Just to reply to the OP’s question: I wouldn’t reduce the taper or sizing and extracting cases will get clicky, if you care about smoothness of your rifle action and sizing dies. This isn’t a 30-06, there is very little to be gained and a lot to be lost by reducing the taper further. I would move the shoulder to gain volume. You can set a false shoulder on 6.5x47 brass with no additional steps to gain the volume you want and 0.010” less neck is hardly noticeable but would gain volume with ease. Are you using Quickload or GRT to target a specific case volume? It really begs the question why you aren’t just going to a 25 Creedmoor though.
Case taper advice 25x47 improved
- Thread starter 762 ULTRAMAGA
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I'm going to muddy the water a bit by suggesting an all new case design. Your idea may or may not make the pf what you want. Take a 6xc, shorten it a bit, form up a 40 degree of you want and neck up to 25. I'd leave the 30 degree , but that's just me. Plenty of room for at least a 6% increase of powder capacity without approaching max pressures. Plenty of room to play.
As far as lessening the taper, the dies being correct make all the difference.
linebaugh
Silver $$ Contributor
Could just get a longer throat, seat the bullets out farther and run 131-138 bullets and it will hit the min power factor with several powders. There has been a thread on here about 25x47, that would be an easy reference to see that it makes power factor.
I was going to dive into NRL hunter until I saw how spead out matches were. I was planning to build a 25x47L so I know it can be done with a little room to spare. Trying to ackley the parent case probably would not net over 100fps so if thats the idea (a bit hard to understand what the OP was going for) it might be smarter to go to a bigger case.
I was going to dive into NRL hunter until I saw how spead out matches were. I was planning to build a 25x47L so I know it can be done with a little room to spare. Trying to ackley the parent case probably would not net over 100fps so if thats the idea (a bit hard to understand what the OP was going for) it might be smarter to go to a bigger case.
X-Caveman
Gold $$ Contributor
I think the OP needs 2,815 with a 135 to meet PF. Are you running a can or a brake? What barrel length? As previously stated, you may have to stand on it pretty hard. The whole NRL Hunter game seems to have been developed around the 6.5 Creedmoor & 140 class pills. I have to stand on a 6.5x47 pretty hard with a 142 & 22-1/2” krieger to make it.
Reducing the taper from .014 to .010 will have virtually no effect on capacity and may create problems with chamber finish and extraction.
Shoulder angle has no effect on case stretching from firing, but a sharper shoulder may prevent as much brass flow during sizing. Also, chambers and dies are often a little closer in tolerance than those made to SAAMI specs, which definitely aids in this.
There is really nothing you can do with the 47mm Lapua brass to get enough capacity increase to make a significant difference in performance. However, if you are able to convince yourself that the minor change you have made in case shape has also given it the ability to handle higher pressures, you can load it to the nuts and see some increase. This is the real secret to every "Improved" cartridge; with some exceptions noted. WH
Shoulder angle has no effect on case stretching from firing, but a sharper shoulder may prevent as much brass flow during sizing. Also, chambers and dies are often a little closer in tolerance than those made to SAAMI specs, which definitely aids in this.
There is really nothing you can do with the 47mm Lapua brass to get enough capacity increase to make a significant difference in performance. However, if you are able to convince yourself that the minor change you have made in case shape has also given it the ability to handle higher pressures, you can load it to the nuts and see some increase. This is the real secret to every "Improved" cartridge; with some exceptions noted. WH
Running a brake and 27" barrel
No interest in a creed, I don't like the case design and I'm having great success with N150 in the x47/GT capacity cases.
As I mentioned already earlier I'm a big fan of 40 degree shoulders and near complete elimination of trimming.
If anything it'd probably be smart to just stick with a 6.5x47 but what's the fun in that..
Yeah I see guys are getting right there velocity wise from a straight 25x47, I think Ackleyizing it will realistically get me about a 50-75 fps gain at equal pressure.
To me that's a win
Maybe.
Maybe not.
I'm coming from my experience with the 7mm-08 Improved 40° (aka AI).
With the 47 case, like the 308 case, you will hardly be gaining any volume with decreasing the case taper. There's not a huge amount of taper to begin with.
