22 December 2014, 01:28
RIP.408/335-grain HV, New GSC "Custom" Bullet
Not just a new varmint bullet for the .408 Chey-Tac sporter ...
The NEWLY DEVELOPED GSC .408/335-grain HV will make for a 400 Bateleur wildcat (.408/.338 Lapua Magnum)
that will easily fit into a 3.600" magazine box length,
as well as .408 Chey-Tac loads that will easily work through the 4.0" box of the MRC PH.
Bullet nose on this one is only about 0.700" long.
The .408/385-grain FN will also work through the magazine boxes of both.

http://www.gscustomusa.com/
The previous trio of 370-grain HV, and 385-grain FN and SP for the .408 Chey-Tac:
22 December 2014, 04:10
RIP335-grainer predicted max velocity for the .408 Chey-Tac sporter with 24" barrel is 3150 fps, or with 26" barrel about 3220 fps.
Lots of interesting load data here:
http://www.gsgroup.co.za/hvloads.htmlThanks, Gerard and Gina.

27 December 2014, 19:14
GerardHi RIP,
It is our pleasure, custom is what we do frequently. I have learned that for every person that asks, there are many who would use it, but do not ask.
28 December 2014, 11:24
RIPThe GSC load data page says 1:16" twist is sufficient for the .408/335-grain HV.
Thus another potential use for this "custom" bullet,
for anyone wishing to modernize a BPCR,
and not afraid of going to hell for such sacrilege:
Consider the Pedersoli "Silhouette" Sharps rifle chambered for .40-65 Winchester with .408" groove diameter and 1:16" twist:
28 December 2014, 18:49
GerardOuch! I just noticed that the phone number is wrong in two places on the package insert RIP posted above. The area code is 269 and not 296 - I will get that fixed today.
02 January 2015, 11:49
RIP http://www.gscustomusa.com/408335HV303.html408335HV303 Technical Profile © Application: General Hunting
Barrel Bore Diameter: 0.401" 10.185 mm The diameter of the barrel from land to land.
Barrel Groove Diameter: 0.408" 10.362 mm The diameter of the barrel from groove to groove.
Bullet Weight: 335gr 21.7g Bullets are guaranteed to weigh within 0.25% of the stated weight.
Bullet Length: 1.56" 39.500 mm
Secant Ogive Length: 0.65" 16.445 mm These dimensions are critical to consistent external ballistic performance and are held constant to within 0.005 mm (0.0002")
Meplat Diameter: 0.11" 2.700 mm
Min Bullet Protrusion: 0.73" 18.420 mm Add the case length to these numbers to determine the maximum and minimum cartridge overall length that is possible with this bullet.
Max Bullet Protrusion: 1.06" 27.000 mm
Bullet conforms to CIP and SAAMI for magazine length. Check the magazine length of your rifle for suitability with this bullet.
Maximum M/V: 3150fps 960 m/s If the maximum muzzle speed is exceeded, dynamic stabilty problems may be encountered.
Short Range Twist: 15.0" / 381 mm or tighter 37.5 Cal/length or tighter Twist recommended if average hunting distances are 200 yards or 190 m. A tighter twist can be used.
Twist: Sg = 1.5: 16.0" / 402 mm 39.5 Cal. in length General hunting twist for average distances to 410 yards or 380 m. A tighter twist can be used.
Minimum Twist: 18" / 457.2 mm 44.9 Calibers in length The twist required for stable flight and good terminal performance further than 410 yds or 380 m.
Minimum Impact Speed: 1600fps 488 m/s At this impact speed, the bullet will open to at least double caliber.
Calculated Ballistic Coefficient - G1 profile
BC = 0.434 3150 fps to 2375 fps 960 m/s to 724 m/s BC values are calculated at standard Metro values and serve as a comparison between GSC bullets. Any comparison with the BC values of other manufacturers is not valid as there is currently no standard method in use between manufacturers.
BC = 0.423 2375 fps to 1600 fps 724 m/s to 488 m/s
BC = 0.417 1600 fps to 0 fps 488 m/s to 0 m/s
Suitable Cartridges, with consideration of the above specifications:
.408" calibers
NOTES
A Gyroscopic Stability (Sg) greater than 1.1 is required for stable flight with HV and HP bullets. For hunting at average 410yds/380m, an Sg of up to 1.5 or more can be used. For longer distances the Sg can be decreased but never less than 1.1.
*Note that Sg increases as twist tightens. *A 1:10" twist is tighter than a 1:12" twist within a given caliber only. *Twist rates given in caliber lengths can be compared across calibers. *Choose a bullet length best suited to your rifle twist and type of shooting. *When a bullet is specified for a given twist rate, it can also be used in any twist that is tighter. Using it in a slower twist than specified, is not advisable. *Some experimentation will be required to determine exact drop tables for your equipment and location.
24" barrel velocities:
3150 fps with .408 Chey-Tac
2750 fps with 400 Bateleur
02 January 2015, 23:20
Cold Trigger FingerThat would be the ticket for a problem bear that couldn't be got up close to. !!