GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Nutcracker on February 11, 2015, 04:05:28 PM
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Hadn't shot the Marauder Pistol much since I got it, been messing around with a couple other guns. The few times I had shot it I thought it was pretty lousy accuracy @ least with what I was shooting in it. When I got it I got some Beeman Kodiaks & FT both copper plated, seems I heard that was the pellet for these guns. Well it sprays the FT like a shotgun and the Kodiaks are a lil better. I decided to try JSBs today. I tethered it @ 2800 psi rough sighted it in @ 20 yards, w/ 18 gr JSB. Have the hammer spring turned as far as it will go. 600 fps, FT @ 640, Kodiak @ 510, JSB 15 @ 600, don't understand that that is the same as the 18 grainers, but that is what it was doing. I have a 16" Gaska barrel, I was going to put on, but now seeing that the 18 JSB looks like it might do ok, don't know if I should put it on. Guess won't hurt to try it. Might put a bigger port & spring. I would like more energy.
(http://i1377.photobucket.com/albums/ah42/acewashington66/td%20001_zpsvqphexen.jpg) (http://s1377.photobucket.com/user/acewashington66/media/td%20001_zpsvqphexen.jpg.html)
All 8 shot groups @ 2800 psi L-R jsb 18, jsb 15 ( can't believe they are so far to the left), Kodiak, & FT ( some of them did not even hit the target)
(http://i1377.photobucket.com/albums/ah42/acewashington66/td%20002_zpslbjzneeb.jpg) (http://s1377.photobucket.com/user/acewashington66/media/td%20002_zpslbjzneeb.jpg.html)
16 shots 18 gr JSB
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The H&N FTT 14.66gr pellet has been one of the favorites for many Prods. In the 5.53 head size, but have seen some that say 5.54 or 5.55 head size has worked well. Might want to give them a try.
With a 0.110" TP, heavy hammer spring, and BSB o-ring buffer, you can get 24 shots @ 16FPE or 16 shots @ 20FPE. Might get a little more above 20FPE but will be down to 8 shots or less.
PS: Is your MM barrel the newer hammer forged barrel or an LW?
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The H&N FTT 14.66gr pellet has been one of the favorites for many Prods. In the 5.53 head size, but have seen some that say 5.54 or 5.55 head size has worked well. Might want to give them a try.
With a 0.110" TP, heavy hammer spring, and BSB o-ring buffer, you can get 24 shots @ 16FPE or 16 shots @ 20FPE. Might get a little more above 20FPE but will be down to 8 shots or less.
PS: Is your MM barrel the newer hammer forged barrel or an LW?
Think I am going to put the other barrel on. I still am amazed how the FT can shoot 3" @ 20 yards and the JSB 18. less than an inch. Sent the wife after some O rings today.
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The right pellet can make all the difference in the world. I have seen some shotgun even at 10yds.
The extra 4" of barrel will help with increased power levels. I have heard that the hammer forged are very tight, and there is some reduction in fps. Overall, you should still be in the positive with the 16" barrel. If I recall correctly, others have found the JSBs to be a good pellet for the hammer forged barrel.
Look forward to seeing your results.
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15 grain jsb in a 14.5 inch gaska barrel here..........it is a GOOD thing 8)
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Ok, got a question. I am putting a 16" Gaska barrel on it, along with a .118 port & a 7 lb spring I got from Normand. The O rings I bought are"70 Buna-N #113 3/32 Width". I would like about 700 fps with the jsbs. If that is possible.
Well questions,
1. How many O rings should I use?
2. Where should I start with my Hammer Spring & Hammer adjustment?
I did not get any baffles, I read some drill a hole in the shroud near the breech.
3. Should I drill a hole in the shroud?
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Ok, got a question. I am putting a 16" Gaska barrel on it, along with a .118 port & a 7 lb spring I got from Normand. The O rings I bought are"70 Buna-N #113 3/32 Width". I would like about 700 fps with the jsbs. If that is possible.
Well questions,
1. How many O rings should I use?
Assuming these are for a BSB buffer, and 18.1g JSB, I would say 3 O-rings.
2. Where should I start with my Hammer Spring & Hammer adjustment?
Hard to say, given your variables (barrel, spring, TP) which I haven't used. The throw adjustment is critical. For just a very rough starting point, 3/4T on throw from full CCW, 5T on Preload from full CCW, on a 3K fill.
