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Posted: 2/5/2009 5:05:11 PM EDT
[#1]
Quoted:
Quoted:
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No fireforming? That is correct. Quoted:case taper the same as .223?
That is also correct. Quoted:I think I'm going to come calling for a barrel soon.
I will keep you posted. The goal was to make a wildcat that all one has to do is expand the neck and resize a standard 223 Rem. by simply running through a resizing die. The challenge of course is to keep of overall length of the round compatible with a standard AR15 mag. This can be done, however this restricts you to bullets like the Speer 87gr and 100gr Hot-Cor and Sierra 87gr., 100gr. Prohunters and 100gr Gamekings. By trimming the neck 2mm you have a few more bullet selection options. Again, thanks Kurt for the inspiration. In the mean time I am waiting for the reamer. 320pf 320pf, I may have given the wrong impression. Are we talking about the .25Bailey? Oh snap.......hijacks suck 
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Posted: 2/5/2009 5:17:12 PM EDT
[#2]
Quoted:
Quoted:
No fireforming? That is correct. Quoted:case taper the same as .223?
That is also correct. Quoted:I think I'm going to come calling for a barrel soon.
I will keep you posted. The goal was to make a wildcat that all one has to do is expand the neck and resize a standard 223 Rem. by simply running through a resizing die. The challenge of course is to keep of overall length of the round compatible with a standard AR15 mag. This can be done, however this restricts you to bullets like the Speer 87gr and 100gr Hot-Cor and Sierra 87gr., 100gr. Prohunters and 100gr Gamekings. By trimming the neck 2mm you have a few more bullet selection options. Again, thanks Kurt for the inspiration. In the mean time I am waiting for the reamer. 320pf 320PF , I wasn't even thinking when I posted .My apologies , I should have been more clear.I was refering to Kurt's 25 Bailey. |
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Posted: 2/8/2009 1:12:28 PM EDT
[#3]
A .25x40 cartridge is pretty interesting. Lots of good bullets in .257. You could load 75 grain HPs for general blasting and anti-zombie work, 100 grain BTs for deer, and 115 or 120 grain TSXes or Partitions for penetrating cover. I played around with an online ballistics calculator and it looks like it would be a fine deer round out to 200 yards.
Just for fun, I did a spreadsheet calculation computing the Bwana Saeed Index from accuratereloading.com, and it generates about the same numbers as a .243 Winnie. Pretty nice for a cartridge that will run in a standard AR upper, and feed from standard AR mags. |
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Posted: 2/24/2009 7:55:12 PM EDT
[#4]
I had to come back and look at this cartridge again.
It's no UBER-cartridge but it seems so satisfying. No fire forming , standard bolt , standard mags... It's just so cute. 
I have my own idea (it's not patented  )for a 27x43 but it just isn't quite as enticing if I have to go through the reamer/dies/bbl procurement .
Do I go for the 25x40 or do I just take my time and do my 27x43? |
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Posted: 2/25/2009 6:09:55 PM EDT
[#5]
Quoted:
Do I go for the 25x40 or do I just take my time and do my 27x43? You could wait a little and partake in my 28x41.5 ... I already have a 7x43 using 6.5x54 brass (*barrel, dies, reamer, brass, etc) |
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Posted: 2/25/2009 7:08:01 PM EDT
[#6]
Quoted:
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Do I go for the 25x40 or do I just take my time and do my 27x43? You could wait a little and partake in my 28x41.5 ... I already have a 7x43 using 6.5x54 brass (*barrel, dies, reamer, brass, etc) I certainly would be glad to entertain it. I've got a lower waiting to become something different and unique . |
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Posted: 2/26/2009 2:26:51 AM EDT
[#7]
Quoted:
A .25x40 cartridge is pretty interesting. Lots of good bullets in .257. You could load 75 grain HPs for general blasting and anti-zombie work, 100 grain BTs for deer, and 115 or 120 grain TSXes or Partitions for penetrating cover. I played around with an online ballistics calculator and it looks like it would be a fine deer round out to 200 yards. Just for fun, I did a spreadsheet calculation computing the Bwana Saeed Index from accuratereloading.com, and it generates about the same numbers as a .243 Winnie. Pretty nice for a cartridge that will run in a standard AR upper, and feed from standard AR mags. Civvie, I am curious, what is the .234 winnie. What case is it based on etc... thanks 320pf |
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Posted: 3/2/2009 2:49:52 PM EDT
[#8]
I shoot the 25x223 in 2 different platforms. One is a 257x223 Harrison Imp on a sako action. the other is a 257 Ingram on a TC Contender. Both are great. The Harrison has less case taper but have to seat bullet deeper to make mag lenght. A 25x223 in an ar shoud be neat.
