GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: shamu25 on August 19, 2015, 12:02:59 PM
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Found a bullet that my 408 Extreme loves. Cast from the RCBS #40-300-SP-CSA mold. They drop at 315 grains with 8 bhn lead. I am looking for a deer load and wondering if this mold can be hollow pointed successfully as it has very little meplat.
(http://i983.photobucket.com/albums/ae315/shamuboat/IMG_1288.jpg) (http://s983.photobucket.com/user/shamuboat/media/IMG_1288.jpg.html)
(http://i983.photobucket.com/albums/ae315/shamuboat/IMG_1287.jpg) (http://s983.photobucket.com/user/shamuboat/media/IMG_1287.jpg.html)
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Contact Erik at Hollowpoint Mold Services.... He will likely suggest fitting a larger HP pin to increase the diameter of the Meplat and push the nose back as part of the process.... There is no problem in doing that, and then you can have whatever Meplat and HP cavity you desire.... Make sure you tell him it is for an airgun, the velocity you are shooting at (and expect the bullet to impact at), and the alloy you are using, as all of those will affect the size of the HP cavity.... If you make it too large, particularly if you make it too deep, the bullet may tend to fragment in combination with high velocity and a soft alloy.... All the factors need be considered to get the desired results....
If you decide you just want to increase the Meplat, you can do that by the same method, just by using a flat pin in the HP conversion.... Erik is the man !
Bob
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thanks for the reply Bob. I spoke with Eric I'm planning to send it to him very soon.when he gets it he said he will let me know what he recommends
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As Bob said, follow Eric's recomendation. You didn't tell us the fps. 800 and especially under is a real problem for large hp'd bullets. One thing for sure, for hunting, the Meplat needs to be larger. Whether HP or not.
With such a tiny mp, its going to over penetrate, with little tissue damage. Sure it will kill, but how quickly is the real question. ;)
It wouldn't hurt at all to get the Bhn down a bit more. Especially when you have it HP'd. I would try pure lead, with no more than 2% tin.
Good looking bullets by the way! 8)
KnifeMaker
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A fine looking molded product and you are pleased with the results! Great. Congrats!
Perhaps it is fine as it is?
You know what your FPS and FT. Lbs. Are. How is it when and after it hits?
I would not mess with a fine mold without reason.
I would carefully set up and drill or trim whatever flat or sample cavities I wanted to try manually, test the results and then decide if /what change is a good idea. I would try several concepts and diameters.
The other suggestions already made are great but I like to fiddle around with hand made prototypes first before changing what works.
I am timid when something works well.
As suggested perhaps a bit more Meplat, in spite of the negative effects of decreasing the BC and slowing it down , it will shock more and perhaps being shorter become even more stable. It would also give more surface to hollow point if desired.
I like the looks of those bullets.
Nice Job
Steve
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At Subsonic speeds, increasing the Meplat diameter will not lower the BC to any noticeable degree.... Supersonic (and Transonic) it very well may....
Bob
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Thanks for the input and kind comments on my casting. The RCBS mold drops beautiful bullets. I recently received a hot plate and digital laser infrared thermometer and it allows achieving good bullets right at the get go. Thanks to this forum for that info also.
I am using soft lead sheet which tests at 8 bhn with my new Lee tester. I have a box of Century springs arriving tomorrow so still testing the 40 cal Extreme before arriving at a velocity at which I am satisfied. I am thinking that I will be shooting these bullets around 850 fps. I like the thoughts about modifying some of the bullets to see how they shoot before sending the mold to Erik. Is it doable to cut off the nose of the bullet on a band saw or similar? How about drilling out hollow points. Not sure how machinable soft lead will be.
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I think Hollowpoint is overrated, I would rather shorten the bullet and increase the Meplat
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That sure sounds much easier. I have cast hundreds of bullets of various calibers but have yet to cast a single hollowpoint bullet. Not sure how the mold even works. The .408 has very limited molds. Been thinking of trying Accurate molds but a bit nervous about picking one. Lots of .408 to .410 on his site but which would be most accurate and effective in the 260 to 280 grain range?
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I believe going to the 260 would be good but I was thinking that a 250 grain would be an awesome weight it will get you well above 900 FPS. The rule of thumb I use for hunting big game is shoot the heaviest bullet I can and still shoot over 900 FPS. The bullet that I have had great luck with on deer size game is the Mr Hollow point 275 Hollow point you can get over 900fps and on many kills with this bullet at 75 yards you will break the entrance shoulder pass through the vitals break the opposite side shoulder and the bullet will be mushroomed nicely just under the skin on the opposite side of the animal creating a nice wound channel with the jagged edges of the hollow point cutting anything in its path and keeping all of the energy in the animal. It is important that you pick a bullet for the size of the game that you will be hunting I think that hollow points definitely have there place for hunting but I also think that solid nose bullets have there benefits for thick large animals if the bullet can not get the penetration on the animal you are hunting then it not good for that situation.
Extreme
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It is important that you pick a bullet for the size of the game that you will be hunting I think that hollow points definitely have there place for hunting but I also think that solid nose bullets have there benefits for thick large animals if the bullet can not get the penetration on the animal you are hunting then it not good for that situation.
Extreme
Well said!
I also agree with Nomadic Pirate: "I think Hollowpoint is overrated, I would rather shorten the bullet and increase the Meplat".
My decision would depend much on the individual gun's performance and twist. Is it stable enough?
In slower twist rifles, I have experienced bullets that were not adequately stable. I can see this in my black powder rifle with its 1:48" twist (It likes round balls best or very short bullets) A vote for larger meplat.
