I got my TJ .250 1-14 twist barrel today.
Beautiful job by Troy on the machining.
Regards,
Roachcreek
Beautiful job by Troy on the machining.
Regards,
Roachcreek
My TJ barrel arrived today
- Thread starter Roachcreek
- Start date
Awesome.. I really interested to see what works out that barrel..I imagine it should work with 55gr + slugs.
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SWEET! Haven't heard from Troy in a while and wondered what he was up to. Can't wait to see how that new barrel performs!
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That’s great - you are the first person I’ve seen here with that barrel…
I have a 24” TJ .250 on an airforce frame. Finally live in a place with a yard where I can shoot it outdoors. I’m actually in the process of trying to figure out what types of projectiles would work best with that barrel
I was not getting great results with NSA 43 grains but maybe need to adjust velocity
I have a 24” TJ .250 on an airforce frame. Finally live in a place with a yard where I can shoot it outdoors. I’m actually in the process of trying to figure out what types of projectiles would work best with that barrel
I was not getting great results with NSA 43 grains but maybe need to adjust velocity
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It is a much modded Kral Bighorn 25 caliber.
I was getting as high as 88 FPE/940 fps and change with the 18 inch own barrel, I dechoked and polished. It uses Troys valve work and a Bulldog spring and .5 liter 4500 psi tank. It is ported to .24 if I remember correctly. I think it will get 110 FPE with the extra 10 inches.
I cast the MPmolds 44.5 in hp and solid 46 grain and the MPMolds 47 grain rn/boat all of which work through the magazine.
I will see how much FPE I can get from it, then try for a sedate 100 fpe tune.
It is apples to oranges comparing it to my old Haley Scandalous which came with a. 1-14 twist barrel that shot great with 75 to 90 grains, I had Doug fit a 1-10 twist barrel also but I never got the accuracy that the 1-14 had, but it was a .257 barrel @ 36 inches.
The flash hider is a airsoft accessory that I retapped to 1/2-20 for my p-rod, it is on there ONLYto protect the 1/2-20 threads as I seem to crash and burn often these days.
Glad to hear your getting settled there MrP.
Regards,
Roachcreek
I was getting as high as 88 FPE/940 fps and change with the 18 inch own barrel, I dechoked and polished. It uses Troys valve work and a Bulldog spring and .5 liter 4500 psi tank. It is ported to .24 if I remember correctly. I think it will get 110 FPE with the extra 10 inches.
I cast the MPmolds 44.5 in hp and solid 46 grain and the MPMolds 47 grain rn/boat all of which work through the magazine.
I will see how much FPE I can get from it, then try for a sedate 100 fpe tune.
It is apples to oranges comparing it to my old Haley Scandalous which came with a. 1-14 twist barrel that shot great with 75 to 90 grains, I had Doug fit a 1-10 twist barrel also but I never got the accuracy that the 1-14 had, but it was a .257 barrel @ 36 inches.
The flash hider is a airsoft accessory that I retapped to 1/2-20 for my p-rod, it is on there ONLYto protect the 1/2-20 threads as I seem to crash and burn often these days.
Glad to hear your getting settled there MrP.
Regards,
Roachcreek
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I was just getting set up to do some casting and I reached for that MP boat tail mold for my 25 caliber run since you get six to pour you can really crank them out,. I have 50 and 60 grain BBT molds if the MP isn’t a good fit. I have some bushings to resize whatever I cast to a common diameter.
Kind of a non sequitur but I figured while casting for .25 I should try out this inexpensive lee .357 “trashcan“ mold. The quality looks good to my relatively untrained eye, but the mold was about a quarter of the price of a typical 4 or 6 cavity air gun mold.
Thanks for the kind thoughts I hope things are going well for you and you are enjoying the spring! It really is a kind of bliss to be in my own place digging out dandelions, mowing the lawn,
plinking when the spirit moves me.
**update: just tried out H and N .250 Slug HP 36 grains. I had the PW at the lowest setting as this gun has a Doug Noble mechanism. They seem to work well with the barrel and hit reliably even at the lowest power setting.