TS |
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Posted: 3/3/2009 4:48:43 AM EDT
[#9]
This is my first post. I actually found this forum because I was looking for a small 25 cal round (I figured it'd probably be a wildcat) to experiment with. I bought a .257 Roberts for my son, so I have the bullets on hand. Instead of dreaming up a new ideas over lantern light post-Katrina, I was going over similar things during a few minutes of downtime here in Iraq while reading the new Hodgdon reloading manual. And, like someone mentioned, I keep coming back to 25 cal.
It seems this cartridge is still in the development stage or is there any chance of having a barrel made? If not for an AR how about a Savage? I think it'd make an interesting reloading project for my son and I when I get back from the sandbox. |
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Posted: 3/3/2009 4:41:41 PM EDT
[#10]
Looking at the Barnes tsx tipped in 80gr form ... >2900fps ?
I'm liking it more. |
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Posted: 3/4/2009 7:54:25 PM EDT
[#11]
Quoted:
I am curious, what is the .234 winnie. What case is it based on etc... Sorry, just the plain ol' .243 Winchester. |
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Posted: 3/16/2009 3:20:58 PM EDT
[#12]
Kurt , your thread is no good without you.
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Posted: 4/10/2009 9:49:09 PM EDT
[#13]
Hey Kurt,
I have not heard from you for a while. I suppose that work has been keeping you jumping. Between work and getting ready for a few early spring 3-gun matches, I sort of stalled out on my 25 project. I have to order two barrel blanks and get back at it. 320pf |
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Posted: 4/11/2009 4:22:06 AM EDT
[#14]
Quoted:
Hey Kurt, I have not heard from you for a while. I suppose that work has been keeping you jumping. Between work and getting ready for a few early spring 3-gun matches, I sort of stalled out on my 25 project. I have to order two barrel blanks and get back at it. 320pf Massive work and roll out of new procedures, etc in the facility where Kurt works. Plus still rebuilding stuff that was destroyed in hurricanes and a fire. |
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Posted: 5/9/2009 11:40:57 AM EDT
[#15]
Updates?
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Posted: 5/11/2009 4:09:52 PM EDT
[#16]
Quoted:
Updates? Been working on a couple things with the 25....quite a bit of load development between builds, play, and work.....the 80gr TTSX @ 28 to 2,900 is pretty neat... 
Kurt |
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Posted: 5/11/2009 6:01:49 PM EDT
[#17]
Glad to hear you're still working with it .
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Posted: 8/1/2009 9:13:24 PM EDT
[#18]
bump before 3 months
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Posted: 8/2/2009 6:58:45 AM EDT
[#19]
I could start a new thread for this but I think that is related to the development of 25 cal. wildcat for the AR platform.
Update on my "25-Bailey-Long"... the 223 expanded to 257 and shortened 2mm. Same shoulder as the 223. Again, thanks Kurt for inspiring me to do this cat. I bought a barrel from PacNor. It is a 22-in. 3-grove 1:10 twist barrel. PTG did my reamer for me. I have my barrel extension (Brownells), dies (CH4D). Now the question for the group. What gas port position would work the best for a 20-in barrel. Thanks in advance for any advice/disscussion. 320pf |
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Posted: 8/5/2009 6:53:33 AM EDT
[#20]
I find this far more interesting than either the 6.5 or 6.8, for various reason... Mags, bolt, velocity potential, brass. I wish this round was further along and I could buy a barrell and "ammo."
