Here are some comments regarding questions that have come up across various forums regarding these projectiles.
For those that have asked regarding freebore/chamber/barrel needs due to past experiences:
The goal with these projectiles, specifically the 30c 155 & 175 as well as the 33c 255gr bullet were put into a very specific problem statement:
1) Use existing, common twist rates for the respective caliber.
2) Use existing, common throat geometry wherever conceviably possible
This promotes shooters to "dip their toes" by trying a box or two of the new projectiles and shooting them without the necessity of long lead, expensive items such as special barrels, special chambers, and special powders.
Being a competitive shooter myself I am immediately turned away by new products which have an initial cost that is hugely influenced by ancillary equipment requirements. As such the Flatline bullets do not generally need highly specialized barrels, cases, powders, or chambers to shoot them.
Therefore super long free-bore chambers are generally not necessary for these projectiles. The load listed above for my rifle is being shot from my usual 308 Win reamer that's setup generically for 175gr conventional bullets. Approximately 0.075" of freebore and a 1.5 degree lead half-angle.
Alan cut a couple of reamers specifically to test the validity of making a throating configuration for these 155's and 175's. As always, Alan's work has shot extremely well. Conventional throats and bore sizes have not shown any appreciable differences as compared to specifically tailored chambers.
Obvious caveat to that statement is the 198/200gr 30 caliber 9 twist projectile. It requires a faster-than-common twisted barrel however it is not so fast as to preclude shooters from also using jacketed projectiles in the rifle with high quality results.
Load data in the form of basic starting suggestions will be forth-coming soon. Alan, Dan and myself are putting together a set of recommendations for customers to begin work-up as I type this.
In the mean time, for those that want to get a jump on thinking about these:
1) The weight class of the projectile is not too applicable to powder selection. The general solution for good powders is to pick a rifle propellant that is approximately "1 step faster" than normal for the weight.
IE: 155's are commonly shot from 308's using highly packed cases of Varget. Anywhere from 45-48+ grains. The 155 Flatline was tested with up to 48 grains of Varget from a 30" barrel with speeds being about 100fps slower than we wanted. When switching to H4895 (see my posted load data above) I tested up to 47.5gr of powder without negative pressure signs and got a stellar load at 45.8gr
One of our early testers/customers for the 155's is shooting 47.6gr of H4895 under his bullets and getting fantastic scores with high X-counts. He will be shooting them in the coming week(s) of Camp Perry World Long Range from his 308 Palma rifle. This is the same rifle he has been shooting all week in Long Range at Camp Perry.
Shortly we will post the complete load data (case, load length, case capacity, powder, primer, etc) for each of our beta test loads in various calibers. Shooters are STRONGLY encouraged to work up loads with safety in mind and advised not to jump immediately to high pressure loads as we all know it can be quite dangerous to do so.
As part of the load data we will provide COAL data and information regarding the various freebore lengths for folks to try in their own rifles should they be interested.
These projectiles are a non-expanding type and as such would likely be illegal for hunting applications in most states across the US. I cannot at this time think of a state that allows non-expanding ammunition for hunting but I won't say something like that doesn't exist because I'm far from an expert on all American hunting regulations.
The will certainly retain higher velocity and energy on target but terminal ballistics are not defined by impact velocity and retained energy/momentum alone. Choosing to hunt with these projectiles as extended ranges is purely the choice of the end user due to the non-expanding nature of the projectiles.
As pointed out regarding "Litz" tested projectiles being used for comparison without the same being done for these bullets yet:
Until about 5 days ago these projectiles were generally unknown to Mr. Litz. Perhaps he saw the flyer from SHOT Show but the bullets were not available for purchase until just recently. Therefore he has not yet had an opportunity to test them. I am confident that his attention to detail in testing will be reflected with the same high-fidelity data he has characteristically published for other manufacturers' product lines.
For those curious about the software:
I will not go into details regarding the specific methodologies but the software solution methods are qualified against well characterized results from acoustic data. The data gleaned through my own testing as well as the highly-regarded, high quality work by Mr. Litz is used as a baseline. I regularly see low single digit differences (1-2, sometimes almost 3%) between my acoustics and software. When I compare the software and the acoustics to Mr. Litz's published data the differences are all within the same realm.
A few examples that have been benchmarks in my software were the Hornady 7mm 162 Amax (1.8% error, predicted lower than acoustic verification); the 7mm 180 Berger VLD (predicted 0.8% higher than verified) and the 30 caliber 175 Sierra Match King (predicted 1.3% higher than verified).
As more data is gleaned from 1000yd and beyond (acoustic) testing I am confident that our published data and the tested data will be in close agreement. Myself, Alan and Dan Warner are all in tight agreement that our data fidelity must reflect the high fidelity of manufacturing and product itself. We welcome constructive feedback and are working diligently to support the customers with necessary data for developing loads and ballistic solutions to compete at a higher level than currently can be obtained.
