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300 WinMag Retumbo or H1000
- Thread starter BrettS
- Start date
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Well went back to the range today and tried a few loads, rifle was fired from a benchrest with a Kahles 6-24i. Rifle is bedded, muzzle brake fitted and trigger has been polished and set at 1.2lb was about 54f here today with a cold 10mph breeze, the barrel just got warm at most as I let it cool a little between shots.
The first 3shots with the Retumbo on the right are similar to what I have previously getting.
I got a little excited when I fired the first 3 shots on the left hand target then things went downhill after that.
The first 3shots with the Retumbo on the right are similar to what I have previously getting.
I got a little excited when I fired the first 3 shots on the left hand target then things went downhill after that.
I then replaced the scope with a NF ATACR 5-25.
Shot a 5 shot group on the right and a 6 shot group on the left, just to rule out any issues with the scope.
Bullets are seated about 20 thou off the lands, I have not tried any other projectiles other than the Berger 215gn hybrid, cases were first time fired. 81.5gns of Retumbo is max in my rifle and groups were similar, but velocity was around 2940fps.
At this point this rifle is not delivering the accuracy I would have expected, so I would welcome some ideas from those more experienced than myself.
Shot a 5 shot group on the right and a 6 shot group on the left, just to rule out any issues with the scope.
Bullets are seated about 20 thou off the lands, I have not tried any other projectiles other than the Berger 215gn hybrid, cases were first time fired. 81.5gns of Retumbo is max in my rifle and groups were similar, but velocity was around 2940fps.
At this point this rifle is not delivering the accuracy I would have expected, so I would welcome some ideas from those more experienced than myself.
What load development have you done thus far? Charge weight, seating, etc. Also, have you tested your groups at longer ranges(200 or 300 yards) to make sure the bullet is stabilizing? Given all this, I would try another bullet, perhaps a 210VLD. My 300WM seems to like them better then the 215's.
BrettS,
Was the 10 mph breeze a full value cross wind? Did it lay down before you shot the groups with the ATACR scope? I think I would leave that scope on the rifle if possible. Barring any significant wind shifts, I like the shape of the groups much better. There seems to be a problem with horizontal in the Kahles, but that could be caused by a condition change.
You might try finding the sweet spot on your seating depth, using the Berger method. I recently saw a post on here where a Berger Tech recommended finding the seating depth sweet spot, then working back up to max. From my experience, I think it is a good idea. It surprised me how much my velocity changed on my 300 Win Mag, the last time I was looking for the right seating depth. Evidently there was a lot going on with the pressure as well. The Berger method for finding seating depth has worked well for me in the past.
After finding the most promising seating depth, work back up to max. Just my opinion, for what it's worth........ Good luck!
Steve
Was the 10 mph breeze a full value cross wind? Did it lay down before you shot the groups with the ATACR scope? I think I would leave that scope on the rifle if possible. Barring any significant wind shifts, I like the shape of the groups much better. There seems to be a problem with horizontal in the Kahles, but that could be caused by a condition change.
You might try finding the sweet spot on your seating depth, using the Berger method. I recently saw a post on here where a Berger Tech recommended finding the seating depth sweet spot, then working back up to max. From my experience, I think it is a good idea. It surprised me how much my velocity changed on my 300 Win Mag, the last time I was looking for the right seating depth. Evidently there was a lot going on with the pressure as well. The Berger method for finding seating depth has worked well for me in the past.
After finding the most promising seating depth, work back up to max. Just my opinion, for what it's worth........ Good luck!
Steve
How/when are you cleaning? If this were my rifle I would get the barrel fouled with about 10 rounds and run a ladder at at least 600 yds with the 215 seated at the lands. I would take the loads that have tight vertical and come back to 100 yds and play with seating depth.
Broz
Well-Known Member
Have you pulled the rail base off the rifle to see if it is moving? If not I would do this and if it is an EGW I would do this for sure.
It appears to me you have a rifle peblem. There is no way it should shoot this badly.
I also see your velocity is low for 78 gr of H-1000. From a 26" you should be close to 2950+ with that charge and at max or above. Chronograph wrong?
Jeff
It appears to me you have a rifle peblem. There is no way it should shoot this badly.
I also see your velocity is low for 78 gr of H-1000. From a 26" you should be close to 2950+ with that charge and at max or above. Chronograph wrong?
Jeff
Thanks for the reply. I have tried various charge weights, but have not played with seating depth. I have fired one 3 shot group at 550yds was around 5" and bullets were stabilized. I have ordered some 210's so I will see how they go.
Thanks Steve, I do suspect that there is a bit of an issue with the Kahles, it's only six months old so I may have to send it in to get checked. The wind stayed relatively constant during shooting, I will definitely look at the Berger post and play with seating depths. I was under the impression that unlike the VLD the hybrid was less sensitive to seating depth.
Thanks, I can shoot out to 550yds at the range, I will give it a try.
Thanks for the reply Jeff, my rail is a Warne and I just screwed it down firmly with a bit of Loctite. My rings are Nightforce ultralites.
I must say that I expected a bit more from this rifle and thought it may improve with bedding and trigger job but those have made no difference at all.
I am using a Prochrony not sure on its accuracy, but was a bit underwhelmed by the velocities shown. I may get a Magnetospeed as I have heard that they are accurate, but can affect poi.
I will try the 210 Bergers and see how I go, ultimately if I have to pull the barrel and fit a new one I will, just want to try everything before it comes to that point.
Broz
Well-Known Member
I have learned to not trust a Chrony. The magnetospeed does change poi on most rifles but has not effected accuracy for me at all. I work with 300 win mags all the time. I have yet to see one not shoot the 215 well with H-1000. Plus I would bet you are closer to 2950 fps dependent of barrel length. close to 3K from a 28". Figure 22 fps per inch of barrel from that.
There is something wrong. I hope its not a bad barrel. But it it were me I would be pulling that rail and bed it to the action. I bed every rail I install.
What is the barrel? I missed that.
Jeff
Broz
Well-Known Member
For what its worth. If you brought me that rifle here is what I would do.
1: Pull the rail. If I saw signs of movement on the underside I would pin it or replace it with a NF rail. Either way it would get bedded to the receiver.
2: I would clean the heck out of the barrel with Bore Tech Eliminator.
3: I would load up 6 rounds with 76.5 gr of H-1000 and a Fed 215 (first Choice) or a CCI 250 if I did not have the Fed 215. Then seat the 215 Bergers just touching the lands to start. Shoot two (3 shot) groups allowing cooling between. 9 times out of 10 this will be a sub moa deal. If not I would go up or down 1 gr of powder. But if it shoots a 2" group I would have to believe the rifle (most likely barrel) has a problem.
Hope this helps.
Jeff
1: Pull the rail. If I saw signs of movement on the underside I would pin it or replace it with a NF rail. Either way it would get bedded to the receiver.
2: I would clean the heck out of the barrel with Bore Tech Eliminator.
3: I would load up 6 rounds with 76.5 gr of H-1000 and a Fed 215 (first Choice) or a CCI 250 if I did not have the Fed 215. Then seat the 215 Bergers just touching the lands to start. Shoot two (3 shot) groups allowing cooling between. 9 times out of 10 this will be a sub moa deal. If not I would go up or down 1 gr of powder. But if it shoots a 2" group I would have to believe the rifle (most likely barrel) has a problem.
Hope this helps.
Jeff