Kind of a non sequitur but I figured while casting for .25 I should try out this inexpensive lee .357 “trashcan“ mold. The quality looks good to my relatively untrained eye, but the mold was about a quarter of the price of a typical 4 or 6 cavity air gun mold.
Thanks for the kind thoughts I hope things are going well for you and you are enjoying the spring! It really is a kind of bliss to be in my own place digging out dandelions, mowing the lawn,
plinking when the spirit moves me.
**update: just tried out H and N .250 Slug HP 36 grains. I had the PW at the lowest setting as this gun has a Doug Noble mechanism. They seem to work well with the barrel and hit reliably even at the lowest power setting.
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Neat combo. it's a 25-20 but in .250 vs .257. I will be interested to hear how the MP HP does, I have that mold but no barrels small enough to shoot it out of..... It is an easy casting mold, I just do not having anything that will shoot it, lol..
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I run the TJ 25 cal 1:14 twist barrel in my Huben it is a 27 inch barrel
it shoots the Varmintknocker 32.80gr slug at a speed at 1070 fps .
it shoots the Varmintknocker 32.80gr slug at a speed at 1070 fps .
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Mike,
That is why I went with the .250 25 auto barrel. My oem Kral barrel is .250 and I size to .251 the 18 and 28 inch barrel, I now have a two barrel system giving me a short powerful carbine and a long barrel power house.
Two screws for the barrel, and three throw levers to transform from a handy 88 FPE carbine with repot to a 100fpe rifle with a big Hawk on it.
I have a tensioned reflex shroud in the works for that long barrel.
RC
That is why I went with the .250 25 auto barrel. My oem Kral barrel is .250 and I size to .251 the 18 and 28 inch barrel, I now have a two barrel system giving me a short powerful carbine and a long barrel power house.
Two screws for the barrel, and three throw levers to transform from a handy 88 FPE carbine with repot to a 100fpe rifle with a big Hawk on it.
I have a tensioned reflex shroud in the works for that long barrel.
RC
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Wow super impressed with the accuracy and power from your Kral!!!Keep us posted on the new TJ barrel on how she shoots!!!!!
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Did some chrony testing today, just turning up the power gradually to see what kind of velocity I can get.
I hit 1049fps or 108 FPE with the 44.5 grain HP MPMolds cast bullet. That is 11 fps per inch for the additional barrel length.
To improve the per inch velocity and aid in cleaning, I will polish the barrel briefly with #7 compound and then finish with a Flitz finish, I picked up an edition 20 fps with my Texan LSS, but this is a different barrel. I plan on giving a very slight taper from chamber to muzzle with the polish. I do thus with a rotating handled solid steel rod with a guide pushing a patch on a jag.
I will have to wait until next week when my daughter gets back from Alaska for some accuracy testing.
I am really pleased with how this Bighorn turned out. The gun is a tank with great build quality. It is a very good value, right now I am 1000 bucks into the Bighorn, I have that much in my P-rod
These are slug guns, at least in the 25. I communicated with another Bighorn 25 owner who uses pellets in his unmodified barrel and Troys tune. He was not all that impressed, I advised him to try slugs, which he did with much better results.
I gripe a lot about short magazine guns, in 25 I can get 47 grains in the magazine, but the 30’s and 357 Bighorns are single shots if you want to shoot slugs of heavier weight.
Regards,
Roachcreek
I hit 1049fps or 108 FPE with the 44.5 grain HP MPMolds cast bullet. That is 11 fps per inch for the additional barrel length.
To improve the per inch velocity and aid in cleaning, I will polish the barrel briefly with #7 compound and then finish with a Flitz finish, I picked up an edition 20 fps with my Texan LSS, but this is a different barrel. I plan on giving a very slight taper from chamber to muzzle with the polish. I do thus with a rotating handled solid steel rod with a guide pushing a patch on a jag.
I will have to wait until next week when my daughter gets back from Alaska for some accuracy testing.
