105Amax is not stable?

[Nocalphoenix]

Hey guys my buddy picked up a VTR in .243 and is having some problems. The VTR has a 1x9 twist and it does not look like it is stabilizing the 105 amax or the 95gr Sierra. His groups are in the 6-8" range at 100 yards and lighter slugs are grouping ok. I have seen stability problems before but they were full on tumbling, these look like they might be tipped just a little bit.

So far it seems like he got a Friday at 5 o'clock gun, horrible stock fit, rough chamber rails that are gouging his brass and a couple other problems. The top two photos are the amax and the bottom one is a TTSX.

 

[Adam B]

Re: 105Amax is not stable?

my 1:7.5 works, I think the 1:9 may be too slow

 

[Victor N TN]

Re: 105Amax is not stable?

He may be trying too long a bullet for that twist.

 

[Rob01]

Re: 105Amax is not stable?

How fast is he pushing them? Sometimes they need to be pushed a little faster to come in. If the load is light I can see them not stabilizing.

 

[Nocalphoenix]

Re: 105Amax is not stable?

So does that look like tipping in the first two photos? The only problems I have seen were with ARs and the bullets were hitting completely sideways...

He knew he could not shoot the Dtacs but it sucks he went with the VTR to get the 1x9 twist to shoot some of the heavy stuff and none of it looks like it will work. If Remington recognized the need to put a faster twist on the LTR and VTR why not go with a 1x8 to make sure their stabilized vs a marginally 1x9?

 

[steve123]

Re: 105Amax is not stable?

Try the 88 grain Bergers or 95 grain BIB's.Both will work in the 10 twist's I've had.

Steve

 

[NOMAD]

Re: 105Amax is not stable?

They recommend a 8.5 twist barrel on the 105's. I was cranking them out at 3050 fps in a 7.75 twist barrel and they tend to want to come apart at fast velocities and wrong twists.

 

[buffybuster]

Re: 105Amax is not stable?

The factory Remington "1/9" twist may not be exactly 1/9. They have a tolerance and this barrel looks like it might be on the slower end of that tolerance (9.25-9.5). Either push the AMAX's faster or go to a shorter bullet.

 

[buffybuster]

Re: 105Amax is not stable?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Norcal Phoenix</div><div class="ubbcode-body">
If Remington recognized the need to put a faster twist on the LTR and VTR why not go with a 1x8 to make sure their stabilized vs a marginally 1x9? </div></div>

Chances are Remington is trying to cover as much of the general market as possible. With a 1/8 twist, they/you run the real risk of having lighter varmint bullets come apart from over spinning. Shoot 55-70gr bullets at near 4000fps, that's about 6000rps. Bullets usually can't take much above 5300rps without coming apart. Remington probably figured that out.

 

[Nocalphoenix]

Re: 105Amax is not stable?

Thanks guys, I will pass him the info.

 

[Religious Shooter]

Re: 105Amax is not stable?

My SPS Varmint with a factory tube looks like it stabilizes the 105 AMax. It shoots the Amax with new RP brass at around .75-1MOA at 100 yards. I'm pushing it to 2930 FPS with 40.8 grains (book max) of Reloder 17.

 

[MTETM]

Re: 105Amax is not stable?

I would ask how fast they were going. We shot them(105 Amax) this weekend in 10 degree weather at 3040 fps in a Shilen 1:10. They stabilized just fine at 100 yards. The plan is to increase the charge, it was a lighter load and see how things go. We will shoot them later this week when the weather improves to 1000 yards.

 

[buffybuster]

Re: 105Amax is not stable?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MTETM</div><div class="ubbcode-body">I would ask how fast they were going. We shot them(105 Amax) this weekend in 10 degree weather at 3040 fps in a Shilen 1:10. They stabilized just fine at 100 yards. The plan is to increase the charge, it was a lighter load and see how things go. We will shoot them later this week when the weather improves to 1000 yards. </div></div>

What altitude?

 

[MTETM]

Re: 105Amax is not stable?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: buffybuster</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MTETM</div><div class="ubbcode-body">I would ask how fast they were going. We shot them(105 Amax) this weekend in 10 degree weather at 3040 fps in a Shilen 1:10. They stabilized just fine at 100 yards. The plan is to increase the charge, it was a lighter load and see how things go. We will shoot them later this week when the weather improves to 1000 yards. </div></div>

What altitude?</div></div>

2850

This was the first time we tried them in this rifle. We only shot a handful to get an approximate velocity and to see if they would stabilize at 100. If the weather cooperates we will get some more data the end of the week or this weekend.

 

[25 Minutes to 1K]

Re: 105Amax is not stable?

Before I switched to 107SMKs in an 8 twist I shot the crap out of 105 Amax bullets in a 1/9.25 twist Savage factory varmint barrel. Stabilized out to 1K just fine.

A good accuracy load I've found in a few different rifles is 48 gr. Retumbo in Winchester brass with a CCI magnum primer. I was getting 3200 fps with no bullets dissolving and good stabilization in 40 degree weather(as cold as it gets normally here).

 

[Superswamp]

Re: 105Amax is not stable?

Fibonacci, Would the 48 gr Retumbo work with Berger VLD 105 gr hunting in 1 in 8 twist? Thanks, Mike