My TJ barrel arrived today
- Thread starter Roachcreek
- Start date
Desertsilver, my MPmols hp mold bullets weight 44.5 grains, but if cast it as a solid it weighs 47 grains.
Thanks Bear. These 25 caliber Bighorns are powerhouses. But a lot of the utility of the Bighorn 25’s is that their magazines will take projectiles up to 50 grains, if the magazines on the 30’s and 357’s were long enough for proper slugs they would be far more than the pellet shooters they presently are.
When I purchased mine from Troy Hammer, I sent him some of my cast bullets to tune it with but I still needed to remove the choke, it was so tight that removing a inch or more did not decrease velocity.
I am a sucker for hot 25’s.
RC
Thanks Bear. These 25 caliber Bighorns are powerhouses. But a lot of the utility of the Bighorn 25’s is that their magazines will take projectiles up to 50 grains, if the magazines on the 30’s and 357’s were long enough for proper slugs they would be far more than the pellet shooters they presently are.
When I purchased mine from Troy Hammer, I sent him some of my cast bullets to tune it with but I still needed to remove the choke, it was so tight that removing a inch or more did not decrease velocity.
I am a sucker for hot 25’s.
RC
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Being my first PCP was a 25 cal I totally understand specially shooting heavier projectiles at those speeds. I would imagine very devastating.
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Desert silver,
The weight difference is due to the alloy. I am using pure lead, or I should say I was using pure lead, since my accident, I have decided that my beloved 55 years of bullet casting is done. My vision problems have caught up to me as far as casting is concerned.
Rc
The weight difference is due to the alloy. I am using pure lead, or I should say I was using pure lead, since my accident, I have decided that my beloved 55 years of bullet casting is done. My vision problems have caught up to me as far as casting is concerned.
Rc
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Desert silver,
The weight difference is due to the alloy. I am using pure lead, or I should say I was using pure lead, since my accident, I have decided that my beloved 55 years of bullet casting is done. My vision problems have caught up to me as far as casting is concerned.
Rc
I'm sorry RC.
It's hell to get old and have to give up the things we've loved to do most of our lives. I'm in kind of in the same boat with dirt/street motorcycles. I'm sure your wife and kids will be a lot happier.
The weight difference is due to the alloy. I am using pure lead, or I should say I was using pure lead, since my accident, I have decided that my beloved 55 years of bullet casting is done. My vision problems have caught up to me as far as casting is concerned.
Rc
I'm sorry RC.
It's hell to get old and have to give up the things we've loved to do most of our lives. I'm in kind of in the same boat with dirt/street motorcycles. I'm sure your wife and kids will be a lot happier.Upvote 0
Giving all my casting equipment and rotometal lead to my son. He can use it for the mdl 1878 engraved Sharps Borchardt 45-100 I gave him after he returned from the Sandbox.
Now I have to find a slug my .250/1-14 likes.
RC
Now I have to find a slug my .250/1-14 likes.
RC
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Here's a question born of ignorance.
Does a TJ barrel arrive ready to install?
By this I mean:
barrel port drilled, leade prepared, barrel crowned and muzzle threaded, ,etc.
In other words, fully machined.
Very curious to know
Thanks
Edward
Does a TJ barrel arrive ready to install?
By this I mean:
barrel port drilled, leade prepared, barrel crowned and muzzle threaded, ,etc.
In other words, fully machined.
Very curious to know
Thanks
Edward
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Edward,
They are a barrel blank only.
This means they MUST be machined to fit your Airgun. Troy Hammer did mine.
RC
They are a barrel blank only.
This means they MUST be machined to fit your Airgun. Troy Hammer did mine.
RC
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RC- my testing with both of my cast MP Molds bullets was a failure. The slugs "looked good" to me, but they absolutely would not fly straight out of the 700mm STX Superior Heavy. Summer is upon us so I do not plan to troubleshoot the problem until fall/winter...
I did, on a whim, order some of the Altaros 49.5gr. At risk of sounding like just another fan boy, I must say that I am a believer. After my casting failure i resigned to shooting King Heavies in the 1020fps range as I didn't want to change my tune..... Surprisingly even with the Superior Heavy liner's 1-18 twist this produced acceptable groups in the 1.5-2" range, but were easily influenced by the slightest breeze. This, to reiterate was done with my regulated Bulldog which I grafted in a 700mm STX Superior Heavy using a Huma FX transfer port inside a piece of 4130 as a thimble/bushing. Then a bunch of layers of CF tubing up to an OD of 19MM.
