Re: looking for a decent priced .50cal semi auto
Here's a few insights into 50BMG shooting that I have learned in the last several years:
I bought the BOHICA bolt action conversion for an AR-15 lower (no longer made under that name). The AR lower is dedicated to this gun and not used for any other purpose. The first problem we encountered was keeping the scope from moving. Our $500 new tactical scope broke in about 10 shots when the scope moved in the mounts and the turret block hit the scope rings in recoil. Fortunately the manufacturer replaced it for free since the rings were his and the scope was rated for 50BMG. I had to use four rings, lap them, and glue the scope to them to keep the scope in place.
Then our adjustable trigger screwed up. When adjusted to a light pull and no creep it was unreliable. Reliability returned with creep added. A messed up trigger on a 50 BMG gun is not for the weak of heart when the gun does not fire with a round in the chamber. A better trigger fixed the problem.
Reloading is the only way to shoot these guns as commercial ammo is EXPENSIVE. It takes one mammoth press to reload 50BMG (a RockChucker will NOT do it). The dies are EXPENSIVE as are the bullets, the cases, and the primers. It takes over 220 grains of powder per cartridge. I bought some CBC Brazilian brass and its case walls were too thin for any neck tension. The result was the bullets were only held in the case by the crimp. The CBC brass went into the recycle bin and was replaced by once fired Lake City brass. Then I found out that the rule of thumb for primer seating of a few thousandth below flush was inadequate. They must be seated to about 0.020 inches below flush. Having a hot gun with a 50BMG cartridge in it that has failed to fire is an eye opener.
The recoil on this gun is big. It pushes your shoulder back about a foot (I observed my shooting partner shooting it). We shoot it with a decelerator pad on it plus a Past shooting pad on our shoulder. The muzzle break aims the gasses rearward such that observers must be at least 20 feet away to avoid getting the gases in their face. When shot over open ground it will raise dust and it will empty the shooting table of anything not nailed down. The concussion is amazing. People over a mile way stopped by to see what we were shooting as the noise from 50BMG is huge. Earmuffs alone are not enough. You have to at least double up on ear protection on the side closest to the gun.
It is fun to shoot but we are still playing with it and have not yet determined the accuracy potential. We set out a steel target at 800 yds and hit it sometimes but we are still working on an adequate steel swinger.
In California 50BMG is illegal so our gun is 50DTC which is legal. It is 50 BMG with the shoulder moved and the case length shortened and the name of it changed. You fire form the cases from shortened 50BMG brass and we are still doing some of that. That is the main reason we are still just playing with it rather than pursuing accuracy testing.
It was all an expensive endeavor even though we bought the least expensive 50BMG we could but we learned a lot and are not sorry we did it. The reloading was the surprise for costs but its done and covered now.