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October 27th, 2012
Houle Bloop Tube (Sight Extension) Gear Review by Robert Whitley
As a competitive shooter and a builder of custom AR-15 accuracy competition uppers, one of the frequent requests I have from shooters is for a recommendation for a good bloop tube. What people want is a bloop tube that is light and strong, one that has no detrimental effect on accuracy, one that works well with many of the existing front sights, and can be removed and re-attached quickly and easily with no loss of zero. For years finding a bloop tube that fulfills all these requirements has been a somewhat elusive exercise. I am pleased to report that I have found the Houle Bloop Tube to meet all my requirements. In my opinion, this is the best bloop tube on the market, by far. You can order a Houle tube from Norm’s Website, TopGunRI.com or e-mail Norm at topgunngh [at] verizon.net.
 Bloop Tubes Designed by a National Champion
Norm Houle is a High Power and long-range shooter who has used these tubes to win National High Power Rifle Championships multiple times in past years. This past summer at Camp Perry, Norm’s bloop tubes were used by top “podium level” shooters in various events, including David Tubb, who won the National Long Range Championship using one of Norm’s tubes. Rodrigo Rosa also used Houle tubes this year to place second in the National High Power Rifle Championship and third in the Long Range National Championship.
I have a couple of Norm Houle’s bloop tubes that I have used with a couple of rifle projects. Here are some of my thoughts on installation and use of the Houle Bloop Tubes:
- Accuracy with the tubes in place is excellent!
- The tube assemblies are two piece clamp-on tube assemblies, and the bloop tubes can be removed and re-attached with no loss of zero (and I mean no loss of zero). This is a big one! Over the years I have had quite a few clamp on tubes, but few of them repeated like these.
- The tubes are very light but also very strong and low profile. Some of the clamp-on bloop tubes I have had over the years were huge, heavy and provided a large side profile (crosswind sail factor for offhand, etc.).
- Norm offers 2″, 4″, and 6″ bloop tube lengths. The tubes are made to work with a .750″ dia. muzzle turn down and both of the ones I have work perfectly with a minimum turndown of 1.625″ long which provides enough “front-back” distance to permit the locating ring and bloop tube to be properly mounted on the barrel at the same time and work as they should. The tubes are also set up to use front sights set up to mount on a .750″ diameter mounting.
- Each tube assembly has a clamp-on locating ring plus a clamp-on bloop tube that positively indexes off a tapered pin that protrudes from the locating ring. The locating ring is light but very strong and absolutely stays put when you clamp it on the barrel end (clamps on with one screw using a common 7/64″ Allen wrench). The bloop tube part of the assembly has two clamp-on screws (use a common 7/64″ Allen to put on, mount and take off).
Using Different-Length Tubes for Different Applications
 You can buy one tube with two or more locating rings and set multiple rifles up so you can move your bloop tube (with front sight attached) from rifle to rifle. You can also use two different bloop tubes to mate up with one locating ring on the same rifle. Norm uses a 2″ tube (with a front sight attached) for offhand and rapid sitting at 200 yards (short tube minimizes crosswind sail factor). For 300-yard rapid prone and 600-yard slow prone, Norm takes off the 2″ tube and mounts a 6″ tube on the rifle (with a front sight attached to it). Norm switches back and forth as needed from match to match (a 4″ tube is also offered). Norm noted that Rodrigo Rosa also used the same Houle bloop tube set-up with two different tubes this year at Perry to take second overall.
The price of a Houle bloop tube assembly with locating ring is $125.00. That’s more than some other brands, but a good value considering the design, features, and high-quality construction of Norm’s bloop tubes. Just as with all sights and optics… you get what you pay for.
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August 26th, 2012
by Robert Whitley
 After Accurate Shooter published the July 31, 2010 Daily Bulletin feature on 6mm BRX Myth-Busting With Bob Crone, further research reveals that there’s more to tell about the BRX, its origins, and its original specifications.
6 BRX Myth-Busters Follow-Up Challenge
I wanted to obtain a print reflecting the true original dimensions of Bob Crone’s 6mm BRX reamer. I hoped to verify the head spacing of the reamer to be .100″ longer than a 6mm BR, and I also wanted to see how Bob’s original print compares to 6mm BRX match reamers currently considered to be the “standard in the industry”.
