crosman .22 1300kt vs 1322

[jmc1980]

i just received my new crosman custom shop .22 1300kt 16 days after i placed my order. i ordered it with a 14.6" .22 lothar walther barrel and a long steel breech. i also bought a flat top piston and valve, stronger hammer spring and enlarged port, and a ss pin from alliance hobby but i won't mod it for a while yet. stock as i received it except for barrel and breech it chronied it with jsb 15.89g's at 8 pumps i got 470-475 fps and at 10 pumps i got 520+ fps. my question is why is this air pistol so powerful already? can i go past 10 pumps like modded guns can? should i even mod it? is it the extra 4.5" long barrel and/or the long steel breech? can the 1300kt be modded like the 1322 with the parts i bought or is the 1300kt different than the 1322?  any other info on this relatively new to me air pistol would be greatly appreciative. thanks in advance,  jeffrey

[kj]

the loger barrels definitely helps some. sometimes the parts from the factory come together for a really good shooter. seems like you got one. yes your parts will fit/work , but if it's shooting good enough for you , you could leave it as is until wear causes it to lose some power. a larger transfer port isn't usually needed unless going above .22 in caliber. if you do take it apart, be sure to smooth out the areas around the cocking arm slot on the inside so you have less chance to damage the o-rings or pump cup upon re-assembly. a bit of emery cloth on a dowel rod works fine for this. i always check the inside of the barrel where the transfe port hole was drilled into the barrel. sometimes this needs smoothed out as well.

a fun gun to shoot and work on as well.
enjoy
kj

[mav72]

Yea, longer barrel helps and the breech helps keep things tight..

Actually, you got me thinking about an issue with mine now. I need to check valve seal/transfer port clearances between the last style 1322 and my 1300KT. I'm hoping its still the same, unlike the older 13XX rear cockers.

[jmc1980]

will a stiffer hammer spring increase velocity by itself without any other mods?

[mav72]

On a 13XX, a stronger hammer spring is used to dump all the air in the valve. It wont give you more power just having it installed.

[jmc1980]

i will try to chrony again tomorrow if i get the chance. i want to see how jsb 18.13 grain pellets do (my diana model 54 .22 loves them). i have a huge assortment of .22 caliber pellets to try. anyone have a 1300kt with lothar walther 14.6" barrel and steel breech that can recommend pellets by weight or just a particular pellet. then again all air guns are known to be finicky when it comes to pellets, however i have been told lothar walther barrels aren't very picky when it comes to pellets.

[kj]

mav is correct, a heavier hammer spring only helps if your gun is retaining air after the shot. usually not a problem until you start pumping past 10 pumps. to check if your gun is retaining air after the initial shot , just cock it and squeeze the trigger. you'll know if there's extra air by the sound.

l.w. barrels ane't usually pellet fussy. i like the rws hobby wadcuters for close (20 yards or less) pesting. the jsb 16gr are really nice and even the old boxed crosman premier. unfortunately they don't make the .22 in the box anymore for some reason.

if you ever get tired of the trigger look up doing the p-rod trigger group. much nicer 2 sage trigger.

peace
kj

[longhunter]

if I had to guess, they're using the new style piston in your 1322. they are reported to be much stiffer, and a better fit to the valve face. that makes them more efficient, building higher pressure, which will translate to higher velocity.

[kj]

if I had to guess, they're using the new style piston in your 1322. they are reported to be much stiffer, and a better fit to the valve face. that makes them more efficient, building higher pressure, which will translate to higher velocity.

hi, do you happen to have a pic of the new piston ?

thanks
kj

[jmc1980]

with the numbers i'm getting on my chrony would my alliance hobby flat top piston and valve raise my 1300kt velocity by the reported 100 fps gained on the 1322 with the same ftp and valve mod. would/should i expect somewhere in the 100fps increase on my 1300kt after ftp and valve mod. i was unaware that crosman is now using a different setup. i have never modded any airgun before and i'm happy this one is at 520+ fps with jsb 15.89's. if i can find the time today i want to chrony it with jsb 18.13's and see if it gets more fpe.

[jmc1980]

if I had to guess, they're using the new style piston in your 1322. they are reported to be much stiffer, and a better fit to the valve face. that makes them more efficient, building higher pressure, which will translate to higher velocity.

hi, do you happen to have a pic of the new piston ?

thanks
kj

longhunter,  i too would like to see a picture of what the new piston looks like. thanks, jeffrey

[longhunter]

I don't have a pic. Somewhere in the crosman gate is a post with pics.
I know that the piston body was beefed up, making it less prone to flex under pressure, and the valve face was machined to more closely match the cup, which reduces headspace. Those are two of the things that almost everyone did to the older guns, to up the velocity.

