FT & JSB 13.43's?

[mwgm2020]

I've been looking at the equipment used on FT match reports. I'm seeing a big move to the JSB 13.43's.

Can some tell me why are people moving to the 13.43's?

I'd imagine the drop would be larger especially past 50 yards making ranging more critical at that difficult ranging distance. So, what am I missing about the 13.43's?

Also, are the original 13.43's or the redesigns being used, or a mixture?

 

[Bramezy]

All depends on the gun. Seeing more and more Thomas rifles being used and they exclusively use the 13gr Monsters and a chunck of the Redwolf/Wolverines use the 13gr RDs. I prefer 10gr myself but some people believe weight is better in wind over speed.
I believe you are just seeing more and more high end guns pop up vs people actually switching.

 

[Franklink]

I agree with @Bramezy about the factors he mentions.

In addition to that, pellet choice in competitions is highly batch specific. Sometimes there will be a good batch of a certain pellet, so people start winning with that one, everyone else sees it, and dog piles that pellet, thinking it's the key to success. Ie, sometimes the supposed superiority is only that, supposed. And sometimes it's only a superior pellet as it applies to CURRENT production.

I feel like the big shifts to a certain pellet happen shortly before a HUGE decline in quality of that pellet. Or rather, the demand makes JSB start cranking more out, and quality suffers.

If people are moving to 13.43s, it's because they perceive a benefit. Whether or not there's actually a benefit is the big question.

Which then opens up the can of worms of confidence in ones equipment....if YOU think it's a benefit, and you're convinced of that enough to have more confidence in it, well then it's a benefit to you.

The rubber meets the road in BC comparisons.

 

[Bramezy]

I agree with @Bramezy about the factors he mentions.

In addition to that, pellet choice in competitions is highly batch specific. Sometimes there will be a good batch of a certain pellet, so people start winning with that one, everyone else sees it, and dog piles that pellet, thinking it's the key to success. Ie, sometimes the supposed superiority is only that, supposed. And sometimes it's only a superior pellet as it applies to CURRENT production.

I feel like the big shifts to a certain pellet happen shortly before a HUGE decline in quality of that pellet. Or rather, the demand makes JSB start cranking more out, and quality suffers.

If people are moving to 13.43s, it's because they perceive a benefit. Whether or not there's actually a benefit is the big question.

Which then opens up the can of worms of confidence in ones equipment....if YOU think it's a benefit, and you're convinced of that enough to have more confidence in it, well then it's a benefit to you.

The rubber meets the road in BC comparisons.

Agree completely.

 

[jps2486]

You are still limited to 20 fpe regardless of the power capabilities of your rifle. If you use 13.4 gr pellets, you are limited to 805 fps. 10.3 or 8.4 a lot higher with flatter trajectory. It’s a matter of choice depending on your rifle and your marksmanship skills. Besides, who cares as long as the target falls?

 

[Bramezy]

You are still limited to 20 fpe regardless of the power capabilities of your rifle. If you use 13.4 gr pellets, you are limited to 805 fps. 10.3 or 8.4 a lot higher with flatter trajectory. It’s a matter of choice depending on your rifle and your marksmanship skills. Besides, who cares as long as the target falls?

Its not the ones that fall that make you question your choices its the ones that dont.

 

[cavedweller]

You are still limited to 20 fpe regardless of the power capabilities of your rifle. If you use 13.4 gr pellets, you are limited to 805 fps. 10.3 or 8.4 a lot higher with flatter trajectory. It’s a matter of choice depending on your rifle and your marksmanship skills. Besides, who cares as long as the target falls?

815 fps is still within range but we can bump the 10.3's up to 915 ish and the 10.65's to something close to that.
I shoot the pellet my barrel prefers meaning the least amount of flyers. My Thomas likes the 13.4 exacts, my Redwolf is all about the 13.4 R/D. My Steyr HFT LG110 is a 10.3 kinda rig... My Crosman challenger is a 10.65 Benjamin platform... and the list continues. So much depends on the Indian and the arrow finding each others sweet spot.

 

[JW.]

For me it is whatever pellet is shooting best out of the barrel in question is the preferred pellet.

