New #2231 200gr SMK for F/TR

[Ilya S.]

Heres a little seating depth test from this morning. 600 yards.

any rounds from touching to 0.012 off, shoot bugholes on 100y ?

 

[Jdne5b]

any rounds from touching to 0.012 off, shoot bugholes on 100y ?

I dont test at 100 but here was a .005 off group in a 15mph wind @ 25°F @ 200yds.

 

[Zero333]

Judging by Jdne5b's pictures of the seated bullets and his 0.170"+0.010"ish freebore... One would want somewhere around 0.110" freebore for these new 200 SMK's.
They would probably work good in a 0.090" freebore too.

I have a 308win barrel with 0.075" freebore and if I see a box of these bullets in a store I'll try them.

 

[jsthntn247]

Judging by Jdne5b's pictures of the seated bullets and his 0.170"+0.010"ish freebore... One would want somewhere around 0.110" freebore for these new 200 SMK's.
They would probably work good in a 0.090" freebore too.

I have a 308win barrel with 0.075" freebore and if I see a box of these bullets in a store I'll try them.

I was thinking a .110 freebore would be optimal as well. My smith just happens to have one also :0 Where are yall finding these in stock?

 

[memilanuk]

Rather than getting a whole new barrel spun up, with a whole new chamber... I wonder if using the Berger VLD seating depth test - i.e. checking the jump 40 thou at a time - and just jumping them more would be a viable option?

 

[paulT]

Yes, more weight forward from where the ogive starts.

A given weight bullet made longer requires its bearing surface be shorter. That extra length has to get metal from some place. Longer bullets need faster twists.

Bart whats your view with the Warner 180g Flat liner bullet at over 1.6 inches in Length and requiring a 1 in 10 or faster twist rate to stablize in .308 is it down to its lighter weight that it doesnt require a faster twist in comparison to the new 200g sierra bullet.

 

[Ned Ludd]

Bart whats your view with the Warner 180g Flat liner bullet at over 1.6 inches in Length and requiring a 1 in 10 or faster twist rate to stablize in .308 is it down to its lighter weight that it doesnt require a faster twist in comparison to the new 200g sierra bullet.

Don't kid yourself, the 180 FLs DO require a faster twist rate than 10 in order to achieve their full intrinsic BC. Minimum "suggested" twist rates by the manufacturer are not always sufficient to net you all the intrinsic BC of a specific bullet, even though the bullet might make it to the target just fine. A twist rate that will give you an Sg of anywhere from above 1.1 to about 1.4 will "stabilize" the bullet sufficiently to reach the target without key-holing in most cases. However, you will be giving up a certain amount of the intrinsic BC of the bullet due to excessive yaw/pitch as it exits the bore. Just because a bullet is stable all the way to the target doesn't mean you're getting everything possible out of it in terms of BC and resistance to wind deflection.

The longer a bullet is, the faster it will generally need to be spun in order to achieve gyroscopic stability. That means increasing bullet length at a given weight will require a faster twist rate to achieve the same stability as for a shorter bullet of the exact same weight. However, manufacturers may not want to list a minimum twist rate for a given bullet that is so fast that almost no one is likely to already have such a barrel spun up for their bullet. If shooting a new bullet required every end user to buy a new fast-twist barrel and have it chambered, sales could easily be negatively impacted. It's analogous to advertising high velocity band G1 BC values, which makes the BC seem higher in comparison to competitor's products. This type of advertising approach has been in use since advertising began. There is nothing particularly nefarious about this; companies are in business to make a profit, which requires selling their product. In order to do that, they will advertise in a way they feel puts the best "spin" (pun intended) on their product to increase sales. So, a manufacturer might advertise the high velocity band G1 BC, or a list slightly slower and more commonly-used twist rate sufficient to stabilize a given bullet, even though it might not be fast enough to net the full intrinsic BC of the bullet. If the end user is only shooting them out to a few hundred yards, they might never notice the difference. But at 600 to 1000 yd, the difference is noticeable, particularly when shooting them in competition over a long period of time. Ultimately, it is up to the end user to be aware of these facts and determine for themselves the difference (if any) required in their setup for "satisfactory" versus "optimal" performance.

