Tuning Uragan .25 - 33.95 pellet (and slug) speed questions

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my87csx481

my87csx481

Member
Jun 6, 2019
387
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Fort Fairfield, ME, United States
My goal is accuracy and precision at 100 yards. I've currently got it tuned to 882 FPS with 33.95 gr pellets (it maxed at 895 at current reg pressure, then I backed off on HS to get to 880ish).

Without disturbing my pellet tune (whatever my pellet tune ends up at), I'd like to shoot the heaviest slug I can, at an appropriate speed for that slug.



I understand every barrel is different. So I ask in general terms: 

How hot should I send 33.95 gr JSB pellets? Or am I already too hot for these? They're nearly hole in hole at 30 yards. They open up quite a bit at 75 yards, but it's windy, and I'm still learning how to shoot, and I don't have any indicators for wind speeds set up yet.

At the same settings....30 gr ZAN's are at 895ish. 33 ZAN's are at 864ish. Maybe I should try a lighter slug (to get the speed up)?

Or stick with the 30's or 33's and run the pellets hotter?

Or can 865 to 895 be fast enough for slugs?

Thanks for any suggestions. Feel free to straighten me out and tell me that my expectations are out of line, and that I need to tune for one specific projectile. (Unfortunately, I don't have the experience to know any better right now.)
 
Thanks all that responded.



Find the best accuracy out of all the Slugs, 

I stick with the JSB MKll's, they are the most accurate projectile my Uragan shoots out to 160 yards.
Click to expand...

How fast are you pushing them?



@scotty1 UA had them at some point (I have some that I ordered about 5 months ago). But I think they're mislabeled. My MKII's and non-MKII's are the same length. But I don't know which ones are correct. Maybe my non-MKII's are mislabeled.

I'm derailing my own thread....how long are the MKII's expected to be? And the regular non-MKII?
 
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The difference between MK2 and non-MK2 is a depth and thickness of the skirt, so that translates to a front balancing of center of gravity.

So far I had no chance to shoot both these pellets in a closed tunnel/hall where there is no wind effecting the flight. But I shoot them outdoors in a mixed forested gun range and so far I have a feel that the non-MK2's groups tighter with a same setting on a gun (FX Impact MK2), @ 880 fps.

Jumping to slugs that means jump up to 960+ fps me personally I had to do some changes with internal parts. When I finished the upgrades I am happy with a slugs performance.

But again soon I realized, that my Impact cannot shoot slugs 960+ fps and pellets 880- fps with just turning the hammer spring tension up or down, I need to open the gun and replace that spring. So I have a decision to make .... that gun will be a dedicated slug gun or pellet gun, but cannot do both.


 
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I am not sure you are going to get better accuracy with slugs at 100 yds with the Uragan 25.

I have tried many sizes and weights with mine, but none have been as accurate as both 25 and 33 gr JSBs.

One of the issues is that adjustments are limited to the hammer adj only as the reg pressure is just way to difficult to adj for tuning, and that can get it out of balance.

I think the only advantage of slugs is they do tend to be better at bucking the wind, but I honestly do not think they are worth the expense of having to try so many weights and diameters and velocity adjusting.

I have accumulated a crap pile of slugs in 22 and 25 and most always find pellets better.

Just my 2 cents worth and bth I love my Uragan 25!


 
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@bighun I'm sorry. I thought I read somewhere that the MKII's were made so they would fit in narrower (FX?) magazines. Which led me to believe they were supposed to be shorter. Maybe I am mistaken, and not remembering accurately???? I'll check the skirts, and under the skirts again ;)

Thanks @KatoKevin454 for the speed.

@bravo1956 - Taking out the reg wasn't too difficult to do. But without a reg tester, setting the pressure is a bit of a guessing game. But adjustment and tuning is doable. Just not as conveniently as an externally adjustable reg. I had to adjust mine for higher pressure to push the 33.95's. They were around 848 with the as-delivered settings. There's a thread on here. Somewhere in the thread are pics and explanations about how to adjust the reg. (thanks to all the contributors in that thread: https://www.airgunnation.com/topic/uragan-on-the-way/)
 
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@my87csx481 - I have seen the post on Uragan reg adjustments, but I think even taking the Uragan apart is a pain in the butt, let alone disconnecting the feed tube, and then guessing where the reg pressure is and then doing it again if not what you want.

I am just referring to tuning with the relationship between reg pressure and hammer spring tension.

Without a reg gauge and the long process of disassembly required to adjust the reg, it is not very practical to consider the Uragan easily tunable. It of course can be done, and maybe worth it if you found a tune that accomplishes your goal, maybe slugs, and then leave it as a slug gun, but as I said I have always had better accuracy with pellets.

Now that is also considering that I have a Dreamline that is just so easy to adjust everything.




 
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I think I was unclear with my original goal/questions.

In an attempt to restate my goal: I don't want to adjust the tune every time I change projectiles. I want to get the best (accuracy and precision) tune I can get for the 33.95 pellets, and then find a light enough slug that will get to 930ish, and still be accurate and have a good enough BC to buck the wind better than the pellets.

I have a plan for my next round of testing.
 
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Can't speak to the Uragan, but in my .25 Maverick, I can drive the 36.2 Nielsen's at 990 fps, and then dial down the hammer to send the 33.95 JSBs at either 950 or 930 fps, both are very accurate, with a slight edge to the 930 fps in accuracy. My philosophy with tuning for slugs and pellets is to tune first for the slug and dial down the hammer for the pellets. Slugs are much more challenging to get the tune right than pellets, so tune for the slugs first. The 33.95s in particular are very forgiving pellets. I have had them work in various guns from 850-950 fps.
 
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