Berger 200.20x Load Developement

[lawrence97]

Looks like It could possibly be a bad lot of primers:

http://forum.accurateshooter.com/threads/cci-br-4-primers-failure-to-fire.3936976/

 

[Ilya S.]

Tried to push 200.20x on 43.5 vihtavuori N140 with LR Murom primed lapua brass, 0.010 off the lands. MV was 2657fps at +2c on my True Flite 32” 10twist 4-grooves heavy palma tube. Very bad groups, 1moa accuracy, no pressure sights
I think its too fast or between two nodes. Will try them slower at 41.5, 42.0, 42,5 and 43.0 vv140.

 

[BP1]

Tried to push 200.20x on 43.5 vihtavuori N140 with LR Murom primed lapua brass, 0.010 off the lands. MV was 2657fps at +2c on my True Flite 32” 10twist 4-grooves heavy palma tube. Very bad groups, 1moa accuracy, no pressure sights
I think its too fast or between two nodes. Will try them slower at 41.5, 42.0, 42,5 and 43.0 vv140.

My 30” 10twist ended up liking 43gr of varget running right around 2618fps.

 

[Ilya S.]

10х, looks hopefully.

 

[jsthntn247]

Your primers not going off is a headspace issue. New Palma brass is on the short size. Try some soft primers or jam your bullets and I'll bet it fixes your problem. I've had the same issue with both my Tr 308's and Palma brass but not with their regular brass.

 

[XTR]

The firing pin protrusion is about 50 thou, I seriously doubt it's headspace.

I've had FTF issues once, changed the firing pin spring and it went away.
Shooting buddy had issues at Raton yrs ago, Borden put a new firing pin in his rifle and the problem went away.

Go figure.

 

[Ilya S.]

Have got nice groups on 42.5 and 43.0 (2627 FPS) of N140 with 0.010 off the lands. But its hard to repeat.
On your feelings guys, the Varget is slower than Vihtavuori N140 ? The recoil on Varget is smoother ? Of course, at the same velocities...I think I have some recoil issue on this bullets. Im shooting with a full cheek pressure and hard push.

 

[memilanuk]

Im shooting with a full cheek pressure and hard push.

Most people can't maintain that kind of contact consistently for a whole string. Groups, yes. 20 shot strings, no.

 

[ballisticdaddy]

My 30” 10twist ended up liking 43gr of varget running right around 2618fps.

This is exactly where my rifle likes to shoot this projectile and have had good results!

 

[Ilya S.]

Most people can't maintain that kind of contact consistently for a whole string. Groups, yes. 20 shot strings, no.

this weeks will try a soft hold.

 

[T-shooter]

this weeks will try a soft hold.

It seems to work better for me. I touch my cheek on the stock as a point of reference but no pressure. Also a very light hold with my right hand and my thumb straight up, not wrapped around. I seat the stock into my shoulder lightly touching but not pulled back. Then just let it jump back into my shoulder pocket. With my .308 with a muzzle brake, the recoil is not bad so no scope bite so far. Also I use a 1-3/4 lb trigger which would be heavy for a benchrest rifle. I notice I don't see nearly as much heartbeat through the scope this way but pulled back firmly, the reticle does move on the target. Consistency is the key. You have to do the exact same thing the same way every time.

 

[Tony1320]

Switched to CCI 450 primers and haven't had an issue since. The action had a brand new firing spring installed not long ago I didn't know about until recently.

 

[Tony1320]

This is exactly where my rifle likes to shoot this projectile and have had good results!

What kind of vertical do you see at 600yards during a string?

 

[Marksman63]

Tried to push 200.20x on 43.5 vihtavuori N140 with LR Murom primed lapua brass, 0.010 off the lands. MV was 2657fps at +2c on my True Flite 32” 10twist 4-grooves heavy palma tube. Very bad groups, 1moa accuracy, no pressure sights
I think its too fast or between two nodes. Will try them slower at 41.5, 42.0, 42,5 and 43.0 vv140.

At 68F I have 45.2 of VV-N140 in Lapua Palma formed cases at 0.015” jump with 3.100” OAL.
Very long throated Benchmark 32” 1/10 barrel

 

[Ilya S.]

at 0.015” jump with 3.100” OAL.
Very long throated

not very long, seems 0.190-0.200 freebore. I just wanna know how do you handle 200 grains at more than 2650 fps ? Or you shoot it free-recoil ?

 

[Marksman63]

not very long, seems 0.190-0.200 freebore. I just wanna know how do you handle 200 grains at more than 2650 fps ? Or you shoot it free-recoil ?

I shot with with a light hold to control verticals but recoil is not an issue. I recently upgraded it with a tuner which seems improving my groups

 

[Tony1320]

I shot some groups at 600m today. If I shoot 5 shot groups the vertical is nice but if I shoot a 10 shot group there's more vertical than I'd like to see. I'm not sure if its the load or me not having the same hold after a while

This is a 5 shot groups look like 5th shot was on the waterline just outside the left side of the target

 

[gsg5pk]

What is the minimum freebore to shoot this 200.20x bullet?

 

[jsthntn247]

What is the minimum freebore to shoot this 200.20x bullet?

120 should be right at the shoulder junction.

 

[Papa Charlie]

I was having a new barrel made by Benchmark and had a discussion with Berger on Freebore for the 200.20X for my .308. Their response to me was that the 200.20X was not jump tolerant, that 0.015" OTL would be a good spot for it. Berger also suggested that I produce a dummy round for Benchmark to use to set the Freebore. The reamer they used was a SAAMI Match reamer with a 0.110" Freebore. When they chambered the dummy, it pushed the round in 0.004". I had loaded a little long to ensure I had plenty of room between the bullet tail and the powder so seating 0.019" deeper to get the 0.015" OTL was not an issue at all.

So I wonder how are you loading the 200.20X, what powder, how much and how far are you off the lands?