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Discussion Starter · #1 ·
I originally started out building a 600 yard F class rifle and after considerable research decided on the 6.5x47 Lapua cartridge. A primary driving factor was the availability of Lapua brass, case neck length (which allows seating longer bullets out farther), the cartridge has a good reputation for accuracy and works in a magazine if desired.
After that initial endeavor I built a 6x47 and a 22x47Lapua. The rationale was all three can be formed from the 6.5x47 Lapua case without having to fireform.

Two of the rifles started out with donor Remington 700 short actions and a Rem 40 XBR action. All except the XBR (which has a trued action/bolt) were fitted with a PTG oversize one-piece stainless bolt with small firing pin and pinned Sako extractor. I then hand honed the bolt to where it was a smooth tight fit and had a gunsmith true the action.
The XBR bull barrel which was originally chambered for 22-250 was set back to accept the 22x47 and was kept at 1:14 twist.

The non XBR rifles are housed in a Stockeys’ LRT aluminum blocked stock and fitted with a Stockeys’ stainless Obendorph trigger guard and floor plate. Much thicker than the original (Fig 1). The XBR target stock was kept as original.
The 6.5x47 Lapua was tested using Lapua 123 Scenar L bullet; for the 6x47 Lapua first with a 105 grain Lapua Scenar and second using a 109 Berger and for the 22x47, a Bibb 52 grain FB was selected. A cut-off section of barrel from the XBR (Fig 2) was used to make a jig for the Bibb bullet to mark were it just kissed the lands. Most of this work was done prior to the powder/primer shortage.

All cases after trimming were turned around 180 degrees and the base was trimmed for high ridges and neck expanded using a Sinclair neck expander to produce 0.0015 neck tension with a seated bullet. Cases were loaded with a variety of powder charges and CCI BR4 primers.

Table 1 shows the results of the testing for all three rifles. Fig 3 provides an example 22x47 target.

Experience: Making the 6.0x47 brass was the easiest with just running the 6.5x47 brass through a 6.0x47 die. The 22x47 was the most intense by first running the 6.5 though a 6.0x47 die and then running that brass through a ‘S’ type die first using a 0.253 bushing followed by a 0.252 bushing. (Although I did read one article where a 0.257 bushing was used on the 6.5 case which I assume would reduce the working of the brass.)

After forming the 22x47 brass OAL was not uniform and had to be trimmed to length using a L.E., Wilson trimmer.
Having just one brass case that will function for all three rounds is a plus. Although, the 6.5 and 6.0 can be similar looking and care taken not to have a 6.0 loaded round placed into a 6.5 chamber. I load only one cartridge at time and shoot only one at a time at the range. To separate them further, a magic marker was used to place a black stripe on the base of the 6.0 round.

All three functioned well with CCI BR4 primers.

All three cartridges were not difficult to load and tune for and produced excellent accuracy.

All bullets tested performed best when seated 0.003 to 0.005 from the lands.

The 6.0x47 Lapua was particularly suited for the 109 Berger with it performing well with just about every powder evaluated. The 22x47 Lapua was well suited for the Bibb bullet with several powders producing excellent results.
The 6.5 and 6.0 x 47 functioned in a magazine. The 22x47 XBR was kept as a single shot.
 

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The Shadow (Moderator)
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All cases after trimming were turned around 180 degrees and the base was trimmed for high ridges
So you mean you trimmed the bottom of the case head, where the primers are seated? 🤔
 

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So you mean you trimmed the bottom of the case head, where the primers are seated? 🤔
That's what he means!
The purpose (based on a perceived benefit) is to 'square' the base of the case to the bolt face to prevent any possibility of 'tipping the case in the chamber. Whether it is of practical measurable benefit or not, it's another minute detail adopted more in precision benchrest circles. Obviously, for it to have any chance of success, the rifle must be 'blueprinted' to begin with, everything about the rifle must be square. The OP's reference to 'removing bumps' would be the outcome of the process. Look at this link, Speedy Gonzalez (Speedco Shooting Sports) has a case trimmer for the dual purpose (trim length and square bases). Can be seen on this link, scrolll way down to item 18. Speedys Guide to Benchrest | Svenska Bänkskytteförbundet

And step #11 on this: Preparing Brass for Match Shooting
 

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Thanks for sharing. Clarify this bit for me, please?

The 6.5x47 Lapua was tested using Lapua 123 Scenar L bullet.
Did you shoot the 123 Scenar, or the 120 Scenar-L?

Though the Scenar-L line is supposed to be more precisely made than the 'plain' Scenar, my 26-cals all prefer(red) the 123 Scenar to the 120 Scenar-L.
 

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I read all of it, lots of interesting takes, but honestly nothing truly definitive. Here's my curve ball for the day, what effect does it have on belted cases? 🤔
 

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The Shadow (Moderator)
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Depends on how you reload, I never reloaded off the belt with my 264 or 338WM. So the result is as expected. 😉
 
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I read all of it, lots of interesting takes, but honestly nothing truly definitive. Here's my curve ball for the day, what effect does it have on belted cases? 🤔
I agree with what Darkker in #8 above. Also, rarely would any [normal] rifle chambered in a belted case be 'blueprinted' to benchrest rifle standards (excepting, perhaps, a 338 Lapua sniper rifle!), nor would the expectation of such chamberings reach benchrest grouping standards. I highly doubt any squaring of the back end would yield any measurable difference. As anal as I have been known to be in some of my case prep. for benchrest competition, squaring the case bases was 'a bridge too far' for me....and I even used to index everything about my cast bullet shooting from mold to out the muzzle!
 