I also see it in my Walther LGV air rifle when I have a longer very heavy pellet . (1:17 1/2" twist) This is especially true when I use a lower power spring. I can see it fly nice about 45 yards and then do weird things like curve or tumble.
The shorter pellet stays accurate and stable.
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Is that bullet accurate in your gun AS IS?
I ask because HP'ting can change accuracy. Been there done that. There are also options. If its a double cavity, you can HP one side and leave the other side in FP configuration. If its a 4 gang mold, Eric can HP 2 cavities and leave the other 2 as is.
Have you thought of choosing another bullet/mold just for HP'ting purposes? A mold with a bigger MEPLAT to begin with. This is another option too.
For me, i DON"T think HP's are overrated and they do work and work WELL. You can see and here it when it strikes a target. For deer, you will get a pass through, especially with that bullet of yours in the picture. Even HP'ting, its going right through. Its too sleek. Even going with a bigger MEPLAT on that bullet, you are changing the design of the original bullet. That's why i asked if it was accurate the way it is now. That bullet can be kept as a good long or short range target bullet.
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http://www.gatewaytoairguns.org/GTA/index.php?topic=94370.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=94370.0) Here is a link to Bob's Boattail Bullets.. He designed a 250 gn .408 and even though I do not have the mold yet, I would highly recommend the BBT bullets based on the results that I have seen! The 250 gn has a huge metplat and should be a perfect big game bullet.... If you decide to hp, you should still land in the 225-230 gn range.
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My head is spinning at this point. Lots of input and it is all really appreciated. I will try to summarize where I am at as I sort some of this out.
1. Got the .408 from Brent a few weeks back. Had already bought and cast several bullets from the 2 Lee molds available in 41 caliber. They drop at 205 and 215 grains with 8bhn lead. Sized them to .4085. My bore slugs at .4085. They do not group well at all. 3 to 4" groups at 50 yards no matter what spring or fill pressure. I owned an Extreme .457 for 2 years so very familiar with these guns.
2. I bought the RCBS mold which drops around 315 grains with this lead. They group in one ragged hole at 50 yards. Way much better than the Lee bullets. Big problem is they will not likely leave a significant wound channel thus my thoughts about getting the mold hollow pointed or at least have Erik increase the meplat. I am aware that the accuracy may be affected.
3. I just bought a RCBS mold on ebay 2 days ago which is their 210 grain mold which I suspect will drop around 225 grains with my lead. It is more like the Keith design so should be a great deer slug even without a hollow point. I am hoping that they out perform the Lee bullets in accuracy but the design is not that much different. Funny thing is that people are telling me that my slow twist barrel favors the lighter weight bullets but so far it seems to do the opposite.
4. Hoping some one has already tried Bob's boat tail in the 250 grain so I can get some to try. If not I am tempted to order the mold.
In the meantime I am sure having fun.
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That bullet looks like the length is very close to the length of the 275 Mr Hollow point bullet I would buy a bag and shoot them if they group for you and they will at 50 yards then I would get the mold made for your bullet. Chris Alls texted me a picture of a hollow point bullet 3 shot group 230 grain at 100 yards .408 that was well under .5 inches center to center. So either way you choose solid nose or hollow point you can get the accuracy at the ranges you are looking for.
Extreme
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You can always get Erik to do a pin style Ray.He can make you a flat and a hp.Ive had him do several of mine for the 457.I will say If you plan to hunt deer with it I would find a hp that is accurate and use it.Ive shot deer with flat nose,hp,round nose,swc,you name it and the hp on DEER is where its at.Cant say the same for tough skinned animals but deer,def My #1 choice.Only thing Ive had come close to a hp was a wadcutter and that tumbled its way threw the deer causing massive damage.But thats just my 2 cents.Its safe to experiment with any though cause even with the roundnose he only made it 75 yards.I dropped 4 last year though on the spot with a 340 gr hp though.
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Jeremy I have taken a lot of deer, pigs, and even an elk with hollow point bullets with the same results that you have seen they drop in there tracks or may go a few feet and fall over. I tried some solid nose bullets on deer and pigs and the kill was not nearly as fast they performed great but not even close to the hollow points (on game of this size). If you have a hollow point bullet that shoots accurate and a rifle with enough power to make the HP penetrate through the vitals it can not be matched by any solid bullet.......
Extreme
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Just had to give an update. Got the RCBS 41 cal 210 gr FP mold in the mail yesterday. Cast some this am. She drops at 222 grains at 8bhn. Shot this 10 shot group at 35 yards. Quite happy with that. I will definitely pursue the hollowpoints. Just a note, Brent, the 275 gr hollowpoints you have me a month ago from Mr Hollowpoint do shoot very well in this gun
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(http://i983.photobucket.com/albums/ae315/shamuboat/IMG_1290.jpg) (http://s983.photobucket.com/user/shamuboat/media/IMG_1290.jpg.html)
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Nice shooting Ray!
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you guys are getting me excited ;D ;D ;D we only have a month til bow season..then 6 weeks later rifle comes in.ive already taken 11 days vac for rifle!!!I cant wait.
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I agree Jeremy, I am so geeked to go hunting with the extreme I almost wish that we could skip bow season
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You got my vote!!Your gonna be shocked at the damage they will do on a deer.I dont even hunt with a powder burner anymore.No joke.Most all my shots where I hunt are a 150 yard max any how.some field but mainly hard woods.I did drop a doe year before last at 100 yards with the 457.I was pretty impressed.ordered some fresh rolls of vac seal bags last week..ready to fill um up!!