Need help to build my Daystate Air Ranger 80 for cast boolits

[johnz]

Hello i am from Greece and this is my first time that i post a thread in that interesting forum,So i have an air ranger 80 .25 cal
which is 80 fpe with 36 grain pellets, the barrel is 23" long and the twist rate is about 17.7:1 and because i slug it i think
is choked.Because this rifle is high powered for common pellets i have accuracy problems.So i want to use mrhollowpoint
50 grain boolits, but before that i thing is better to replace the barrel.Can someone help me please with the specs of the new barrel? what is the best twist rate? length? I figure the muzzle velocity will be about 880-900 ft/sec and the
bullet is 50 grain, .251 cal , .463 length.The rifle working pressure is 3600 psi.
Thank"s.
John.

[HollowPoint]

I'm not completely clear on what you are asking but is sounds like all you have to do is replicate the dimensions of your existing barrel with a barrel that has a bore and rifling twist made for conventional cast bullets rather than the pellets you're shooting now.

I've heard good things about the Daystate air rifles so I'm assuming that you could most likely get the exact information you're looking for from the DayState Forums.

http://www.daystateforum.com/

What I'm not sure of here is if you're asking about your DayState's barrel dimensions so you can replicate them with another barrel or, if you're asking about what dimensions the bore of a new replacement barrel should be if you plan on shooting .25 caliber cast bullets out of it.

I also want to welcome you to this cast bullets forum. What ever barrel you decide on, you can't go wrong by coming here and inquiring about what cast bullets to use.

HollowPoint

[johnz]

I try to found informations to the Daystate forum but they are not what i need. I want to replace the existing barrel with a new barrel
just for cast bullets, i dont want to shoot any more pellets,but i"m not sure about the properly twist rate?the size of the breach ? the length?
Thank"s.
John.

[MT Chambers]

I'd contact someone like Veral Smith and see if he could make a mold for you that is lighter then 80 grs. and about .252" dia. to give you some leeway as to size. Try it in the existing barrel before replacing barrel, note that most barrels are made for pb therefore have diff. dimensions ...258".........I can't think of a better platform for cast bullet airgun than the Ranger 80, and I'm trying to save you from having to rebarrel, if funds aren't a problem them rebarrel with a .258" barrel....lotsa cast bullets and molds out there for that size!

[HollowPoint]

I'd contact someone like Veral Smith and see if he could make a mold for you that is lighter then 80 grs. and about .252" dia. to give you some leeway as to size. Try it in the existing barrel before replacing barrel, note that most barrels are made for pb therefore have diff. dimensions ...258".........I can't think of a better platform for cast bullet airgun than the Ranger 80, and I'm trying to save you from having to rebarrel, if funds aren't a problem them rebarrel with a .258" barrel....lotsa cast bullets and molds out there for that size!

I agree with this statement. I've seen alot more folks re-barrel from .25 caliber to a .257 caliber just so they could shoot cast bullets. Most of these guys are shooting AirForce Condors but the principal is the same.

Your DayState appears to generate as much power as a stock Condor Air rifle so I'm sure that with the lightest .257 cast bullet you'd still be near to the 880-900 fps velocities you listed. Another plus would be that you'd have something that few other DayState owners have.
You'd have a DayState AirRanger chambered in .257 caliber. I don't know of anyone else who has one in that caliber.

HollowPoint

[johnz]