FWIW - a 10-twist is not enough to produce an Sg of 1.5 (or greater) with the 180 FL bullet, not even close. They'll make it to the target just fine from a 10-twist; i.e. it is not so slow a twist as to render them gyroscopically unstable. However, you may be giving up a significant amount of the intrinsic BC, and therefore wind resistance. What is the point of spending the kind of money those bullets cost, and then throwing away performance? In F-Class competition, even a single point or "X" can decide the match. No one in their right mind gives away performance (or points) needlessly. In contrast, in other types of shooting, the amount of BC given up by using a slightly slow twist barrel may not be noticed as much as long as the accuracy/precision remained satisfactory.

The FL bullets are exceedingly long for at least a couple reasons. First they are made of a material not nearly as dense on average as a lead core bullet. Therefore, they need to be longer than a lead core bullet of the same weight, unless they had been designed with a ridiculously long bearing surface, which might defeat the purpose of improving BC, as well as introduce other unwanted issues. The 2nd reason they're so long is because lengthening (and pointing) the nose is probably the simplest way to increase BC. I don't think anyone would argue that the FL bullets are extremely long and pointy relative comparably-weighted lead core bullets. They are so pointy, in fact, you really have to be careful when working with them; it is very easy to get your fingertips jabbed because the points are so sharp. In any event, the twist rate necessary to achieve an Sg of 1.5 or better from a 180 FL bullet is fully in accordance with their shape and sectional density; there is nothing "unusual" about their required twist rates relative to lead core bullet of comparable weight.

 

[Trevor60]

I dont test at 100 but here was a .005 off group in a 15mph wind @ 25°F @ 200yds.

You have peaked my interest in this bullet (i have a 9t) and i will be looking to test a box or a dozen.
thanks for sharing
have you tried jamming; starting with .24thous and working backwards in 3thous increments


All the best
Trevor

 

[Bart B.]

Bart whats your view with the Warner 180g Flat liner bullet at over 1.6 inches in Length and requiring a 1 in 10 or faster twist rate to stablize in .308 is it down to its lighter weight that it doesnt require a faster twist in comparison to the new 200g sierra bullet.

While that bullet will leave at 2600 to 2700 fps from 308's, it's length will need a 9 inch twist, maybe an 8.5.

Sierra 30 caliber 240 grain HPMK (1.6" long) needs a 1:8 twist leaving at 2200 fps from 28" long 308 Win barrels.

 

[swc123]

Maybe its time for the International F-TR community to revisit the idea of placing a cap on the bullet weight allowed.........

 

[Ned Ludd]

Maybe its time for the International F-TR community to revisit the idea of placing a cap on the bullet weight allowed.........

No, it isn't.

 

[paulT]

Don't kid yourself, the 180 FLs DO require a faster twist rate than 10 in order to achieve their full intrinsic BC. Minimum "suggested" twist rates by the manufacturer are not always sufficient to net you all the intrinsic BC of a specific bullet, even though the bullet might make it to the target just fine. A twist rate that will give you an Sg of anywhere from above 1.1 to about 1.4 will "stabilize" the bullet sufficiently to reach the target without key-holing in most cases. However, you will be giving up a certain amount of the intrinsic BC of the bullet due to excessive yaw/pitch as it exits the bore. Just because a bullet is stable all the way to the target doesn't mean you're getting everything possible out of it in terms of BC and resistance to wind deflection.