I can be happy all day with a 85gr ttsx at 28-2900 and a 85gr bt at the same velocties. That would be everything I ever wanted out of an AR. Yes, I know a 6.8 beats that, but I really like what the 25 offers. I would really like to see some numbers on 75 gr bullets. |
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Posted: 8/5/2009 12:44:07 PM EDT
[#21]
Quoted:
I find this far more interesting than either the 6.5 or 6.8, for various reason... Mags, bolt, velocity potential, brass. I wish this round was further along and I could buy a barrell and "ammo." I can be happy all day with a 85gr ttsx at 28-2900 and a 85gr bt at the same velocties. That would be everything I ever wanted out of an AR. Yes, I know a 6.8 beats that, but I really like what the 25 offers. I would really like to see some numbers on 75 gr bullets. This just seems like an excellent concept for a bigger-bore more optimized cartridge that is within the 5.56mm boltface & standard magazines envelope. |
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Posted: 8/5/2009 6:38:54 PM EDT
[#22]
Quoted:
I could start a new thread for this but I think that is related to the development of 25 cal. wildcat for the AR platform. Update on my "25-Bailey-Long"... the 223 expanded to 257 and shortened 2mm. Same shoulder as the 223. Again, thanks Kurt for inspiring me to do this cat. I bought a barrel from PacNor. It is a 22-in. 3-grove 1:10 twist barrel. PTG did my reamer for me. I have my barrel extension (Brownells), dies (CH4D). Now the question for the group. What gas port position would work the best for a 20-in barrel. Thanks in advance for any advice/disscussion. 320pf Send me an EMail with proposed loads and I can give you a starting point for port size |
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Posted: 8/11/2009 2:16:59 PM EDT
[#23]
PLEASE make something happen with this project. Looking forward to future developments.
30 rounds of 80ttsx at 2900? I'll take that all day. or 30 rounds of 85BT at 2900, 200+ fps faster than the 75gr .223, better bc, 10 grains heavier. All with a simple barrel swap. |
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Posted: 8/12/2009 6:11:58 AM EDT
[#24]
Quoted:
PLEASE make something happen with this project. Looking forward to future developments. 30 rounds of 80ttsx at 2900? I'll take that all day. or 30 rounds of 85BT at 2900, 200+ fps faster than the 75gr .223, better bc, 10 grains heavier. All with a simple barrel swap. You can also get 30rds of 6.8SPC in the 85gr TSX at 3030fps with a 16" barrel. Barrett makes 30 round mags (little more expensive per mag, but they rock in quality). I have a big place in my heart for .257 cartridges, though. I would like to see a high capactiy .257 cartridge in the AR. Would be sweet... |
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Posted: 8/13/2009 7:55:14 PM EDT
[#25]
Quoted:
I could start a new thread for this but I think that is related to the development of 25 cal. wildcat for the AR platform. Update on my "25-Bailey-Long"... the 223 expanded to 257 and shortened 2mm. Same shoulder as the 223. Again, thanks Kurt for inspiring me to do this cat. I bought a barrel from PacNor. It is a 22-in. 3-grove 1:10 twist barrel. PTG did my reamer for me. I have my barrel extension (Brownells), dies (CH4D). Now the question for the group. What gas port position would work the best for a 20-in barrel. Thanks in advance for any advice/disscussion. 320pf For your 20" barrel, I'd keep it heavy .850 under the handguards all the way to the rifle gas block seat/shoulder. This way, you can start with a rifle postion and work backwards to midlength or to carbine gas position if you need to –– can't go the other way (carbine to rifle) cause you can't add metal to your barrel. |
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Posted: 8/29/2009 7:07:01 PM EDT
[#26]
Quoted:
.....I would like to see a high capactiy .257 cartridge in the AR. Would be sweet... Not sure what qualifies as a high capacity .257 cartridge but I got to see a couple running today at the Lake Charles range, one based on the 6.8SPC parent case and another off the x39/grendel/PPC parent case.....I think there has been a similar grendel based cat out there called the 257TED for a pretty good while..... Got to see a couple new .25x40s running also.....a 18" middy and a 20" rifle.....the 18" middy was sweet, nice color scheme Miss Bailey 
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Posted: 8/30/2009 5:22:41 AM EDT
[#27]
We need a report on these! They are too interesting for just tidbits here and there.
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Posted: 10/5/2009 8:19:53 AM EDT
[#28]
Bump for update.
