Test #2/ 4400 psi fill with new 4500 psi Bottle
Wind finally quite blowing for a while this morning, and I had some air, sooooo= A test was in order. 😀
This is with teh New 4500 PSI Bottle that DMan got in for us. And a good looking Bottle it too!
I had been shooting it at 3800 psi with good results, but wanted to try somthing different with it. I have kept the .257’s Power Wheel on 7 to 8 for a long time. But just for shit’s and giggles I decided to raise the pressure and see what would happen.
I had alread tried this at 8 on te PW, and anything over 3850 and the shot would drop like a rock. 😯 This was starting out at 1020 fps. @ 3850 psi with the NOE 60 grain 20/1 lead tin/ bullet. Now keep in mind that this was quite an improvement over teh Factory AF Bottle filled to 3000 psi. (although I cheated and filled to 3400 several times) which gave me a top velocity of 1020 at the 3400 fill. 3200 would give me 960 and the factory recomemded 3000 psi would clock in at 930. So what would the 4500 psi bottle and pw adjustment do with my short 21″ bbl?
:8: She really started shooting at 4000 psi with the pw pushed up to 10 and then started to drop fps again if pushed any higher. Time to get radical!!!
I tired the full on adjustment maxed out on the PW at 4500 psi adn Nope, dropped like a rock. 😥
I gave her one last try and moved the fill down to 4400 psi. And WOO-H00!!! 😀 Happy Days!!!
I finally got a killer Bell Curve at this setting. Here are the numbers, But First, with out accuracy, numbers are useless! The 257 Talon/Dor started shooting un-blievably consistenty, as in shooing clover leafs at 80 yards. Time and Again. From just under 1/4″ to just under 3/8″ at the 80 yards. with many of the groups only one slightly larger hole and usually one bullet making one touching hole. (there always has to be one, right!) 👿
So now that it can shoot a Squirells eye out at 80 yards, what were the numbers?
Starting with a 4400 psi fill they were:
1037 @ 44 PSI
1051
1061
1060
1045
1041
1033 Ending at 3800 PSI
Man I was and still am Stoked!!! :8: Only 600 PSI, and shooting just under super sonic. Perfect for my LDC’ed Critter Gitter!!!
Thats 75 psi, or 5.17 Bar per shot at a starting 150 FPE and ending at 142.2 FPE
Hell Yeah!!!
KnifeMaker
Knife
All Replies
That’s interesting Doug. of course, a pb has much higher pressure and can upset the bullet to fill the bore. But our ag’s dont’. But still, It shot just fine, with higher velocity.
I tried some smaller dia.’s today and they shot for crap. They were .2567, so I guess, blow by?
Knife
It should be no more than 1/2 th. 😥
I rolled a few bullets between a pair of precision ground steel bars until they were some what close to the .2573. Some were smaller. Or under bore size. What was strange, is that it didn’t seem to matter that they were slightly under sized. They were more accurate than the .2587’s and picked up almost 30 fps with no other mods. And the biggie besides the increased accuracy, is that the shot count was almost 3 times grater! (before the poi dropped at 80 yards.) :8:
I would think that it would make for even less barrel leading as well. A Win-Win! 😀
Knife
Hmmm??? Thats kinda interesting.
I found that I often had similiar results with just undersized bullets in many of my powder burning handloads. The most noticible being a 12″ Contender .224 1:10 twist shooting the Hornady .45 grained SX bullet chambered in .22ppc. The hornady 45 gr .22 was avail. In .224 or .223 and there always seemed a slight percieved tighter group always when shooting the .223 that I had accidentally purchased. Soon thereafter I experimented with numerous .22 chamberngs in a variety of guns with most all preference being slightly undersized. Only exception was military barrels such as the 5.56mm NATO AR-15A2 and Ruger mini 14
I think that the military spec barrel was always a bit sloppier, but in most every circumstance it always seemed that most .22 bullet chamberings always did better in .223 when avail. As opposed to the actual prescribed nominal .224 usually available.
As a result I was always on the lookout for the odd .223 bullet offerings as they seemingly offered improved accuracy in most all of my sporting arms.
The other thing that got the fps up was discovering that my sizer was way “TOO BIG”! The bore slugs at .2573 and teh sizer is putting them out at .2587-so one and a half tho. over the bore dia.
It should be no more than 1/2 th. 😥
I rolled a few bullets between a pair of precision ground steel bars until they were some what close to the .2573. Some were smaller. Or under bore size. What was strange, is that it didn’t seem to matter that they were slightly under sized. They were more accurate than the .2587’s and picked up almost 30 fps with no other mods. And the biggie besides the increased accuracy, is that the shot count was almost 3 times grater! (before the poi dropped at 80 yards.) :8:
I would think that it would make for even less barrel leading as well. A Win-Win! 😀
Knife
Howdy Knife,Its always funny to me to pick up my 12in. 22, and shoot it now
Howdy MAW!
I don’t know right off the bat. I’ll weight it the next time she is apart.
sorry. I do know that the spring was 9 lb when Douig sent it. But it is no doubt weaker now. I never released the tension on it until recently. So it has probably taken a set.
Played a bit more with it Fri. It setteled down at 1080fps after a bit of top hat polishing. this with the 60 gr. NOE bullet. :8:
This is right at 155 fpe now. A far cry from it’s beginning years at 20 fpe when it was a .20 Talon ss. 😆
Knife
What size hammer are you running Mike?
Yessir!!
And thanks Doug-R-Up! I think we’re in for some Great Times! 😉
Knife
MAW, I think we have the same valve. Or at least very similar. Both the .25 Dyotat valves. Not the .257 valves.
Knife
Sweet, thanks again Doug!!! What type of O-ring? Did you get my PM about the barrel riding hammer??
O ring is 116. I use krytox 205 to lube o rings.
McMaster Carr has it $17 for small tube or $47 for 2 ounce tube.
I was going to ask about an o-ring… What size/type? there isn’t one in the package, or on the valve… any recommendations for silicone grease? Thanks again Doug!! :8:
No. Just put a little silicone grease on the o ring and threads and snug it up.
I absolutely did, and boy does it look sexy AS fuck w/Doug’s valve in it… I can’t wait to get this build going! Thanks Dman!!! One question- do I teflon wrap the tank-side threads when I thread it in?
- You must be logged in to reply to this topic.
Sure wish RoachCreek would chime in on this.
Knife