It's not like improving the 250 Savage or any of the X57 Mauser cases.
Where you'll see a volume increase would be by going to a steeper shoulder angle and pushing the shoulder forward.
And even that isn't a huge amount.
Based on the 51mm case, I ended up with about 1gr of increased case volume.
I did end up with almost 50fps increase over the standard 7mm-08. But I'm pushing fairly hot.
The real difference is going to be bullet and powder choice.
In my circumstances I gained almost 130fps with a 140gr Berger VLD and RL17.
Still running hot, but pushing a 140gr bullet at 2,916fps from a 22" barrel.
I kinda went a different route. I took .199" off of a 257 Roberts Ack Imp die and had the reamer ran in the same short depth in the barrel. One pass of 243 brass thru a shortened FL die and I am done. No fire forming required. The result is a 25 Compact Buck Buster. No custom dies, no custom reamer.
I don't know what PF it is as I don't compete. If I have a formula I could tell you the PF. I also don't stay on top of the dimensions for the latest and greatest cartridge. I may have a 25 CM or 25x47L and not know it.
I don't know what PF it is as I don't compete. If I have a formula I could tell you the PF. I also don't stay on top of the dimensions for the latest and greatest cartridge. I may have a 25 CM or 25x47L and not know it.
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It will not. Not unless you are shooting in Fantasyland. Since the change in capacity is miniscule, the change in velocity will be likewise, unless you bump the pressure up significantly. Sorry. WH
Just a few things to consider. These guys in this video are planning to shoot their 25 X 47 rifles next NRL season and they say 2900 FPS is where they will try to be. I settled on my load with Berger 135 gr. LRHT @ 2950 FPS and have been to 3000 FPS. The tune looked better @ 2950 FPS so my reason for settling there. I contribute my M V to the personal reamer my builder designed. I shot the 10 shots listed on the Garmin in a tad cooler weather than when I developed the load so the M V is a reflection of that. You may follow my thread here if you like.
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Thats impressiveJust a few things to consider. These guys in this video are planning to shoot their 25 X 47 rifles next NRL season and they say 2900 FPS is where they will try to be. I settled on my load with Berger 135 gr. LRHT @ 2950 FPS and have been to 3000 FPS. The tune looked better @ 2950 FPS so my reason for settling there. I contribute my M V to the personal reamer my builder designed. I shot the 10 shots listed on the Garmin in a tad cooler weather than when I developed the load so the M V is a reflection of that. You may follow my thread here if you like.
What powders are you using to break 2850?
Edit: checked out your thread, very cool.
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Thanks, I along with my shooting buddy SVT_Tactical plan to keep it updated as we progress with the rifles.
135 GR. BERGER LRHT 2.131 O M 2.883 COL T/L B S .465 B C .650
POWDER VV-N540 38.3 GR. PRIMER CCI 450 .281 BU. T/S -10-
SEATED @ 2.124 O M 2.876 COL .007 OTL
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Alex Wheeler
Site $$ Sponsor
I have a handful of guys on the 25×47. 133s at about 2880 with varget in a 28" barrel. You can take them to 3000 but they shoot best around 2900. So with a 27" barrel I think you should be right there. And there are powders that will run faster, varget seems to be the most accurate. These are all long range BR rifles. I dont have a huge number of them out there but percentage wise they do more winning than anything.
Well I appreciate everyone's input
I've ordered the 40 degree improved reamer with .010 taper.
The designer was very helpful and confirmed that it won't be a problem since the TPI is above their recommended minimum.
I've ordered the 40 degree improved reamer with .010 taper.
The designer was very helpful and confirmed that it won't be a problem since the TPI is above their recommended minimum.
Infrequent Shooter
Gold $$ Contributor
Huge fan here of Zack D, 6x47 and 25x47. Maybe the 25 is starting to get some traction finally.
B23
Gold $$ Contributor
When BJ/Sierra came along with their high BC 131 that seemed to really get the ball rolling and get peoples attention on what could be with a high BC 25 cal. The water was already warm when Berger and Hornady jumped in with their new high BC heavy for caliber 25's and that seemed to really heat things up.
I'm not aware of a time when 25 cals had more interest among the shooting sports world than it does right now.
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