I like the idea to re-barrel it .257 cal but the problem is that the max tuning up for the air ranger that could be done from my gunsmith
here in Greece is that: tuned air ranger 80 .25 cal with factory barrel 23", twist rate about 17.7:1
258-120bar RANGEMASTER 36grains
ft/sec m/sec ft/lb
..1) 1118 340 100
..2) 1124 342 101
..3) 1108 338 98
..4) 1109 338 98
..5) 1108 338 98
..6) 1103 336 97
..7) 1117 340 100
..8) 1121 342 100
..9) 1116 340 99
10) 1115 340 99
11) 1115 340 99
12) 1122 342 100
13) 1116 340 99
14) 1118 341 100
15) 1108 335 98
16) 1104 336 97
17) 1109 338 98
18) 1103 336 97
19) 1100 335 97
20) 1095 333 96
21) 1095 333 96
22) 1092 333 90
23) 1088 326 94
24) 1083 330 94
25) 1072 327 92
26) 1062 324 90
27) 1066 320 91
28) 1060 323 90
29) 1058 322 89
30) 1054 321 84
31) 1053 321 88
32) 1045 318 87
33) 1040 317 86
34) 1024 312 84
35) 1026 313 84
36) 1024 312 84
37) 1021 311 83
38) 1013 309 82
39) 1015 309 82
40) 1008 307 81
41) 1001 305 80
42) 999 304 80
43) 994 303 79
44) 988 301 78
45) 985 300 77
46) 979 298 76
47) 968 295 75
48) 966 294 74
49) 960 294 73
Do you think that the power is enough for bullets that is .257 cal and weigh more than 50 grain?

[melloairman]

I do not think you are going to make it with a .257 heavy bullet . One thing that might help is a longer barrel . Every inch should yield 8-10 fps . out to at least 28 inches . Here are some readings of my 201 that has a 28 inch .250 barrel . See the difference between 52 and 62 grain bullets . You stated you wanted to use Mr. hollow point bullets which are normally as pure and soft as you can get . Might be a problem if your barrel is chocked . With a chocked barrel I have had to use a 8 bhn or harder alloy bullet to maintain accuracy . LBT can make a mold for your 25 caliber barrel that you have now if you are wanting to cast . GL Marvin

[melloairman]

Is there any way you can load two pellets into the barrel at the same time and chrony with the added weight ? Marvin

[johnz]

Yes i like the idea of a .257 cal but i"m afraid also that i need more power than tuned air ranger could have, the problem is the construction of the rifle , if you use very powerfull hamer spring then the pin that push the hamer back to cock after some use will brake bacause it is about 4mm if it was thicker, about 6mm no problem but there is no place to fit a thicker pin.So i think that the best option is 28" barrel
un choked but i"m confused with the rifling i use the dimensions of mrhollowpoint 50grain bullets on Greenhill formula and give me 1:20.2 twist rate when i use that in the twist rate stability calculator http://bulletin.accurateshooter.com/...ty-calculator/ i had an sg:1.3 and from what i read the sg should be between 1.5 and 2.Any suggestion?

[HollowPoint]

The guys that I know of that have re-barreled from .25 to .257 caliber are using 1 in 10 twist barrels but, they're shooting bullets in 90 to 100 grain weights. They're set up for long range shooting.

On the Shilen Barrel website it list calibers and twists rates in .257 barrels using a 1 in 14 twist that will stabilize bullets up to 90 grains. I think I'd go with the 1 in 10 but that's my preference. You have stated that you have lighter bullets in mind. I'm afraid this is one of those situations where you'll have to factor in the type of shooting you plan to do with it and make your decision based on that.

If or when I do such a barrel swap I plan on going with a 7mm caliber barrel for long range shooting. This will require a twist rate of 1 in 10 for the bullets I have in mind. It will also limit my shot count to around five or six full power shots before topping off again.

HollowPoint

[Pakprotector]

hey-Hey!!!,
I think this will do it for you; not too much mass and they seem to fly well.
http://www.gatewaytoairguns.org/GTA/...?topic=58933.0

It also gives you the required barrel twist. Greenhill does not care about shape, and these were designed with the more capable sub-sonic software from Border Barrels. Emphasis was placed on minimum drag, and accuracy...the rebated boat tail is a shape Lapua did some interesting work on, and the air driven experiments seem to bear that out.
cheers,
Douglas

The 257420 will drop around 70 gr, and with 80-85 FPE on tap, that will yield low 700's in fps. Cut it to 50 gr, and 85 FPE is more like 880 fps.

[johnz]

I like that but they start produce that mold? i can order it?I want to try the possibility to have accurate long range shooting with that barrel
before i replace it.

[rsterne]

Yes, the mold is available from LBT, the order number is 25-52-BST.... You can order it in whatever diameter you want, or you can send Veral a slug of your barrel and he will make it to fit....

Bob

[johnz]

Thank"s i"ll contact with them.