The longer a bullet is, the faster it will generally need to be spun in order to achieve gyroscopic stability. That means increasing bullet length at a given weight will require a faster twist rate to achieve the same stability as for a shorter bullet of the exact same weight. However, manufacturers may not want to list a minimum twist rate for a given bullet that is so fast that almost no one is likely to already have such a barrel spun up for their bullet. If shooting a new bullet required every end user to buy a new fast-twist barrel and have it chambered, sales could easily be negatively impacted. It's analogous to advertising high velocity band G1 BC values, which makes the BC seem higher in comparison to competitor's products. This type of advertising approach has been in use since advertising began. There is nothing particularly nefarious about this; companies are in business to make a profit, which requires selling their product. In order to do that, they will advertise in a way they feel puts the best "spin" (pun intended) on their product to increase sales. So, a manufacturer might advertise the high velocity band G1 BC, or a list slightly slower and more commonly-used twist rate sufficient to stabilize a given bullet, even though it might not be fast enough to net the full intrinsic BC of the bullet. If the end user is only shooting them out to a few hundred yards, they might never notice the difference. But at 600 to 1000 yd, the difference is noticeable, particularly when shooting them in competition over a long period of time. Ultimately, it is up to the end user to be aware of these facts and determine for themselves the difference (if any) required in their setup for "satisfactory" versus "optimal" performance.

FWIW - a 10-twist is not enough to produce an Sg of 1.5 (or greater) with the 180 FL bullet, not even close. They'll make it to the target just fine from a 10-twist; i.e. it is not so slow a twist as to render them gyroscopically unstable. However, you may be giving up a significant amount of the intrinsic BC, and therefore wind resistance. What is the point of spending the kind of money those bullets cost, and then throwing away performance? In F-Class competition, even a single point or "X" can decide the match. No one in their right mind gives away performance (or points) needlessly. In contrast, in other types of shooting, the amount of BC given up by using a slightly slow twist barrel may not be noticed as much as long as the accuracy/precision remained satisfactory.

The FL bullets are exceedingly long for at least a couple reasons. First they are made of a material not nearly as dense on average as a lead core bullet. Therefore, they need to be longer than a lead core bullet of the same weight, unless they had been designed with a ridiculously long bearing surface, which might defeat the purpose of improving BC, as well as introduce other unwanted issues. The 2nd reason they're so long is because lengthening (and pointing) the nose is probably the simplest way to increase BC. I don't think anyone would argue that the FL bullets are extremely long and pointy relative comparably-weighted lead core bullets. They are so pointy, in fact, you really have to be careful when working with them; it is very easy to get your fingertips jabbed because the points are so sharp. In any event, the twist rate necessary to achieve an Sg of 1.5 or better from a 180 FL bullet is fully in accordance with their shape and sectional density; there is nothing "unusual" about their required twist rates relative to lead core bullet of comparable weight.

Thanks for your detailed post gstaylorg.

 

[paulT]

While that bullet will leave at 2600 to 2700 fps from 308's, it's length will need a 9 inch twist, maybe an 8.5.

Sierra 30 caliber 240 grain HPMK (1.6" long) needs a 1:8 twist leaving at 2200 fps from 28" long 308 Win barrels.

Bart I believe with .308 the 180 fl could easily be spun at 2800-2900fps with Longer 30-32in barrels throated Long for more case capacity even with 1 in 9.5 -1 in 10 barrels i guess shooting at higher Altitude than sea levels will play its part in helping keep bullet stability & accuracy for long range reasonable with a 1 in 9.5 and 10 twist barrels.

 

[dcali]

Maybe its time for the International F-TR community to revisit the idea of placing a cap on the bullet weight allowed.........

Although this wouldn't bother me in the least, we'd miss out on all the good bullets coming out if manufacturers could just hone in on one specific weight. What fun is that?

More seriously, the .308 case limits the weight pretty well in practice, as we're finding out.

 

[Laurie]

Maybe its time for the International F-TR community to revisit the idea of placing a cap on the bullet weight allowed.........

Lines of thought like this are generally found among those who believe in so-called level playing fields for ammunition quality. GB and British Commonwealth 'Target Rifle' (our version of Fullbore sling shooting with the 308 and iron sights) long took this view, going further and banning handloads for all major competitions and competitors were issued with arsenal manufactured 7.62 ammunition. The GB NRA Journal regularly saw the pros and cons argued over - allowing more freedom would remove this fictional level playing field, those with time and money and expertise to experiment with handloads and different bullets would be given an unfair advantage etc etc.

