Finally chronographed my .260 Rem.

[cleveland48]

I finally managed to buy a chronograph, so I decided to chronograph my handloads for my 260 that have been shooting so well.  But most of these loads average velocity was faster than it said in the manual.  Can some of you tell me why this is? All my manuals test their loads with 24 in. barrel's I believe.  Mine is a browning a-bolt II synthetic stalker with 22 in. barrel and a 1 in 10 twist rate.
140 GR. Hornady SP                                                    130 Gr. Nosler AB                 120 Gr. Nosler BT
47.0 Gr. of IMR 7828 (max load!!)                                  48.0 Gr.  of RL 22                 46.5 Gr. of H4350
Avg. Vel. 2804 fps ( Lee manual says 2755 fps?)         Avg. Vel. 2920 fps                Avg. Vel. 3024 fps

All of these loads were chronagraphed 15 feet from the muzzle.  For some of these to be faster than they were published could some of the muzzle blast still have messed up the readings on my chronograph?  These loads also showed no signs of dangerous pressure levels.  Just wondering if this is normal or not.  Thanks for the help guys.

[bilmac]

 Even the experts don't claim to know why one barrel will shoot faster than another, they cite such things as chamber dimensions, bullet leade, barrel dimensions as variations that can affect velocity. Those are nice numbers though, the 260 slings some nice long bullets at very respectable speeds, my idea of just about the ultimate deer antelope shooter.

[RaySendero]

All of these loads were chronagraphed 15 feet from the muzzle.  For some of these to be faster than they were published could some of the muzzle blast still have messed up the readings on my chronograph?  These loads also showed no signs of dangerous pressure levels.  Just wondering if this is normal or not.  Thanks for the help guys.

c48,

I find its a good idea to buy a box of factory loads with the same bullet I'm using to reload - Then use them as a standard to compare my reloads and check chrony over time.  They'll last 10 years - i.e. shoot two a year.

[cleveland48]

I've got a few of the Remington core-lokt's in 140 gr. factory loads left.  I just found them and I'm gonna try them out tomorrow and see how fast they are.  But I don't have any factory loads in a smaller weight to compare my reloads too.  About how far from the chronograph do ya'll usually get?  It seems like most magazine's I read they test from about 12 feet i believe.

[Don Fischer]

I set my screens 10' in front of the muzzle and haven't had a problem. Impressive velocities. I run about the same with my 6.5x55. If I didn't have it, I would get a 260!

[cleveland48]

Thanks Don,

My older brother has a swede and I'm trying to work up a load for him.  If you don't mind could you tell me what your using in your swede.  I made some loads for his but they didn't do what I expected(2400 fps in 22 in barrel Win. Mod. 70 with 130 gr. accubonds.)  I got to looking afterwords and the book I got the load from used  an old mauser with 29 in barrel(which would explain how they got a couple hundred more fps than I did.)  The load I used was a Nosler Accubond with 44.8 of H 4831.  He is looking for around 2800 to 2900 fps is this possible with the Swede.  Anyways thanks.

[RaySendero]

About how far from the chronograph do ya'll usually get?

ten feet

[Don Fischer]

I'm using two different powders in it, H450 with the 129gr Hornady and RL-22 with the 140gr Hornady. Truth is with the 129gr bullet, the load I'm using is the first load I worked up with it. I don't recall the vel right off but the 129gr was about 2800fps if I remember. The 140 gr was well over 2700fps and this out of a 22" barrel. I have a Mod 70 featherweight. Seems I did a bit better in my ex's swede. It is a Parker-Hale 1200 re-barrled with a 23" barrel.

One problem with using H450, I don't know if I can get more, nobody around here has it. Failing that, I'll try RL-19 and IMR 4350.

EDIT:

One more thing about the velocity your getting. It was probably worked up in a milirary swede and they operate at lower pressure. Modern action's can be worked up a good bit past them pressure wise. The Nosler book I have worked up the loads in a Lilja barrel and I'm guessing a different action. 125gr Partition they are geting 3100+ fps.

[drdougrx]

I set mine 10ft from the muzzle and almost NEVER get the published ballistics for any of the published loads.

[usherj]

The faster velocities may be due to the 1 in 10" twist rate. The most common twist rates for 6.5s are 1 in 8" and 1 in 9", which is what was likely used in the manual testing. I believe the slower twist rate could result in higher velocities, but I don't know to what extent. As long as you are able to stabilize the 140s and get decent accuracy, which appears to be the case for you.

[pa hog]

We shot our 270wsm's and 300wm today at the range we put chrono 14-15' away as always and did'nt have any trouble 15' is recommended with our chronograph it's a Shooting Chrony Beta Master. A full boat .260 at 15' should be ok,did you have sky screens installed,sometimes the sun will mess with you. I did blow the skyscreens off once with 55gr V-Max/ 39.5gr varget load with a .22-250 at 5' @4100fps+

[cleveland48]

Yeah I had the sky screens on.  I tested some factory core lokt 140's I had lying around today.  They were almost identical to the 140's I loaded with IMR 7828.  But they had a higher extreme spread.  I believe the the lowest velocity I got with them was 2760 or so, and the highest was around 2840.  They ended up averaging just a hair over 2800 fps.

[john keyes]

 

those are some killer numbers. wow.

I just got back from checking my 260 for next week opening up deer season and I only fired eight rounds, no scope adjustments, all dead on.

I'm shooting H414 and rem 140 gr corelocts. The H414 is dirty but the load is too good and it cleans up easily.

I need a chrono bad.

[cleveland48]

I understand how it feels to need a chrony.  Between gas goin back and forth to school and a small part time job it's still hard to come up with the money.  We just bought the one that is 80 or 90 dollars but so far it seems to be working pretty good.