Recreating the Original 6mm BRX Reamer Print
Clymer Precision was contacted to obtain a print of Bob’s original reamer. Todd Wilms, the current owner of Clymer Precision (and a heck of a nice guy as well) went back in the Clymer archives and pulled the records of the dimensions of Bob Crone’s 6mm BRX reamer. Todd then entered them into Clymer’s current reamer drawing program and has generated a current drawing reflecting the original 6mm BRX reamer. The print (see below) confirms the head space of the 6mm BRX to be .100″ longer than a 6mm BR (i.e. 1.267″ min at a shoulder datum diameter of .350″).
Comments on Bob’s 1996 Clymer Reamer
In many ways, the print dimensions are very close to what is currently recognized as the “standard in the industry” for 6mm BRX reamers, however in other ways there have been some definite changes:
A. Body Diameter: A chamber body diameter of .470″ is still in wide use today with 6mm BRX reamers (that’s measured .200″ forward of the bolt face). The current Lapua 6mm BR brass has a web diameter very close to this diameter and one should be wary of trying to tighten this dimension. If anything, running a little looser (like the .4708″ dimension similar to that used with the 6mm Dasher) would not hurt the performance of the 6mm BRX cartridge a bit.
B. Shoulder Diameter: Bob’s original reamer had a shoulder diameter of .4609″ (the same as a 6mm BR Norma), however many current 6mm BRX reamers now use a .460″ shoulder diameter which helps avoid overworking the brass there if readily available commercial dies are used.
C. Max Chamber Length: Bob’s original print had a “max chamber length” of 1.570″ (the same as a 6mm BR Norma), however many of the current 6mm BRX reamers have shortened this up a little. This is because, when 6mm BR brass is fire-formed into 6mm BRX brass, typically the brass shortens. Indeed, this author’s 6mm BR brass shrinks in OAL from around 1.555″ to around 1.547″ when it is fire-formed to 6mm BRX brass. A max chamber length in the range of 1.560″ – 1.565″ is seen often with 6mm BRX reamers these days.
D. Neck Diameter: While Bob’s reamer has a .262″ neck, this has for the most part given way to either a .269″ (sometimes .268″) turned neck, or a .272″ (sometimes .271″) no-turn neck, with the neck diameter typically selected based on the actual dimensions of the brass to be used.
E. Throat Angle: Bob’s throat angle was one and a half degrees, which seems to be standard and in wide use today with the 6mm BRX.
F. Freebore: Bob’s freebore length was 0.00″ because his smith used a separate throater to set the throat length Bob wanted for specific bullets. These days, a built-in freebore in the range of .104″ – .125″ seems to be very common with 6mm BRX reamers. Freebore in that range is seen by many as a good choice for the readily available 105- to 108-grain 6mm bullets.
6mm BRX — Real World Specs
Here are measurements on Robert Whitley’s 6mm BRX brass, as fire-formed, full-length sized and ready to load in a no-turn chamber.
Base to shoulder = 1.170″
Base to neck/shoulder junction = 1.333″
Overall case length (fired 2x and re-sized 2x) = 1.547″
Shoulder diameter (resized) = .459″
Diameter .200″ forward of base (resized) = .470″
Neck diameter loaded = .269″
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June 1st, 2012
 Here’s good news for AR shooters looking for a 6mm option. 6mm HAGAR brass is now available from Hornady, and it looks like this brass is quite good. Those of you who follow the National Matches at Camp Perry know that Carl Bernosky won multiple National High Power Championships shooting the 6mm HAGAR cartridge from an AR Platform rifle. The 6mm HAGAR was derived from the 30 Remington cartridge, and it has the same case head diameter as the 6.8 SPC, also a 30 Remington derivative.
