GTA
Airguns by Make and Model => Diana Airguns => Topic started by: ER00z on December 02, 2021, 08:49:33 PM
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Diana did a wonderful thing, making many (all?) of their piston seals the same diameter of 28mm. But I'm confused on the stroke length of the 460 compared to the other models. Of the "Magnums", the 34 has the shortest stroke, the 350 has the longest and the 48/54 models are in the middle. I thought the 460 stroke was closer to the 48/54, but recently read it's actually closer (nearly identical) to the 350?
The spring of the 460 is nearly identical to that of the 34, much shorter than the 350 spring. Is the 460 very efficient in comparison, or did I miss understand something scanning through information? Could a "heavier"/longer spring ment for the 350 work in the 460 mechanically without issue?
Thanks in advance.
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The D460 has 1 mm shorter stroke than the D350. But it has higher efficiency, because the 460 has a short transfer port, while the 350 has quite a long one. The D48-56 also have very short, efficient TP's, but they also have a much shorter stroke than either the 460 or the 350.
Over three decades of chasing power, from 1987 to 2007, Diana has gone from a shortish stroke and a high-efficiency TP, to a very long stroke and a low-efficiency TP, to a very long stroke and a high-efficiency TP, or the logical end point of springer power development.
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Thanks for the reply Duke.
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I just went through my .177 460, bringing the power up from sub12ftlbs. I had detuned previously to use "common" pellets, but have a HW97 to fill that role now and the 460 hasn't had much use lately. Now with the OEM spring again, I noticed power is on the high side. Honestly didn't own a chrony when I initially bought the gun, so not certain of original numbers.
After some slight dieseling, the gun settled in the 930's with H&N Baracuda Hunter 10.49gr pellets, low of 933, high of 938 over a dozen shots or so (shot 40-50 shots to help things settle down before chrony-ing). Quite a few right at 935-936 fps, so not sure if gun is still lightly dieseling, as there's no smoke after the shot. Are these "normal" power levels for the .177 460?
Lol, this 460 in .177 makes as much power as my .22 caliber 470TH and 98K, just surprised me a bit...
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I just went through my .177 460, bringing the power up from sub12ftlbs. I had detuned previously to use "common" pellets, but have a HW97 to fill that role now and the 460 hasn't had much use lately. Now with the OEM spring again, I noticed power is on the high side. Honestly didn't own a chrony when I initially bought the gun, so not certain of original numbers.
After some slight dieseling, the gun settled in the 930's with H&N Baracuda Hunter 10.49gr pellets, low of 933, high of 938 over a dozen shots or so (shot 40-50 shots to help things settle down before chrony-ing). Quite a few right at 935-936 fps, so not sure if gun is still lightly dieseling, as there's no smoke after the shot. Are these "normal" power levels for the .177 460?
Lol, this 460 in .177 makes as much power as my .22 caliber 470TH and 98K, just surprised me a bit...
Zack;
In GENERAL, pellet MV's in excess of the 875 fps are not stable in the long range.
Having a high energy is only useful if the pellet can be placed in the right spot.
SOME guns can shoot a bit higher than the 875 fps accurately but they are an exception. AND the BC's of pellets grows smaller as the velocity goes higher. So, in most cases, each pellet has a "ballistic optimal" where the pellet is stable, the trajectory smooth and uniform (no corkscrewing) and the loss is not that great from the start.
Besides, expansion depends on impact speed, not energy, so as long as you hit the target at about 560-600 fps the Baracudas (BHE and BH) will expand. Launching them at around 875 will ensure impact speeds of this magnitude at useful airgun ranges.
Good luck and keep us posted!
HM
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Slight aside
A site called STRAIGHTSHOOTER tested 33 .177 and 19 .22 pellets in RWS 350s
The muzzle velocity for the Baracuda Hunter was nearly the same 925 fps-making the muzzle energy dead on 20 ft lbs- ballistic coefficient .018
10 yards 854 17 ft lbs
25 yards 767 14 ft lbs
50 yards 650 10 ft lbs
Only 3 of 31 .177s were 20 or more ft lbs - peak was 23 ft lbs(a light-6.4 grain pellet) 13/19 .22 were 20 or more ft lbs
The 460 and the 350 seem to be nearly identical in respect to velocity energy- not a surprise
It would be interesting to hack a springer barrel-start very long-24 inches or so)-see at what length it actually loses velocity.
Barrel by the inch does that for firearms cartridges-
I have 2 Daisy 880s- cost about $40 each-but I don't think I have the heart to hack one of them-I really love them-
with the fiber optic accessory sight I really shoot well with them
The 350 has a fiber optic ft sight too-so guessing it will really agree with my eyes.
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Hector, thanks for the reply.