The assembly is all held together with a combination of JB Weld and Loctite 680.... Swapping from King Heavies with no other changes resulted in 20-22 shots of 845-850fps. At 100 yards the Altaros was right at 2" lower poi. Groups of 1.5" or less have been relatively easy and consistent across a fulll fill, even with a bit of breeze. Those groups frequently have 3 shots inside of .5". I'm not saying these are the best available slugs as I have not tried any others, but I am saying they shoot pretty good out of this particular contraption and I will likely buy more. So far this is about as content as I have been with my small bore bulldog.
Down to around 3000psi in my regulated tank, after I exchange for a fresh tank I may swap to my high pressure tube and do some 3500psi unregulated testing to see if I can find decent >100fpe tune. There is no real reason to do this other than curiosity, as 78-79fpe seems to be doing just fine from an accuracy perspective.
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Mike,
Not being able to get out much, combined with the safety troubles I have had with casting, I have given up, just something the nearly blind should do.
Having stated this, I think much of the trouble with the MPMold in 8 cavity is the difficulty in the slugs not being uniform. That in,my opinion, is the real problem with gang molds in smal diameter slugs. The design of that slug does seem to work, just too bad they are not coming out of a 2 cavity mold.
I experienced accuracy problems also when my daughter took me shooting, but had decided it was due to trouble seeing through the scope on such a bright day with almost no retinas left.
I have considering some of the Altaros slugs and some of the heavier NSA slugs, 44 to 55 grain, to get in the 880 to 900 fps realm.
I slugged my barrel at .249, so that should open up the possibility of using store bought ammo and give my family some piece of mind. Three weeks later and I have been able to shed the bandages, with the exception of resealing the booster which I did mostly one handed with Lani fitting the wrenches to the screws for me.
I need to find a single shot tray for the Bighorn and figure 100 slugs will last me.
Any suggestions on slugs in that weight range?
RC
Not being able to get out much, combined with the safety troubles I have had with casting, I have given up, just something the nearly blind should do.
Having stated this, I think much of the trouble with the MPMold in 8 cavity is the difficulty in the slugs not being uniform. That in,my opinion, is the real problem with gang molds in smal diameter slugs. The design of that slug does seem to work, just too bad they are not coming out of a 2 cavity mold.
I experienced accuracy problems also when my daughter took me shooting, but had decided it was due to trouble seeing through the scope on such a bright day with almost no retinas left.
I have considering some of the Altaros slugs and some of the heavier NSA slugs, 44 to 55 grain, to get in the 880 to 900 fps realm.
I slugged my barrel at .249, so that should open up the possibility of using store bought ammo and give my family some piece of mind. Three weeks later and I have been able to shed the bandages, with the exception of resealing the booster which I did mostly one handed with Lani fitting the wrenches to the screws for me.
I need to find a single shot tray for the Bighorn and figure 100 slugs will last me.
Any suggestions on slugs in that weight range?
RC
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RC -
Your tenacity to continue with the hobby and wisdom to walk away from casting are admirable.
Unfortunately I just do not have much slug experience to go by. Really I didn't know if my accuracy problem was my caveman grafting of the STX liner to the bulldog or if it was my poor casting skills. So I chose to try ammo that had proven to be successful with the Superior Heavy liner, ultimately I chose to try the Altaros after reading about their successes in competition.
Depending on how you look at it I am glad to learn it wasn't the liner/barrel transplant, but my casting skills.
I would say you couldn't go wrong with the Altaros and they now make them in 49.5, 60, and 67gr. That long 67gr would probably be a good match for your 1:14 barrel and the power you're producing.
