With a (.177) 350 Mag what are the best groups that can be expected say at 50 yrds? I'm using CP's and Jsb Heavyies. What can be done to the rifle to achieve the best that it can do?
If the shooter's doing his part, and is using his gun's favored pellets (that he has found by trial and error), shooting from a bench rest the 350 should be capable of producing sub 1" groups at 50 yards. Mostly, it's down to the shooter holding the rifle properly, and the same way each time, and taking the time to line up his shot and follow thru after the shot. All this also assumes that there's a properly mounted scope that's up to the task.
Totally agree with jason. The 350 like most springers is hold sensitive. First you have to shoot 1,000-1,500 pellets through it until it smooths out and becomes tamed. 2nd like Jason said make sure you have pretty good scope for the task at hand. For frequent 50yds shooting, I 'd get at least a 12X magnification scope (like 4-12x40) so you can see the bullseye or center dot on the paper clearly. I would use a sand bag gun rest or a bipod/tripod from a sitting position. If the hold is the same all the time, you should be able to get around a 1" CTC group. If you get 1.25", no biggie, just keep trying and make sure the scope (scope creep) or the mount don't move! Use loctite on the screws and mark (know) exactly where the back of the mount is, so you can notice if there is any movement easily. If you are getting very erratic groups it could be the scope does not hold its zero, or it's not a tough scope for Magnum springers.
Your groups will also get a better if you get the gun lube-tuned with debur & hone. Your 350 will shoot much smoother and accurately after a tune.
It's good you are shooting the JSB heavies. I hope you are also shooting the CP heavies. Those are the best pellets you can use. Also the heavier the pellet the better with a .177cal 350. You don't want to be shooting at 1,100fps. 900-1,000 is where you want to be and you are doing that with the heavier CP & JSB.
Again it's all about the shooter too. If you know to hold your breath and not move the gun at all, you should be able to get 1" groups. You might want to just rest the forearm on your palm at first and shoot a few rounds. You may find it's more accurate that way. Let us know how it works out.
I've shot over 2,500 rds. Using a rest I can shoot 1" groups at 50yrds most of the time. I'm using a Leapers 6x32x50 swat scope, eye cuff, one piece mount w/ stop. Vortec barrel tuner, everything loctited, using Jsb exact heavies or CP heavies....Doing all the right stuff (I think). Practice shooting couple times a week..having alot of fun. I know 1" at 50yrds is pretty good, just keep trying to maybe bring it down to 1/2 or so consistantly. (I have done 1/2" a couple of times but are rare) I think the gun may be capable, but don't think I am. Just thought I might be missing something. Practice,practice,practice. Thanks for the help
Ken, you have a Vortek accuracy tamer? I thought someone was making a version of those again.
I have one but not on any rifles right now. Though it might find a home on my 124 though.
Harry, its a type of harmonic balancer you put on the end of the barrel and its weight can be adjusted forward and back to "tune" the harmonic resonance, or barrel whip at the end of the shot cycle.
Scope is TS rated. As for the Vortec I really don't know if they work or not. In theory they sound good. I know it does something, as when I put it on my POI changed about an inch. My groups, I think went down maybe a third or so. Hard to tell as the gun was breaking in at the time. . It lenghtened the rifle about 2-3" so now it's about 50" inches long. I think an eye cuff helps as much as anything because it centers the eye to the scope exactly each time Great big ol thing and with the monster scope it weighs quite a bit. But with size and weight comes stability. Now that the gun is set up pretty well I can start playing around with the Vortec and try to shoot tacks at 50...practice..practice..practice.