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Posted: 10/5/2009 4:05:02 PM EDT
[#29]
Quoted:
Bump for update. made up an initial set of barrels from 10" to 24" to test......I'm kinda partial to the 10" pistol and the 16 and 18" middy......I haven't seen where the 20" has a big enough advantage over the 18 with the given case capacity, don't have enough capacity to make use of slow powders with the longer barrels, and if you use the fast powders with the longer barrels the bottle neck and long bore = pressure hanging around longer than I like.... 10" pistol likes 4227 16" middy likes 1680 18" middy likes 2015 and 2230 I haven't tried every powder on the planet, but I've tried several....... Quoted:
We need a report on these! They are too interesting for just tidbits here and there. I wish I had more to offer than what's on the thread, have around five barrels that we've been shooting, have a couple sets of dies ( the dies seem to be the long lead item with wildcat projects right now, have waited as long as 7 months for a set ) They shoot great and transition from .223 with only a barrel swap and a set of dies,....no other mods needed.... Quoted:
Quoted:
.....I would like to see a high capactiy .257 cartridge in the AR. Would be sweet... Not sure what qualifies as a high capacity .257 cartridge but I got to see a couple running today at the Lake Charles range, one based on the 6.8SPC parent case and another off the x39/grendel/PPC parent case.....I think there has been a similar grendel based cat out there called the 257TED for a pretty good while..... Got to see a couple new .25x40s running also.....a 18" middy and a 20" rifle.....the 18" middy was sweet, nice color scheme Miss Bailey
blabber mouth.....
Quoted:
PLEASE make something happen with this project. Looking forward to future developments. 30 rounds of 80ttsx at 2900? I'll take that all day. or 30 rounds of 85BT at 2900, 200+ fps faster than the 75gr .223, better bc, 10 grains heavier. All with a simple barrel swap. thanks for the interest.....to keep things dependable for hunting, the 18" middy likes 25.5gr of 2230 with the 80TTSX = 2,825fps.....22gr 1680 will make around 2,875fps, not for soft brass in the 18" barrel, works fine in the 16" with about 50fps less velocity.... Quoted:
Quoted:
I find this far more interesting than either the 6.5 or 6.8, for various reason... Mags, bolt, velocity potential, brass. I wish this round was further along and I could buy a barrell and "ammo." I can be happy all day with a 85gr ttsx at 28-2900 and a 85gr bt at the same velocties. That would be everything I ever wanted out of an AR. Yes, I know a 6.8 beats that, but I really like what the 25 offers. I would really like to see some numbers on 75 gr bullets. This just seems like an excellent concept for a bigger-bore more optimized cartridge that is within the 5.56mm boltface & standard magazines envelope. Thanks, we've been pretty happy with the ones we built....lately it's been easier to create a whole new one-off cat than it has been to make several of one... Quoted:
......Now the question for the group. What gas port position would work the best for a 20-in barrel. 20" rifle.... .077" is what I started with..... |
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Posted: 10/5/2009 8:30:40 PM EDT
[#30]
762x40mm,
In your experience with the velocity potential of the 16, 18 and 20 inch barrels. It sounds like the 20 inch barrel may not give you all that much. So if I build a 20 inch barrel the gas port is about 0.077in in the standard rifle position. An eighteen inch barrel the gas port in the mid-length position also about 0.077 in. Thanks 320 |
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Posted: 10/6/2009 2:20:48 AM EDT
[#31]
I probably send a couple hundred rounds down-range before I ever put a gas port in a new cats AR barrel......with the AR cats I've messed with I like to figure out the velocity window or potential of the cartridge with a given weight range of projectiles before working on getting it to cycle.....with the .25x40 it's 80 to 100gr and 2,500 to 2,900fps depending on weight.....so to say which port will or will not work with your different cartridge would be irresponsible and a guess at best....I can only offer what has worked on mine....
After I figure out the working window of the cartridge I start out with a port on the smaller side or one based off a similar cartridge.....pick a load within the window that I like, load one round in a mag at a time opening the port until the BCG locks back on a empty mag, then all that's left is to final tune .....this is of course using standard weapon components ( BCG, buffer, spring,....) but if your wanting a low recoil impulse rifle or sub-sonic with custom recoil components start with them in the rifle first....SBRs and pistols can be a little different because they usually require faster powders to get full burn in a short distance, but the basics are similar... I have taken ports to the point of saying this is my 80gr rifle and that is my 100gr rifle..... the definition of universal is its made to work with nothing....... |
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Posted: 10/6/2009 7:42:46 PM EDT
[#32]
Quoted:
Quoted:
.....I would like to see a high capactiy .257 cartridge in the AR. Would be sweet... Not sure what qualifies as a high capacity .257 cartridge but I got to see a couple running today at the Lake Charles range, one based on the 6.8SPC parent case and another off the x39/grendel/PPC parent case.....I think there has been a similar grendel based cat out there called the 257TED for a pretty good while..... Got to see a couple new .25x40s running also.....a 18" middy and a 20" rifle.....the 18" middy was sweet, nice color scheme Miss Bailey
High capacity as in BETA C mag loaded to the gills with 80gr TTSX...that kind of high capacity! 
