1377 to 1322 upgrade, my results. Need stronger hammer spring?

[kcatx]

Today I upgraded my 1377 with Crosman steel breech to a 1322. I still haven't decided which barrel I am going to keep as I have a 14.65" one from a 2250, a Mellon Air 12" one (*very* nice! Will order more!) or what I currently have on there which is a 24" Crosman barrel. 
I ordered from Mellon air the Adjustable FT piston, FT valve, bolt and 2289 barrel band.  Installed them all today.
Before I installed the FT piston and valve I did some baselining:

.177 pellets are CP 7.9's
.22 pellets are CP 14.3's

Stock 1377, 10 pumps:   506 fps   4.49 fpe
       15 pumps:   555 fps   5.40 fpe
            20 pumps:   573 fps   5.76 fpe
( I also tried a CP Heavy 10.5 with 20 pumps and got 497 = 5.76 fpe )

.22 testing using the stock valve/piston
I then put on the 10 inch, 14.6 and 24" barrels and tested with the stock valve/piston.

10 inch:
10 pumps:  444 fps  6.26 fpe
15 pumps:  468 fps  6.92 fpe
20 pumps:  508 fps  8.19 fpe (only tried this once, not 5-6 times like the others)

14.6 inch:
10 pumps: 466 fps  6.89 fpe
15 pumps: 490 fps  7.62 fpe
20 pumps: 508 fps  8.19 fpe (only tried this once, not 5-6 times like the others)

24 inch:
10 pumps: 513 fps 8.35 fpe
15 pumps: 549 fps 9.57 fpe
20 pumps: 566 fps 10.17 fpe (only tried this once, not 5-6 times like the others)

This was all very tiring, and as of yet I had no idea how much harder pumping would be with the FT piston in :-)

I installed the FT piston and valve and tested ONLY with the 24" barrel:

8 pumps:  526 fps 8.78 fpe
9 pumps:  544 fps 9.399 fpe (note all 6 shots I took were 554.x fps!)
10 pumps: 552 fps 9.67 fpe
11 pumps: 562 fps 10.03 fpe -- NOT dumping all it's air.

Since it wasn't dumping all at 11 pumps I wasn't going to go any further, but wanted to try at least one shot with 20 pumps and got 2 shots with the air:
1st shot 483 fps 7.40 fpe
2nd shot 550 fps 9.60 fpe
7.4 + 9.6 is 17 fpe!  I want to be able to dump all that in a single shot!

..so to reach this goal I guess I need a stronger hammer spring?  Should I just go and order a 2200 magnum spring?
I may hit Ace Hardware tomorrow and see if there is something that I can use there in the meantime.

Suggestions?

[ Note I'm posting this same text to multiple AG forums ]

[Bentong]

I used Mellon's power adjuster to compensate for higher than 15 pumps to dump all air in one shot. I used a stiffer before the adjuster and it made cocking harder and noticed the hammer pin started to get bent and the valve stem starts to mushroom with the stiff spring. I seldom go higher than 10 pumps to get rid of nutters digging in my backyard to 20 yrds.

[kcatx]

Several people have suggested the MellonAir power adjuster ( http://mellonair.myfreesites.net/index.php?p=1_8_Power-Ajusters ) rather than just replacing the spring-- that sounds like a good idea to me as well so I'm going to order one of those right now :-)
If I could get 15 fpe on 15 pumps as others report I'd be satisfied (at least for now, you know how these things go :-) )

[1377x]

15fpe should be achievable at 15 pumps with a 24" barrel
im getting 11+fpe at 15pumps using a 14.5" barrel and cphp's

[quickster47 †]

To get 15 FPE you will need to be hitting about 802 FPS with 10.5 grain pellets.  Certainly doable but will definitely take some work.

Carl

[kcatx]

Note this is now .22 not .177.

I ordered both a power adjuster from Mellonair as well as a new 18" barrel.  I have a 24" on there now but I think it needs a new crown-- I could never be very accurate with that barrel on a 2240 and am seeing the same issues on the 1322.