I did not get any baffles, I read some drill a hole in the shroud near the breech.
3. Should I drill a hole in the shroud?
I assume you have a shroud to match the new barrel. My experience on prods, trying the near breech hole, with and without magic sponge, did not appear to make a noticeable difference. Your results may vary.
If someone wants some of these orings, PM me. I have a hundred pak. I doubt I ever use them all. I will mail half of them to one person and they can mail some to others. They are so cheap may not be worth your time.
See above:
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Ok, got a question. I am putting a 16" Gaska barrel on it, along with a .118 port & a 7 lb spring I got from Normand. The O rings I bought are"70 Buna-N #113 3/32 Width". I would like about 700 fps with the jsbs. If that is possible.
Well questions,
1. How many O rings should I use?
Assuming these are for a BSB buffer, and 18.1g JSB, I would say 3 O-rings.
2. Where should I start with my Hammer Spring & Hammer adjustment?
Hard to say, given your variables (barrel, spring, TP) which I haven't used. The throw adjustment is critical. For just a very rough starting point, 3/4T on throw from full CCW, 5T on Preload from full CCW, on a 3K fill.
I did not get any baffles, I read some drill a hole in the shroud near the breech.
3. Should I drill a hole in the shroud?
I assume you have a shroud to match the new barrel. My experience on prods, trying the near breech hole, with and without magic sponge, did not appear to make a noticeable difference. Your results may vary.
If someone wants some of these orings, PM me. I have a hundred pak. I doubt I ever use them all. I will mail half of them to one person and they can mail some to others. They are so cheap may not be worth your time.
See above:
Thanks that will give me a good start.
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Ok, been messing around with it for a few hours now. Turning and Burning. Freezing cold outside. But here is where I left it for now. This is with the 16" barrel, .118 port, longer spring and the 3 o ring thingy. Have hammer Spring turned CW as far as it will go & Hammer 1.5 turns. Filled to 3000 psi with JSB 18.13 Exact. 40 shots.
1.590 594 614 617 655 649 657 658 639 x 638 680 684 ( 2600) 683 685 696 x 699 707 707 701 701 705 713 700 705 716 710 710( 2000) 711 708 701 706 705 706 x 692 698 679 678 (1400 psi)
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696-711-698 for 23 shots with Es of 15. 19+ FPE, it looks to me you are getting 3-4 FPE with the 4" of extra barrel. How is the accuracy?
Hammer preload: If you are turning CW and it stops, your spring is too long and binding. The prod preload dis-engages the threads at max preload.
With 3 orings and 1.5 turns on the throw, you might not be engaging the buffer. But, if you are happy with the string, shoot it for now.
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696-711-698 for 23 shots with Es of 15. 19+ FPE, it looks to me you are getting 3-4 FPE with the 4" of extra barrel. How is the accuracy?
Hammer preload: If you are turning CW and it stops, your spring is too long and binding. The prod preload dis-engages the threads at max preload.
With 3 orings and 1.5 turns on the throw, you might not be engaging the buffer. But, if you are happy with the string, shoot it for now.
I don't know about accuracy yet. never got that far. I tighten and loosened so much trying to get 700 fps, I started to get confused. But the only way I got to 700 was to tighten the hammer spring until it just stopped doing anything( just spins). So on the hammer I may have it so long, that the striker may be hitting the valve head before the body of the hammer hits the o rings? I will fiddle with it some when it gets above zero. To freakin cold here to think. And with my previous history I am not allowed to do any shooting in the house. :D However that is about what I was expecting as far as useful shots in the 700 fps range. I was a little surprised that it was not until around 2500 psi that it started getting close to 700. I thought it would be higher???
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I was a little surprised that it was not until around 2500 psi that it started getting close to 700. I thought it would be higher???
Sounds like your spring. What is a "7lb" spring? The spring I use (as suggested by FuzzyGrub) is 1.5" x .30
" x.042". I think they have like a 10lb or 11lb load capacity.
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I was a little surprised that it was not until around 2500 psi that it started getting close to 700. I thought it would be higher???
Sounds like your spring. What is a "7lb" spring? The spring I use (as suggested by FuzzyGrub) is 1.5" x .30
" x.042". I think they have like a 10lb or 11lb load capacity.
Yes it is 7 lb, but is longer than the one I took out. If I put a 10 lb spring in, will I get more shots around 700 fps or will it just start giving me 700 fps nearer 3000 psi?