At 25-30 yards, groupings have been great, unfortunately when I pushed the H&N B.H. pellets to 50+ yards I did encounter some issues, especially with a light head-wind helping the deceleration/over stabilization (starting to corkscrew), lol. I was hoping they would fair well at distance, but physics decided otherwise. I'll include a photo below.
Before I detune the gun I'll test some Beeman/H&N Silver Points I have on hand, they're slightly heavier at 11.(?) grains. I'm hoping they're accurate, but only own one gun that ever liked them.
I'll be traveling soon and hope to take the 460 with me. It's (potentially) silly accurate and lighter than the 54 Air King Pro. But either one will serve me well while away.
Circled in the photo below are the first five shots from this morning at 52 yards, using Baracuda hunters. Shortly after I was chasing my tail trying to dial it in before I realised the issue...
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Charles, thanks for the information. I'm still very surprised the 460 makes similar power as the 350 with much less spring. I guess it's all in the design.
Just so you know, the 350 from Numrich comes with globe sight with a "spike" post, at least mine did. If your interested in a fiber optic globe sight, Field Supply has Truglo globe sights for $5 (last I knew).
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Hector, thanks for the reply.
At 25-30 yards, groupings have been great, unfortunately when I pushed the H&N B.H. pellets to 50+ yards I did encounter some issues, especially with a light head-wind helping the deceleration/over stabilization (starting to corkscrew), lol. I was hoping they would fair well at distance, but physics decided otherwise. I'll include a photo below.
Before I detune the gun I'll test some Beeman/H&N Silver Points I have on hand, they're slightly heavier at 11.(?) grains. I'm hoping they're accurate, but only own one gun that ever liked them.
I'll be traveling soon and hope to take the 460 with me. It's (potentially) silly accurate and lighter than the 54 Air King Pro. But either one will serve me well while away.
Circled in the photo below are the first five shots from this morning at 52 yards, using Baracuda hunters. Shortly after I was chasing my tail trying to dial it in before I realised the issue...
Zack
The BH is still a medium weight for caliber pellet. Try the 10.3's from JSB or the Baracuda Match in all three head sizes
If you want to go hunting, then the Predator, or the BHE is a better pellet in general.
About why the 350 needs more spring than the 460 the reason is that the long TP of the 350 requires a higher pre-load to make the piston stay as put as it can be made without an anti-bounce-piston (ABP) architecture.
And yes, that is the best example of why the break barrels are considerably less efficient than the sliding compression chamber/fixed barrels when using traditional pistons.
The solution is an ABP in the break barrel, as our comparison of power plant swaps between an LGU and an LGV demonstrated:
https://www.ctcustomairguns.com/hectors-airgun-blog/shot-cycle-dynamics-in-3-spring-piston-airguns-chap-4 (https://www.ctcustomairguns.com/hectors-airgun-blog/shot-cycle-dynamics-in-3-spring-piston-airguns-chap-4)
And yes, that is how good the ABP's can be.
Keep well and shoot straight!
HM
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Hector, thanks for the response.
I tried using the Beeman Silver Arrow pellets (not the silver points, lol) which were 11.5gr, but they didn't fair very well in the 460.
The H&N Baracuda Match pellets are sometimes hard to come by now, but will attempt to acquire some. The main reason for using the Hunter 10.49gr pellets is I bought quite a few a couple years back, when they were on sale (200 count tins). I do have some JSB and Air Arms 10.3's on hand, I'll also give them a try. Just waiting for weather to play nice when I have time available.
Worst comes to worst, I could space up the spring I had in there previously, which needed more preload. The spring settled a bit, and was shooting H&N FTT's at 770fps, give or take. It was very accurate, but trajectory wasn't as flat as I wanted at range.
I'll get things sorted eventually, lol. Take it easy.
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Hector, thanks for the response.
I tried using the Beeman Silver Arrow pellets (not the silver points, lol) which were 11.5gr, but they didn't fair very well in the 460.
The H&N Baracuda Match pellets are sometimes hard to come by now, but will attempt to acquire some. The main reason for using the Hunter 10.49gr pellets is I bought quite a few a couple years back, when they were on sale (200 count tins). I do have some JSB and Air Arms 10.3's on hand, I'll also give them a try. Just waiting for weather to play nice when I have time available.
Worst comes to worst, I could space up the spring I had in there previously, which needed more preload. The spring settled a bit, and was shooting H&N FTT's at 770fps, give or take. It was very accurate, but trajectory wasn't as flat as I wanted at range.
I'll get things sorted eventually, lol. Take it easy.
Zack,
If we sorted things out immediately, ¿what would we do then? LOL!
Keep well and keep us posted!
HM
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I just went through my .177 460, bringing the power up from sub12ftlbs. I had detuned previously to use "common" pellets, but have a HW97 to fill that role now and the 460 hasn't had much use lately. Now with the OEM spring again, I noticed power is on the high side. Honestly didn't own a chrony when I initially bought the gun, so not certain of original numbers.