BTW, I did exchange a cylinder so I now have full fill capability again. This allowed me to do some preliminary unregulated testing with my high pressure, OEM length tube. Understand this Bulldog has .328 porting feeding an FX Huma Slug transfer port, so porting is relatively huge. Couple that with my balanced valve and this thing is capable of insane power. I normally run a 30gram MDS hammer with this valve, regulated in the 1800-2000psi range. Swapping to a 60gram hammer and very little hammer free flight, 3500psi pushed the MP 48.3gr airgun bullets 1150-1170fps!!!!! I toned things down a bit by dialing in more gap/hammer free flight and I am seeing a decent 10 shot tune of 48.3gr that goes 1080-1105-1080fps. Pretty crazy for a .250. But that is what big porting, high pressure, and 700mm of barrel will do..... Very early phases and I am not certain if I will do anything other than chrony testing at these power levels, but it is useful to know what the upper ends of capability are.
Your tenacity to continue with the hobby and wisdom to walk away from casting are admirable.
Unfortunately I just do not have much slug experience to go by. Really I didn't know if my accuracy problem was my caveman grafting of the STX liner to the bulldog or if it was my poor casting skills. So I chose to try ammo that had proven to be successful with the Superior Heavy liner, ultimately I chose to try the Altaros after reading about their successes in competition.
Depending on how you look at it I am glad to learn it wasn't the liner/barrel transplant, but my casting skills.
I would say you couldn't go wrong with the Altaros and they now make them in 49.5, 60, and 67gr. That long 67gr would probably be a good match for your 1:14 barrel and the power you're producing.
BTW, I did exchange a cylinder so I now have full fill capability again. This allowed me to do some preliminary unregulated testing with my high pressure, OEM length tube. Understand this Bulldog has .328 porting feeding an FX Huma Slug transfer port, so porting is relatively huge. Couple that with my balanced valve and this thing is capable of insane power. I normally run a 30gram MDS hammer with this valve, regulated in the 1800-2000psi range. Swapping to a 60gram hammer and very little hammer free flight, 3500psi pushed the MP 48.3gr airgun bullets 1150-1170fps!!!!! I toned things down a bit by dialing in more gap/hammer free flight and I am seeing a decent 10 shot tune of 48.3gr that goes 1080-1105-1080fps. Pretty crazy for a .250. But that is what big porting, high pressure, and 700mm of barrel will do..... Very early phases and I am not certain if I will do anything other than chrony testing at these power levels, but it is useful to know what the upper ends of capability are.
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Mike,
I ordered some Altaros 67 grain slugs today. At that price I wonder if Parker Schnable from Gold Rush furnished the ore.
I ordered a little Kral single shot loader, but whether it fits will be determined once it gets here. I could not find a 25 cal loader with the swing out option, all were 177 and 22. I suppose I could just open up a 22 single shot loader if the one I ordered does not work.
RC
I ordered some Altaros 67 grain slugs today. At that price I wonder if Parker Schnable from Gold Rush furnished the ore.
I ordered a little Kral single shot loader, but whether it fits will be determined once it gets here. I could not find a 25 cal loader with the swing out option, all were 177 and 22. I suppose I could just open up a 22 single shot loader if the one I ordered does not work.
RC
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I was a little worried about meeting the 803 fps recommended by Altaros for the 67 grain bullet, so I did a test, I sized down a 73 grain .258 257420 cast bullet. The first sizing was to .253 then .251. This was still oversized for the .249 groove diameter, but it chambered.
I filled to 4K using the same Hammer spring pre-load.
I fired only one shot which registered 810 fps/105 fpe for the now 251420 73 grain bullet.
Looks like I will have power to spare, but I still need a new sizer.
I have a problem on what to size to. The groove diameter is .249, which would require a .250 sizer, however the bore diameter is 243, which Desert Silver has pointed out and the TJ specs confirm, makes every slug out there a tight bore rider. So perhaps I should size to .247 or .248 to reduce the effort to chamber the slug. More than enough of the bullet diameter should be left over to fill the riffling grooves.
An example of a typical bore rider bullet is the Lyman 457425 which is the same as the 500 grain slug used in the 45-70-500 US military 1873 Trapdoor Springfield. Upon chambering the bullets nose is supposed to be a perfect fit to ride the rifling or bore diameter’s, unfortunately black powder fouling can make loading difficult without a blow tube. Fortunately this fouling is not a problem in Airguns, but most long .25 Airgun bullet designs, like the Altaros King .250 bullet appears to have a nose that may be oversized for my .243 bore.
