What work did you just do?

[quickster47 †]

Gippeto that 1701P is sure shooting good.  Glad you are enjoying it also. 

Carl

[WyoMan]

Polished a little burr out of the chamber/transfer port area... IMO was the reason "tighter" fitting pellets were not grouping as well as expected. Re-did the crown while I had it at the lathe, then ran a few patches with bore bright through. Pretty much everything I've tried except the Crosman "competition" wadcutters is grouping fairly well now. A few of those groups were three shots through the same hole before opening up...there's more potential yet to be realized.

Don't have any other wadcutters to try...will include some in the next pellet order. Any suggestions for a good wad cutter?

Al

I have had that happen alot.....always assumed it was either me or pellet inconsistency (including the loading process), guess is that it's not the gun 

[breakfastchef]

Don't have any other wadcutters to try...will include some in the next pellet order. Any suggestions for a good wad cutter?

Al

If you are shooting the pistol at stock velocities (@450 fps), any of the RWS or H&N offerings would be excellent. I primarily shoot 7.x-8.x grain RWS R-10 Match and H&N Match Pistol (4.51mm). If you prefer a heavier pellets, look at RWS R-10 Match heavy  (8.2 gr), RWS Meisterkugeln Rifle (8.2 gr) and H&N Sport (8.18 gr).

[HappyHunter]

Any suggestions for a good wad cutter?

Hey Al, I just received a tin of these from Airgunsource to try out and now wish I ordered a sleeve of them...VERY accurate in my 1750 PCP (haven't tried them in the '78 yet)  http://www.airgunsource.com/store/index.php?product=JSB.S100&c=199   Not sure if your neck of the woods has 'em or not... Haven't seen them listed on D&L's site or SSSO either...

Before trying the JSB's, I had (and still have) great results with the 8.18 gr H&H Finale Match Rifle...

Oh, yeah....Nice shootin' btw! 

[Cwlongshot]

I took my 1377 with me last weekend up to my deer camp. I am able to shoot up there without bother or worry. I also brought the crony. 

Well I found that at 8/9 pumps I was only just over 500fps... @ 13 pumps I was just a tiniest bit more. Then at 17 518 and at 20 520... Something was wrong. I figured it to be the head space.  I was correct, I removed the piston and O rings and checked. The pump closed to the pump tube with no resistance. Almost half a revolution of the piston head had the piston and valve contacting each other 5/8-3/4'' from closing. Perfect!

I put everything back together and WOW I topped out at 772 with a 7.2g Laser and 622 fps with a 13g Big Boy!! 

CW

[Trophyhunter49]

I took my 1377 with me last weekend up to my deer camp. I am able to shoot up there without bother or worry. I also brought the crony. 

Well I found that at 8/9 pumps I was only just over 500fps... @ 13 pumps I was just a tiniest bit more. Then at 17 518 and at 20 520... Something was wrong. I figured it to be the head space.  I was correct, I removed the piston and O rings and checked. The pump closed to the pump tube with no resistance. Almost half a revolution of the piston head had the piston and valve contacting each other 5/8-3/4'' from closing. Perfect!

I put everything back together and WOW I topped out at 772 with a 7.2g Laser and 622 fps with a 13g Big Boy!! 

CW

Way to go

[targettgii]

Some nice numbers CW. 

[WyoMan]

I took my 1377 with me last weekend up to my deer camp. I am able to shoot up there without bother or worry. I also brought the crony. 

Well I found that at 8/9 pumps I was only just over 500fps... @ 13 pumps I was just a tiniest bit more. Then at 17 518 and at 20 520... Something was wrong. I figured it to be the head space.  I was correct, I removed the piston and O rings and checked. The pump closed to the pump tube with no resistance. Almost half a revolution of the piston head had the piston and valve contacting each other 5/8-3/4'' from closing. Perfect!

I put everything back together and WOW I topped out at 772 with a 7.2g Laser and 622 fps with a 13g Big Boy!! 