Max power for 13.43 grains is 818.84fps (20 ft-lbs exactly) and with the 2% velocity 'buffer' you can shot them up to/at 835.22fps and not get disqualified. 13.73 grains is 809.84fps (20) & 826.04fps (2% velocity).

Max power does not mean that these heavy pellets will work best going as fast as they can, its very barrel dependent. I've shot 10.34's at 895 and had them spiral because they were going too fast.

The redesigned Monsters suck out of both of my Thomas rifles.

 

[Raider03]

For me it is whatever pellet is shooting best out of the barrel in question is the preferred pellet.

Max power for 13.43 grains is 818.84fps (20 ft-lbs exactly) and with the 2% velocity 'buffer' you can shot them up to/at 835.22fps and not get disqualified. 13.73 grains is 809.84fps (20) & 826.04fps (2% velocity).

Max power does not mean that these heavy pellets will work best going as fast as they can, its very barrel dependent. I've shot 10.34's at 895 and had them spiral because they were going too fast.

The redesigned Monsters suck out of both of my Thomas rifles.

How do you take the velocity ES into account, subtract half from the +2% velocity limit?

 

[NAProf]

You are still limited to 20 fpe regardless of the power capabilities of your rifle. If you use 13.4 gr pellets, you are limited to 805 fps. 10.3 or 8.4 a lot higher with flatter trajectory. It’s a matter of choice depending on your rifle and your marksmanship skills. Besides, who cares as long as the target falls?

Actually, the formula typically used gives you 820 fps for 20 FPE using the 13.4 gr pellet. In the Grand Prix competitions there is a 2% allowance on velocity to allow for different chronograph types the shooter might have calibrated to and the official one at the match. This means that you could go as high as 836 fps. Though if you shot that over the chrony at a match the Marshal would likely have you shoot several more to make sure your average wasn't above 836.

The reality is that a 10 fps difference in velocity is what most of us would like to get as an ES for a shot string. And it would not make that much difference on your score as the KZ size is such you don't have to hit a 2.5mm x (as in BR target shooting) to knock over the target. Wind holds and ranging are much bigger factors IMHO.

Cheers,
Greg

 

[mwgm2020]

And the increase in holdovers using the 13.4's is one of the things that I am asking about. Hawke Chairgun is calculating more than 0.97" POI drop from 50 to 55 yards using the 13.4's with a 30 yd zero. Whereas 10.43's have a 0.69" drop from 50 to 55 yards. That is a 0.27-inch difference at a difficult distance to range HFT at 16X.

Do the 13's resist the wind that much better that makes it worth it?

 

[AirNGasman]

Assuming equal accuracy, pick your poison. Less wind drift, or flatter trajectory? Logic would dictate it depends on wind conditions.

.

 

[Bramezy]

Assuming equal accuracy, pick your poison. Less wind drift, or flatter trajectory? Logic would dictate it depends on wind conditions.

.

Here comes the issue. Why do you say less wind drift? You say heavier pellet at slower speeds has less wind drift vs lighter and faster?
BC calculators say otherwise. There is a point of where the heavier over takes the lighter with wind resistance but the speeds aren't allowed for the class. Ive been told by people with many successful years of experience in this game that the lighter and faster bucks the wind better. Take all small cartridges for example. a 17hmr at 18grains moving 2,500fps has little drift in low winds, enough you dont have to hold much if any vs a .22lr 40gr going 1,050fps at a closer range has way more wind drift. Lots of discussions on this matter out there and people will argue back and fourth all day but when does the math and science take into account?

 

[JW.]

Here comes the issue. Why do you say less wind drift? You say heavier pellet at slower speeds has less wind drift vs lighter and faster?
BC calculators say otherwise. There is a point of where the heavier over takes the lighter with wind resistance but the speeds aren't allowed for the class. Ive been told by people with many successful years of experience in this game that the lighter and faster bucks the wind better. Take all small cartridges for example. a 17hmr at 18grains moving 2,500fps has little drift in low winds, enough you dont have to hold much if any vs a .22lr 40gr going 1,050fps at a closer range has way more wind drift. Lots of discussions on this matter out there and people will argue back and fourth all day but when does the math and science take into account?