[quickster47 †]

Using Crosman Premier Ultra Magnum in .22 cal weighing 14.3 grains you will need to get 688 FPS to achieve 15 FPE.  Very doable.

Carl

[NorthStaR]

I'm getting 11+ FPE on 14.3 GRN pellets, 20" barrel and a FT valve at 10 pumps. 
Mine has a slightly reduced space for the hammer spring (spring guide and homemade stock adaption take up space)
so I cut off a few coils to allow it to cock properly (3 I think if I remember right).

I think a stronger spring will dump the air, a power adjuster is in theory the same approach without a stronger spring.
Personally, I'd either do the power adjsuter OR the stronger spring. I don't think you'll need both.

I would (again personally) favour the stronger spring over an adjuster. An adjuster will put unnecessary constant stress on a spring,
even whilst relaxed and that may cause it to weaken in time. A stronger spring will stay strong and is allowed to relax when not in use.

I guess my reduced spring area would have a similar effect to the power adjuster except my spring is cut down to counter the effect.

Alternatively you could use a lighter spring in the valve and still gain. Springs are a lot cheaper too! 

All IMHO. 

[kcatx]

Today my 2289 pump grip, Mellon Air power adjuster and 18" Mellon Air barrel arrived!
I pulled the 24" barrel off and installed all the new goodies.
After some initial problems with the power adjuster (basically I put the top screw in too far which impeded the spring) I was able to get it to dump *almost* all the air at 15 pumps.   
Now with 10 pumps it does 550-562 fps with 14.3 grain pellets.  So a high of 10.03 fpe.
With 15 pumps it was 596-613fps.  High of 11.93 fpe.
So basically the power adjuster itself gave me a fpe increase even though I decreased the barrel length from 24" to 18".
Note I have a TKO muzzle brake on there as well which people say cuts 10-15 fps (never measured).

My transfer port seal could use some work as I noticed it's a bit bent from all my swapping and manhandling.  It's actually a thin bit of (brass? copper?) tubing with some poly tube around it.  I believe I got it from a Green forum member sometime ago-- I can't quite remember :-)  I imagine if I replace it I'd gain a few fps.

The extra power is nice, but the biggest thing I noticed is that this thing is DEAD ON now!  I always thought that 24" barrel wasn't the most accurate thing out there which was why I didn't keep it on a 2240 a few years back.  The Mellon Air barrel shoots GREAT!   

Other than *maybe* tweaking the transfer port itself and the seal, I think I'm done-- the gun shoots great, is quiet and with the 2289 pump handle is much more comfortable to pump.

Thanks everybody for the advice.

[quickster47 †]

Well that is some good news and some interesting results from the changes you made.  Especially the resulting power changes.

Carl

[1377x]

good to hear it is working out for the most part
which bolt did you get?
it sound s like you have a transfer port from treerathunter iirc thats his tag
since its .22 you could open up the barrel port a little.mine is opened up to 5/32
but my valve exhaust port is still stock.

[kcatx]

My bolt is the Mellon Air SS long probe.  I suppose I may gain a little more if I went to the flow through.
Hmm.. I did get a new drill press ($49 with coupon at Harbour Freight!) so maybe I'll go and open up that valve one day soon.   I guess to do that I'd need to take the valve all apart though, not really looking forward to that.
Oh yeah, it *WAS* treerathunter with the Can't Leak Port Seals, after I GTMF I found it.

[1377x]

in my experience there isnt much difference between the flow through and long probe in a 13XX.others may say differently.with a higher powered gun the long probe worked best for me.
i opened up my other valve and barrel by hand with a 5/32 drill bit using a tap wrench,angled the port with a dremel round ball bit 1/8 iirc
im going to do my valve as soon as i can get a new end cap with power adjuster.i have heavy hammersprings but they make charging the gun harder.
good luck with your future mods!

[quickster47 †]

I suppose I may gain a little more if I went to the flow through.

Even if you do NOT gain any more FPS with the flow through probe, you will get more consistent shots because the flow through probe will always seat the pellet in the same place in the leade.  Because of the way different pellets are made the long probe will insert them a varying depths in the leade.

Carl