6.5 x55 BJ AI new barrel test

[rardoin]

Earlier this winter I had 2 new Bartlein barrels spun up for my F-open rig, one in 1:8 and one in 1:8.5 twist for shooting 142 gr bullets.  I had bought 300 RWS cases with the reamer/die package when I started this chambering and had issues with fireforming that brass in a fireforming barrel I had chambered along with the original barrel.  I was finally able to get the RWS brass fireformed a couple of months ago but it would just act 'funky' in the new 8 twist barrel; it would have a little insertion bind whether I bumped the shoulders back up to 0.008" and used a small base die insert.  Nothing seemed to work well and at least 1/3 of the cases had 'palm smacking hard' bolt lift.  I could never get consitently good groups so I decided to $hIT-can that brass and start from scratch with new Lapua brass and develop a fireforming load that may be decent enough to shoot in local monthly matches and improve my wind skills.  I went out today and shot 3 loads at 48.0-48.5-49.0gr of RL-23 for velocity/pressure tests and the Magnetospeed put the 48.0-48.5 loads in my 2930-50 velocity target with the bullet at its usual 0.015" OTL sweet spot.  I then loaded 5 cartridges at 48.0, 48.3, 48.6, and 48.9gr with four 48.0 fouler/sighters.  Not expecting earth shattering results for a fireforming load I first shot four foulers/sighters to get my POI in the correct spot since I had removed the scope after the Berger SW Nats for travel.  The first two shots were about 2 minutes low/ 1 minute left in the same hole.  Lucky, I was supposing.  I dialed up 2.5 and right 1.0 and shot the other two....in the same hole again.  Well, I might have something here....maybe.  I had 5 rounds each for four charge weights and proceeded to shoot at 100 yds.  10-15mph from 6:30-7:00, no flags just holding fire on perceived big changes.  The first charge weight (same as foulers) in one big hole...2950's avg velocity.  My dad and I had a 5 MOA grin each.  The next charge had a slightly larger hole with diagonal stringing and 2700's avg velo (it did what my last barrel did at this speed....nice to have a trend).  This fireforming load shoot with my last barrel with 10+X fired/ neck turned and performance selected cases.  WTF???  Nice to be able to fireform while shooting a competitive load.  I needed the break after screwing with the RWS brass for so long.  I have a habit of trying to re-invent the wheel and should have sold off the RWS brass and stuck with what everybody else uses....Lapua brass .

[Fuj]

I have to stop reading your posts. My check book starts doing the
happy dance again.....

[mnbogboy]

rardoin,
Just plain nice!
When fireforming loads shoot like that you know you have a winner.
Good shooting,
Randy

[rardoin]

Put on another barrel to test....hoping it will not end up as a high price tomato stake cause I'll be putting in the spring garden in a couple of weeks .

Bartlein 5R 8.5 twist, 30" with Ezell tuner.  Took the same new brass test from the 8 twist barrel and did a fine charge spread from 47.8-48.2gr RL-23 in three 0.2gr increments.  Shot at 100yds in 8-12 06:00 winds but suspect minimal effect at 100yds.  Five shots per group with 10 'foulers' on lower left at 1st charge weight.  I think I can work with this one too.

[jvw2008]

You're lookin pretty there Robin ?

[Ranger 188]

W.T.H.   Looks like Robin is poking holes in that target with that pencil again.  LOL  Even his fouler are tight.  Nice shooting.

[DHuffman]

I'd say you're on it Robin.

[gman47564]

and that boys is why we pay attention to what robin has to say... great shooting robin...

[rardoin]

I've been very lucky to have 3 good barrels for this rig.  I will give a lot of credit to my gunsmith for his meticulous attention to minor details and his ability to indicate the bore and index it.  It makes the nodes broader and more forgiving.  I will also attribute the nice wide nodes in these last two barrels to the tuner hanging off the end as it's dampening effect alone makes the barrel much easier to tune than the first barrel (which was not threaded for a tuner).  I am really looking forward to collecting data while testing the tuner under different conditions this year.

