is far more common with firearms than airguns these days because most air rifles come with scope bases already machined into their receivers or scope tubes. 

Check scope ring alignment

To lap a set of scope rings you first mount the rings to the rifle. Then use a special pair of alignment tools that are the same diameter as the rings and taper to a point. When they are mounted in each ring with their points together, they either prove the scope ring holes are aligned or they show the misalignment.

scope ring align
Scope ring alignment tools.

ring misaligned
This is what a misaligned set of rings looks like when the tools are mounted.

If you don’t have these alignment tools you can use the lapping bar, though it will not tell you as much. A lapping bar of the same inner diameter as the rings is set in the lower ring halves. The bar looks like a scope tube. If this bar just drops into the lower rings you can proceed, but if the bar will not drop into the lower halves of the rings you must investigate why. This is where the alignment tools really pay off. 

You may discover that there is a fundamental problem that prevents proceeding. Or you could just stick the scope in the rings and try to mash it down into place by tightening the top ring caps. I have seen that done and it usually results in a dented scope tube, if not a broken scope.

How are scope rings lapped?

Scope ring lapping is grinding the inside of the scope rings to fit the outside of the scope tube. Let’s assume the lapping bar did fit down in the rings as it’s supposed to. Step one is to remove any material from inside the ring so the lapping bar can contact the ring directly. Some rings have non-slip pads inside and they must be removed.

The lapping bar is then coated with lapping compound, which is a fine grinding paste. Put the ring caps on over the lapping bar and snug them down, but not so tight that the bar can’t be moved. Now the lapping bar is both rotated and worked back and forth just a little to remove the high places on the inside of the rings. As you rotate and work the bar around, tighten the cap screws every so often, so you get an even lap. Lapping should go very quickly, but that does depend on the material from which the rings are made. Aluminum will lap much faster than steel. As you lap if you remove the bar and clean the rings you’ll see the high places that are being worn away.

Finish the job

Remove the lapping rod and clean off all the compound from the rings. Clean the lapping bar too. Then replace any material you may have removed from the rings before lapping if you really want to. A lapped set of rings will grip a scope much better, so the material may not even be necessary

Want to do it?

Lapping compound is sold in many places and is easy to find. Make sure it’s for the material your rings are made from.

A complete lapping kit can be purchased at several places online. One for both one-inch rings and 30mm rings will run about $75 and up. It includes both the alignment tools and the lapping bars in both ring sizes.

The big deal

Okay — if the rifle is an airgun and IF you buy quality rings, they probably don’t need to be lapped. Today’s scope bases and scope rings on and for airguns are very high quality. Lapping is more for the firearm user who uses two-piece rings and had to have two scope bases installed on his rifle by a gunsmith. There are so many variables there that lapping is still a viable option. But with a good set of airgun rings on a modern air rifle, lapping should be a thing of the past.

Summary

Scope lapping will never go away as long as gunsmiths attach ring bases after the gun is made. This happens a lot with older military arms. Modern firearm should come with bases that are in alignment, and the use of the Mil Std. 1913 Picatinney rail system has all but eliminated scope base issues. Combine that with a set of quality rings and the need to lap all but disappears.


Benjamin Marauder Semi-Auto (SAM) PCP Air Rifle: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Benjamin Marauder Semiauto
Benjamin’s new Semiauto Marauder repeating PCP.

Part 1
Part 2
Part 3
Part 4

This report covers:

  • Important announcement
  • Back with the Benjamin SAM
  • Pulled the baffles
  • Loading single shot
  • The test
  • Crosman Premiers
  • JSB Exact Jumbo RS
  • Air Arms 16-grain domes
  • Discussion
  • UTG scope was a huge benefit!
  • Summary

Important announcement

Pyramyd Air will be redoing the website and the blog design next week. The anticipated cutover date is Wednesday evening, 1/27/21. Therefore my last blog posting before the new site goes live next Thursday will be this Friday, 1/22/21. There is a possibility that the blog will also be dark on Thursday, 1/28/21.

Nobody likes missing the blog for several days, but I will use the time to get several things done that take a lot of time. Please bear with us as we make this transition. I will remind you of this tomorrow and Friday, too. Now on to today’s report.