I am really pleased with how this Bighorn turned out. The gun is a tank with great build quality. It is a very good value, right now I am 1000 bucks into the Bighorn, I have that much in my P-rod
These are slug guns, at least in the 25. I communicated with another Bighorn 25 owner who uses pellets in his unmodified barrel and Troys tune. He was not all that impressed, I advised him to try slugs, which he did with much better results.
I gripe a lot about short magazine guns, in 25 I can get 47 grains in the magazine, but the 30’s and 357 Bighorns are single shots if you want to shoot slugs of heavier weight.
Regards,
Roachcreek
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I turned the Bulldog spring out 2 turns after recording a single shot of 1049 fps a couple days ago.
Today I shot a string of 9 shots with the 44.5 grain MPMolds hp I cast and size to .251 I stated before that I was wanting a 1000 FPE rifle and for 1 magazine I am close.
This is a string shot without the valve return spring and averaged 1001 for 9 shots. I thought I had shot 10 shots but either the 10th did not record or in my blindness I only loaded 9.
1-1021 4200 psi
2-1049
3-1030
4-1035
5-1023
6-997
7-997
8-947
9-917 3300 psi
My next test will be with the vrs installed. It will be interesting to see how the Bighorn reacts to reinstalling the vrs. The above string teases me with the beginning of that highly vaunted Bathtub string or simply a lower velocity shot that what shot 2 through 5. However it may also flatten out the string into a 2nd magazine.
I have not yet polished the barrel, in the past I have fireiapped several barrels and I have polished several barrels using a jag, rotating handle solid rod with #7 followed by flintz. I am considering firelapping with Flintz, maybe 50 shots with Flintz imbedded in the bullet by rolling them between two steel sheets coated with Flintz, I welcome thoughts from experienced barrel tuners on this.
Regards,
Roachcreek
Today I shot a string of 9 shots with the 44.5 grain MPMolds hp I cast and size to .251 I stated before that I was wanting a 1000 FPE rifle and for 1 magazine I am close.
This is a string shot without the valve return spring and averaged 1001 for 9 shots. I thought I had shot 10 shots but either the 10th did not record or in my blindness I only loaded 9.
1-1021 4200 psi
2-1049
3-1030
4-1035
5-1023
6-997
7-997
8-947
9-917 3300 psi
My next test will be with the vrs installed. It will be interesting to see how the Bighorn reacts to reinstalling the vrs. The above string teases me with the beginning of that highly vaunted Bathtub string or simply a lower velocity shot that what shot 2 through 5. However it may also flatten out the string into a 2nd magazine.
I have not yet polished the barrel, in the past I have fireiapped several barrels and I have polished several barrels using a jag, rotating handle solid rod with #7 followed by flintz. I am considering firelapping with Flintz, maybe 50 shots with Flintz imbedded in the bullet by rolling them between two steel sheets coated with Flintz, I welcome thoughts from experienced barrel tuners on this.
Regards,
Roachcreek
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I had not cleaned the barrel after 50 slugs, which in my experience could mean a slower velocity due to fouling, so I cleaned the barrel, then polished with Flintz.
I turned up he power one turn on the hammer spring. My scba tank filled to 4100 psi and I fired 10 shots.
1053
1043
1043
1035
1016
1036
1031
1021
1030
1024
Starting pressure 4100, ending pressure 3500 a 2nd magazine will take it to 3000psi
Average velocity and FPE, 1033/105.5.
Well I am tickled with this string, it is a kral cliff string, but only drops 27 fps over 10 shots.
RC
I turned up he power one turn on the hammer spring. My scba tank filled to 4100 psi and I fired 10 shots.
1053
1043
1043
1035
1016
1036
1031
1021
1030
1024
Starting pressure 4100, ending pressure 3500 a 2nd magazine will take it to 3000psi
Average velocity and FPE, 1033/105.5.
Well I am tickled with this string, it is a kral cliff string, but only drops 27 fps over 10 shots.
RC
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that's pretty tight for 10 shots tuned up top and unregulated. With those numbers at that pressure I am assuming there is a fairly small port somewhere in the airpath. That is likely helping control ES a bit but also why so much pressure is required. Finding that restriction would be key to either more energy or lower fill pressures, if you were interested in further changes. You may just leave well enough alone with what you have going now.
