Canadian Airgun Forum

Sort of a warning here.

I just bought a 13-77 "C" version last week.

The manual states that the minimum number of pumps is 3. For the "C" version it should be 5. It would be nice to see this stated in the printed manual, but not a word....

With it's restricted transfer port, 3 is NOT enough to have the pellet clear the barrel.




13-XX regular sized port above. It's hole is .138". This one came out of a 13-89, and has a bit of a different appearance compared to the modern ones.

13-77 "C" version port below. It's hole is .086".

I drilled that port out to .140"

Even after that, 3 pumps is still sort of iffy for getting a 7.9 gr dome to clear the bore. 2 out of 5 attempts at 3 pumps resulted in a pellet lodged in the bore.

With the .086" port, I could not get a pellet to clear in 3 pumps at all...

I had bought a 13-77 "C", new in the clamshell packaging a little over a year ago, and it's port was already .140", and required no modification.

More on the current Canuck version of the 13-77 in a while...

-D.S.

_________________
"Ain't no half-way"
-S.R.V.

That's it there. Bought new last Saturday at Cabela's in Winnipeg.
I tested with the 7.9 gr Crosman F/T domes, boxed.
At 5 pumps with the reduced flow t/p, it averaged 284.2 fps with an extreme spread of 51.3 fps.

At 8 pumps with the reduced port, it averaged 372.5 fps with an extreme spread of 14.5 fps.

At 10 pumps with the reduced port, it averaged 436.1 fps with an extreme spread of 8.3 fps.


With the .140" port, at 3 pumps it averaged 228.4 fps with an extreme spread of 53.7 fps. This was an average out of 5 shots. I actually shot 7 and had 2 lodge in the bore. All other averages were taken over 10 shots.

5 pumps calmed the gun down a lot. It averaged 357.6 fps with an extreme spread of 12.5 fps.

8 pumps averaged 449.7 fps with an extreme spread of 13.1 fps.

10 pumps averaged 488.4 fps with an extreme spread of just 7.6 fps

I have the "standard" non-restricted flow port diameters of both the 13-77 and 13-22 at .140" in my shop log.

That ain't a bad show for a cup piston gun. I will get a flat top piston into it sometime later this week, hopefully.
It came with a beaut of a rifled bore. This bbl actually engages the head of the F/T domes.
The bluing on these bbls is getting awfully thin. It looks like un-polished, un-carded cold blue...

-D.S.

_________________
"Ain't no half-way"
-S.R.V.

That spruced it up! Kind if worrisome they are restricting the port that much, when they had it perfectly fine before. I wonder what is behind that new change. Definitely not designed to get more sales, that's for sure!

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Website: https://airgunarcheryfun.ca/

I thought the non-PAL versions of the Crosman pumpers were not allowed to exceed 500 fps no matter how many pumps you used?.... I know a stock 2289 did that, even if you pumped it 40 or 50 times.... Crosman may state 10 pumps maximum, but more does cause an increase in velocity.... Since all the 13XX/2289's are considered handguns, over 500 fps would make them Restricted.... Just sayin'....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal; Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!

Looks like he just set this one the same as the one he bought new last year.

Quote "I had bought a 13-77 "C", new in the clamshell packaging a little over a year ago, and it's port was already .140", and required no modification."

If it only gets 430's at ten pumps, not a lot of output for the input, =), especially when a 1322 gets 460 at ten pumps with double the ft/lbs.



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Website: https://airgunarcheryfun.ca/

Maybe Crosman decreased the port size to compensate for the newly-designed, more efficient piston?

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

Hi guys.

Crosman has gone this route before with the "C" market air guns, most notably the 13-XX series. At least they seem to be holding off on a return to the valve bleed vent

The concern of the original topic, of course, is a Canadian air gun "neophyte" lodging pellets in his/her bore while following what is out-lined in the user manual.

I think most of us here are quite familiar with the pistol modification rules on this board, and there is no intent on my part to circumvent those rules. I'm still under the limit with a mass market pellet with the way the gun currently sits.

IIRC, the maximum pump limit in the old 22-89 user's manual was actually 8 pumps....

I did a little preliminary accuracy testing tonight.
I got a steel breech and probe onto the gun, and mounted an old favorite scope of mine~ a Weaver 4 X 38 mm Marksman with a plain fine crosshair.



I swapped out the sear spring for one a lot lighter. Trigger pull is still too heavy though.

This bbl really wants to shoot, despite the heavy trigger. I will later on get this onto a P-rod grip frame and trigger.



Perfect pull-ring tab take-out at 12 meters. 8 pumps with the fore-arm on a rest.

The trigger makes group shooting a bit of a challenge. I did get one 3 shot cluster of .21" on centers, which is very, very good for a hand gun, even if it is from partial rest.

This may be the most accurate Crosman barrel I have, except for the L/W on my 1701-P.

-D.S.

_________________
"Ain't no half-way"
-S.R.V.

I spoke too soon!
There is a bleed vent hole on the rear of the valve. The diameter on this one is a lot smaller than previous iterations. I had to drill it out in order to get the 4X40 tap started. The last *old* one I did, the tap threaded right in with no pre-drilling.

At least now, with the vent plugged and the FTP installed, 10 out of 10 cleared the bbl at 3 pumps.
No time to chrony or anything like that- just more or less function test and check for leaks...

-D.S.

_________________
"Ain't no half-way"
-S.R.V.

After about a month of trying to get consistent groups out of the 13-77's bbl, I decided to give it a rest.
I took the L/W bbl off my 1701-P ( gauge is kaput ), and sat down for a quick hour off the bench tonight.



5 Old and slightly stale 8.2 gr Meister's. Not bad, but they're getting to the bottom of the tin, and there's the odd out of round skirt encountered now. When there's time, I'll try the R-10 stuff in both variants. They are a lot fresher than that old tin of Meisters.



5 Metal mag predators. I can do my happy dance now!
The vertical dispersion is not all that surprising out of a pistol length bbl. I think with better glass aboard, this rig is gonna shoot very tight indeed.




Test platform. The much mentioned favorite K-3 60-B aboard.
P-rod trigger and grip frame. Breech band. I can group reasonably well with the mid range parallax set K-3. 12 meters is still a shade on the out of focus side, but not by very much.

I had to do a couple of things to get the L/W bbl to work on this pistol. I had to modify the bolt probe. The standard 13-77 probe is too large in diameter for the L/W bbl. The machined bbl transfer port inlet will not work with a 13-XX transfer port. I went with ice maker poly tubing for a port, and it works very well.

-D.S.

_________________
"Ain't no half-way"
-S.R.V.

Very nice shooting!

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Website: https://airgunarcheryfun.ca/

This is getting interesting!



Off hand at 7 meters with a 14 year old Tasco .22 Red Dot aboard.
I used a modified Weaver "grip" on the pistol, with the to of my left forearm against my left knee. ( I was kneeling with right knee on floor ) The flyer at left was me not quite settled in...



There's what it looks like.

At 12 meters, my groups expanded to fist sized, and that has everything to do with my eye-sight.

This is very impressive from a guy who ain't much of a pistol shooter.

I have to decide on the end use for this thing, and am leaning towards a truck carbine with a small modern scope aboard.

Still, part of me wants to check out a Bushnell TRS-25 red dot before coming to a decision.

Does anyone here have experience with this ultra compact red dot? The little bit of info I've been able to get ids that it has a rheostatically controlled 3 m.o.a. dot.

Wouldn't mind a few opinions from those that have experience with that red dot...

-D.S.

_________________
"Ain't no half-way"
-S.R.V.