.30 1-17" Barrel
In the last few weeks I have fitted the first barrel to my F class rig (True Flite Barrel Block Stock with Barnard P action)
After utilising our "Through headstock chambering system" to achieve Bore axis accurate chambers, I screwed in the 24" full diameter barrel, and started prepping the Brass....
As with most Bench rest calibers, the Brass requires close attention. We purchased Lapua 6mmBR cases, then re-sized the necks to 30 cal using a Redding S type F/L Di, although for this process we left out a bushing, as this could cause a jam.
After re-sizing the neck using lubrication (in this case Imperial wax) I turned the necks to .328" diameter when loaded, as we are using the Randy Robinett Reamer which has a .330" neck.
After this we trimmed the cases back to 1.502" using a great Trimming tool made in house from info supplied by Tony Titheridge.....big thanks to Tony for all his help in this development......I also uniform sized the primer pockets, and deburred the mouth of the case inside and out.
To be sure I then fitted a Bushing to the F/L Di, and removed the expander ball, replacing it with a locking nut that clears the neck.....then I ran all the cases back through the Di.
Now with prepped brass, we fitted Federal match primers, and loaded 34 grains of 2207 (all load details stated are only intended to suit the rifle I am writing about) along with 125 grain Speer TNT projectiles to a recommended OAL of about 56.5mm.
I must mention I had to make a 6" drop tube to load these, as the powder will over flow the case if just dumped in..... the drop tube helps pack the powder in, and ends up about half-way up the neck.
I wanted to be sure all I had done was correct, so I fired 6 rounds down our Live Fire Tube, and F/L sized them using a .325" bushing, and all worked well, so I proceeded to fire form all the cases I used for testing in the workshop as the weather was crap, and I wanted to get past this point of testing.
The next day was nice and clear with very little wind, so I headed to the range for some 100 yard tests......I was chuffed to see nice 5 shot groups straight off the mark averaging about 1/2", and after I had shot 17 rounds, the barrel was just starting to warm up, I was liking this rig....
After several trips to the range I felt this barrel had more to offer, so I slugged the bore and found a few minor tightspots, so we lapped the barrel lightly, and went back to testing....I finished load development with the Rifle shoting constant 1/4" 5 shot groups with ease at 100 yards, and my best 5 shot group measuring a cool 0.081"
Final load data was 35.2 grains of well packed ADI2207 powder, the 125 grain TNT's loaded to approx OAL of 57.2mm.
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6.5mm 1-8.5 Twist SG 6 land and groove.
As you may already know Steve Mann and I (Grant) developed a 7mm 1-9" twist barrel with a different configuration to the rifling. Basically we changed the sides of the lands to more of an angle to create what looks like a truncated pyramid in a cross-sectional view. We call this the "SG". Our objective was to cause less damage to the projectile's copper jacket and eliminate the sharp edges on the lands, reducing the effect heat has on sharp corners and also to make cleaning the barrel easier. This worked as well as we hoped, helping me achieve success in F Class target shooting this year with my 32" .284 Win setup using 180gn Berger VLD's.
We have now used this technology to develop a 6.5mm "SG" barrel except this time we have SIX lands and grooves. Our initial tests show it has definite potential as a target barrel.
We based our tests on a Howa 1500 rifle we had just accurised and rebarreled in 260 AI with a 26" barrel, a Bell and Carlson stock, and a Leupold VX1 scope. Due to time constraints I bought a box of factory Ammo with 140gn Sierra Gamekings.
The first objective was to run the barrel in, so being a brave man and believing in our product.......I got Steve to pull the trigger first!!! The first rounds through caused some copper fouling which I cleaned out, and polished the throat with some JB's. Once I was happy the barrel was run in, I took it into the field to try for some 100 yard groups (remember these are standard 260 factory rounds, so are being fireformed) and to zero the scope. Once I sorted the scope out, I managed a 7.5mm three shot group, and my friend Andy managed a four shot group (with a breeze picking up) that was 38mm across but only about a 3mm deviation in height. I was very happy with these results.
We now had twenty fireformed cases and a "run-in-barrel", so after trying a few "safe loads" Steve reloaded 18 rounds with 139gn Scenars and 45gns of ADI2213sc. Out to the range again, and with a 5mph wind we shot six 3 shot groups @ 100yds. After the first fouling shot was 1" high, the next 2 went 1/2" apart, then five groups were inside 16mm, and the last group was inside of 1/4". This barrel has awesome potential, and given a better scope, and time to work up a load, I am sure we could have this rifle humming. I have three barrels currently being put together for some "Test pilots" and are waiting on their results.... so watch this space.....
Some time later......
We have now fitted a lot of 6.5mm 1-8.5" barrels, and they are proving themselves really well.
I sent a test barrel to Vince Bottomley in the UK, and this is what he reported just after Christmas......
Hi Grant, Happy New Year! I finally built a rifle over Christmas for the barrel you sent me. If you recall, it was one of your six-groovers in 6.5mm with 1 in 8 twist. I decided to chamber it in Lapua 6.5x47. The barrel cut really nice and once run-in, I got virtually no copper out of it. I built the rifle for the UKBRA 600 yard Championship – round two was held on 27th December so I just had time to run it in and sort a load. I managed to win – first time out! As you know, we have an on-line mag. at www.targetshooter.co.uk so I will be giving True-flite barrels plenty of publicity. Thanks again for a great barrel – I wish you and True-flite Barrels a very prosperous New Year. Best regards