Listings for 219 Zipper
Die Set 219 ZIPPER (.224)
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RCBS 219 Zipper Imp 40Â° Trim Die-(57006)-NIB
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Used RCBS 219 Ackley Zipper 2 die set including a FL sizer & seater die
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Hornady Series IV Specialty Die Set, 219 Zipper
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Related 219 Zipper information
cycbb486 said: Well I thought I would share an observation tht came about today for me. Yesterday I decided to pull out my Rem 700 6BR with a 10 twist and fire a few reloads down range. It had not been fired since August 30. The load at that time was 30.8 grs of H4895 and a 95 gr Sierra Match King coming out of the 26" barrel at around 3100 + or -. It was jammed 10 thou into the lands. The temp that day was not known as I did not mark it down. I would assume that it must have been in the low 20's celcius that day. I know there was not a lot of wind when I fired that group. The 95 gr SMK had no problem stabilizing at 1000 yards. My best target was 4 out of 5 shots into a group just under 6". I was tickled as hell for only my second time shooting at that distance. The holes in the target at that distance were perfect little round 6mm holes. The rest of the story. Yesterday I loaded up JUST 7 rounds to confirm the load was still pretty good despite the more than 40 deg temp swing. Set a target out at 100 and proceeded to shoot the 7 rounds and not hit the paper. I adjusted the scope thinking I had not rezeroed after shooting at 1000 yards but could not confirm as I only had 7 rounds. The only thing that I had done since it was last shot was strip the barreled action out of the stock and give a thorough wipe of oil to prevent rust and reassemble. It went into the locker until just yesterday. When I got home I checked to make sure nothing was loose. All seemed 100%. Decided to clean the bore thoroughly and make more loads to check the gun at 100 yards today. Made 16 rounds of the exact same load as yesterday. The only difference was going up to 31.0 grs from 30.8. Headed to the range, stapled a target at 25 yards, set up on rest and fired. There was no hole in the paper. Totally baffled I was. Since I played with the turrets yesterday I figured it must be low so I aimed at the top of the target and fired again. Finally, a hole but about 5" to low. I adjusted and fired again. That was better, but something was wrong. The hole looked mighty big for a 6mm hole. I proceeded to the target only to find that the 95gr SMK's were no longer stabilizing they were keyholing. Went back fired once more and another keyhole. Now I was starting to think, why? I began to draw some conclusions and some of which I was pretty sure of the answers. I thought I would share what I figure is the culprit. What could be a good or what one thinks is a good load one day and the next not worth sh++. In reality when I built my 10 twist it was built around shooting the 95gr Berger. This was re an article I read from another site. I chose the 10 twist and the 95gr Berger because on paper at 1000 yards balistically the 95 gr Berger gave BETTER downrange ballistics than the 107 SMK's. I did not know iif I would ever shoot at 1000 so I was not concerned whether or not I could shoot to that distance. The 95gr Bergers proved to stabilize so I was happy but I thought I would try the then new 95gr SMK. They appeared to work and work well out to 1000 in August. In theory the 10 twist is marginal for stabilization of the 95gr Berger or SMK but they appear to have worked for me until the last couple of days. What happened? The only logical explanation I can find is the lack of muzzle velocity required to stabilize the 95gr SMK out of the 10 twist barrel. It was the velocity that helped stabilize those bullets and not the twist alone. The bullets needed that velocity to stabilize them which in Aug was around 3100 fps in say a +20deg temp. Today it was more than 40 degrees colder trying to shoot the same load just .02 grs more powder. It is not enough extra powder to make up the lack in velocity to stabilize the bullets. Make sense? I think that is the explanation. Tommorrow I will load up the same 31 grs but this time with the 95 gr Berger bullets which have approximately 55 thou shorter bearing surface than the 95gr SMK's and see whether or not they stabilize at 100 yards. I have not played with the Bergers and H4895 as of yet but I will give it a shot tommorrow and see what comes of it. I will not pull the current loads but will put them away until it warms up in the summer and try them again to see what happens at that time. I would like to think they will be okay????????????????? I will take my chronograph and fire a round over it with the 95GR SMK's and see what they are coming out of the muzzle at. I would think there will be a substantial loss of velocity. I may try and bring the velocity up to make up the difference and see what happens as long as the pressure signs stay within limits. Any thoughts from the PRO's out there?????????????????? Make sense? Calvin
br*therjack said: Velocity does, indeed, have something to do with stabilization. Plug your numbers into the spreadsheet noted below, and it should shed some light on it for you: w ww.nfa.ca/nfafiles/cfjarchive/ballistics/bulletstabilitycalc.xls
G*nderite said: Velocity is a function of ammo temp. If you take ammo to range in an insulated cooler (and add a 2 liter Coke bottle of hot water to keep ammo toasty) the ammo need not be cold when shot. Put the 5 test rounds in a shirt pocket as you shoot. This keeps ammo at body temp (98 degrees - real toasty). This should launch bullets at same velocity as summer. But air is cold and much more dense. The denser the medium the higher the RPM requirement to stabalise. Your testing was cold (slow) ammo in dense air with marginal twist. If you have the pressure room, increase the powder charge to increase velocity to offset the air density. Always shoot ammo at same temp. Other than hunting, this is easy to do. A shirt pocket can suffice.