After some slight dieseling, the gun settled in the 930's with H&N Baracuda Hunter 10.49gr pellets, low of 933, high of 938 over a dozen shots or so (shot 40-50 shots to help things settle down before chrony-ing). Quite a few right at 935-936 fps, so not sure if gun is still lightly dieseling, as there's no smoke after the shot. Are these "normal" power levels for the .177 460?
Lol, this 460 in .177 makes as much power as my .22 caliber 470TH and 98K, just surprised me a bit...
Thats good power .....
My D460 is giving me around 860fps with JSB 8.44 I guess similar to my hw95 in .177 ... but shes super accurate
Good to see one .177 D460 here : )
Cheers,
Pravin
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Pravin, thanks for reading and the reply. The 460 in 4.5mm/.177 caliber is one of my favorites, doesn't seem very talked about nowadays. Seems you have yours all sorted out :D
Thank you for giving velocity and pellets used. I was having an internal battle on what power level to tune for based on Hector's velocity advice, lol. I figured either 17-18ftlbs with 10.3-10.5 gr pellets or 13-14ftlbs with 8.4-8.6gr pellets. I'm now thinking 13-14ftlbs is the way to go ;D
Take care
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Velocity wise, this 460 has come full circle. I was shooting H&N FTT's (8.6gr) at 770 fps when I detuned, and now I'm shooting JSB Monsters (13.4gr) at 770-775 fps. Lol. I have yet to make any internal adjustment to the gun. Velocity is still about 930 +/- with the Baracuda Hunter 10.49's after several hundred shots.
The 13.4gr pellets (in .177) seem to be straining the power plant a bit, indicated by the feed back from the spring and the lower FPE output, but they are very accurate and predictable in the wind (which there has been plenty of). Normally I would use the JSB monsters in a pcp, but have been impressed with the results in this springer. No target cards to display at this time, but when I read the wind correctly I can hit a 1.25" spinner at 50 yards, and no issues hitting the 2.5" spinner, even with stronger gusts of wind. For fun I strung up a tin just shy of 60 yards and peppered it with holes ;D
Not exactly target work, but very entertaining. When the winds subside I will print some groups to see what's to be had. I still need to dig out the JSB 10.3's to test... eventually ; )
I'm not sure how long the 460's internals will hold up to these heavy pellets, but I have seals and springs on hand if the need arises. Hoping to stretch the range further, but may possibly be asking too much for the .177. Would be fun to do a comparison between .177 and .22 at 75+ yards one of these days.
Thanks for reading, take care.
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Pravin, thanks for reading and the reply. The 460 in 4.5mm/.177 caliber is one of my favorites, doesn't seem very talked about nowadays. Seems you have yours all sorted out :D
Thank you for giving velocity and pellets used. I was having an internal battle on what power level to tune for based on Hector's velocity advice, lol. I figured either 17-18ftlbs with 10.3-10.5 gr pellets or 13-14ftlbs with 8.4-8.6gr pellets. I'm now thinking 13-14ftlbs is the way to go ;D
Take care
Good to know ... D460 is super accurate rifle , some times better than my 95 ... she kicks hard though ;) fun to shoot !!
Keep spare seals I guess rest D460 is built like a tank anyway , don't worry about putting strain on the power plant shes solid built IMO ..
Cheers.
Pravin Dalvi
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Velocity wise, this 460 has come full circle. I was shooting H&N FTT's (8.6gr) at 770 fps when I detuned, and now I'm shooting JSB Monsters (13.4gr) at 770-775 fps. Lol. I have yet to make any internal adjustment to the gun. Velocity is still about 930 +/- with the Baracuda Hunter 10.49's after several hundred shots.
The 13.4gr pellets (in .177) seem to be straining the power plant a bit, indicated by the feed back from the spring and the lower FPE output, but they are very accurate and predictable in the wind (which there has been plenty of). Normally I would use the JSB monsters in a pcp, but have been impressed with the results in this springer. No target cards to display at this time, but when I read the wind correctly I can hit a 1.25" spinner at 50 yards, and no issues hitting the 2.5" spinner, even with stronger gusts of wind. For fun I strung up a tin just shy of 60 yards and peppered it with holes ;D
Not exactly target work, but very entertaining. When the winds subside I will print some groups to see what's to be had. I still need to dig out the JSB 10.3's to test... eventually ; )
I'm not sure how long the 460's internals will hold up to these heavy pellets, but I have seals and springs on hand if the need arises. Hoping to stretch the range further, but may possibly be asking too much for the .177. Would be fun to do a comparison between .177 and .22 at 75+ yards one of these days.
Thanks for reading, take care.
Zack;
If you feel that the spring is telling you the system is being strained, then add a heavy washer at the FRONT end. In front of the top-hat, and test.
Keep us posted!
HM