min.seating depth 6.5x284 savage model 12 "F"class
I hope i am in the right forum.I own the above rifle and have been building some loads for it and have had fantastic results with H4350 and also H4831Sc behind 142SMK's.my question is the incredibly long throat of the savage rifle.i have learned over the years of handloading that you should have at least the bullet dia in the case but my best loads are with .020" jammed in the lands that leave only .125" of bullet in the neck,that is not counting the taper of the boat tail,my question is ,do you think that is enough bearing surface?? i have avg. .187"-.250" groups with this oal but am a bit concerned about so little bullet grip in the case mouth so i seated them an additional .100" giving them a .225" in the neck but my groups have opened up to 1/2". on another note i am disappointed with my velocity as i cannot reach the 2950-3000 fps that his caliber is famous for.i have had good luck with 53.2Grs of H4831Sc but velocity is only 2850 fps. using my CEDII Millenium chronograph and i also have a sweet load of 49.3 grs of H4350 but again only 2800 fps.i am not that impressed with the velocity as i sold a custom built 6.5x47L that put 140 bergers in at 2850 fps and shot .375" all day long.Getting back to my original question is that enough bullet in the case for consistent accuracy?? i was also wondering if i went to a VLD in say 140 gr i would not be in the lands at all given the design of that bullet.i am worried with so little bullet in the neck that runout could be a real issue.. i plan on using this oal for "F" class shooting in the spring
Re: min.seating depth 6.5x284 savage model 12 "F"class
I guess it depends. Each situation is different. I'm shooting the 139 Scenars in mine, and the 140 Berger VLD'S. I have all my reloading stuff packed now, and about 80 percent of my shop is also packed, so I can't quote exact measurements. It sounds like your throat is longer than mine. I'm shooting mine with the Bergers jammed .010, and I believe the Scenars "on". I may have that backwards though. I had flyers with the SMK's.
Do you have a concentricity gauge? Also, do you know how much neck tension you're running? With groups in the .2's, you must have something right. What's your extreme spread in velocity? What do your groups look like at 600 and 1K yds?
I'm running H4831sc myself, but I can't get near your powder charge! I'm running 50.0 grs with the one bullet, and 50.5 grs with the other. I'm running right at 3000-3050 with both bullets. I'm using Lapua brass and Fed match primers too. I'm wondering about your chronograph. Is there someone else you shoot with that has one to compare against?
Also, food for thought, if you don't want to live with the long throat issue, you can either rebarrel, or have a smith set yours back and rechamber. I ordered my 12F as a stocked action from Northland, and ordered a McGowen bbl with it.
Re: min.seating depth 6.5x284 savage model 12 "F"class
Quote:
Originally Posted by 300ultramag
i have learned over the years of handloading that you should have at least the bullet dia in the case but my best loads are with .020" jammed in the lands that leave only .125" of bullet in the neck,that is not counting the taper of the boat tail,my question is ,do you think that is enough bearing surface?? i have avg. .187"-.250" groups with this oal but am a bit concerned about so little bullet grip in the case mouth so i seated them an additional .100" giving them a .225" in the neck but my groups have opened up to 1/2".
This is an old wives tale that you have already proven to be inaccurate. Why would you have to have a bullets diameter in the case, and what would it improve, or do? If what you are doing it is working, then do it! Seat the bullet where the gun likes it, and go from there, don't worry how much is in the case. I follow the same rule as many competitive 6PPC benchrest shooters do, we fill the case with powder 1/2 way to 3/4 the way up the neck with powder and seat a bullet where it shoots best, many times the the bullet just barely in the case. Heck, with a 30BR the most used powder charge takes a long tube to get the powder in the case, and the powder is almost to the top of the neck, then a bullet is seated barely into the case on top of it. To add to this, as the chamber grows longer from firing, we have to more the bullet further out to get to the same spot we was once at, untill it is rechambered. Even though this is a diferent type of shooting disipline, my point is these guys strive for the utmost in accuracy where wins come from thousands of an inch, my point is if there was any truth what so ever that a bullet had to be in the case a bullets diameter they would be doing it, but the fact is they are not doing it.
Don't get fixated on speed, some barrels are slower than others and some are faster, it is just the name of the game. You could pick to of the top notch barrels made, and have one made right after the other, and they will preform compleatly diferent. The speeds that you are trying to match are at what length of barrel that they have listed? Is it the same as yours? If your gun is in factory form it will have a 30 inch long barrel, IMO it is just too long. I am willing to bet you would pick up speed if you cut a few inches off the barrel. Are they shooting a rough factory savage barrel or a smooth, hand laped, cut rifled, barrel like a krieger? Again if it works, just go with it. Don’t worry that you’re not getting the same speed that someone has advertised, it might just even be a difference in chronographs, and they can be skewed. It might be a powder manufactor fudging there speed to sell powder.