The 30°-shoulder 6mm HAGAR is just about the longest 6mm cartridge that can be loaded in a two-column AR15 magazine and still feed reliably. The advantage of the 6mm HAGAR is that it offers enough “boiler room” to drive 6mm bullets to impressive velocities, yet it can still fit and function well in AR mags. But note, if you are restrained to a mag-length COAL, you can pretty much rule out using 95-108 grain bullets, because they would have to be seated too deep in the HAGAR case. That actually means that the “advantage” of the 6mm HAGAR’s case capacity is lost to some degree — at least when using long, heavy bullets. On the other hand, when loaded with shorter varmint and hunting bullets, such as Hornady’s 75gr V-Max, you can load to 2.260″ mag length and use nearly all of the HAGAR’s case capacity.
For this reason, we think the 6mm HAGAR may ultimately prove more popular with varminters than with the High Power crowd (at least those who do not want to modify their mags to allow heavy 6mm bullets to be seated longer.) If you’re using shorter bullets, you can fill up the HAGAR case and drive 60-75 grain projectiles at serious velocities.
 6mm HAGAR Basics
The 6mm HAGAR uses a 6.8 SPC AR-15 bolt and 6.8 SPC magazines and a conventional upper receiver, barrel extension, and bolt carrier assembly. Typically this cartridge has been used for varminting, hunting, and High Power competition. We think the 6mm HAGAR should be a kick-ass cartridge for varminters shooting ARs with shorter varmint bullets.
On the other hand, because the 1.775″-long HAGAR case takes up so much space in an AR magazine, the 100-108gr bullets aren’t well-suited for mag-fed 6mm HAGAR applications (unless the mags are modified). These same 100-108 grainers DO work well in single-load situations provided the chamber is properly throated for such bullets.
NOTE: Some High Power shooters have slotted AR mags to allow loading of long bullets up to 2.340″ max, i.e. beyond normal mag length. See modified magazine at right.
Hornady’s 6mm HAGAR Brass Is Shipping Now
Until recently, 6mm HAGAR brass was hard to obtain. Cases could be formed from 30 Rem brass, but this was a tedious, time-consuming process. Now, however, quality 6mm HAGAR brass is available from Hornady. An initial run of 150,000 pieces of 6mm HAGAR brass was produced. Vendors who got some of the first run of HAGAR brass include AR-X Enterprises LLC (Robert Whitley) and Creedmoor Sports.
Robert Whitley reports: “We’ve received our first shipment of factory 6mm HAGAR brass from Hornady. This Hornady 6mm HAGAR brass is hard at the base but well annealed at the neck. The brass has a small primer pocket and a small flash hole. All of these features enable the brass to hold pressures well and to remain serviceable and usable for multiple re-loadings. Internal H20 capacity of the brass case is right around 37.0 – 37.5 grains of water weight. With its larger case capacity the 6mm HAGAR can accurately push the bigger 105gr to 108gr bullets in the range of 2800 fps (when these bullets are seated long and single-loaded, not mag-fed). However, because of its rather long case length (1.775″) relative to max mag-fed cartridge OAL of 2.260″, the 6mm HAGAR may work best with the smaller and lighter 6mm bullets (75gr and under).” [Editor: Do the math … 2.260″ minus 1.775″ leaves only 0.485″ clearance for a bullet to extend beyond the case mouth.]
Loading Long Bullets to Mag-Limited 2.260″ COAL Is Neither Practical Nor Wise:*
6mm HAGAR Brass, Dies, Mags and Complete Uppers Offered
Along with 6mm HAGAR brass (at $84.00 per hundred), ARX Enterprises has 6mm HAGAR dies, and magazines. ARX Enterprises is also building complete match and varmint AR-platform uppers chambered for the 6mm HAGAR. You can find out about all these products on Robert Whitley’s 6mm HAGAR web page. To order 6mm HAGAR uppers, die sets, brass, magazines and related products contact:
AR-X Enterprises, LLC (Attn: Robert Whitley)
199 North Broad Street
Doylestown, PA 18901
(215) 348-8789
e-mail: rcw3 [at] erols.com
*Left = 75gr Hornady V-Max at 2.260″ OAL (bullet diameter at mouth of case is .243″.)
Left Center = Berger 100gr BT at 2.260″ OAL (bullet diameter at mouth of case is only .225″.)
