STX TWIST RATES

[huntjunky]

Wanted to ask here (too lazy to do the research), does anyone know the comparative twist rates for an Impact .25 STX default pellet liner as opposed to the proposed slug liner? I assume there is no difference for the 600mm relative to the 700mm. If not, how about the same question for the .22 caliber? And for you FX Gurus, what about the 30 caliber? Anyone...anyone....

 

[Gunny994]

.25 STX 

pellet liner A 1:30

pellet liner B ?

slug liner A?

does that help?  

i would also like to know, I haven’t been able find any info.

 

[Bob_O]

For the 22, I thinks it's 1:21 for the pellet liner and 1:16 for the slug liner. I'll know for sure next week when my slug liner comes in. I'll pull both liners and measure.

 

[STO]

For the 22, I thinks it's 1:21 for the pellet liner and 1:16 for the slug liner. I'll know for sure next week when my slug liner comes in. I'll pull both liners and measure.

This is good info to have. You're the man for getting and sharing it. I wish it were just published on product listings, as it is significant. 



*edit* It says I have to spread the love, and can't give you another +1 so...... 

 

[huntjunky]

Wouldn't it be interesting if the slug liner shot pellets as well or better than the stock pellet liner? Discounting the variation in chokes, a faster twist rate might play favorably into the barrel harmonics and pellet stability unless it's too stable, at longer ranges, and doesn't follow trajectory. 

 

[mtnGhost]

Wouldn't it be interesting if the slug liner shot pellets as well or better than the stock pellet liner?

I sure hope so - I'm planning to tune for 23gr NSAs, and I'd be very happy to find pellets that are compatible with that tune without much adjustments.

 

[AirSupply]

I 

This is taken from one of Matt’s videos If the spin rate is the same when he’s shooting these pellets at 950fps the twist rate isn’t going to be 1:16

It will be very similar to the pellet line in my opinion

 

[Bob_O]

I think "most pellet barrels" might be referring to Lothar Walther and not FX. For instance, the twist rate on my Ultimate Sporter was 1:17.

 

[Dairyboy]

The .22 slug liners are the same as the pellet liners according to this thread, twist wise that is. Around 1:20ish and a hair looser

https://www.airgunnation.com/topic/early-impact-22-slug-liner-report/

 

[Bob_O]

It's possible that the latest slug liners have a faster twist rate, I'll know this coming Tuesday evening.

Matt did initial slug liner testing at the FX factory early on as you may know, but he also went back recently for more testing. So maybe there was a change, which I wouldn't be surprised being this second batch of slugs liners took so long to get here.

Also, Air Hunters have been doing lots of testing as well. One thing I've noticed is they always shoot for 930 to 950fps regardless of slug weight. Their latest results are with the Crown 600mm shooting 23gr NSA slugs at 915fps. That's as fast as they can get it going through the Crown.

They've also got the slugs shooting under 1" at 100yds in continued testing. I wouldn't be surprised at all if FX is getting field reports from them. I'll check with Roelf to see if he can tell me what twist rate his slug liners are.

 

[Bob_O]

1:18 twist rate for the 600mm 22 caliber slug liner.

 

[Bob_O]

1:16 twist rate for the 700mm 22 caliber slug liner.

 

[mtnGhost]

Edit: duplicate

 

[mtnGhost]

My slug liner arrives today, I'll measure the rate and share the results.

 

[AirHunters]

Thanks Bob. Yes, 1:18 for the 600mm .22 liner and 1:16 for the 700mm .22 liner. The 600mm is designed and tested for the 23gr NSA Slug at 930fps and the 700mm for the 26gr NSA Slug at 930fps. Although both do fine up to 950fps with the groups opening up ever so slightly. Roelf

 

[mtnGhost]

Thanks Bob. Yes, 1:18 for the 600mm .22 liner and 1:16 for the 700mm .22 liner. The 600mm is designed and tested for the 23gr NSA Slug at 930fps and the 700mm for the 26gr NSA Slug at 930fps. Although both do fine up to 950fps with the groups opening up ever so slightly. Roelf

.218 I'm guessing? I had ordered those and .217 and hadn't seen where Nielsen said Impact customers were reporting better success with .218. Do have any idea if the .217's are shootable? 

 

[AR]

Thanks Bob. Yes, 1:18 for the 600mm .22 liner and 1:16 for the 700mm .22 liner. The 600mm is designed and tested for the 23gr NSA Slug at 930fps and the 700mm for the 26gr NSA Slug at 930fps. Although both do fine up to 950fps with the groups opening up ever so slightly. Roelf

What if one would like to shoot 21gr with the 600mm and 23gr with the 700mm is that possible? 

 

[Bob_O]

Your question is probably not directed to me but I'll offer my take on it.

Matt and the Air Hunters no doubt have tried most, if not every, sensible combination of slug weights, barrel lengths and velocity.

Twist rates were probably developed around the weights that performed the best during testing.

That's not to say that you are limited to only shooting that specific weight at that velocity. You might find a combination of other weights and velocities that work well enough.

I have a few hundred 19 and 21gr slugs, as well as some recently ordered 23gr slugs. You can bet I'll try the lighter slugs as opposed to throwing them away. Maybe they'll be decent for close to mid-range targets.....who knows.

But consider that in 22 caliber, the lighter slugs are very short, which probably isn't advantageous no matter how you look at it.

 

[AR]

Ok thanks Bob 

 

[huntjunky]

Thanks for checking with Roelf, Bob. I'll make note of weights vs twist vs length vs slug diameter. I'm actually interest in .25 & .30 but this info can be interpolated for basic principles. I'll go measure twist rate on pellet liner for my .25/700 mm, as this is still vague based on information here. I'll report back. Thanks to all member's for your help.