New GSC 338 LRH bullets.

[BryanLitz]

It's difficult to make a direct comparison due to the strong velocity dependence.

For the 232, I measured an average G1 BC of .565 from 3000 to 1500 fps.
For the 267, I measured an average G1 BC of .593 from 3000 to 1500 fps.

GS custom's average from 3000 to 1200 fps is .686 for the 232.
GS custom's average from 3600 to 1200 fps is .798 for the 267.

Not a direct apples-to-apples since the speed bands are different, but the trend is clear.

-Bryan

 

[Gerard Schultz]

Hi Bryan,

Please let me know what the speed and the twist rate of the barrel was with which you measured the GSC BC numbers.

 

[BryanLitz]

Hi Gerard,

Both were tested from the same 1:8" twist 338 Win Mag.

The 267's averaged 2608 fps and the 232's were going 2865 fps.

Both had SG's over 2.0 so they were fully stable.

-Bryan

 

[MudRunner2005]

2$ a bullet it's going to be a real turn off for these though.

I didn't think it could get any more ridiculous than the price of CEB's...But I guess I was mistaken...

 

[Gerard Schultz]

MudRunner2005,

GSC is similarly priced to CEB and lower than many other turned bullets. We are even lower in price than North Fork and Swift A Frames. Refresh your browser and have a look at our latest price list and quantity packaging. On top of that, GSC does not charge for the design of a custom application as many other companies do.

We can never be as cheap as cup and core bullets or stamped bullets, but there are advantages to the way we do our bullets that cup and core or stamped bullets cannot match.

Bryan,

That would explain the lower BC. The two bullets that you tested from an 8" twist are designed to be fired from 9" and 10" twists. For an 8" twist in 338, you should be using the 309gr SP bullet. At the distances you are talking, tractability with the 232gr and 267gr SPs will be too strong and the bullet will fall sideways on the going down side of the trajectory. This makes a much bigger hole in the air and BC drops appreciably. We give this information on our technical profile for each bullet.

On the new format page, we also caution against using the BC figures we give for comparison with other manufacturers. Our BC numbers are pretty close to the truth, if they are used as we indicate. No other company gives such detailed technical advice and, once a reloader accepts that GSC does things differently, our technical data is found to be correct. The only way to get closer is by doing drop tables at the location. Using a BC number as 'advertising' is not good and using a BC number for 'comparison' falls in the same ballpark. We do neither.

Also, BC numbers cannot be 'averaged'. The bullet spends much more time at the lower BC when one does long distance work. Averaging multiple BC numbers will skew the final result and giving a single G1 BC number makes no sense in any case.

 

[Edd]

How many bullets do you have to buy to get a custom design?

 

[Gerard Schultz]

One box. That could be 50 bullets or 25, depending on the size of the bullet. You give the details and application and we design the bullet.

 

[Edd]

One box. That could be 50 bullets or 25, depending on the size of the bullet. You give the details and application and we design the bullet.

I'm going to email a reamer print to you. Maybe you could look at the throat and recommend a bullet to me. I would want your HV style bullet. My barrel twist is 9.5". I failed to put that in the email.

 

[Gerard Schultz]

No problem, I will look at the mail and get back to you by Wednesday/Thursday. I am finishing another project and it will take a day or so.

 

[BryanLitz]

Mr Schultz,

You stated:

tractability with the 232gr and 267gr SPs will be too strong and the bullet will fall sideways on the going down side of the trajectory. This makes a much bigger hole in the air and BC drops appreciably.

This is not accurate.

I've tested (measured time of flight over long range) many bullets in various twist rifles. Faster twist produces equal or higher BC's, not lower. They myth of small arms bullets 'failing to trace' comes from high angle artillery fire where the scale and angles are dramatically different.

You can read about these live fire experiments in: Modern Advancements in Long Range Shooting: Volume I

The first part of this book explores many questions related to twist rate including drag in supersonic and transonic flight with extensive instrumented live fire.

There's a great deal of evidence supporting equal or higher BC's for faster twist, even as SG exceeds 2.0, 2.5, 3.0+

On the new format page, we also caution against using the BC figures we give for comparison with other manufacturers. Our BC numbers are pretty close to the truth, if they are used as we indicate. No other company gives such detailed technical advice and, once a reloader accepts that GSC does things differently, our technical data is found to be correct. The only way to get closer is by doing drop tables at the location. Using a BC number as 'advertising' is not good and using a BC number for 'comparison' falls in the same ballpark. We do neither.

I've tested many of your bullets, as well as other solids and conventional bullets using a common method. The results are published in: "Ballistic Performance of Rifle Bullets":
https://store.appliedballisticsllc.com/ProductDetails.asp?ProductCode=0005

You can make meaningful comparisons of BC's which are tested using common methods, and averaged over the same velocity bands. That's what I've done an published in the above reference. Tested BC's of GS Custom bullets fall consistently short of the computer predicted values on your site both as averages, and at specific velocities.

Also, BC numbers cannot be 'averaged'. The bullet spends much more time at the lower BC when one does long distance work. Averaging multiple BC numbers will skew the final result and giving a single G1 BC number makes no sense in any case.

I agree; if you're going to use G1 BC's it's best to piece-wise define them with velocity. Better yet, use a BC referenced to the G7 standard which has less variation with velocity as compared to G1's.

Even still, averaged G1 BC's can be quite useful, if they're averaged for the range you're shooting. And you can compare bullets' performance by comparing their G1 BC's which are averaged over the same velocity range.

