Ladder Testing (no target, chrono only) advice?

[3-0-hate]

Its too hot to shoot outdoors at any meaningful distance, so I went to a nice air conditioned indoor range and shot at 100 yards.. 67* on the lane while it was 97* outdoors. Ill take it. But that meant I was not able to shoot a ladder on the target, not with a 7mm mag anyways. This is my hunting rig, a Browning X-Bolt, 7mm Rem Mag.

I was ladder testing 168gr Nosler Accubond LR's and Hornady 162gr SST. Everything was loaded in .3gr incriments, with each charge being trickled up to the kernel in weight on an old Lyman M5 beam scale. I was using IMR4350 for all the tests. Im pretty sure I know where I want to load on the SST's, at 59.9gr, but what about the Nosler loads? My guess is 62.0gr, because I would like to have as much velocity as possible out of the muzzle, and that should net me a fairly respectible 2930ish mv. The other option is 60.4gr, but that would reduce my MV by more than 100fps..

What say you guys? Where would you focus your efforts if you were me?

Thanks!

 

[d_train821]

What was the SD of the paler when you got up to 61.5? Maybe there was a bad round in there that messed up the set. I would re load that top end and check it out again.


Sent from my iPhone using Tapatalk

 

[3-0-hate]

I was shooting only 1 round of each charge weight to find a flat spot. It is entirely possible that the magneto speed shifted forward too far and read poorly. It was hard to keep the bayonet from sliding forward toward the muzzle with each shot on this thing, even in a lead sled. If it was my unit, I would be putting some rosin or something on the strap to help keep it from moving.

 

[_Windrider_]

I was shooting only 1 round of each charge weight to find a flat spot. It is entirely possible that the magneto speed shifted forward too far and read poorly. It was hard to keep the bayonet from sliding forward toward the muzzle with each shot on this thing, even in a lead sled. If it was my unit, I would be putting some rosin or something on the strap to help keep it from moving.

Did you have the rubber guard on it that goes between the strap and the barrel? I've never had mine slip, even on a .338. 59.7-60 on the 162 looks promising and I agree on the 168, reshoot that 61.5.

 

[3-0-hate]

Did you have the rubber guard on it that goes between the strap and the barrel? I've never had mine slip, even on a .338. 59.7-60 on the 162 looks promising and I agree on the 168, reshoot that 61.5.

I had the rubber pad on it.. The barrel coating on my x-bolt is pretty slippery and it would keep moving forward. It was clamped down pretty tight.

I will re-shoot that 61.5 load and check. Maybe load 5 of each of the upper end loads on the 168..

With the 162s, I was thinking about splitting the difference on the 59.7 and 60gr loads, loading 5 at 59.7, 59.8, 59.9 and 60 and seeing how it pans out.. It only needs to be minute of deer/elk, but if I can get it dialed in as much as possible, I will feel better about taking it afield.

Thanks for the suggestions.