UPDATE: Corsair+ 7mm (part 1)

I know its been a while but finally got out for a quick shooting session this past Monday with the Corsair+ 7mm.

BARREL/MOLD DRAMA:  To this day, I have bought and installed a TJ barrel liner with 1-14" and one with a 1-10" twist.  This first video I made on the completed gun was with the 14" twist barrel.  You can see the video here:  https://www.youtube.com/watch?v=Lct_L6BtRdE&list=UUDBsDGN9infjfprvoHuqE6w  The performance with the 14" twist was really good and showed promise but at the time, i owned LESS than STELLAR bullet molds from LEE and I knew groups could be better.  I also had a LBT mold on order while I tested the 14" twist barrel.  When I finally got the LBT mold, I discovered that the 14" twist barrel was too big with a bore diameter of .2853".  And 7mm should be .284".  Unfortunately, when I ordered the LBT mold, I ordered it at .285" not currently knowing the TJ's barrel in 14" twist would be too big.  PHWEW!  HOPE THIS MAKES SINCE.  So now, I order a 10" twist TJ's barrel and upon receiving it, the barrels bore MIC's at .2833" which is not pretty tight.  Again, 7mm is .284.  But in this case, tighter is better.  When the barrel was machined and installed, Doug Noble and I noticed that the gun dropped some major speed.  Why you ask?  The faster the twist, the more the friction on the bullet as its pushed forward.  The slower the twist, the faster a projectile can move down the bore.  This phenomenon really rears its ugly head with airguns.  Remember, unlike a PB gun, we don't work off of upwards of 40,000-60,000 psi.  This gun works off of 3600 psi OPTIMALLY!  And when the 1-10 twist is installed, the Corsair lost about 60 FPS.  Doug made me one hell of a nice custom sizer at .2836" but I was not happy with the performance of the 10" twist barrel OVERALL.  Not only was the speed down but the overall accuracy seemed to be OK to me.  Lastly for the 1-10" twist, i bought a NOE mold in 7mm and it's called the THOR bullet.  This bullet has a very wide MEPLAT and once tested, AGAIN, I was less than happy with the barrel/bullet combos. So now, because I have too much free time on my hands, I decide to RE-INSTALL the 14" twist barrel and to re-order a new LBT mold but this time, I would order it at size .287" so I am only sizing down a thousandths and a half (so to speak...lol).

So this brings us to now.  With the new LBT mold on its way and the 7mm TJ Liner with 1-14" twist barrel installed, I cast up more THOR bullets and I head out for a quick shooting session.  It became readily apparent that the 14" twist was a better overall performer in 7mm ON THIS PLATFORM (corsair+).  I actually shot a decent 1.5" 100 yard group with those bullets and I couldn't get anywhere near that with the 10" twist.  After going to South Carolina and hunting/shooting with RJ Porter, it was apparent that the 14" twist barrel was the way to go.  Not just because I killed a pig with it that weekend...lol!  I was ringing steel plates out to 135 yards consistently with this barrel and the THOR bullets DESPITE THE FACT THAT I SAW "SPIRALING" OF THE THOR BULLETS ON VIDEO.  I could not wait till the newer LBT came in due to its lower weight and shorter length which should improve the spiraling therefore accuracy (more on that later).   So now, this past Monday, I head out and do some quick testing before the winds became unbearable.  Initial testing and grouping have really shown promising and I am expecting groups to be really tight at extreme ranges.  Or shall I say, my future goal for this gun is to remain under MOA at extreme ranges and so far, things look like with a little more attention to detail and some UPGRADES, I can achieve just that.

This group is with the 1-10 twist from a while back.  The higher pressure was just so the projectile could maintain enough speed to stay accurate.  And that is because of the much tighter 1-10 twist and these long bullets.

Here is the group from MONDAY at 55 yrds.  Now, on this groups, you should note the different FILL PRESSURES and I will add this, there are slightly different hold techniques for the set of groups.  YES, the Corsair is hold sensitive.  Don't ask why.........I don't know.  But the small tiny groups was done with a light hold.  As though I literally was holding a newborn baby.  this gun has always been like this.  Even brand new and in 308.

This groups is at 110 yards and is starting to show some potential.  Not only from this group and the one at 55 yards but from me shooting at 210 and 430 yards also (more to come later).

I must stress also that not only is there an upcoming change to the Corsair in the very near future but, these groups were also shot with UNSORTED BULLETS.  The reason why I mention this is because, after coming home from this shooting excursion, I actually weighed many of my bullets and I found some in this batch that varied OVER 1+ grs.  So I threw many of them back into the pot except for some.  The ones is kept only varied no more than .5 a grain.  So I immediately started recasting and this time, I kept all bullets that weight anywhere from 130.5 grs UP TO 131 grs even.  So no more than half a grain.  So when i shot the above groups, slugs could have weight 1 to even 2 grs different.  NOT ANYMORE!  I will be keeping a tight lid on my weight variances for each gun now.  With long range, THIS IS NECESSARY!

Tofazfou

STAY TUNED!