[Fuj]

Any pics of the tuner, or is it the same as what Shiraz has ?.
Hardly see anyone in my neck of the woods using a tuner, even
the Ridgway boys. 

[rardoin]

I use an Ezell PDT.  My gunsmith looked at me with sceptical amusement when I gave it to him with the specs for the muzzle end shoulder and threading.  He said he would let me be the guinea pig .  I was the only person on the line until a match ago that runs a tuner.  However, when I went to the Berger SW Nats, there were many tuners on the guns there.  A tuner will only help keep a tuned load in tune while temeperature/humidity changes; it will not make a mediocre load great.  It was purported to broaden the tune window with loads and I am witnessing that with the two barrels I have threaded for the tuner.  That benefit is enough to make it worth the money.

Ezell Tuners:  http://www.ezellcustomrifles.com/home-3/pdt-tuners/

[jvw2008]

With or without a brake?

[rardoin]

With or without a brake?

No brake.  I don't think Mike E makes a 'braked' model...I know Harrel's does.  Brakes are for sissies anyway  ( so says the man shooting a 22lb rifle fully rested )

Per NRA High Power F-class rules...brakes are personna non grata.  On a F-open rifle I don't think a brake would be of significant benefit unless shooting a 300 mag or higher horsepower cartridge.  Sure is nice to be on a line with 15-100 rifles and not get bitch-slapped in the side of the head with a percussion wave .

[rardoin]

Shot a 'combo' 597-34x with the first match for the 8.5 twist fireforming brass in the process (600yd F-class).  The groups were forming very well.  I say combo because I let the Match Director (also a good friend), who had a minor health problem recently and could not get brass loaded for today, shoot the middle string.  He cleaned it at 200 having never shot an open rifle before; he shoots F-TR with a .308.  I think he is hooked!.  The 3 points I dropped were all overcalls on the let-offs....totally operator error and nothing to do with the gun or load.  I am extremely pleased with the way this barrel is shooting while blowing out the case over 4 grains capacity in the process....just don't seem right .  I can't wait to get the formed brass skim turned and find the neck tension it likes.  I also am anxious to perform tuning with the muzzle tuner.  The tests I have been doing on fireforming brass are looking very encouraging.

[rardoin]

Finally got about 275 cases formed and neckturned/trimmed and performed an OCW test using RL-23 and the Precision Ballistic 142gr VLD at its known good seating depth of 0.015" off light touch.  I loaded 5 cases per group down to 48.6 and up to 49.2gr (5 foulers at 49.0gr) with 0.0025" neck tension (about 0.001" more than I usually run in this set-up but I did not have a mandrel that would get me there so I went with what I had).  I am aiming for a node that should be right around 2930-2960fps and since my last barrel shot VERY well at 2950-60fps using 49.0-49.2gr I figured my spread would cover the sweet spot.  NOT.... .  The lowest charge produced 2886 fps avg.  This was a bit abover my expected node but I expected this 8.5tw barrel to be a little faster than the 8tw for a given charge but not that much.  I decided to run the rest of the groups as long as I was not getting excessive recoil/tight extraction.  The best group was at 49.0 (like the 8tw barrel) but smoking along at 3022fps but the node is a bit narrow.  This cuts my windage at 1000yds in a full value 10mph wind near .4MOA...not an insignificant amount.  But, I don't know if it will hold up to under .5 MOA at 600-1000yds over a 22-26 shot string.  My small brain says run the higher node but the big brain says load down lower and find the slower node.  I will listen to the bigger brain on this one but I will give the higher node load a test at 1000yds in a a string at a match in  few weeks and compare loads under actual conditions.  It will be E-targets so the feedback will be most useful.

Test below....shot at 100yds as way too much mirage andwind with gusts from 5:00-7:30 for anything further out: