.264 Win Mag load development time

[BIG MO]

My good friend just treated himself to a new Rem Sendero in .264 Win Mag for Christmas and it will be coming to my house on Monday for the usual treatment to include tuned handloads. I'm really looking forward to working with this rifle in this caliber. If I can get it to produce 1/2 moa or better with the Berger 140 vld clocking somewhere between 3100 to 3200 fps it will make a great long range Coues deer rig.

I have darn near all the reloading manuals and of course there is shooters nest etc. But I would welcome anyones personal experience with this caliber shooting 140 grain bullets to include preferred powder, primers, seating depths, brass and any other tips that you found key in maximizing the performance of this caliber.

Thanks in advance.

 

[Wookie316]

H870 will get you the most FPS while still being very accurate, but it's dirty discontinued powder Mine liked 74gr H870. Both 264 Win Mags I had liked 64gr RL25. That put me right around 3100 FPS with a 140gr.

I found both AA8700 & US869 to be too slow. 77gr was max & only gave me around 3080 FPS.

I am hearing a lot have good luck with Retumbo. My rifle didn't seem to like it. 65gr was max in mine.

The 264 Win Mag likes slow powders. I'd like to see what 50BMG or the new RL50 would be like?

A 264 Win Mag seems to be very picky, but once you find the sweet spot, they are a very fast & accurate round.

I ended up opening up my 264 Win Mag to a 6.5mm-300 Win Mag. I get 3275 FPS from 79gr H870 & a 24.5" barrel. Gotta love that 6.5mm BC.

Good Luck

 

[apexmtnman]

I'm still working on the best loads for my rifle (Rem CDL SF). I've tried IMR 4831, H450, Re22 and Retumbo. My last load was 68 gr of Retumbo WW cases, Fed 215M primers, Berger 140 gr bullets seated .010 off the lands. My chrono showed an average of 3166 fps with a SD of 16. My three shot groups were in the 3/4 inch range. When the weather gets a little better I intend to do some more testing.

 

[BIG MO]

Very good info fellas! Thanks for sharing. Anyone else with experience or tips for this cartridge please throw your two cents in.

The weather is perfect here in AZ. I will post my progress with this rig during the next couple weeks. I will throw everything at this rig including the kitchen sink until its a solid 1/2 moa or better. Wish me luck!

 

[BIG MO]

Well boys, this .264 Sendero is a fine shooting rifle. I installed a Jewel trigger group, threw together some 140 Berger test loads with RL22 and Retumbo and popped over to the Range yesterday. With virgin Nosler brass the rifle pretty much shot everything I ran through it at .5 - .6 inch.

My fastest test loads were clocking about 3050fps. Next trip to the range I will up the horsepower and see what she does in the 3100 to 3200fps range. Who knows, after a full battery of testing and load tuning this baby may be a 1/4 inch rig. Once I squeeze everything out of a good load we will see what she does at the 1000 yard line.

 

[Wookie316]

Sounds like a shooter. I'd be willing to bet with the speed you are getting, you are about max with RL22. Retumbo should take you over 3100 easily though. Good luck.

 

[BIG MO]

Update on the Sendero SFII .264-

70 test rounds to date with the 140 Berger. I have focused on Retumbo and RL22 with good results. I worked upward with the Retumbo to 71 grains and 3350fps. Worked up to 66 grains of RL22 and 3200fps. The RL22 has consistantly shown the tightest groups and this will probably be my choice between the two. Interesting enough, this is the exact charge of RL22 I currently use in the 7mmRM with a 180 Berger @3000fps.

I have all the reloading manuals and these charges are waaay over the listed max. I'm scratching my head a little bit due to this but all pressure signs in this rifle are within normal. Primers are not excessively flattened, primer pockets are holding firm, and bolt articulation during ejection is like butter. This rifle
seems to have one of the smoothest, easy to clean bores I have experienced with an off the shelf rifle. Also, I'm seating the bullets for a generous jump to the rifle lands.

At these velocities the rifle is shooting pretty tight. From the start the rifle has shown a consistent pattern. From a cold bore the first two rounds go .3-.4 and the third round will open the group to .5-.7. My guess is stress in the barrel affecting POI once the heat starts to set into the barrel. I'm very pleased with results like this shooting Bergers at 100yds. Bergers are my least favorite bullet for shooting 100yd groups.

As soon as I get a modifed Hornady cartridge case for my Stoney Point overall length gauge, I am going to do more testing with different bullet seating depths. Also, I'm going to give the brass a light neck turning and put some time in with the chronograph to check velocity consistency.

I'm still a little ways away from 1000yd testing, but it won't be long.

Its 70 degrees and sunshine here in Arizona. Perfect shooting conditions!

 

[Wookie316]

That is wild !!!! You are 7gr over what my rifle would take with RL22 & 7gr over on Retumbo also.
I was using 140gr Accubonds so that may play a part on a few of those grains too?
If I could have got those speeds out of mine before I rechambered it, I'd of been a happy guy.
I push 3300 FPS with H870 & a 140gr out of a 24.5" tub now from my 6.5mm-300 Win Mag. H870 is good but dirty, want to get my hands on some new RL50 to try.

You are doing very well if those are the #'s you are putting up.

What brass & primer?

 

[SomeRumbum]

I have also had great success with RE-25 and Nosler 120 Ballistic Tips. In fact, my Sendero has a Leupold scope with Kenton knob that dusts rocks out to 800 yards. Start with recommendations and work up. You should find that pressure builds slowly, but velocity gets up there pretty quick. I am shooting these at 3300 fps. Have fun!

 

[BIG MO]

Using Nosler brass and CCI mag primer. If I was seating the bullet into the lands or very close to lands these loads would probably go waay to hot. But with some generous jump, she is running pretty smooth.

 

[roninflag]

BIG MO- the .264 sendero has to be a great coues deer rifle. i would like to see a side by side comparison by someone with a weatherby accumark in 257 weatherby. it is quite cool in flag 11 degrees this moring. i have had good success with h-4831 in 7mm both long and short. i would think that would work in the 264 and it is an extreme powder

 

[264junkie]

Great info guys!
Keep the updates coming

 

[BIG MO]

Thanks for the feedback fellas! Glad there are some interested parties out there. This is a pretty sweet cartridge with a lot to like in a long range rig. I glass bedded the action last night.

I'm anxious to get my 6.5mm neck turning mandrel and hornady modified cartrige case. Should arrive from Midway early next week. I'm curious to see what story different seating depths has to tell.

Yep, there is H4831 and alot of other good powders I have in the cabinet if the RL22 or Retumbo doesn't prove out down the stretch.

That .257 weatherby is a real hot rod, but it is tough to argue with the BC of the 6.5mm 140 Berger VLD. I haven't run any numbers, but probably after 600yds or so the 6.5mm @ 3200+ fps will start stretching a lead. By 1000yds, it is probably no contest.

 

[264junkie]

Thanks for the feedback fellas!

By 1000yds, it is probably no contest.

Just the thought of it makes me smile