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bjornborud
Tonight I hit the range in full stride with two new gadgets in addition to my XCB rifle: A new in the box MagnetoSpeed V3, and an equally new Breech seater from Tim Malcolm aka Goodsteel.
Just to cover the MagnetoSpeed chronograph very simply: It works perfect with cast bullets, is very simple to install and use, and appears to be very accurate when I compare today’s loads with those previously shot and chronographed. After shooting I took the little SD card out of the display unit, hooked it up to the computer, clicked on the log file and Voila! it opened up the entire range session in Excel. Now I can tape the data on the targets along with the groups for more clarity.
The Breech Seater was a very interesting contraption, and from my limited use of it today I am starting to believe that breech seating helps accuracy at high velocity.
All shooting tonight was done with The NOE 310-165-FN bullet, lubed with White Label 2700+ (Carnauba Red)
First off I shot 2 strings with fixed ammo to confirm the velocities I posted in my previous post. I estimated that a load of 45 grs. W760 would give about 2550 fps, and tonight’s shooting showed the following chrono results:
Both ES and SD were within reasonable limits.
Then I shot a string with LeveRevolution. That’s when things started to heat up, velocity wise:
Very good velocities, spreads were a little more uneven. I’ll be trying to push this powder even higher to see if it’ll break 3000 fps with accuracy.
Breech seated reduced loads didn’t seem to have a large advantage over fixed ammo loads. I shot 2 strings with 13 grs. Unique, accuracy was about the same:
The most interesting experiment of the evening came when I attempted to shoot 5 cases pre-loaded with 56 grains RL22. This charge fills the case to overflow, so I have to put a “lube cookie” in the case mouth to be able to load the case:
Breech seating the bullet:
And the result was pretty decent:
All in all a very interesting night at the range, I’ll post more when I have more data to share.
bjornborud-
Replies
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Larry Gibson
Positively wonderful!. What I said could be done 8 years ago is proving true. I get about 2550 fps from 45 gr of 760/H414 and 2700+ with the LeveRevolution powder. Your “Bertha” has an additional 3″ of barrel and we again see the velocity increase. As we also know we need to cast as close as a perfectly balanced cast bullet and launch it w/o inducing imbalance. This NOE 30 XCB bullet design is proving up the task of withstanding the acceleration of such loads. Breach seating (obviously kudo’s to goodsteel for his expertise in making the BS tool!) is definitely showing us the induced imbalances do happen to the bullet during transition from the case through the throat into the bore. Progress is definitely being made and demonstrated!
Larry Gibson
richardbrinkman
I have been following along and you are doing some very interesting stuff. But I wonder about the lube cookie what ever the stuff is would that not introduce more lube if not too much lube into the barrel and have a great effect on the accuracy? Would not something like floral foam be better? Just asking?
Richard
sgt.mike
😮 Absolutely good work on the Breech seater Kudos to Tim on the concept and holding tolerances down. When this was talked about I had my doubts, and favoured Muzzle seating methods but, the proof is there. Great work Bjornb and Goodsteel on the Breech Seater. It worked way better than I figured it would which proves to show no one has all the answers, but collectively there is a wealth of knowledge.
On the Mango chronograph, That is just slick glad to hear that it works with cast although I wondered why it would not.
Like usual Great Post Bjornb great information.Larry Gibson hit something to be obvious and so true bullet quality is key. Before launching the bullet in Jacketed velocity. Sure any one can send one down the tube at High velocity but to keep the components (bullet, lube,powder) in line by careful selection to assist in accuracy goals is another task. Bjornb demonstrated that taking concepts that have worked and careful consideration does yield results, although I must use some humour here sometime not the results that was desired. But like learning to walk you just have to fall to succeed sometimes if it was easy anyone could do it.
