back in the spring i started loading for a t/c encore .260rem. unlike most of my rifles, this one has been more headache than anything. accuracy is not what i want. i have lightened the trigger, floated the barrel and tightened up the action with a larger hinge pin. i size all my cases as close to .0015 headspace as possible. i will get 2 shots close together and then have a flyer. it seems with most loads i will get a flyer, no matter if its a 3,4, or 5 shot group. now that its warmed up down here on the gulf coast i've had to back off on my powder charges, some as much as 2 grains. i can't load anywhere close to listed max without having cratered primers. even with my 26" heavy custom barrel i can only muster about 2900fps with this rifle using 120gr. BTs and about 2850fps with 125 PTs. one load in particular back in may clocked 3004fps. last week, the same load clocked 3188fps. i don't go more than about 40-50 shots without cleaning. Those T/Cs sure do look and feel good, but thus far performance isn't up to par in my opinion. any commets welcome.
.260 velocity varies with temperture
- Thread starter warden1
- Start date
I shoot an Encore with a .260 Bullberry Medium Custom Sporter barrel. My barrel is also floated using the Bullberry hanger system and I installed an over size hinge pin from Bellm back when I was just using it as a muzzle loader. My trigger pull is 2.5 pounds with Bellm springs and polishing.
I shoot 120 gr BT's with no accuracy problems. My 3 shot groups are MOA @200 yards. At 100 yards I'm getting consistant 3/8" 3 shot groups.
Here is the load data I am using.
Case - Remington
Bullet - Nosler 120gr BT
Powder - H4831 @ 48.5gr's
Primer - Remington 9 1/2
COL - 2. 900" Which is .010 off the lands in my chamber.
Note: I like the H powders when shooting here in the hot and humid south, because they don't seem to be affected as much by temp changes as some of the others.
I shoot 120 gr BT's with no accuracy problems. My 3 shot groups are MOA @200 yards. At 100 yards I'm getting consistant 3/8" 3 shot groups.
Here is the load data I am using.
Case - Remington
Bullet - Nosler 120gr BT
Powder - H4831 @ 48.5gr's
Primer - Remington 9 1/2
COL - 2. 900" Which is .010 off the lands in my chamber.
Note: I like the H powders when shooting here in the hot and humid south, because they don't seem to be affected as much by temp changes as some of the others.
- Thread starter
- #3
devil dawg,
in keeping 120gr. BTs .005 off the lands, i can only seat my bullets to 2.810". this is a foxridge barrel. evidently i have a short chamber throat. i have a load of H4831 i'm going try in the morning. oddly enough, this encore is the only rifle i've ever gotten cratered primers. actually, i don't know if they are really cratering. its like they get a sharp ridge around the edge of the firing pin notch after firing. also, i've never had a rifle's velocity vary so much with temperature change. i wonder how slow this load will be when it gets cold. the humidity down here is terrible and i'm sure that does nothing to help my load performance. have you tried H4350? this powder seems to give the best velocity so far for, but at the expense of "too" hot of loads.
in keeping 120gr. BTs .005 off the lands, i can only seat my bullets to 2.810". this is a foxridge barrel. evidently i have a short chamber throat. i have a load of H4831 i'm going try in the morning. oddly enough, this encore is the only rifle i've ever gotten cratered primers. actually, i don't know if they are really cratering. its like they get a sharp ridge around the edge of the firing pin notch after firing. also, i've never had a rifle's velocity vary so much with temperature change. i wonder how slow this load will be when it gets cold. the humidity down here is terrible and i'm sure that does nothing to help my load performance. have you tried H4350? this powder seems to give the best velocity so far for, but at the expense of "too" hot of loads.
Guy Miner
Master Loader
- Apr 6, 2006
- 17,675
- 5,491
warden 1 - what powder are you using that gives this wide swing in velocity?
It's actually fairly common. I learned the hard way, shooting a .308 load on a hot day in a 600 yard rifle match. I had to throw away all of my nice Lapua brass afterwards. Don't know what the heck the velocity was, but the VV N135 did NOT react well to a 20 degree shift in temperature.
I switched back to Varget, and haven't had a problem since. Hodgdon's "extreme" powders do pretty well in temperature shifts.
Regards, Guy
It's actually fairly common. I learned the hard way, shooting a .308 load on a hot day in a 600 yard rifle match. I had to throw away all of my nice Lapua brass afterwards. Don't know what the heck the velocity was, but the VV N135 did NOT react well to a 20 degree shift in temperature.
I switched back to Varget, and haven't had a problem since. Hodgdon's "extreme" powders do pretty well in temperature shifts.
Regards, Guy
Even the so called "extreem" powders will vary at high temps. They work better at temps below 75F or so in my limited experiance. Keeping the ammo out of the sun and letting the barrel cool fully will help. I have never found the wide swings you are seeing though. Maybe 75-80 fps max over temps from ~20- 90 F.
I use R19 in my 260s with 125-140 gr bullets with fairly good accuracy and velocities. H4831 and R22 also are good high velocity choices but accuracy suffers in my rifles. H4350 or R19 are my choices for 120 gr loads.
I use R19 in my 260s with 125-140 gr bullets with fairly good accuracy and velocities. H4831 and R22 also are good high velocity choices but accuracy suffers in my rifles. H4350 or R19 are my choices for 120 gr loads.
.260 Handgun
Beginner
- Jan 9, 2006
- 48
- 0
Wish I had some great advice, but I don't. My 15" barrel is from foxridge and its shoots better than I do. I use varget powder with 0.5 grains less than max in my 120BT and 125PT loads. Even in the hot Oklahoma sun on 100 degree days the primers aren't cratered. The throat is about the same as your barrel (2.815 with 120 BT). My barrel likes'em .020 off the lands so my loads are dialed in at 2.795. I've heard of a few people with similar problems from foxridge barrels. Maybe you were one of the lucky ones that got a bad barrel. If I had a rifle barrel I think I would give RL-19 a try. It's my powder of choice for my '06 with heavier bullets and the data looks good on it in the .260 with heavier bullets, too. Good luck!
