Accuracy issues with an old Crossman 760

[Corn-Picker]

My father gave me a Crosman 760. Based on what I could find online I believe it to be a 1975-77 model (ABS stock and forearm, metal automatic-cocking bolt).

The air rifle is all original. I put a cheap Crosman 4x scope on it. Groups at 10 yards are four inches. I took the scope off and used open sights, groups at 10 yards were around four inches. The variation in the left-right direction is comparable to the variation in the up-down direction. I'm using "H&N Sport Field Target Trophy Green" 5.56 grain lead free pellets.

Any ideas as to why the accuracy is so bad?

Should I try pumping it and then waiting 5-10 minutes before shooting to see if there is a slow leak?

I'm not opposed to fixing this problem by throwing money at it, I could use an excuse to buy a new more powerful 22 caliber air rifle. But, if there's a known issue/simple fix with these Crosman 760's I'd give it a try.

 

[rcmodel]

I believe it has a smooth-bore barrel like a BB gun.

What you got is what you get.

If it had a rifled barrel, it would be much more accurate with pellets..

rc

 

[MikieG]

I think RC is right. The 760 pumpmaster was designed to shoot both bb's and pellets. This would be a smooth bore if memory serves me. I gave up on those when my stock broke off. Same thing happened to my AIR 17. Seems like i have seen some early production guns that had wooden stocks.
The 760 and the 880 were hard on the hands as you approached 10 pumps, they smacked shut with such force that the vibration literally hurt.

 

[ColtPythonElite]

I got a new one in 1978 for my birthday. At 10-15 yards it was easily pop can accurate. Nuisance birds sure weren't safe.

 

[Corn-Picker]

You are correct, it is a smooth bore, but I was hoping that accuracy would be better.

So, to go back to square one, most people consider an accurate center fire rifle to be one that holds one MOA at one hundred yards. What's considered accurate for a 22 caliber air rifle, and how much will it cost me to get there?

When I discuss air rifles it's with respect to hunting, not to 10 meter match, so I'm not interested in the low-velocity offerings. I've been surfing pyramid air's website. The PCP guns look nice, but they start around $500 and then you have to buy a $200 hand pump on top of it.

 

[rcmodel]

Any half-way decent quality spring cocker will shoot one ragged hole for 10 shots at 10 yards.

That translates to squirrel & rabbit head accuracy at 25 - 50 yards.

A .22 cal offers better small game killing power.
A .177 offers flatter trajectory.

I am quite happy with my two Beeman non-magnum spring-cockers.

The C-1 .22 carbine puts out 670 FPS, and whops squirrels like they got hit with a truck.
(35 pounds cocking force)

The R-7 .177 puts out 700 FPS and shoots pretty flat out to 40 yards or so.
(18 pounds cocking force)
So you can shoot them all day without wearing yourself out.

The super-sonic magnum class air rifles weigh as much as an M1 Garand.
And wear you out cocking them.

Plus, air rifle pellets don't remain super-sonic more then a few yards.
And accuracy is destroyed getting in and out of super-sonic speed.

rc

 

[Pete D.]

PCPs

I am fond of PCP airguns. I have three....two are .22s and shoot very nicely out to 25 yards. Soda cans are easy. Closer in, twigs on the sides of trees are viable targets.
The third PCP is .45 cal and shoots as well as the .22s. It is loud. It will push a 200 grain LSWC at 600 fps and a .458 LRB at 700 fps (chrono'd).
A pump is nice to have but pumping one of these babies up to 3000 psi is a lot - a lot - of work. Most shooters buy a scuba tank and top off with that.
Yet another expense. The best choice in Scuba is a carbon fiber tank rated at 4200 psi.....more fills at max pressure. Of course, those tanks are yet more $ than the 80 Cu. ft. 3000psi tanks.
Pete

 

[OrangePwrx9]

The Crosman 2100 Classic is a very nice and very accurate pump air rifle that can be had for around $70. They often sell refurbs on the Crosman site for less than $50. I bought a refurb and couldn't tell it from new. It can handle .177 pellets and BBs but has a rifled bore. With pellets it's a tack driver.

Airgun repairs aren't cheap. I made the mistake of having an old Crosman 766 repaired. Cost around $75 to get it to hold air. It was and still is a good shooter, but I should've junked it and just bought the 2100 Classic. The 2100 is virtually the same gun.

 

[MikieG]

I really like the self containment of springers. No extra crap. Just plain ole fun

 

[Corn-Picker]

So my father recently gave me another air rifle (he is trying to get rid of some stuff he doesn't use). This one is a much more recent gamo spring cocker. It's rated at 1000 fps lead / 1200 fps polymer, and it has a rifled barrel.

Accuracy is much better than the Crosman 760, I'd say two inches at 25 yards, though that was in a slight wind (using H&N 5.56 lead free semi-domed ammo). I've read that these spring cockers "break in" after a few hundred shots? I've ordered a few other types of lead free pellets, after this is broken in and the wind dies down I'll see which one is most accurate. I'm hopeful as one or two of my five shot groups were very small (< 0.25") with one outlier.

Once I try out 4-5 different types of lead free pellets I'll post the results and more specifics about the rifle/scope/rest combo. I noticed that I could predict that a pellet was going to be an outlier if it fit extremely loose/tight in the bore, so ammo quality control is some part of the issue I believe.

I find the recoil of this rifle extremely obnoxius -- I'd rather deal with the recoil from my welter weight 308 than from the Gamo. It's not a hard recoil obviously, but the "twhang boing brngggg" is like nails on a chalkboard to my senses.

 

[ontarget]

I felt the same way about my Gamo. So I returned it to Cabela's and got a Benjamin Nitro Piston and love it. Totally different recoil and no twang.