first time .257 builder
Hello all!
I’ve been a long time reader and now a first time poster on this forum. I have learned a ton from here and hoping to learn more. Would like to say thank you to all of you for the wealth of knowledge. Currently I have two .257 builds going that are constantly in the trial and error mode of research and devolopment. I know the parts are out there to just plug and play, but being a machinist of 20+ years with quite a bit of gunsmithing involved, its more satisfying to me to build the parts and pieces myself. My .257 is built on a standard condor frame while the other build is for a friend on a condor ss frame. Both barrels were machined from 25-06 barrels. The twist is a little fast in my opinion at 1-10″ but for the price i had to try it. So far they both shoot 1″ @ 100yds consistently and have acheived better than that on more than a few occasions. They may be replaced with different barrels in the future but for now they work. Bullets are dropping at 73.8 grns from my lyman 257420 moulde and are sized at .2575″. With all that being said, it’s down to the air power. On my rifle I have the tophat set at .126″. The ports in the tophat have been slightly modified in hopes to allow a little more airflow. Other than that both valves are bone stock. Gun is usually tethered to the scuba tank which is sitting at 3200-3300psi. Currently shooting 74 grn bullets with that setup at 875fps out of my 24″ barrel. That’s not too bad i guess but I would like to see those bullets flying between 950 and 1000fps. I think it would do wonders for my performance at longer ranges. I know barrel length is one issue I will battle as far as velocity goes. What I’m wondering is, is the extreme valve from R&L that big of a change over what i have now or do I need a Dyotat valve? I see ways that Airforce could have made the valve different to deliver more air but reality is what it is. Have plans drawn to make a couple new pieces for the stock valve to allow a bigger tophat stem and bigger hole. Also have plans drawn for just a revised tophat. Not sure what way to go at this point. Do I have anything left to gain from just a tophat or is it time for some more serious valve work? Again, thanks guys and thanks in advance for any further info. :twak:
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Viewing 9 replies - 1 through 9 (of 9 total)
+1,
You can practically try it out by not fully closing the sprue plate while casting if you have got all the other parameters right.
Smaller holes make for a better base. I make remake all my plates with .090″-.100″ holes and I get perfect bases.
That’s a great idea! Did you make that yourself or where does a guy find one of those? Can’t seem to keep the sprue plate tight enough on my mold. Doesn’t seem to cut the base of the bullet like I would like to see. Can’t help but think that’s not going to be good for accuracy.
Or a 10mm thick custom sprue plate also produces an awesome base with a ladle.
I wish i had bought a bottom pour pot to get more force to help square off the tail of the lyman 257420 bullets.
Knifemaker was talking about using RC SHOCK OIL 10 wt. from LUCAS OIL or EBay for lube. You might look up his posts.
Thank you for the response lurker#1. I’ve been casting bullets for quite a few years but by no means would I say I have it down to a science. What have you done that worked or didn’t work? Trying to figure out bullet lube currently. Silicone oil seems to work good so far. Also trying floor wax. Hoping it works well but have yet to shoot any bullets I’ve treated with it. Sounds like you are going to have a nice airgun soon. Hope you enjoy it as much as I have mine. I have a blast shooting it.
Hey Tibby :tag:
I have a .257 coming soon from Dyotat100. I figured if I’m going to shoot the moon I’d better have Doug build it.
I See you are a DIY’r. That’s great, I’m just a tinker’r.
Have you read what rifle50 is up to ❓
Some of these guys are busy about their projects but very willing to help others. Doug, dayotat100, can help steer you in the right direction and makes all the pieces. I hope he or some of the others chime in soon. I love to learn from you doers even if I don’t the machinery to join in. If you’re getting into casting bullets I could tell you my recent mistakes :whistle:
Thanks for all the info out there… looks like I’ll figure this out for myself…
Viewing 9 replies - 1 through 9 (of 9 total)
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That’s a hell of a good tidbit there. Never gave that a thought but it makes perfect sense. Thank you guys. Will try that one out immediately.