-Bryan

 

[tim_w]

GSC bullets, I have used them numerous times and the price compared to others of equal is inline if not better.

Something else people may not know. If you want a new type of bullet created (as long as its a mono) Gerald will make it for you at no added cost to you. You just need to buy a couple boxes or a box. His thought, as he told me is, if someone goes thru the trouble others will likley want it as well and as they make the lower demand ones to order its not as if they lost much in overhead. He made them for us during dev work on the 6.8 spc. He made both the SP and HV class. We had specific needs as we were also restricted by the AR 6.8 mag so the sp in particular had to be within a certain OAL yet we wanted the most aerodynamic we could get. Gerald worked with us and after a few months we had bullets. I will say that if they are coming from SA you need to have patience, otherwise do not bother. If its from one of the USA distr then thats dif. As ours were new designs I dealt directly with Gerald and his daughter who were extremely helpful and excellent CS.

I do think like so many manf which up until recently all used software predictions the BC numbers are inflated. One thought I had based on some of the recovered bullets was that the bands were almost completely worn off smooth from the rifling. My thought for the best way would likley be a progressive/gain twist ending in the twist rate needed. The other effect that faster twist rate should have is to do even a better job of removing the drive bands and thus them being only a minor at best effect on the BC down range.

Again these are a niche bullet and certainly not everyone needs or is willing to pay for them.

I have been thinking about trying out there 6mm SP which have a length of 1.51" so very long and even accounting for the inflated software only BC prediction and thus deducting 20% you will have a 6mm with a BC of around .600 for a 109gr bullet. My experience with them in the past in every caliber I have tried is that they can be driven a significant amount faster than any other bullet design because of such a small bearing surface from the drive bands. Then using a barrel with a twist starting @ 8.5 and ending @ 6- 5.5. It would be a dedicated barrel specifically for those bullets for long range target shooting. My thought was to use it on a savage action thus making it very ease to do switch barrels.

More than anything I am curious to see how it would do and to setup my 2 CED M2 chrono along with drop and get true accurate BC G7 numbers. My guess is with the wildcat base based on the 6.5x284 I can push them to 3400 in a 26-28" barrel still no way even with the shorten case it will feed from a SA mag

 

[azsugarbear]

Great post Tim. How have you found the accuracy of these bullets?

 

[Gerard Schultz]

Mr Litz (Seeing that we have gone all formal )

There's a great deal of evidence supporting equal or higher BC's for faster twist, even as SG exceeds 2.0, 2.5, 3.0+

This is easy to do then: Shoot our 232gr 338 SP bullet in a standard twist 338 (1:10) and see if your measured BC goes up or down.

Tested BC's of GS Custom bullets fall consistently short of the computer predicted values on your site both as averages, and at specific velocities.

That is because you are using the incorrect twist rates and 'average' our BC numbers. Use the numbers as I clearly direct and you will find that they are as close as you can get without shooting actual drop tables.

For example:

The 232 grain SP was advertised about 20% higher than I measured.

For the 232, I measured an average G1 BC of .565 from 3000 to 1500 fps. GS custom's average from 3000 to 1200 fps is .686 for the 232.

With the BC numbers and speeds we give, to properly reference ballistics calculating software, the bullet will spend approximately 0.9065 of a second to get from 3000fps to 2125fps. That is halfway to 1200fps. It then spends another 1.6409 seconds to go the other half, from 2125fps to 1200fps. This is why we say on our website that our BC numbers cannot be used to compare BC numbers to those given by other manufacturers. Above all, the three BC numbers we give cannot be averaged because the result makes no sense. The BC numbers are only given so that software can be dialed in as a starting point.

We tested the 232gr bullet in a 338LM out to 1600m and found that it went subsonic between 1400m and 1500m. This compares very well with the BC numbers on our website but we used them as intended. Incidentally, the 232gr bullet (338232SP) is still on the old data format. We are gradually changing to a new format which is clearer in the information given. Note that we do not 'advertise' BC numbers to gain sales as some other manufacturers do. We simply state the calculated fact.

Better yet, use a BC referenced to the G7 standard which has less variation with velocity as compared to G1's.

I considered that and found that G7 tables did not fit the profile of GSC copper monometal bullets and was not accurate enough.

 

[tim_w]

Great post Tim. How have you found the accuracy of these bullets?

As good as any of the premium match bullets. ON the 6.8 they were in AR-15 but we had numerous .25 groups and that's the best that setup had done with any bullet. ONe thing I do really like about these CNC micro lath turned bullets is on the SP they have a needle point tip and the weight is dead on. I weighed 200 and never had a variance over .001 grain. These were of course a smaller lighter bullet than a .338 so I can not say it would hold to that or if its a % of the total but still it was better than any bullet. Honestly I expect this for a bullet made from high quality copper that is made on a CNClathe machine.

My point is not to be a fan boy as when something is wrong I will call it; anyone that knows me knows this about me. Do not ask if you do not want what I think is the truth.

I lost my BC numbers from my testing of the 99 gr SP 6.8 bullets but they did allow us to keep the bullet super sonic thru 1K from a 18" and sometimes even a 16" barrel but in that is was in the transonic range.

We also worked with Nosler and Barnes to create bullets of the proper weight range and OAL for the 6.8 in the AB and TTSX. The issue being .270 bullets are usually to heavy or long. The ideal for the 6.8 was 95-105 gr. It was the ideal balance for COAL limitations, BC and velocity. It was actually our work with Gerald@ GS that helped us to establishm and test these parameters. Sort tf the catalyze of it all.