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Posted: 10/7/2009 1:57:10 AM EDT
[#33]
Quoted:
Quoted:
Quoted:
.....I would like to see a high capactiy .257 cartridge in the AR. Would be sweet... Not sure what qualifies as a high capacity .257 cartridge but I got to see a couple running today at the Lake Charles range, one based on the 6.8SPC parent case and another off the x39/grendel/PPC parent case.....I think there has been a similar grendel based cat out there called the 257TED for a pretty good while..... Got to see a couple new .25x40s running also.....a 18" middy and a 20" rifle.....the 18" middy was sweet, nice color scheme Miss Bailey
High capacity as in BETA C mag loaded to the gills with 80gr TTSX...that kind of high capacity! got some..... will a beta loaded with 87 TNTs work?, don't think I have that many 80s left, got a couple thousand 87s .......if so, we can post some pics or maybe a video this weekend.....but, sorry no fun switch..... |
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Posted: 10/11/2009 7:47:29 PM EDT
[#34]
Quoted:
I probably send a couple hundred rounds down-range before I ever put a gas port in a new cats AR barrel......with the AR cats I've messed with I like to figure out the velocity window or potential of the cartridge with a given weight range of projectiles before working on getting it to cycle.....with the .25x40 it's 80 to 100gr and 2,500 to 2,900fps depending on weight.....so to say which port will or will not work with your different cartridge would be irresponsible and a guess at best....I can only offer what has worked on mine.... After I figure out the working window of the cartridge I start out with a port on the smaller side or one based off a similar cartridge.....pick a load within the window that I like, load one round in a mag at a time opening the port until the BCG locks back on a empty mag, then all that's left is to final tune .....this is of course using standard weapon components ( BCG, buffer, spring,....) but if your wanting a low recoil impulse rifle or sub-sonic with custom recoil components start with them in the rifle first....SBRs and pistols can be a little different because they usually require faster powders to get full burn in a short distance, but the basics are similar... I have taken ports to the point of saying this is my 80gr rifle and that is my 100gr rifle..... the definition of universal is its made to work with nothing....... Kurt, I took your advise and I am running the gun without a gas port to see how it runs before I the port in. Here are my results from this weekend. 6.35.43mm (257/223) project Load Data: (standard disclaimer as with any wild-cat, use at own risk and work up slow) 100 gr Speer SPBT (16-inch barrel) 23.0gr H4895 = 2294 fps 23.5gr H4895 = 2336 fps 24.0gr H4895 = 2350 fps 24.5gr H4895 = 2400 fps 25.0gr H4895 = 2463 fps 25.5gr H4895 = 2505 fps 75 gr Hornaday V-Max (16-inch barrel) 25.5gr H4895 = 2560 fps 26.0gr H4895 = 2600 fps 26.5gr H4895 = 2678 fps 27.0gr H4895 = 2728 fps 27.5gr H4895 = 2803 fps I think that H4895 is a bit too slow of a powder for this cartridge. Also there is no way that I can get anything close to the amount of powder in this cartridge as that listed for the 257 Kimber. I have some IMR 3031 around to try but from the data posted on Kurtz's 25/40mm, I think that 1680 may be the best powder. We will find out. By the way, Thanks Kurt for the inspiration for doing this wildcat. Your 25/40m has provided a lot of the "heavy lifting" for this Cat. 320pf Edit: added information on barrel length |
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Posted: 10/12/2009 2:00:48 AM EDT
[#35]
Quoted:
I think that H4895 is a bit too slow of a powder for this cartridge. Also there is no way that I can get anything close to the amount of powder in this cartridge as that listed for the 257 Kimber. I have some IMR 3031 around to try but from the data posted on Kurtz's 25/40mm, I think that 1680 may be the best powder. the 4895 numbers look ok........usually, with the case capacity we're talking about, in my stuff 4895 seems to work well in the smaller bore calibers.... .20, .223, etc...in a .223 with a 69 MK and 25gr 4895 it works out to 3,000fps, and it's compressed..unless you tamp fill tamp fii, then it's really compressed... I always ended up having un-burnt powder in the action and barrel using 3031.....again, I had luck with smaller bores..... don't forget about 2230..... 1680 does seem to be the best all around, watch the charge with barrels over 16".....especially if using soft brass.... |
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Posted: 10/12/2009 4:39:51 PM EDT
[#36]
I got a couple e-mails today asking about layout and measuring the usable capacity of a couple wildcats that are being worked on....