NOE makes nose sizers for this problem but not in the diameter I need, perhaps a compromise is required such as a .247-.248 sizer and not size full length. Also needed is a .250 sizer for the bullets driving bands.
Regards,
Roachcreek
I filled to 4K using the same Hammer spring pre-load.
I fired only one shot which registered 810 fps/105 fpe for the now 251420 73 grain bullet.
Looks like I will have power to spare, but I still need a new sizer.
I have a problem on what to size to. The groove diameter is .249, which would require a .250 sizer, however the bore diameter is 243, which Desert Silver has pointed out and the TJ specs confirm, makes every slug out there a tight bore rider. So perhaps I should size to .247 or .248 to reduce the effort to chamber the slug. More than enough of the bullet diameter should be left over to fill the riffling grooves.
An example of a typical bore rider bullet is the Lyman 457425 which is the same as the 500 grain slug used in the 45-70-500 US military 1873 Trapdoor Springfield. Upon chambering the bullets nose is supposed to be a perfect fit to ride the rifling or bore diameter’s, unfortunately black powder fouling can make loading difficult without a blow tube. Fortunately this fouling is not a problem in Airguns, but most long .25 Airgun bullet designs, like the Altaros King .250 bullet appears to have a nose that may be oversized for my .243 bore.
NOE makes nose sizers for this problem but not in the diameter I need, perhaps a compromise is required such as a .247-.248 sizer and not size full length. Also needed is a .250 sizer for the bullets driving bands.
Regards,
Roachcreek
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it will be interesting see how the Altaros work with your TJ's barrel. Your attention to detail around sizing reemphasizes the sheer volume of variables that are available for us to control, or attempt to control.
In my Superior Heavy the 49.5gr ATP slugs shoot about 35fps slower than the 48.3gr MP bullet. Since they shoot so close in velocity, the MP bullet makes a great substitute for chrony test/tune. My liner is still choked, I do recall Knifemaker/Mike reported success removing the choke from early slug liners. I haven't shot anymore targets, I probably will not until we are finished with my next MDS hammer design and retune around more heavy of a hammer than my current one which only weighs in at 31.5grams. Targeting the 45-50 gram range with the next hammer design, which is a bit light due to having a recess/cavity for the SSG's spring guide to intrude when cocked. I will have a second core design that allows for OEM style hammer springs which should weigh in the 60-70gram range. both will have adjustable peek strikers. I am hopeful the combination of adjustable valve lift and balance chamber volume will work well together once I figure out how the two interact.
In my Superior Heavy the 49.5gr ATP slugs shoot about 35fps slower than the 48.3gr MP bullet. Since they shoot so close in velocity, the MP bullet makes a great substitute for chrony test/tune. My liner is still choked, I do recall Knifemaker/Mike reported success removing the choke from early slug liners. I haven't shot anymore targets, I probably will not until we are finished with my next MDS hammer design and retune around more heavy of a hammer than my current one which only weighs in at 31.5grams. Targeting the 45-50 gram range with the next hammer design, which is a bit light due to having a recess/cavity for the SSG's spring guide to intrude when cocked. I will have a second core design that allows for OEM style hammer springs which should weigh in the 60-70gram range. both will have adjustable peek strikers. I am hopeful the combination of adjustable valve lift and balance chamber volume will work well together once I figure out how the two interact.
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Mike,
Do we have any idea what the diameter of the bore riding section, the nose, is?
I still need to find ammo for my oem 18 inch Bighorn barrel to shoot through the magazine. Have you tried any of the NSA mid 40 grain 250 ammo?
RC
Do we have any idea what the diameter of the bore riding section, the nose, is?
I still need to find ammo for my oem 18 inch Bighorn barrel to shoot through the magazine. Have you tried any of the NSA mid 40 grain 250 ammo?
RC
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RC-
I do not have the 67gr, I have the smooth 49.5gr. I pushed a couple through an STX Superior standard. The one on the left was pushed through the choke, the one on the right was pushed up to the choke, then pushed back out the breech end.
I haven't tried any NSA .250 stuff.
I do not have the 67gr, I have the smooth 49.5gr. I pushed a couple through an STX Superior standard. The one on the left was pushed through the choke, the one on the right was pushed up to the choke, then pushed back out the breech end.
I haven't tried any NSA .250 stuff.
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