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Yes it is 7 lb, but is longer than the one I took out. If I put a 10 lb spring in, will I get more shots around 700 fps or will it just start giving me 700 fps nearer 3000 psi?
Hopefully FuzzyG will answer, but here is my guess. It will move the string up in pressure, but it will also allow you to get more FPS out of it at those pressures, with less "preload". I think with the 10lb spring and 3K you can see almost a 20 shot string at 800fps, with the ability to turn it back to 700fps and see your same #'s.
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Yes it is 7 lb, but is longer than the one I took out. If I put a 10 lb spring in, will I get more shots around 700 fps or will it just start giving me 700 fps nearer 3000 psi?
Hopefully FuzzyG will answer, but here is my guess. It will move the string up in pressure, but it will also allow you to get more FPS out of it at those pressures, with less "preload". I think with the 10lb spring and 3K you can see almost a 20 shot string at 800fps, with the ability to turn it back to 700fps and see your same #'s.
That's sounds cool. Who sells those?
I just found them, Hillair has them 6.88 shipped. Just ordered one. I also found that size on Century Springs, but figured you had to order a bunch. I have a McMaster-Carr catalog but could not find that size, but in the book they say they will make any spring you want. If someone wanted to order in bulk.
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If you decrease your fill pressure and/or increase hammer spring your curve will flatten out at the expense of shot count.
In the Marauder rifle owners manual it says that greater accuracy may be reached at fill levels of 2600PSI or below.
My rifle is a .25 That I have modified to shoot .177 and .22. It is definitely more accurate at lower power levels.
Good luck! It sounds like you are off to a good start and headed in the right direction.
B.R.A.S.S.
Greg
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here is the one I have been using from McMaster-Carr: http://www.mcmaster.com/#9435k67/=vz9ai7 (http://www.mcmaster.com/#9435k67/=vz9ai7)
They have a music wire version that is a little less $. I have used others from H/W store, too. There is a slight variability, but not much.
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Thanks, I see them now. I overlooked them. That catalog is huge.
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The springs from McMaster Carr showed up this morning. Man that company is fast. Was 10 below this am, got to 10. So tried a few shots. With the new spring. 5 CW on HS , 1 CW on HT. 3000 psi 18.1 JSB
650 660 670 672 663 670 685 680 693 671 682 687 677 (2500) 679 685 691 688 691 698 692 690 687 686 681 675 672 674 670 670 669 660 657
Then tried 6 CW HS, 2 HT. ( figure that was way to much on HT, but it was so cold.
707 710 717 723 725 725 726 734 732 725 723 713 708 689 688 678 ( 2000)
Will split the difference tomorrow and see what happens.
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The springs from McMaster Carr showed up this morning. Man that company is fast. Was 10 below this am, got to 10. So tried a few shots. With the new spring. 5 CW on HS , 1 CW on HT. 3000 psi 18.1 JSB
650 660 670 672 663 670 685 680 693 671 682 687 677 (2500) 679 685 691 688 691 698 692 690 687 686 681 675 672 674 670 670 669 660 657
Then tried 6 CW HS, 2 HT. ( figure that was way to much on HT, but it was so cold.
707 710 717 723 725 725 726 734 732 725 723 713 708 689 688 678 ( 2000)
Will split the difference tomorrow and see what happens.
You know I didn't realize you were using 18.1's when I said you should be able to get to 800fps (you would with 14.3's)
Anyway that first string looks pretty good to me. Except for that 5th shot, if you take off the first 2 and last 2 you have 28 shots all over 18FPE within 4% (last shot is just 1fps under)
I would try 1.25-1.5HT and then somewhere between 5 and 6 on HS
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What fps would produce the most accurate groups with a 15.89 JSB? Or would a lighter pellet than that be more accurate?
The last adjustment I did was 5 3/4 HS. 1.5 HT , 3000 PSI Fill. 15.89 JSB ( I was using the 18.1 grains, but think they may be to heavy)
700 722 710 712 722 727 725 745 751 (2700) 759 762 763 772 771 749 (2500) 762 753 761 757 757 759 754 760 759 750 759 (1900)748 742 743 738 737 724.
I did all of this with the AR stock off, when I put the stock on and was sighting in, I noticed "sputtering" @ 1900 psi.
Think I am going to back things off a little and try to get more consistency and see how the accuracy is there, worry about more energy later.