Back with the Benjamin SAM

Okay, we’re back at it with the Benjamin Semiautomatic Marauder again today! Today will be a quicky but also an important-y. Brilliant reader, Kevin, reminded me of how I could bypass the SAM magazine by loading singly and see what the rifle was really doing. Reader GunFun1 said his SAM was shooting way better than what I showed you in Part 4. So — today is the day we find out for sure!

Pulled the baffles

Reader RidgeRunner advised me to pull all the baffles first, to verify that none of them was being hit by a pellet. I pulled all seven of them and the large holes through each one are clearly not being touched by pellets. We can rule out the baffles as a problem that causes inaccuracy. That leaves either the barrel or the magazine. Given that this is a semiauto, I suspect the magazine. Loading each pellet singly will make the determination.

Loading single shot

Because of the narrow SAM receiver slot that’s cut for the magazine, loading pellets single shot is not straightforward. At least it wasn’t for me. I tried needle-nosed pliers with a long thin nose, but what worked best was a hemostat — long thin clamping pliers used by surgeons. I didn’t clamp them. I only held onto each pellet loosely until the bolt pushed the pellet into the rifle’s chamber.

The test

I tried to repeat the first accuracy test from 25 yards exactly. The rifle was rested directly on a sandbag at 25 yards and the pellets were loaded singly. I positioned a light to shine on the breech so I could see to load the pellets. Care was taken not to damage them in any way. I did not adjust the scope for this test, but I will have more to say about the scope in a bit.

Crosman Premiers

In the first test that is covered in Part 4 I sighted-in with Crosman Premiers and also shot the smallest group of 10 with them. It measured 0.454-inches between centers.

Loading singly this time 10 Crosman Premiers went into 0.349-inches between centers at 25 yards. That’s enough better than the first test to be significant. The point of impact shifted over to the right but remained just as high as it was in the last test.

SAM single Premier group
When loaded singly the SAM put 10 Crosman Premier pellets into 0.349-inches at 25 yards.

JSB Exact Jumbo RS

Next up were ten JSB Exact Jumbo RS pellets. In the first test the SAM put ten of them into 0.521-inches at 25 yards.

In today’s test by loading singly the SAM put ten JSB RS pellets into 0.431-inches at 25 yards. That’s quite a bit better than the last test. As before, the point of impact also shifted to the right just a little.

SAM single RS group
Ten JSB Exact Jumbo RS pellets went into this “Mickey Mouse” group at 25 yards. It measures 0.431-inches between centers.

Air Arms 16-grain domes

The final pellet I tested is the one I was most interested in. In Part 4 the Air Arms 16-grain dome scattered all over the paper at 25 yards. The 10-shot group measured 1.159-inches. Would loading singly help this pellet?

Well, it did help! This time ten of the singly-loaded Air Arms domes went into 0.46-inches at 25 yards. It is the largest group of today’s test, but it’s almost the same size as the smallest group in Part 4 when the magazine was used! I find that fascinating!

SAM single Air Arms group
When loaded into the SAM one at a time, ten of the Air Arms 16-grain domes went into a group measuring 0.46-inches between centers at 25 yards.

Discussion

It should be clear to everyone that the SAM magazine is the reason the first accuracy test didn’t do so well. This is not my air rifle so I can’t modify the magazine the way reader GunFun1 told us about, but if I could I would. The SAM feeds reliably enough, though when I load it singly there is a slight problem. Longer, fatter pellets do not seat into the breech deeply enough to clear the air transfer port in the breech. That’s why I didn’t shoot a test group of Beeman Kodiaks. I shot four and had trouble getting them past the air transfer port unless I let the bolt slam on them. That seemed to open the group, so I stopped the test.

I will also point out that today the SAM is not very picky about the pellets it likes. That means we can rule out the barrel as a potential problem.

UTG scope was a huge benefit!

I told you that I mounted the UTG 4-14X44 SWAT scope on the SAM for Part 4. Well, that illuminated etched-glass reticle is worth the price of the scope! It made seeing the crosshairs so easy against the black bullseye!

Summary

This SAM is very accurate and today’s test proves it. The magazine may need a period of prolonged break-in. Or GunFun1’s modifications might do the trick.

I will shoot the SAM at 50 yards. Because of what we have seen today I will also load singly for that test. If I owned the rifle I would modify the magazine, but I will be sending it back and the mag has to remain as it came to me.