picked one thats pretty basic and being built by a few guys... cartridge specs: .223 parent brass opened up to .25cal shortened to 43mm maintain .223 body taper, same body shoulder junction height, does't require fire-forming I start by making up a model cartridge with a cut-away to to check the bullet base location, in this case a Hornady .25 cal 75gr set to mag length of 2.255".... as can be seen in the picture the bullet base sets about .020" below the shoulder neck junction.....I then make up a case a little above the bullet base.....this acts as a representation of the usable powder capacity of this cartridge..... 
Fill the case to the top with powder, in this instance Hodgdon 4895 
All that's left to do is dump it out and measure it.... 
so with this particular combination: .25x43mm case, Hornady 75gr set to mag length, and 4895 powder, the usable case capacity is 24.3 grains of powder..... hope this helps..... |
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Posted: 10/12/2009 6:34:02 PM EDT
[#37]
Kurt,
A very clever way to check case capacity. COOL. I checked my brass (R-P) and I came up with 26gr of usable case capacity. I did do a little tapping. Then I was curious just to see how much 1gr of powder is. For 4895 it is about 35 to 37 granules of 4895. Tapping would settle the powder to a higher density. That would account for some of the difference and also there is some differences between the different brass manufactures.
I used the published loads for the 6x45mm in the Hodgdon reloading manual for a starting reference. For example Hodgdon lists: 6x45mm 70 gr HDY SP H4895 (24" barrel) Start: 25.5gr.-2809 fps; Max: 27.5gr.-3034 fps 75 gr HDY SP H4895 (24" barrel) Start: 25.0gr.-2704 fps; Max: 27.0gr.-2952 fps 90 gr SPR SP H4895 (24" barrel) Start: 23.5gr.-2509 fps; Max: 25.5gr.-2721 fps 100 gr HDY SP H4895 (24" barrel) Start: 22.0gr.-2414 fps; Max: 24.0gr.-2616 fps Given the larger bore diameter I started with the the 6mm 70 gr data for the 257 cal 75 gr bullet. Similarly with the 257 cal 100 gr bullet. Thanks for another great pointer. And yes it does help.
320pf |
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Posted: 10/17/2009 5:08:25 PM EDT
[#38]
Have been getting several calls and e-mails about the 6.8 variant since I posted a pic of it a couple weeks ago...
The 6.8 and 7mm x40mm are two of the easiest wildcats I've done due to the ability to use and the availability of 7mm TCU dies, no long wait for custom dies......the chamber reamer we had made was laid out to compliment use with the RCBS Gold Medal Match FL 7mm TCU die with a .296 neck bushing..... Had a local shooter interested in one.....this is the 16" middy he ended up with and the loads we shot today......it's still in the white but should get the Duracoat tomorrow.... 
90gr TNT 25gr 4895 = 2,250 fps 90gr TNT 26.5gr H322 = 2,571 fps 90gr TNT 21gr 1680 = 2,400 fps 90gr TNT 22gr 1680 = 2,550 fps 90gr TNT 23gr 1680 = 2,625 fps 90gr TNT 24gr 1680 = 2,737 fps 90gr TNT 25gr 1680 = 2,826 fps 90gr TNT 26gr 1680 = 2,880 fps 90gr TNT 26.5gr 1680 = 2,911 fps This build was really easy, began life as a $69.00 F54 contour 1:10 that was cut to a 16" medium weight middy...the 7mm TCU die had close to .100" cut off the bottom of the forming die to give a case length a little over 40mm...that's pretty much all of the special work, with the exception of de-ribbing a couple $14.00 PMAGS...... 