CW

Seen that happen before.....if it happens again you might be chasing deformation / wear.....20 pumps is a lot....too much unless you have increased the volume of the valve. Don't want to discourage you but the pages of forum history are filled with hot pumpers that are not around today.....I destroyed my first one and don't want that to happen to you.....

[Cwlongshot]

Seen that happen before.....if it happens again you might be chasing deformation / wear.....20 pumps is a lot....too much unless you have increased the volume of the valve. Don't want to discourage you but the pages of forum history are filled with hot pumpers that are not around today.....I destroyed my first one and don't want that to happen to you.....

This valve has been ported and two threads removed for increased volume.

In watching the vel numbers I still see vel increasing nicely to twenty. But since I do not intend to shoot much at all at twenty pumps I stopped. I agree having to pump that much IS greatly increasing wear and tear on the works!

BTW I have shimmed the pump linkage and I stalled a solid 3/16" pin for improved longevity.

Back to the valve, I would like to pin it, but after my last mishap need to be careful. I have also read that porting and increasing volume is not that beneficial in a 177 unless you really push things. That is not my intent here. Mostly I did it to "see" what I might get. Any how. I have been wanting a 2289 too and I already have another FTV pleated but not cut for more volume. SO I hesitate to pin before I may get the 2289. As if I do, I will swap valves THEN pin.

I would really like a brass piston instead of the derlin one I have now too, just waiting to see if one turns up less than the price of the gun... I have seen some for $35 hoping to trim that too... :

Thanks for the info! I LOVE the friendly and free sharing of such information!! It's a huge part of what makes this a fun and great place! KUDOs brother!

CW

[Brent]

I had tore down the 1701P and did some touch up work to the barrel. Finally had an opportunity to do some shooting with it this afternoon. Still room for improvement, but I don't think the barrel is an issue any longer. Some chrony work will be next on the list.

Results of the afternoons shooting. Five shot groups @ 10m benched. 3-9x32 bug buster.

A little pellet testing and then shot down from a fill with the two seemingly best pellets...looking for a sweet spot. Seems the 10.3 JSB's get the nod overall. Will try washing the CPHP and see how/if that helps.





And for reference...some before groups.



Soooo many things to tinker with on this pistol.....I'm loving it!

Al

Very nice shooting Al!!
What do you have in mind next, to improve on that? Not much more room to go up from here

[BDS]

CWL  "20 pumps" that's a beater on that poor gun IMO.

What we sometimes lose sight of is.. that all the sheet metal linkage that we shim and bush and valves we pin etc etc, the gun is till just light gage sheet steel and it will crack or deform on you before long 

[agninja]

CWL  "20 pumps" that's a beater on that poor gun IMO.

What we sometimes lose sight of is.. that all the sheet metal linkage that we shim and bush and valves we pin etc etc, the gun is till just light gage sheet steel and it will crack or deform on you before long 

That's okay. It just gives you an excuse to start a new build...or order new parts.

[Gippeto]

What do you have in mind next, to improve on that? Not much more room to go up from here

The intent will be to find a velocity where the groups appear to be the tightest, then tune the pistol around that velocity.

Regards,

Al

[Davio]

Time to share:  If you get an anodized aluminum breech from BNA, it will EASILY accept the metal breech end cap if you do two simple things and make one simple decision.

First, just drill out the end of the breech with a 17/64" drill bit.  You only need to go in about 5/8".  The breech bore back there is exactly .25" and the OD of the cap stem is .254.  Okay, part 1 done.

Second, that breech has a flat for the standard rear sight.  A perfect little flat that hems it in rather nicely I will add.  The metal sight that can be flipped for peep or for notch must be shortened because it interferes with the rounded cap you just installed. So, you have to decide whether you want peep or notch. 

Finally, simply grind off the end of the one you decide against... and then touch up the steel edge you ground off that is now on the bottom with Birchwood Casey touchup pen. 

Beautiful fit and finish.  Took me less than 5 mins and that included cool down time from the belt sander.

[BDS]

Very nice Davio...