And then there is poly vs traditional rifling and then the number of grooves all of which will impart effect into the shot. Deeper cuts in the pellet allow it to climb or drop in a cross wind. Different rifling changes the BC.

Pellet shape is also a factor, less cross section will tend to not move as much (relatively speaking) as a pellet with a lot of cross section. An easier experiment would be to test a poly against a 12 groove using the same pellets at the same speed.

I'm pretty sure I have less hold off using 13.43's out of a 15" poly than I was using 10.34's out of a 12 groove 24" barrel....and every 20 cal (13.73's) shooter I have spoken with swears that they have less hold off than I currently do (13's in the 15" poly)... Cameron Kerndt being one, Scott Schneider another (not that I agree with everything they say...). I have notes I can check but not on me currently.

 

[JW.]

@Raider03:

I keep my maximum velocity under the 20 ft-lb or 20 ft-lb + 2% velocity. I shoot multiple fills and track my velocity during practice and matches.

Typically I tune to as close to 818 as I can and then if there is some float in hot weather if I tuned during the winter I won't go over the 2% max.

For the Worlds you can't be one fps over the 12 ft-lbs so I tuned to around 715fps (with 10.34's) and monitored the rifle during practice and the first day of the match to make sure I did not go over...

***For some reason I could not quote your post, it would not post my response. What is up with the auto-mod, it COMPLETELY misses full on swear words and then blocks completely harmless posts. And it was my first post of the day so i'm not spamming.***

 

[Bramezy]

And then there is poly vs traditional rifling and then the number of grooves all of which will impart effect into the shot. Deeper cuts in the pellet allow it to climb or drop in a cross wind. Different rifling changes the BC.

Pellet shape is also a factor, less cross section will tend to not move as much (relatively speaking) as a pellet with a lot of cross section. An easier experiment would be to test a poly against a 12 groove using the same pellets at the same speed.

I'm pretty sure I have less hold off using 13.43's out of a 15" poly than I was using 10.34's out of a 12 groove 24" barrel....and every 20 cal (13.73's) shooter I have spoken with swears that they have less hold off than I currently do (13's in the 15" poly)... Cameron Kerndt being one, Scott Schneider another (not that I agree with everything they say...). I have notes I can check but not on me currently.

Thats an area I am not super familiar with, grooves and the affect on the pellet.
Id be interested to see some science on that. Off to google I go when that kind of time allows.

 

[SDstephan]

Why risk getting bounced over a few fps?
I cannot tell any difference how my Thomas shoots between 800 and 815 fps.

 

[Franklink]

Thats an area I am not super familiar with, grooves and the affect on the pellet.
Id be interested to see some science on that. Off to google I go when that kind of time allows.

< 20fpe BC comparison

@Arzrover did some extensive ballistic coefficient testing and posted his results in the projectiles section. https://www.airgunnation.com/threads/difficult-choices.1282745/ Just wanted to share it here since it's so relevant for field target and perhaps some ft diehards only follow the FT...

www.airgunnation.com

 

[Raider03]

@Raider03:

I keep my maximum velocity under the 20 ft-lb or 20 ft-lb + 2% velocity. I shoot multiple fills and track my velocity during practice and matches.

Typically I tune to as close to 818 as I can and then if there is some float in hot weather if I tuned during the winter I won't go over the 2% max.

For the Worlds you can't be one fps over the 12 ft-lbs so I tuned to around 715fps (with 10.34's) and monitored the rifle during practice and the first day of the match to make sure I did not go over...

***For some reason I could not quote your post, it would not post my response. What is up with the auto-mod, it COMPLETELY misses full on swear words and then blocks completely harmless posts. And it was my first post of the day so i'm not spamming.***

Thank you for the info.
My post was held for review by a moderate.
?

 

[humbled.ag]

For a time I was running NSA 15g slugs in hunter class. Because of the shape and weight, they maintained velocity further out. This meant that the rounds dropped slower/shot flatter than you might think. My 55yd holdover was about an inch lower than the Air Arms 10.3. In a comparable wind they had half the hold off of a pellet. It would be nice if they hadn't been banned. Oh well.