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Howdy Merbeau. To Clarify, you had a gun smith true the action? Is this to mean blueprinted? Does the case head need truing after all the sizing? After truing the case heads, I would think, you'd have to go over the primer pockets to make sure they're all the same depth. I've only read that someone trues-up the case head; never known anyone who actually does. Seems that you have experience handloading and have decided to enter a different dimension of shooting.
At what distance did you shoot the group you posted?
Regards,
CJR50
 

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Hopefully Merbeau will return to his (this) thread for further discussion, but he may not, as this is his singular post in about 12 years as a forum member.
This is an interesting subject (case base squaring) that deserves some additional comment from the many knowledgeable members here, IMO.
For those that have not, I'd suggest reading (at least) posts #12 and #13 in the link I provided in #6 above and again here: Case head squaring
I was really surprised (shocked?) by the results shown (in #13 of the link) for the Lapua BR cases, which are generally considered to be the best, most consistent brass available.
I'm not saying whether [I believe] case squaring is or is not a worthwhile endeavor, but the subject is interesting and it doesn't hurt to add to one's knowledge.
 

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The Shadow (Moderator)
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Hopefully Merbeau will return to his (this) thread for further discussion, but he may not, as this is his singular post in about 12 years as a forum member.

I was really surprised (shocked?) by the results shown (in #13 of the link) for the Lapua BR cases, which are generally considered to be the best, most consistent brass available.
It's actually his fourth posting in 12 years(had to double check). If you read his posts, and watch his login times; he isn't coming back for a discussion. Call it a persistent drive-by account, not a human waiting to interact with other humans.

I know those who are kneeled at the alter praying, will tell you Lapua is ultra-mega-ninja... If you read along in the primer pressure testing I shared, what's mystical about it is their pricing.

Cheers
 

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Darrker, I misspoke, I should have said it was Merbeau's singular 'thread starter', his other three posts were replies to other posts. I should slow down and be a little more specific/precise, my bad!:oops:
 

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The Hog Whisperer (Administrator)
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I figured the cases would 'square' themselves, on the first firing... not sure how there could be any other outcome?
 

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Mike is right. The purpose of having an action square to the bore is so the first firing makes the case right with the world.
Hard bolt lift is many times cause by an out of square bolt face that shows up at higher pressures.
 
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I figured the cases would 'square' themselves, on the first firing... not sure how there could be any other outcome?
Mike is right. The purpose of having an action square to the bore is so the first firing makes the case right with the world.
Hard bolt lift is many times cause by an out of square bolt face that shows up at higher pressures.
Guys, You may disagree with the guy in my link, but he says (read post #13 in the link) he has checked cases that have been fired multiple (many!) times in a 'trued action and a custom action and it is still not square. The cutter still took brass off the high side.' He has tried it, I have not, so I can't pose a counter argument. I simply don't know, but regardless, I personally see little value for the effort involved. I no longer 'travel in the benchrest circle', so I don't know if it is even a current practice in the precision communities, or if it was a 'flash in the pan' back then (2005?). Apparently Merbeau is still performing the step in some fashion that he did not detail in his passing reference to it. If he comes back to read the responses, hopefully he will feel compelled to elaborate.
 

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I've squared the bases on br cases, it's as simple as turning the case around backwards in a Wilson trimmer, it would be hard to prove that there's a benefit, but it makes you feel better, kinda.
 

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Discussion Starter · #18 ·
It's actually his fourth posting in 12 years(had to double check). If you read his posts, and watch his login times; he isn't coming back for a discussion. Call it a persistent drive-by account, not a human waiting to interact with other humans.

I know those who are kneeled at the alter praying, will tell you Lapua is ultra-mega-ninja... If you read along in the primer pressure testing I shared, what's mystical about it is their pricing.

Cheers
Ok, there are several questions in this thread regarding squaring of the case base. I learned this technique from a structural engineer who I shoot with/against and did the rebuilding of my Rem 700 XBR. He also made the jig for the Bibb bullet from a cutoff portion of XBR barrel. He claimed the scope base holes near the front created a flex point. So my original 27-inch barrel ended up (after alternation) at 24 inches. He has competed in numerous competitions and was in many national matches. He actually told me about squaring the case head and uses a real full scale mechanical lathe for his cases in his shop. It is correct that truing the bolt (i.e, squaring it up) is necessary for this to be effective. I do not have access to a large mechanical lathe but case trimmers are in actuality mini lathes. The process makes the case head level and flat so it sits square on the bolt face.

Secondly, I did use the Lapua 123 Scenar for testing in the ^.5x47 Lapua.

And yes I do not post often. I do, however, interact with people. I have posted quite a bit on long range hunting forum. For years I was a NRA Bullseye Shooter and NASSA skeet shooter. Nine years ago I was diagnosed with a rare eye disease called lateral corneal dystophy which eventually required eye surgery and two corneal transplants and artificial lenses. I took up rifle shooting because the scope could help make up for my vision alternation. So in the last several years I have more reason to post because of much more involved technique for rifle reloading.
 

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The Hog Whisperer (Administrator)
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Just curious, how much "squaring" would be expected? A few thousandths?

Is there any point at which you say..... that one's just too crooked, and toss it?
 

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Just curious, how much "squaring" would be expected? A few thousandths?

Is there any point at which you say..... that one's just too crooked, and toss it?
Mike, I can't answer your question, but am responding because of a related topic that has not yet been addressed.
Obviously, removing any amount of material from the back end of the case will have headspace implications. As such, the process begs the question; Does one remove the same amount of material from all cases to result in a common headspace affect and required 'adjustment', or do you remove just the amount required to square the cases on an individual basis, resulting in a variable headspace condition? Does one account for correcting the headspace by fireforming the cases using a false neck sizing or jamming the bullet into the rifling using a 'standard cut chamber'? Or, does one prep. a large quantity of cases identically and then cut the chamber to the resulting headspace requirement? Just thinking out loud about the varying possibilities.
 
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