7.62x39mm, 6.8x40mm (aka: Nemesis), 5.4x39mm 
Quoted:
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Got anything in .27 based on a .378 rim ?
.27 cal 6.8x40mm ( AKA: Nemesis ) .......I never posted anything on it cause the Kramer 6.8 UCC got flamed so bad...but it works pretty damn good.....has a little mechanical advantage over the .25 or 6.5......the advantages that the .25 has is totaly un-modified mags, including HK 416 mags which are very .223 specific....and a little better BC when using the 100gr SMK.... one thing that is kinda neat with the x40 theme is once you cut the neck off of the .223 parent case it can be used cross platform in the .25, 6.5, 6.8, 7, and 7.62......I take 7.62x40 brass and run it in the dies for .25 and .27 all the time.....one pull, done.... the .27 works great but does require mods be made to some magazines to help reduce mag stack tension....I think they found the same thing with the Kramer.... You wouldn't happen to have a side-by-side pic of the .25 and .27 would you ? sure... I'll take some of the whole line-up.....probably post them over in the x40 thread..... 5.4x39, 25x40, 6.8x40, 7.62x40, 7.62x39, 358 ARk 
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Posted: 10/17/2009 5:26:37 PM EDT
[#39]
And you had me all convinced to buy that 7.62x40...what's the saying, "get both"?
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Posted: 10/17/2009 7:02:39 PM EDT
[#40]
Do you have any bbl's in 1:11 or 1:12 to test the .277 with ?
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Posted: 10/17/2009 7:33:17 PM EDT
[#41]
Kurt,
I was doing a bit of research, trying to figure what powders to try next for the 25-223Ar. I noticed that you have tried loads using 18-to-20 gr of 4227 to push 85 gr Nosler BTs to between 2514 to 2686 fps. I then came across some 6.8 SPC load data from Hodgdon. The Hodgdon source lists IMR4227 and LilGun pushing a 90 gr SPR HP between about 2600 to 2900 fps. Here are the Hodgdon Loads (24-in. barrel): LilGun:____20.0 gr=2784fps––-22.7gr=2923fps IMR4227: __21.0 gr=2590fps––-23.9 gr 2795fps So I was thinking of trying both of these powders (LilGun and IMR4227) on the 75 gr V-Max and on some 85 gr Speer TNT and 85 gr Nosler BT. I know that LilGun is a bit fast, but Hodgdon thought is was OK for the 6.8. The expansion ratio [case volume to bore area to case volume ratio for the two cartridges is about the same (~0.0017in^2/grH2O)] for the two cartridges. So I am planning on scaling the 4227 and LilGun starting loads back to about 18 gr and work up from there. So what are your thoughts on this? I have not been able to find any 1680 locally, so I am going to order some on line next week. 320pf |
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Posted: 10/18/2009 6:43:12 AM EDT
[#42]
Quoted:
And you had me all convinced to buy that 7.62x40...what's the saying, "get both"? It looks like the availability of parts is getting better....but I've been leaning toward wildcat ideas that take out a little bit of the 'custom'.....the total conversion on either the 6.8x40mm or 7x40mm was around $288.00 each excluding the chamber reamers and can be done with off the shelf components and access to a machinist.... barrel blank $69.00 barrel extension $19.00 contour blank $100.00 die parts $100.00 total $288.00 the first set of 25x40mm dies was around $250.00 just for the dies IIRC....... |
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Posted: 10/18/2009 6:55:47 AM EDT
[#43]
Quoted:
Do you have any bbl's in 1:11 or 1:12 to test the .277 with ? not unless you have one you want to send me .....naw, I've got a 12 blank sitting on the bench that needs to be contoured and a member is sending me a 13 / 3 that he wants me to take a look at.....
considering the SPC data and gell-o shots with the 90TNT run between 2,600 and 3,100 I don't feel too bad with numbers in the 95 to 97% range with the 1:10.....it's a .272 so its bite isn't quite as bad as a .270, that helps a little..... a while back when the Kramer came out a pretty well known member here asked me what I thought about it.....I said I would of done it a little different, so I guess this is it.... |
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Posted: 10/18/2009 2:13:11 PM EDT
[#44]
got some calls today about people wanting to build their own 6.8x40mm wildcat......