[mav72]

 The new pistons look similar to the old ones but look to be made of some sort of flat finished fiberous plastic.

I worked on my 1300KT last night. It turns out I was having seating issues between my older custom shop barrel and the new transfer port on my 1300KT. The tolerances seem a little tighter but with a little wriggling and patience, I got the parts to seat properly.

It kind of leads back to the question weather to mod or not. I could have just axed the transfer port and put in a piece of refrigerator hose but I'm not really modding the gun for all out power. I usually just mod for a specific build (e.g. power), damadged/worn gun with no attainable parts, or in minor cases, just to tighten and seal things up a little.

If the gun works well and you like it, there's no need to mod it. I have a few airguns like that. Now, if you've got the modding bug, go get a wallyworld 13xx and mod that bad boy.

[jmc1980]

The new pistons look similar to the old ones but look to be made of some sort of flat finished fiberous plastic.

I worked on my 1300KT last night. It turns out I was having seating issues between my older custom shop barrel and the new transfer port on my 1300KT. The tolerances seem a little tighter but with a little wriggling and patience, I got the parts to seat properly.

It kind of leads back to the question weather to mod or not. I could have just axed the transfer port and put in a piece of refrigerator hose but I'm not really modding the gun for all out power. I usually just mod for a specific build (e.g. power), damadged/worn gun with no attainable parts, or in minor cases, just to tighten and seal things up a little.

If the gun works well and you like it, there's no need to mod it. I have a few airguns like that. Now, if you've got the modding bug, go get a wallyworld 13xx and mod that bad boy.

so is the new piston/valve flat not cup shaped like they always were? i have an aluminum flat top piston and valve that i want to use. would that be any better than the new plastic flat piston/valve? also, can i pump this new flat plastic setup more times or is that only for flat metal piston/valves?

[mav72]

The new pistons look similar to the old ones but look to be made of some sort of flat finished fiberous plastic.

I worked on my 1300KT last night. It turns out I was having seating issues between my older custom shop barrel and the new transfer port on my 1300KT. The tolerances seem a little tighter but with a little wriggling and patience, I got the parts to seat properly.

It kind of leads back to the question weather to mod or not. I could have just axed the transfer port and put in a piece of refrigerator hose but I'm not really modding the gun for all out power. I usually just mod for a specific build (e.g. power), damadged/worn gun with no attainable parts, or in minor cases, just to tighten and seal things up a little.

If the gun works well and you like it, there's no need to mod it. I have a few airguns like that. Now, if you've got the modding bug, go get a wallyworld 13xx and mod that bad boy.

so is the new piston/valve flat not cup shaped like they always were? i have an aluminum flat top piston and valve that i want to use. would that be any better than the new plastic flat piston/valve? also, can i pump this new flat plastic setup more times or is that only for flat metal piston/valves?

The new piston/valve are still cup designs. The flat top parts are more efficient than the stock parts so they would be better at pumping air into the gun. You can go higher on the pumps with a stock setup but eventually you loose efficiency more so than the aftermarket parts. With more air, the stock hammer spring may not be able to dump all the air, hence a stronger spring or power adjuster.

[jmc1980]

with the numbers i'm getting on my chrony would my alliance hobby flat top piston and valve raise my 1300kt velocity by enough to even bother. i was unaware that crosman is now using a different setup. i have never modded any airgun before and i'm happy this one is at 520+ fps with jsb 15.89's. if i can find the time today i want to chrony it with jsb 18.13's and see if it gets more fpe.

my jsb 15.89 pellets average 532 fps with 9.99fpe. my jsb 18.13 average 500 fps with 10.07 fpe. is 1 "better" than the other? would the 18.13 be better for longer range? would the 15.89 be better for shorter range? i am using them for small game hunting and plinking. is 1 more accurate than the other? the fpe is so close between them, i hope someone can shed some light on differences  between these 2 different weight pellets for me.

[kj]

test them for accuracy off a rest , preferably at the distances you'd normally shoot at. whichever one is most accurate with your testing is the best one to use. in airgun hunting/pesting , accuracy is the key. then practice/plink with pellet.

peace
kj