Right Center = Sierra 107gr MatchKing at 2.260″ OAL (bullet diameter at mouth of case is only .222″.)
Right = Hornady 105gr A-Max at 2.260″ OAL (bullet diameter at mouth of case is only .225″.)
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October 11th, 2011
105gr Hybrid Tests Demonstrate Excellent Accuracy and Consistency
By Robert Whitley
After the initial Daily Bulletin Report on the new Berger 6mm 105gr Hybrids, I did some accuracy and consistency field testing with these new bullets. They shot so well, I thought an update was in order. My 100-yard testing has revealed much about these new bullets — all of it good so far. The test rifle was a MAK Tube Gun with a trued Rem 700 action (glued in), with a 6mm Brux 30″, 1:8″-twist barrel chambered with a no-neck-turn 6mm BRX chamber (1.563″ max case and .120″ free bore). The 6mm 105gr Hybrids fit and work well in this 6 BRX chamber configuration. (CLICK HERE to view a print of the reamer I used for the 6 BRX chamber.)
Hybrids Show Excellent Accuracy in Prone Tests (with Sling)
As some may know, I am predominantly a prone shooter and do most of my load testing prone with a sling. I chose to do the same with these Hybrids, to see how they would perform when fired as they would be in a prone match. In this case, shooting prone with sling, I shot four 10-shot groups (two 10-shot groups in each of two range session). All four groups were right around .5 MOA (i.e. each group about .750″ edge-to-edge, minus a bullet diameter of .243″ = .507″). The new Berger 6mm 105gr Hybrid bullets had no problems doing this. The groups shot were also consistent with the best groups I have been able to shoot in the past with the Berger 108gr BT bullets and the Berger 105gr VLD bullets, and I consider both of those bullets to be excellent and accurate. There is no question in my mind that these new Hybrid bullets are accurate, and the consistency is there! Check out my test targets below.
The two 10-shot targets above were shot at 100 yards on September 30th, prone with sling. The 6 BRX load was: Berger 6mm 105gr Hybrids, Lapua brass, 32.0 grains N140, Federal 205M-AR primers, .020″ jump. Note: If you put the targets over each other the groups line up perfectly.
These two 10-shot targets (above) were shot at 100 yards on September 23, prone with sling. The 6 BRX load was: Berger 6mm 105gr Hybrids, Lapua brass, 31.0 grains H4895, Federal 205M-AR primers, .020″ jump. When I can shoot 20 Xs in a row (as I did with these two targets) the rifle is really shooting well.
Accuracy needs to be coupled with consistency, especially when running longer strings of fire or in matches demanding a larger number of hits on the target. I am pleased to report that I have found the Berger 105gr Hybrid bullets to be consistently accurate bullets (i.e. there were no anomalies or fliers, they just keep going where you pointed the rifle). At each of the last two range sessions I shot back to back 10-shot groups with no break between the two (i.e. 20 shots in a row and only switching to the next target after 10 shots). Not only did the individual 10-shot groups stay tight, but if you hold each first target over the second target, the groups are right on top of one another. This is what I look for in terms of consistency — that I can keep shooting, and the bullets keep going right into the group, with no odd fliers.
105gr Hybrid Bearing Surface and Optimum Free Bore
Shooters may wonder how the new 6mm 105gr Hybrids function with the existing freebores on chambers set up for current Berger 105gr VLDs and Berger 108gr BT bullets. Based on the investigation and measuring of various chambers, here are some general guidelines:
1. For a chamber with a 1.5° throat angle, and the bullets touching the lands, the Berger 105gr Hybrid bullets sit up in the neck a little further than both the current production Berger 105 VLD Target bullets and the Berger 108gr BT bullets.
2. Based on basic measuring and testing, for the junction of the boat tail and bearing surface of a 6mm 105gr Hybrid bullet to be in the same spot as other bullets, the 105 Hybrid (Lot #3079) would need about .020″ – .025″ less freebore than recent production Berger 105gr Target VLD bullets (Lot #3220) and about .030″ – .035″ less freebore than recent Berger 108gr Target BT bullets (lot #2791).
