Tuning The underappreciated Beeman 1357

[Neu]

Picked this little bullpup up a few days ago on the cheap. First time putting it across the chronograph it was shooting at 1070 fps with 10.5 grain pellets and had a horrible cliff and only about 30 shots from 3000psi to 1200psi. Spent a few days playing with different hammer springs (size and strength ratings) and did a bstaley o-ring mod on it. So far it's gotten a 1000% better. Settled on the stock spring with 2 coils cut 2 turns in from flush and 2 2.4mm orings 1 behind the hammer stop that the valve pin sits in and 1 in front of it. This string was with crosman 10.5's from 3000 psi to right around 2000. I'll try 2.5 turns in tomorrow.

 

[Neu]

After some more adjustments I'm done I think I have it were I want it. Not to shabby for a sub $200 none regulated bullpup with a 136cc air tube and a few days of tuning it.

 

[elwoodblues]

It doesn't get any better than that 100+shots in the mid 700's I'm getting about the same on my 1357 got a 1358 that gets about 70 shots about 700 fps

 

[Neu]

It doesn't get any better than that 100+shots in the mid 700's I'm getting about the same on my 1357 got a 1358 that gets about 70 shots about 700 fps

Yeah I am pretty happy for the $180 I paid for it I am super happy with it. 40 yards @ .57 on a 10 shot group. Unfortunately that's about the limit for my yard. It's built like a tank, not a huge fan of the picatinny that's on it wish it was more like the tipan's or similar. Definitely thinking about the getting a .22 or .25.

 

[elwoodblues]

I also picked up a couple of the pistols 2027 and 2028 they also give me about 60 decent shots out of a 50cc tube just unreal got the 2027 for 108 bucks.

 

[nobody1]

Picked this little bullpup up a few days ago on the cheap. First time putting it across the chronograph it was shooting at 1070 fps with 10.5 grain pellets and had a horrible cliff and only about 30 shots from 3000psi to 1200psi. Spent a few days playing with different hammer springs (size and strength ratings) and did a bstaley o-ring mod on it. So far it's gotten a 1000% better. Settled on the stock spring with 2 coils cut 2 turns in from flush and 2 2.4mm orings 1 behind the hammer stop that the valve pin sits in and 1 in front of it. This string was with crosman 10.5's from 3000 psi to right around 2000. I'll try 2.5 turns in tomorrow.

View attachment 362566

That shot string looks great for target shooting up to about 50 yards.

My 1358 is really accurate with CPHP at about 50-60 yards.

And the 1357 and 1358 barrels have 1/2-20 UNF threads, which is important if you want to make them quiet.

 

[1handwill.gc]

It doesn't get any better than that 100+shots in the mid 700's I'm getting about the same on my 1357 got a 1358 that gets about 70 shots about 700 fps

Looks like you’re here in Washington if you don’t mind watch your tune for your 1358

 

[elwoodblues]

Looks like you’re here in Washington if you don’t mind watch your tune for your 1358

I put a lighter spring in both the 1357 and 1358 let me see if I can find the size and length

edit ok found it
This is too easy to call it a mod. 1.0 mm wire, OD 10 mm, cut to length 84 mm.

This was from a gta post on a 1358, I did cut mine to 83mm and turned hammer adj in one full turn from all the way out.

I get about 75 -80 shots on a 3100 psi fill in the 850-900 fps range

For the moderator I used a TKO22 .875 1/2-20 very quite
and edit once more

I got mine from aliexpress but in later threads seems mbmastercar has one that is just about the same

https://www.mcmaster.com/compression-springs/compression-springs-7/length~3-1-2/od~3-8/3.5 lengthOD 0.375" ID 0.293" wire 0.041" 2.5" 2.87 2.87 Zinc-Plated Spring-Tempered Steel Closed 6 9657K228 $9.77

 

[1handwill.gc]

Thank you very much. That makes sense. I just need to find me a little shorter spring thank you very much they keep them on the bull’s-eye

 

[elwoodblues]

it's truly amazing how many shots these Beeman give considering the small air tubes 136cc and 50cc on the pistols