Just started shooting a Remington 700 VSSF in 220 Swift, w/ Leupold 6.5-20/50MM LRT. It shoots ~0.5" groups with factory ammo (both Federal 50 gr. Sierra 3750 FPS and 40gr. Hornady VMax moly 4110 FPS). I just started working up loads nad noticed that the bullet jump was very large with the factory ammo, almost 0.170". I get 0.090" jump with a 0.22 seating depth for a 50 gr Hornady VMax Moly, and 0.170" for the 40 gr VMax Moly with 0.212" seating depth.
Being a newbie, I read where the jump is usually on the order of a few tens of thousands. I have measured and re-measured this a bunch of times, so I am sure that I am right. I have the bullets seated one diameter into the neck, with no more left to go. Is this the rule for the 200 Swift? Any suggestions on loads? I am staring with 50gr Hornady VMax moly over VV140. I get 0.75" groups at about 3550 with 37.5 gr VV140.I am thinking that I need a slower powder, such as VV160. Any and all advice appreciated. Love this gun.
Posts: 46 | Location: Maple Valley, WA | Registered: 10 February 2003
techshooter; I have owned an identical rig to yours for about 3 years now, except my Leupold has the smaller objective lens. My rifle has quite a long throat as well, but still shoots very well. I seat bullets just about .015" less than one caliber into the case. You will have to watch bullet "pull" with this system since if it varies much, you will not get the accuracy. I use 40 grains of Vihtavuori N-140 for about 3950 FPS, but you need to approach carefully from below to be sure it's safe in your gun. Other pet loads are: 40 grains of IMR4064, 40.5 grains of Reloder 15, and 43.5 grains of H380. All these shoot in the .5 MOA area in mine. I have not had as good accuracy with either N-150 or N-160. Regards, Eagleye.
Eagleye: Thanks for the information. I am neck sizing the cases, and have the ability to turn them as well. I have a bushing style neck die on order, so that may help with keeping the "pull" consistant. Any experience with H414? It looks like a good powder for the Swift from the little research I have been able to do. I'll stay with the VV140 for now and go up. I stopped at 38.0gr, with no signs of pressure. The groups looked like it was approaching another sweet spot, so that was my next step. Thanks again.
Posts: 46 | Location: Maple Valley, WA | Registered: 10 February 2003
Techshooter your jump will vary from gun to gun and load to load. I have the same rifle as you only with a Leupold 8.5 X 25 X 40. It shoots .5 MOA. My load is 39.5 Gr of IMR4064 with a 50 Gr. V-max. Terminal performance is awesome.
My Remington 700 VSSF really seems to like IMR 4831. My load is almost compressed with 55 gr Nosler Ballistic Tips. I know that it's not a traditional Swift powder but it works for me. Also my jump is about .0005 and yes I have to watch neck tension.
I've owned half a dozen .220 swifts, and you couldn't seat the bullet against the rifling on any of them without slmost having the bullet falling out of the case. However, only one shot much more than .5 inch groups. I've seen similar problems with other calibers, like a .375 H&H, where seating depth is almost always governed by magazine length. I'll bet your .220 shoots fine. My all-time favorite loads are with Hornady or Sierra 55-grain bullets in front of 39 gr 4064 or 43.5 H414. These are plenty warm so work up slowly, just in case. I just replaced a barrel that had fired about 4500 rounds, mostly the H414 load, so barrel life isn't that bad either. It would still shoot 1 1/8 even though the first couple of inches looked like a snakeskin.
Posts: 2788 | Location: gallatin, mo usa | Registered: 10 March 2001
I have been loading 37.5 of VV550 in my Swift. Federal match primers, 52g Berger bullets....one hole groups if I do my part. Try VV550 you will like it.
Hello All, My VSSF with Jewell trigger, 6-24X40 4200 is coming up on 2000 rounds. Currently shooting 55 grn. BT's with 40.2 RL15 and 210M. .060 from lands (whats left of em).I've got a problem I can't figure out. On my fired cases I can drop a bullet in some and some are so tight you would have to use the press. It don't matter whether it's new, 10 times fired, turned necks or unturned. I've used Remington, Winchester, and Norma brass it all does it. Any idea's Thanks, Mike
Posts: 10 | Location: pisgah Al | Registered: 18 January 2003
Yes, it was very interesting. It makes perfect sense. Being an engineer, I have always looked for explanations that have a solid basis in physics. I am going to user your method to develop my 220 Swift loads. Fortunately, I currently have a lot of target and chronomenter data to get started.
One question: If the rationale is to find the load "recipie" that gives the most consistant pressure/velocity over the largest variation in parameters, could one not then use the chronometer data (velocity, standard deviation) to estimate the optimum load? Again, as you so eloquently explain, you can then fine tine the "dwell time" in the barrel via the seating depth parameter to put the exit time right on a stable node. I gather that your group averagin method serves to estimate the load recipe that has the smallest variance in the muzzle velocity. Did I get this right?
Posts: 46 | Location: Maple Valley, WA | Registered: 10 February 2003
You are describing what could be a very dangerous situation. Your firearm should not be fired until you discover the root cause of the problem. Do the cases show signs of excessive pressure?
Possible causes : 1. The case necks are too thick for the chamber neck. What is the OD of fired casenecks before and after seating bullets? 2. The case necks are too long for your chamber. How long is you chamber? How long are your cases? (Sinclair's sells a caliber specific case necklug that would allow you to make this measurement.)
I do not have a 220 Swift, but have read several articles that attributed rapid thickening and lengthening of the case necks to the combination of relatively shallow shoulder and large case capacity. If not controlled, these factors have the potential to cause catastrophic pressures.
