Chickenthief is spot on. Why it took three pages to ask if you used lube or not is the first thing I thought of on page one (forgive me...been away for a while and just saw this thread) I can ramble on for days and days on my Texan experiences (I have the .308 and the .50) . Your experience is SO FAMILIAR because I went through similar with the .308. Through tons of experimenting and 1000's of shots on the range my gun became (in my opinion) one of the best performing Texan .308's in the country (based on what others have said about theirs) Some of this will undoubtably transfer over the .50. I will grant that I cannot offer a ton of advice directly related to the .50 as I have not put more than 40 shots through mine due to time, weather, and just using my other guns. Also, .50 ammo is super-expensive; I have a NOE mold but haven't started pouring/sizing bullets yet.
Here are a few bullet points that may help you understand what you're dealing with. Granted, these are only my opinions and no ONE of us knows more than ALL of us:
1) Texans shoot crappy out of the box.
2) Ammo choice/air pressure is a delicate balance that determines everything.
3) The slugs must be lubed. Period. If not, your barrel will be instantly fouled and all results after that useless.
4) An aftermarket stock like a Diamond will increase accuracy by stiffening the chassis.
5) I never slugged my barrel(s), but I should. My .308 is a happy camper with bullets sized to .309. I HAVE fire lapped my .50 but as I said above, I haven't begun the process of fine tuning yet.
6) I recommend tuning down you power...maybe a lot. Perhaps if you dropped 30-40 fps you might see those groups start to tighten up.
7) There are a bunch of factors that all have to align for topnotch accuracy. PSI/bullet shape/bullet weight/proper sizing just to name a few.
8) My .308's accuracy is greatly improved by using my old-school Hunter Supply suppressor with the split-collar clamped on the barrel. Must act as a harmonic dampener
These are just a couple off of the top of my head. My guess is that you thought what I thought when you bought it...couple of practice shots, maybe some adjustments on the air pressure and power setting, and groups will be stacking up hole in hole. Unfortunately, that didn't occur, and I was as frustrated or more so than you. But I persevered, pulled out of it, and proved the haters wrong. I also found out that what others said was the 'ticket', didn't always work for me. I spent an ass-load of money, time, and tears getting confident. Don't give up. Accept the challenge and solve the puzzle. It can be done.
I attached a picture that I have attached countless times to other posts about the woes of barrel fouling. This is what happens when you shoot a Texan out-of-the-box with no lube. I'm embarrassed that I didn't notice it sooner, but I was a newbie and just didn't know. If I can save others the agony by sharing this, great. Talk about accuracy issues? I couldn't hit a target at 25 yards. Needless to say, it was quite a project to restore my barrel and it's a miracle that it shoots as good as it does now after the cleaning it took to unclog it. And the results from all of that range time, casting, bullet sizing, etc. is on the target. the targets are 200 yards and 300 yards respectively. The turkey was at 215 yards.
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