r*berti11 said: Velocity does, indeed, have something to do with stabilization. Plug your numbers into the spreadsheet noted below, and it should shed some light on it for you: w ww.nfa.ca/nfafiles/cfjarchive/ballistics/bulletstabilitycalc.xls If you download this spreadsheet and plug in values for the SMK and Berger bullets you will see that the shorter Berger bullets are better stabilized but only marginally, (stability factor of 0.8 for Berger and 0.7 for Sierra). Both of these values are well below optimal stability, usually around of value of 1-1.5. Keep in mind that the formula in this spread sheet can is simplified for standard atmospheric pressure and temperature, as Ganderite mentioned as the air gets colder and denser the bullet will slow down faster, but twist is affected independently of this decrease in velocity. There is an excellent article in Precision shooting, March 2005 that reviews this. They also work thru an example similar to what you have mentioned here. In 1988 a bench rest shooter in 'Dunham Bay, NY' experienced keyholeing while shooting a 70gn boat tail bullet, but not with a shorter flat base bullet. The temperature was -10F. The stability of the slightly longer bullet was decreased enough to result in the keyholes. Given that your loads are marginally stabilized at standard temperatures (59F) it is not surprising that you have keyholes at -20C. If you what to read the article PM me, I will send you a PDF.
cycbb486 said: I knew I was lucky with the 95 gr SMK's working out of the 10 twist barrel. Like I mentioned I am going to head off to the range shortly and try the Bergers out and see what happens. I will keep you guys posted on the velocity of the loads.
cycbb486 said: from the range and it did not take very long. Yes, only 3 shots and I was packing it up. The temp is -23deg celcius. Probably a good 40 deg colder than it was in August. What did I find? The velocity really never changed from August with the H4895. It was only 2 shots of the 31grs of H4895 and the 95gr SMK's but the velocity was 3099 and 3112. So it is not a velocity issue. It must be as mentioned the density of the air, temp, along with the marginal barrel twist. The 95gr Bergers with 31 grs had VERY stiff bolt lift and the lone shot I tried was traveling at 3163. It did not stabilize as well. The key holing was not as bad as the SMK's but it was there. I definately learned something today. I also learned that the H4895 appears to be quite stable despite the GREAT temp swing. Until next time, Calvin
B*omer said: I'm finding this interesting. I couldn't get 107 gr MK's to stablize in my .243 22" 1:10 Lilja, regardless of temperature, but I did get nice groups with the 95 gr Lapua Scenar. Now I have to go out in the cold to see if these maintain their stability. Thanks a bunch!
cycbb486 said: you got the right idea on trying them in the cold you MAY get a surprise. What is weird is I used my Rem 700 243 Win with 105 A-Max's all fall deer hunting and they were okay. The barrel is the factory 9.25 twist. In reality it may not be enough twist to stabilize but they made it to 500 no problem then. I will have to try them now to see if they still work???????? The load I was using with them wasRL 19 so I know it is not as temp stable as H4895 so I should be able to bump velocity a bit and see waht comes of it. This may be todays task.
B*omer said: In previous testing, I did not find that temperature stable powders were any particular advantage in cold conditions. If the ammo has had the opportunity to get cold, prior to fired, I would anticipate a loss of 150 fps, even with Hodgdon's Extreme powders. Temperature stability is more of a concern for those who live in very warm climates, and that is what the Extreme powders are designed to tolerate. Last winter when I chronographed loads at -32, I saw no difference between Re-19 and H-4350 when compared to velocities I had observed in warm weather. This year I'm going to do some shooting with H-100V which is claimed to be cold temperature stable, but we'll see if it really is.
cycbb486 said: have you found anyone who has it in yet? I have been eyeing it up as well.
S*putin said: It was the velocity that helped stabilize those bullets and not the twist alone. It isn't velocity or twist rate that determines if a bullet will be stable. It is the rotational rate (RPM) of the bullet itself. The rotational speed of the bullet is determined by both the twist rate of the barrel and the velocity the bullet travels down the barrel. Lets say we had a very fast twist barrel of 1:4. If the bullet velocity is very low, say 300 fps, the bullet would not be stable because it would be spinning at a very slow rate.
N*rthman999 said: The cold does really have to be kept in mind. For some reason shooting in the cold always reminds me of one new years when we tried to shoot off some fireworks at -40. The roman candles were "guaranteed" to go 250ft in the air and they were going like thirty! Powder isn't that drastically affected, but when I hunt in the cold, I carry one "emergency" round in the rifle, and my real shooting ammo in my inside breast pocket. Works for me.