In the end, such restrictions nearly killed the discipline. There never will be a level playing field other than in having a good set of overall regulations on things like rifle weights. Those with money who really want to buy a small advantage in a restricted discipline will have several rifles each with a slightly different spec barrel to try with different batches of issue ammo, or produce a few extra fps MV. If you're wealthy (or retired and comfortable) and don't need to go to work every weekday, you can practice on a major range like Bisley seven days per week and get to know every wind flag's displays intimately. It still won't make up for a skill shortage though if that exists.

When F-Class spun the restricted FTR sub class off, the whole argument started again with the proponents of tighter regulation claiming it was a budget 'starter' discipline and that the rapid development of FTR equipment and cartridges that has continued unabated almost from year one has been a disaster with 'pounds buying points'. Such critics want to see major restrictions on ammunition, bipod footprints, scope power, even the rifle having to be based on a factory model.

There is a reasonable argument for having such a discipline. The Scandinavian countries use a single rifle model, the SIG-Sauer STR 200 for their major internal and international prone sling competitions. It is a superb rifle and being a factory model is low priced compared to custom built F rifles. It has a quick-change barrel system allowing pre-chambered replacements to be fitted with perfect headspace in a few minutes or to switch between the two cartridges used, 308 Win and 6.5X55mm.

That isn't F-Class though which quickly became like formula motor racing, a development discipline whether in FTR or 'Open'. Ten years ago none of us saw how far and fast the 308 (or 223 for that matter) would be developed. Without FTR, there would be a lot fewer bullets and they'd have a lot lower BCs. Much as I love Sierra and its traditional 7-calbre radius tangent ogive bullets, development of both more advanced designs and improvements in QC were 'gentle' and took place over decades rather than single years. Without FTR, it's arguable if there would be nearly as many 0.308 match bullets as there are now, nothing like the weight range, nor would everybody's manufacturing quality be so good. Just compare the two 200gn Sierra MKs - the one that has been around for 30 (40?) plus years and the just announced new 200.

One can approve of this process or decry rapid if expensive development. But .... like it or not, target shooting is a technically orientated sport like many others. Here in the UK, international gold medals in the Olympics and other major competitions by British cyclists have produced a huge surge in interest in the sport and created no end of jobs in bicycle design, manufacturing and retail. Have you looked at a modern pushbike recently? The costs and high technology materials and design in what are (like firearms) relatively simple machines at a basic level are staggering. And it's not just those that compete at high level who're splashing out large sums either - even commuter bikes have gone high-tech. I don't hear anybody say that road-racing cyclists should be limited to steel frames and wheel rims with traditional wire spokes - or maybe if you're inside that sport, the same calls for restrictions apply. Like it or loathe it, if your sport relies on manufactured equipment with a potential for technical and materials development, those upgrades are going to happen and they usually don't come cheap, certainly never for free.

 

[titch--]

Judging by Jdne5b's pictures of the seated bullets and his 0.170"+0.010"ish freebore... One would want somewhere around 0.110" freebore for these new 200 SMK's.
They would probably work good in a 0.090" freebore too.

I have a 308win barrel with 0.075" freebore and if I see a box of these bullets in a store I'll try them.

Just wondering if you have found a box of these yet?

 

[B23]

FYI, anyone is looking to purchase some of these new SMK's they have them for sale on the Sierra website. I received my 200 SMK's last week and their new 230 SMK will be here today.

If anyone cares, the length of the 200 is 1.591 and the bearing surface length is .335.

 

[Ilya S.]

Its time to 8-9 twist barrels for modern FTR rifle ?

 

[Zero333]

Just wondering if you have found a box of these yet?

No sir. I'm not really looking either. It's just that if I see a box at a gun store when I'm there, I'll get it to try.

 

[dcali]

I’m concerned that by the time you spin up some of these needle bullets the accuracy just won’t be f class level, especially at 600. just because you can make a bullet longer and higher BC doesn’t mean you should. I’m not sure if we’ve hit that limit yet but we’ve got to be close.