162 Amax doesn't like to be jumped?

[targetterror]

I had loaded up some 162 Amax bullets for my Stevens 200 in 7mm-08. I had loaded them to 2.925" OAL - about .025" off the lands - and they shot well, about 1 MOA. I tried seating them back to 2.875" so they would fit in the magazine, and the shots were all over the place, 2-3 MOA. It seems odd that the bullets would be that upset by an additional .05" jump, or is that how they perform?

It was also in the 30s today, and in the teens when I shot previously. I was shooting 39.0 grains of IMR 4064, so I would expect a slight increase in velocity in the warmer temperature, but I would think not enough to through the shots so much.

 

[19Scout77]

Re: 162 Amax doesn't like to be jumped?

Never had an issue jumping 162s in my 7wsm

 

[jrpilot]

Re: 162 Amax doesn't like to be jumped?

7mm 162 amaxs have worked great with a jump for me.

 

[targetterror]

Re: 162 Amax doesn't like to be jumped?

Interesting. I'm wondering if I didn't let the barrel cool down enough (its the pencil Stevens barrel). I thought I had, but maybe I'll try again.

 

[BOLTRIPPER]

Re: 162 Amax doesn't like to be jumped?

my thoughts are your powder choice......try 4350

 

[mscott]

Re: 162 Amax doesn't like to be jumped?

Mine are jumping, but every rifle is different. I can't believe that small of a change would kill your accuracy. Did you run them over a chrono to see how velocity has changed? I'd load 5 or 10 to your original specs to make sure it is the seating depth and not something else.

 

[RobG]

Re: 162 Amax doesn't like to be jumped?

I load mine to jump .010. Any closer and the groups opened up.

 

[targetterror]

Re: 162 Amax doesn't like to be jumped?

I went back to the range today, and the load was fine. Very odd. I think either the barrel was too warm, or my position was off. I had tried a higher prone yesterday, which worked fine with a 120 grain bullet load, but maybe the recoil of the 162 doesn't work with that position. I shot lower today, and it grouped about 1.5 inches at 200 yards, and most of that distance was vertical.

 

[mwroseberry]

Re: 162 Amax doesn't like to be jumped?

The stevens 200 has a 1 in 11.25" twist barrel. It really isn't made to stabolize anything over 130gr. The 162 really needs run in a 1 in 9.5" twist or faster so you're lucky to be shooting those bullets at 1 MOA as it is. Go with some 120 or 130gr bullets and I promise you that your groups will shrink drastically.

I am awaiting delivery on a Mcgowen 26" bull barrel with a 1 in 8 twist so I can run the 162 amax and the 180VLDs if I want. It states right on the Amax box that it's designed for a 1 in 8 barrel.

Good luck,
Merritt

 

[targetterror]

Re: 162 Amax doesn't like to be jumped?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwroseberry</div><div class="ubbcode-body">The stevens 200 has a 1 in 11.25" twist barrel. It really isn't made to stabolize anything over 130gr. The 162 really needs run in a 1 in 9.5" twist or faster so you're lucky to be shooting those bullets at 1 MOA as it is. Go with some 120 or 130gr bullets and I promise you that your groups will shrink drastically.

I am awaiting delivery on a Mcgowen 26" bull barrel with a 1 in 8 twist so I can run the 162 amax and the 180VLDs if I want. It states right on the Amax box that it's designed for a 1 in 8 barrel.

Good luck,
Merritt</div></div>

Mine is 9.25" twist. The Stevens 200 7mm-08 barrel (at least the older ones) have this 1 in 9 twist. Savage switched to 1 in 11 twist for a while, but apparently just recently switched back to a 1 in 9.25.

 

[mwroseberry]

Re: 162 Amax doesn't like to be jumped?

You got lucky. If I was you I wouldn't go over 150gr in a 1 in 9.5. But if you can stabolize them more power to ya. As far as being jumped why do you want them in your magazine anyway? If you are hunting with them you probably want to go with SSTs which is more made for hunting anyway. For matches you want to load all your rounds by hand to make sure the powder temps on all your rounds stay as constant as possible. Round in a blind internal mag have the tendancy of heating up and throwing rounds.

With my stock steven barrel in 308 I could only shoot the first three rounds rapid then I'd have to wait 40-60 seconds with the bolt open to cool the barrel properly so that I could hold tight groups with it.

Good luck,
Merritt