As comparison, I am working on a STX Superior Heavy .25 grafted into a Bulldog, 700mm version. it is ported huge, like .328 and using the Huma FX transfer port, so that is an obvious advantage. In tube regulated with approximately 70cc plenum, IIRC. I need to measure plenum again. Reg currently set right at 2000psi. I put the first rounds over the chronograph today. Using that same MP 44gr hollowpoint 2000psi pushes them 970fps. Using the MP 48gr airgun bullets 2000psi pushes them 930fps. Just for kicks I put some King Heavies into the trap, they are running 1080fps. I haven't done any real tuning yet, its running a heavy hammer and the Pitbull spring, but initial results are 15 shots of the MP 48gr at 920-930fps on a single 3kpsi fill, OEM tube. The hammer/spring combo has it running up on the plateau, I cannot dial enough spring out of it to lower velocity....Not off to a bad start though.
Anyway, I do appreciate your sharing the results of your Krahl conversion, it helped inspire me to the testing mentioned above.
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Mike,
Oddly enough, I filled to 3800 today and averaged 107 FPE. Dropping to 3700 psi dropped the energy a bit.
I am loving the Bighorn, but will love it more when Troy gets my reflex shroud finished. I’m sure. I have that heavier 48 grain MPMold and need to cast a few for this project.
RC
Oddly enough, I filled to 3800 today and averaged 107 FPE. Dropping to 3700 psi dropped the energy a bit.
I am loving the Bighorn, but will love it more when Troy gets my reflex shroud finished. I’m sure. I have that heavier 48 grain MPMold and need to cast a few for this project.
RC
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Tried two new bullets today in the TJ barreled Bighorn.
A 50 grain swayed hp from Griffith that I sized diwn to .251.
1-971 starting pressure 3800 psi
2-966
3-966
4-949
5-957
6-955
7-939
8-939
9-935
10-930 ending pressure 3500 psi.
Average 950 fps/100 fpe.
The 2nd bullet, I cast yesterday which is the MPMolds 48 grain round nose boat tail from the 8 cavity aluminum mold, I wish they made it in a cavity brass mold as a 8 cavity mold will never show the consistency of a 2 cavity mold that and well…it’s aluminum. I would eventually like to yay this bullet loaded backwards to impart more energy to the target.
1-993 starting velocity 3800 psi
2-996
3-997
4-998
5-925 very hard chambering perhaps unsized
6-955
7-976
8-970
9-984
10-970 ending pressure 3500 psi.
Average 976 fps/101 FPE.
One more bullet to try, which is the 44.5 grain bullet cast without the hp.
Regards,
Roachcreek
A 50 grain swayed hp from Griffith that I sized diwn to .251.
1-971 starting pressure 3800 psi
2-966
3-966
4-949
5-957
6-955
7-939
8-939
9-935
10-930 ending pressure 3500 psi.
Average 950 fps/100 fpe.
The 2nd bullet, I cast yesterday which is the MPMolds 48 grain round nose boat tail from the 8 cavity aluminum mold, I wish they made it in a cavity brass mold as a 8 cavity mold will never show the consistency of a 2 cavity mold that and well…it’s aluminum. I would eventually like to yay this bullet loaded backwards to impart more energy to the target.
1-993 starting velocity 3800 psi
2-996
3-997
4-998
5-925 very hard chambering perhaps unsized
6-955
7-976
8-970
9-984
10-970 ending pressure 3500 psi.
Average 976 fps/101 FPE.
One more bullet to try, which is the 44.5 grain bullet cast without the hp.
Regards,
Roachcreek
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Rc, I believe the mp slug is 47 grains. How's the accuracy? I wish they made a 2 hole version of it. The only place I have to hear the mold up is on the pot. I have a hot plate but it draws to much power and makes my generator turn on.
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Depending on your casting process and lead mix cast bullets vary in weight. My most recent batch of these I cast averaged around 48.3gr....Busy weekend so I doubt I will be able to put any to paper. By this time next week I should have some data. I'm starting slow, in the 880fps range.
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