This is what I used..... RCBS 7mm TCU F/L sizer die Gold Medal Match part # 34234 cut .095" off the bottom of the sizer.... RCBS .296 neck bushing (can use smaller if you want more neck tension) part # 81611 RCBS 7mm TCU seater die part # 34238 I used the expander / decap out of my 270 Win but the RCBS 270 taper # is 9833 Kiff / PTG made the reamer.... I use this barrel drawing.... 
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Posted: 10/19/2009 8:22:05 PM EDT
[#45]
Kurt , can you hook me up with a 6.8 bbl ?
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Posted: 10/19/2009 8:32:42 PM EDT
[#46]
Out of curiosity what is the case length on the 358 Ark? 35.5mm or shorter might open up an interesting possibility.
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Posted: 10/20/2009 1:47:11 AM EDT
[#47]
Quoted:
Kurt , can you hook me up with a 6.8 bbl ? I'll send you an IM some time today..... |
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Posted: 10/20/2009 1:59:20 AM EDT
[#48]
Quoted:
Out of curiosity what is the case length on the 358 Ark? 35.5mm or shorter might open up an interesting possibility. I run my 358 brass at 1.425" ( 36.195mm ) .........there should be enough room in the neck to trim it back another .7mm 
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Posted: 10/20/2009 7:54:16 AM EDT
[#49]
Hello Kurt, have you tried bullet weights in the 110 to 130 grain for the 6.8X40mm yet? I'm Interested to see what AA1680 and AA2460 powders can achieve in the 6.5mm-223 (6.5mm AR-TCU project) class, as this sits very close to your 25X40 and 6.8X40mm wildcats.
The only powders I have on hand are AA1680 & AA2460, hence my question. I'm also experimenting with the 6mm-223 AR loads, there seems to very little if any data with the AA1680 powder in 6mm-223. Althougth, I see you have it listed for your 25X40 wildcat in the weights I'm Interested In (85gr.-95gr., mag length) with a 20" bbl.. Seems It should be good for the 6mm-223/6X45mm as well in a 20" bbl. length. Well what can I say...your wildcats are just fantastic, I especially love your 7.62X40mm. Your thoughts/suggestions, Thanx, |
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Posted: 10/20/2009 4:19:43 PM EDT
[#50]
Quoted:
I was doing a bit of research, trying to figure what powders to try next for the 25-223Ar. I noticed that you have tried loads using 18-to-20 gr of 4227 to push 85 gr Nosler BTs to between 2514 to 2686 fps. I then came across some 6.8 SPC load data from Hodgdon. The Hodgdon source lists IMR4227 and LilGun pushing a 90 gr SPR HP between about 2600 to 2900 fps. So I was thinking of trying both of these powders (LilGun and IMR4227) on the 75 gr V-Max and on some 85 gr Speer TNT and 85 gr Nosler BT. I know that LilGun is a bit fast, but Hodgdon thought is was OK for the 6.8. The expansion ratio [case volume to bore area to case volume ratio for the two cartridges is about the same (~0.0017in^2/grH2O)] for the two cartridges. So I am planning on scaling the 4227 and LilGun starting loads back to about 18 gr and work up from there. some say H4227 and IMR4227 are the same, I don't agree.....IMR under the wrong conditions will train wreck quick.... lil-gun is pretty versatile....under the wrong conditions equally train wreckable.... Quoted:
........have you tried bullet weights in the 110 to 130 grain for the 6.8X40mm yet? I'm Interested to see what AA1680 and AA2460 powders can achieve in the 6.5mm-223 (6.5mm AR-TCU project) class, as this sits very close to your 25X40 and 6.8X40mm wildcats. The only powders I have on hand are AA1680 & AA2460, hence my question. I'm also experimenting with the 6mm-223 AR loads, there seems to very little if any data with the AA1680 powder in 6mm-223. Althougth, I see you have it listed for your 25X40 wildcat in the weights I'm Interested In (85gr.-95gr., mag length) with a 20" bbl.. Seems It should be good for the 6mm-223/6X45mm as well in a 20" bbl. length. yes, I've tried 110s and 130s......I like the 85s and 90s.... in larger cases my loads of AA2460 and H4895 are almost identical....within a tenth or so....in the smaller cases the density of 2460 seems to work a little better in my stuff... |
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