3. Since the Hybrids are designed to work both in the lands and jumped away from the lands, some extra freebore may not be a bad thing. In truth, the 105 Hybrid bullets should work well and fit well in various 6mm chamberings (such as 6 BRX, 6 Dasher, 6mmAR etc.) which have been optimized for the previous generation, non-Hybrid 6mm Berger 105s and 108s.
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May 4th, 2011
The 6mmBRX (6BRX) is an outstanding cartridge that has set world records and harvested many trophies. Just last week Peter White used his 6BRX to win the NBRSA 600-yard Nationals convincingly. Peter loves his 6BRX, but he has one gripe — he must use two different dies to size his cases because a standard 6mmBR die won’t reach down far enough. White uses a .308 Win or .243 Win die to size the bottom of his 6BRX case then finishes up with his 6mmBR FL bushing die.
 Redding 6BRX Dies Available Soon
Now 6BRX shooters have a single-step solution — Redding 6BRX dies. Robert Whitley has commissioned a special run of Redding 6BRX dies. Robert will offer a Redding Type ‘S’ full-length sizing die that will size the whole case, with bushing control over the neck. What’s more, Redding 6BRX micrometer-top Comp Seaters will also be available. Robert, who runs 6mmAR.com, expects these special-order Redding 6BRX dies to arrive within a few weeks. This is a very limited run of 6BRX dies, and Redding is not currently selling them through other sources. So if you want a Redding 6BRX Type ‘S’ FL sizer or Comp Seater die, you’d better contact Robert soon. Order through:
AR-X Enterprises, LLC (Attn: Robert Whitley)
Phone: (215) 348-8789
Email: rcw3 [at] erols.com
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 6BRX Cartridge Basics
The 6BRX is a modified version of the 6mmBR Norma case. The 6BRX has the shoulder blown forward about 0.100″, but it retains the same 30° shoulder angle of the parent case, and the same sidewall angle. You can use “normal” 6mmBR dies for the 6BRX — that’s one of its appealing factors — but the 6mmBR full-length sizer will miss part of the bottom of the case down near the web.
To compensate for this, many 6BRX shooters full-length size their brass first with a .308 Win or .243 Win FL Die, and then switch to a 6BR die. That system works, but it creates unnecessary steps. With a dedicated 6BRX sizing die, you can size the whole case in one pass, so you don’t need to use two dies. The $89.95 Redding Type ‘S’ Full-length bushing die sold by Whitley is one-die sizing solution that works. Whitley will also offer a package of the 6BRX Type ‘S’ FL sizing die plus a Redding Comp Seater for $199.95. That gives you a complete set of dies for your 6BRX wildcat. |
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February 14th, 2011
Barry O. (aka “TheBlueEyedBear”) is a long-time AccuateShooter Forum member and friend of the site. Each year he manages to acquire another good-looking, great shooting rifle. In 2009 he took delivery of an amazing 4000 fps 300 WSM varminter, and for 2010 he put together a fantastic 6mm Super LR long-range varminter on a BAT SV action. Barry actually sourced many of the components for his new rifle through our AccurateShooter Forum Free Classifieds. CLICK HERE to read all about Barry’s new BAT-Actioned varmint rifle, the latest in our popular Gun of the Week Series.
CLICK Photo to Read Full Story
The Richard Franklin walnut LowRider stock (above) for Barry’s new rifle came from fellow Forum member “Preacher”, who also did most of the metal work. The gun is chambered as a 6mm Super LR. This is a 30°, long-necked wildcat based on the .243 Winchester parent case. The 6mm Super LR was developed by Robert Whitley, who wanted something similar to the 6XC, but with “more boiler room” to push the 115s comfortably at 2950-3050 fps.
The 6mm Super LR wildcat is easy to make. Robert Whitley figured out how to reform domestic .243 Win brass with one simple pass through a Redding 6mm Super LR full-length sizing die. Robert has commissioned these dies from Redding. He’s got them in stock right now. Call Robert at (215) 348-8789 to order. You can learn more about the 6mm Super LR on Whitley’s www.6mmAR.com website.
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