In closing Bjornb great work as usual keep up the good work and the knowledge sharing.😮 Absolutely good work on the Breech seater Kudos to Tim on the concept and holding tolerances down. When this was talked about I had my doubts, and favoured Muzzle seating methods but, the proof is there. Great work Bjornb and Goodsteel on the Breech Seater. It worked way better than I figured it would which proves to show no one has all the answers, but collectively there is a wealth of knowledge.
On the Mango chronograph, That is just slick glad to hear that it works with cast although I wondered why it would not.
Like usual Great Post Bjornb great information.Larry Gibson hit something to be obvious and so true bullet quality is key. Before launching the bullet in Jacketed velocity. Sure any one can send one down the tube at High velocity but to keep the components (bullet, lube,powder) in line by careful selection to assist in accuracy goals is another task. Bjornb demonstrated that taking concepts that have worked and careful consideration does yield results, although I must use some humour here sometime not the results that was desired. But like learning to walk you just have to fall to succeed sometimes if it was easy anyone could do it.
In closing Bjornb great work as usual keep up the good work and the knowledge sharing.Mango chronograph? Must be the chimp in you sarge.
LOL love it. now not to drift any further from the post as it is the OP wishes but ya just have to have fun with this stuff.Again great results and observations Bjornb
Now to apply some of what you have used (methods, etc) on to the ought sixes here in the stable to see where the limit is in a differant post. Because of bore conditions of what I have right now I suspect I will max out quicklytimmalcolm
Glad it worked out for you Bjorn.
The breach seater was a concept based on what we know about shooting HV cast. Everybody agrees that the lions share of the imballance to the projectile happens at engrave. Otherwise paper patched bullets could not be driven to 3000FPS.
My thought was to control the engraving of the projectile with the breach seater so that it’s perfect every time, and why not? Considering the time and expense people go to to achieve HV with cast, (often recommending casting as many as 2000 bullets (which is committing to $450 of expense if you do any math) simply turning a little bit of metal on the lathe is a simple thing.Now basing success on one range session is not wise, and I can’t wait to see what future outings yield, but 5 shots in a .900 group at more than 2800FPS cannot be ignored. Very very impressive Bjorn.
rhbrink:
The seating depth is fully adjustable. You simply set the depth so that the plunger anvil touches the throat, then back off .010 for safety.erty
swheeler
ianharris
Sub-moa accuracy at over 146K rpm, not to mention 2850 fps in a .30-caliber………… all by fixing the launch. Imagine that!
What I find interesting is the difference between a perfect “Morse Taper” static fit between bullet and throat with fixed ammunition and that of a pre-seated, pre-engraved bullet. A lot can go wrong in that first half inch of bullet travel, in fact most all of what goes wrong happens there, I think we can finally all agree on that.
Bjorn, a HUGE thank you for all that, and especially (I think!) for promptly testing that new gizmo which will now cause me to deplete some funds. I’m glad I delayed my .308 specialty die order until you tested that thing out with cast.
Gear
Sub-moa accuracy at over 146K rpm, not to mention 2850 fps in a .30-caliber………… all by fixing the launch. Imagine that!
What I find interesting is the difference between a perfect “Morse Taper” static fit between bullet and throat with fixed ammunition and that of a pre-seated, pre-engraved bullet. A lot can go wrong in that first half inch of bullet travel, in fact most all of what goes wrong happens there, I think we can finally all agree on that.
GearFortunately, we no longer have to imagine anything. It was demonstrated (finally) and very well.
I’m surprised you found disagreement with somebody over the damage happening in the first inch of rifling. From everyone I have talked to on all sides of the HV CB crowd, the only thing that everyone agreed on was that point exactly. Each camp has their own trick for getting past this succinct issue, but some see power in being a teacher, and some take power by withholding information.
I think this is a place where the teachers are welcome.Personally, I’m trying to explore every way that the launch can be manipulated. The breach seater was too obvious not to do.
Larry Gibson
richardbrinkman
sgt.mike
timmalcolm
daveridenour
erty
swheeler
ianharris
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