One thing to consider is that the 350 Magnum, which is one of my top 5 all time favorite break barrel spring guns, is a bit of a unique creature in the airgun world in that it has the power to project heavy pellets with tremendous efficiency and plenty of power to spare. The beauty of this is that even with the heavier pellets, the trajectory is still fairly flat - all things considered.
Many people feel that heavy pellets are hard on springs and suggest shooting light pellets, BUT in a large magnum gun like the 350, a light pellet, even when it fits snugly in the breech, lacks the weight to offer enough resistance to the air that is being compressed and thusly, they are unable to provide an adequate "air cushion" which serves as an "air break" to keep the piston from slamming into the bottom of the air compression tube which is VERY HARD on the piston seal and will quickly lead to "seal failure"!!! Additionally, the sudden stop imparts a very acute harmonic vibration as an "oscillating waveform" that has a very high amplitude and very high frequency which is hard on the spring in and of itself!
I do not advocate shooting heavy pellets in a low to mid powered springer airgun, but the 350 Magnum is a power house that will throw the “heavy lead” with authority and grace!
While I do not like to use the posted results of other shooters as a basis for a "rule of thumb", I have found that the info over at Straight Shooters is very accurate!
I used the Crossman Premium Ultra mags to shoot targets and hunt with as these were the only heavy pellets available in my area.They were a little hard [no expansion] on game, rabbits and grouse but killed alright.I would have kept the gun in a .22 but found it too fussy pellet wise.I sold it to a buddy that just had to have it and he is unable to find suitable pellets.How are the Beeman silver arrows 11.5gr I think?Still have my son's 34/.22 and bought a HW80K/.22 for myself.Lot easier to mt a scope on and built for power from day one.Thanx for the info..Harold
I think NOT!! Aside from the fact that a nice break does look "Cool",, it also provides other distink advantages as well. Makes for a great handhold that makes cocking easyer (especially on carbine lenth brls.)Also I might add,, I feel in certain applications they contribute to better harmonics thus contributing to better accuracy,, my own tests would seem to prove this point. Look at the new "Fuercraft"? carbines from RWS,,see that big ole honkin break on them?? I was informed today it is steel,,a weight to compensate for weight lost due to the shorter brl. Muzzle breaks certainly have thier place,, much more than a cool accessory,, I personally believe they can be "tuned" for greater accuracy & "Harmonics". Now,, I just need me a metal lathe!!LOL!! Tim.
did not want a delrin or aluminum brake barrel but a combination with weight. Brass came to my mind with the tip having an air chamber of just 1/2"
went to my machinist and after 3 day's of back and forth came with the plan, 6" of round brass drilled to receive the barrel with the the air chamber up front. It was so tight it was stamped to the barrel, no hex screws whatsoever. the air gun has 20" of barrel now instead of 19.5
It made a BIG difference in my model 34, .22 cal. tuned by John in PA. Shoots 720 fps with 14.3 CP's and rising. Complete airgun from his twin brother the model 40 which comes with a UMAREX muzzle brake. I think the harmonics changed and improved the accuracy by putting weight at the tip of the muzzle, plus the small air chamber to dissipate the explosion of air coming right behind the pellet as it exits the barrel
no problem with balance since I drilled the shoulder stock and slid an equal amount of weight in the rear
warren
PS: that's my theory and I am sticking to it LOL
and remember "it's 30% the gun and 70% the shooter"
I knew the 350 had it in it to group I guess it's just a matter of barrel harmonics[skilled shooter] and correct ammo.............Harold *can you imagine one in .25?
The 350 is a good gun, and somewhat underestimated in my view. Therefore, you should be able to get something used, cheap in .22" somewhere, then write to Umarex or Pyramid air and a buy an 0.177" cal. barrel assembly. Change the barrels and test. Jot down results and post.
Now, cut the barrel JUST IN FRONT of the barrel block. Drill the old barrel out leaving a 14 mm's hole where the barrel was, if possible ream the hole to precisely this diameter, mill a slot/groove in the underside that cuts across to the barrel hole for almost the full length of the block, but leaves at least 3 mm's around the hinge-pin hole. Now put across in there three 4 mm's flat head screws, I usually do it from right to left, so that I can loosen the thingy with my right hand when I am holding with my left. If you need to cut the slot full length, you will later need to make sure that you can add a filler block in the hinge pin hole section, so that this section works properly. Alternately, if you can drill really clean holes and ream them real well, three sets of grub screws going into slightly off-centered dimples will create enough interference to hold the barrel in place and tighten everything well. Remember we want a firm hold with little or no bore distortion, we do not want a single screw deforming the bore just ahead of the chamber or a collar creating a choke just in front of the hinge pin.
Lathe turn the 0.177" rear end to 13.96 mm's and make sure the finished diameter is polished smoothed, without the screws being tightened, the barrel needs to slide in and out just right, at this point you need to turn the recess for the breech seal.
Make the chamber end of the barrel bore to admit the pellet the barrel likes most. Re test, jot down and post results.
Now you can get a .25" cal. barrel from Tim MacMurray or from other source. Cut from the rear end to desired length, 12" should be more than good in .25". Make the chamber end just a slight bevel (A rolled up cone of 380 grit wet-or-dry paper works well for this), we still need to find out which pellet is preferred by the barrel. Turn the rear end of this barrel to 13.96 mm's final polished smooth diameter, so that it slides in the block as well as the breech seal recess.
Mount the .25" barrel and test.
Jot down results
Post, with pictures, so that we can all see.
See, we can all have fun! LOL!
Just partly kidding, while I cannot perform this conversion myself for lack of tools, I am confident it would give good results, should you try to tackle it.
Could you not just thread the barrel to the breach block and either silver solder it or locktite/glassbedding compound.Then mill the barrel flat to the breach face.I can get 16mm HW/.25 blanks or for twice the $$$$ Walther choked .25 barrels.It wouldn't be getting removed anyways so permanent is best........Harold
