264 win mag 140/retumbo

[remingtonman_25_06]

Been doing a bit of shooting with my dads model 70 264 with a 26" bartlein and 140g nbts. First couple outings i was getting 3200fps with 71g retumbo and .5 MOA in new winchester brass. The 3rd time out it was doing like 1-2" MOA with the same load. After the 3rd outing all the brass had been fireformed. So I came home fl sized/trimmed and loaded up a few with 71g retumbo again just to see what was going on. This morning I was back to under .5 MOA this time at 3290fps. Pressure is definitely up there but man does it shoot. Question is, am I playing with fire here or? I dont see many 264s getting 3300 with 140s and retumbo. What are your thoughts? QL throws out 71.5-72 at 3150-3175...

 

[FOTIS]

what caused the 1-2 MOA?


I would slow it down to 3150 just to be safe and make the brass last longer

 

[remingtonman_25_06]

No idea POP....thats my head scratcher. First 2 outings did 3200-3250 at .5 moa...3rd did 1-2 moa. Didnt crono 3rd outing as i thought it was the load and was just gonna zero and stretch her out a bit. All 3 those outings were new brass. This morning i loaded them up after being sized and trimmed. Back to .5moa at 3300fps.

 

[remingtonman_25_06]

Tried h4831sc at 62/63/64 as well...62 at 2950fps .5 moa 63 at 3000 .75moa 64 at 3051 .75 moa...so its either 62g h4831sc at 2950fps at .5moa or 71g Retumbo at 3290fps at .4moa.

 

[1Shot]

This will go to show you that no two rifles are the same. I have a custom Rem. 700 Shilen barrel 1 in 9 twist 27 3/4" 264 Win. Mag. I am shooting 66.5 grs Retumbo with 130 Nosler Accubonds and average 1/2 moa accuracy and 3350 fps. 67 grs Retumbo left ejector marks and loosened primer pockets. Retumbo is a great powder but you can go from no signs of over pressure to way over pressure in a small change when you get near the top.

For an explanation of what happened with your accuracy change could be the new cases. Sometimes new cases can do some crazy things. I bought a new Rem 700 Stainless synthetic 7mm Rem mag a few years back. I got 100 new Remington cases. I started doing a load work up and accuracy was all over the place. My best load was about 2". All the time I was using the new cases. I thought this rifle was going to have to go down the road because it was not going to be accurate. When I ran out of new cases I part sized some cases with a FL sizer, just sizing the neck and bumping the shoulder a little. I loaded up the load that shot the 2" groups before because it was the best it had done. It was 139 gr Hornady's with AA3100 powder. When I shot the first shot I could see it on the target when I fired the second round at the target there was still only one bullet hole in the target. I fired the third shot and still there was only one bullet hole in the target. I thought "GREAT NOW THIS THING WON'T EVEN KEEP A BULLET ON THE PAPER". I had two rounds left so I fired them and after firing the last shot when I looked through the spotting scope there was still only one bullet hole in the target but it looked a little larger than before. I walked down range to the target and low and behold all five shots had went into a ragged hole. I found that it did not really matter which bullet I used with AA3100 or H4831 right at max loads as long as I used a case that had been fired in that rifle and part sized it shot bug holes.

 

[gerry]

This will go to show you that no two rifles are the same. I have a custom Rem. 700 Shilen barrel 1 in 9 twist 27 3/4" 264 Win. Mag. I am shooting 66.5 grs Retumbo with 130 Nosler Accubonds and average 1/2 moa accuracy and 3350 fps. 67 grs Retumbo left ejector marks and loosened primer pockets. Retumbo is a great powder but you can go from no signs of over pressure to way over pressure in a small change when you get near the top.

I found the same in my 264 WM with the 130 gr AccuBond and 129 gr Hornady Spire Point, 67 gr was a bit warm. With 140 gr Partition's Hodgdon's max load of 63.5 gr was definitely max, I suspect that since my gun has some throat erosion I may be able to go a bit higher now but not much. The 156 gr Norma Oryx and 155 gr Lapua Mega bullet can take up to 65 gr but I use 64 gr just to be safe.

 

[SJB358]

Jorey, what kinda of chrono are you running. I get 3200 pretty nicely with RL25 in my 264 on fired cases though. I don't waste too much time trying to do ultimate loading till my cases have been fired at least once. Some chambers change the cases enough where I don't hardly waste the time anymore.

I don't think 3290 is absurd with the 264 and Retumbo but it definitely warm. Like Fotis was saying, 3200 is right there and pretty easy on cases. RL33 was easily able to get a little more, but still, 3200'ish was the sweet spot for my gun.