Chokes and velocity

[Dr. Kralenstein]

Got the bugs worked out I think. I ordered a jumbo hammer which is longer and heavier than the standard hammer, and has the sear face in the same location as the shorter action. It weighed in at 63 grams vs 41 grams of my np03 hammer.

I cut it down to allow more spring tension and then drilled it out for the 12mm springs. Got down to 47 grams, and then added the VetMx brass weight/guide which brought it up to 52 grams.

Also found out the Biathlon lever was bent at the back and causing the bolt to not fully seat and leak air. Also the reason why it was so damn hard to cock. It's much better now.

I'm now getting 21 shots averaging 835 up to 855 and down to 820. So 3 full mags in the curve. It's quieter and much more powerful! 130 fpe sure will knock some critters flat out stupid!

 

[Vetmx]

And now you finally have a good barn gun. Now go shoot down a barn with it.

 

[Dr. Kralenstein]

And now you finally have a good barn gun. Now go shoot down a barn with it.

During this whole process I've come to the realization that I don't even need a big bore. It was more of a "can I do it?" thing. The itch has been scratched. I'll probably hold on to it for awhile and eventually sell it to someone who will get some use out of it.

 

[Dr. Kralenstein]

Got a chance to take the 357 out to 50 yards today. This was the result.

7 shot full mag. First 2 shots were the lower right ones, then it's on til about half of 3rd/last mag and starts to drop. Easy enough to compensate. Rifle is also wearing a 3x9x40 CVLife junk scope. Looking into better glass now.

I set up a 2x4 to check penetration, and it went right through it and lodged in an oak log behind the 2x4. It's in there about 1/2"-3/4" or so. Not bad at all... should work on starlings.

 

[rafajpg]

Got a chance to take the 357 out to 50 yards today. This was the result.

7 shot full mag. First 2 shots were the lower right ones, then it's on til about half of 3rd/last mag and starts to drop. Easy enough to compensate. Rifle is also wearing a 3x9x40 CVLife junk scope. Looking into better glass now.

I set up a 2x4 to check penetration, and it went right through it and lodged in an oak log behind the 2x4. It's in there about 1/2"-3/4" or so. Not bad at all... should work on starlings.

AWESOME!!! I wish my BigHorn 357 could do that, did you remove the choke at the end of the barrel?, lead build up is terrible on this gun, but <I am afraid to remove the choke and loose accuracy. But it does pretty well with JSBs at 50m for a non regulated gun. What do you think it was the best mod to boost performance?

 

[mtnGhost]

First, it would be helpful if you knew the specs of the barrel...bore & groove; but this is not absolutely neccessary. You will need a MICROMETER (NOT Caliper) to measure the diameter of your pellet. Some pellet/slug manufacturers give the precise measurement of the ammo in 100th of an inch (i.e. .216, .217, .218 for .22 caliber ammo). Larger calibers usually don't have as many size options. Measure the diameter of the head of that pellet and make note of it. What you want to do next is take that pellet, and push it through the barrel, rear to front, till it exists the front of the barrel. This means you will first need to remove the barrel from the breech, if possible and you feel inclined to do so. Measure the diameter of the HEAD of that same pellet after it comes through the barrel. THAT, is the diameter of your choke. What you want to do moving forward is purchase pellets that are sized by the manufacturer as close to your choke diameter as possible...OR, you can buy a pellet sizer in the size of your choke and resize pellets that are slightly off. This would be your best bet without and avoiding any hardware changes

Definitely need a decent mike with enough resolution (and gauge blocks to calibrate). The 15 degree points on mine have made it a lot more convenient to measure casts.

Cerrosafe is also pretty awesome for casting bores when you use it correctly. An ingot seems to last forever too.