Troubleshoot custom 300 weatherby reloading issues 180 hammers

[JMW67]

the sled is a scope eating machine even more so if it is getting weighted

 

[Vol1975]

I am helping my uncle get his new build up and running. It's a 300 weatherby built from the ground up by a good local smith with premium components. Topped with a new nightforce SHV F1 and nightforce rings.

He did maybe 10-12 rounds for break in and then wanted to get a load dialed in.

Shooting 180gr hammer hunters in virgin weatherby brass over RL 23, fed 215M primers.

At 77.5 and 78gr he shot three shot groups with all holes touching. Going around 3150 with 20fps ES. Very promising and typical in my experience with hammers. After some more "tinkering", he starts to get large 2-3 in groups...so he comes back to the 78gr load and it sprays a 3in vertical dispersed group.

We checked screws and mounts nothing appears loose.

here's the "kicker" (pun intended)...most of this shooting is being done from a Lead Sled. I hate those things and won't use them but he likes his. My theory is that he's losing scope zero with that much recoil into a solid wall!

Any other ideas??

never had a problem shooting from a sled and I've shot a lot with mine with magnums. I'd say 20 years give or take. My Guns dont have a break on them and I don't like the recoil when trying to develop loads on magnums. Shooting a couple is one thing but a couple boxes over the course of a morning is to much even for me and I'm not light my self.
when I find a load I shoot then from a bag or typical shooting position that you would shoot from the field.
with that it sounds like something has changed quick.
my thought is change scope, although I have never had a scope just fail. To me that scope and rings you have should be good but there is always bad ones in a lot. also have someone else shoot the gun.

also. I would clean it again and check all things for possible looseness on the gun. Again.
2xents

 

[DDWing]

I am helping my uncle get his new build up and running. It's a 300 weatherby built from the ground up by a good local smith with premium components. Topped with a new nightforce SHV F1 and nightforce rings.

He did maybe 10-12 rounds for break in and then wanted to get a load dialed in.

Shooting 180gr hammer hunters in virgin weatherby brass over RL 23, fed 215M primers.

At 77.5 and 78gr he shot three shot groups with all holes touching. Going around 3150 with 20fps ES. Very promising and typical in my experience with hammers. After some more "tinkering", he starts to get large 2-3 in groups...so he comes back to the 78gr load and it sprays a 3in vertical dispersed group.

We checked screws and mounts nothing appears loose.

here's the "kicker" (pun intended)...most of this shooting is being done from a Lead Sled. I hate those things and won't use them but he likes his. My theory is that he's losing scope zero with that much recoil into a solid wall!

Any other ideas??

Put a good muzzle brake on it and get rid of the lead sled.

 

[North Idaho Hunter]

By chance do you have a self timing muzzle brake on this weatherby?

I've had 3 rifles (all heavy recoiling rifles) loosen the self timers and cause this.

 

[Shane Lindsey]

By chance do you have a self timing muzzle brake on this weatherby?

I've had 3 rifles (all heavy recoiling rifles) loosen the self timers and cause this.

Can you explain what you mean by loosen them?

 

[North Idaho Hunter]

@Shane Lindsey all 3 werent torqued down tight by the smith, with several shots down range they would slowly loosen up causing issues with accuracy - once i realized what was going on after a full tear down and retorque of the first gun i torqued it back down and retimed. i was able to quickly figure it out on the next two that showed problems with zero shift/bad groups.

 

[Shane Lindsey]

So the brake became loose and changed the POI? Makes sense.

 

[North Idaho Hunter]

yep POI/zero shift and loss of accuracy.

 

[snox801]

I would say like other ditch the sled. I've ruined many scopes with them.
Almost gave up on vortex after two in a row did exactly what you are saying 3" change but would put two in same group then shift 3" up or down.
Got mad at vortex after finding it was them failing. Went to leupold and out of chance it lasted longer but eventually it to gave up and that's when someone mentioned the sled does it. Ditched the sled and haven't had an issue since.
This was when I first started shooting and boy was I sure the sled was the only way I'd learn to shoot well.

 

[willfrye027]

By chance do you have a self timing muzzle brake on this weatherby?

I've had 3 rifles (all heavy recoiling rifles) loosen the self timers and cause this.

No brake. But that is a good thought...goes along with the "something is loose" theory!

 

[Blue Ridge Rifleman]

the sled is a scope eating machine even more so if it is getting weighted

The engineer in me can't get my head around this. Since the action moves less and more slowly in the sled, acceleration and deceleration of the scope would seem to be less. What am I missing?

 

[JMW67]

with the action moving it lessens the jolt to the optics

 

[MZmoose]

It's all virgin brass he's only about 20 rounds into it.

my money is on the scope. It's a lot of recoil slamming into that lead sled for such a heavy recoiling gun to begin with. But who knows

I have a lead sled. It's not like slamming into a wall unless you bolted it to the bench. It basically adds weight to the shooter. It's like having a guy with an extra 25lbs in his shoulder shoot the gun. The gun recoils and the sled moves on the bench into your shoulder. That being said, I use mine to shoot groups when testing a load. I don't use the strap to hold the barrel down and I covered the front rest with a cotton cloth so my stock is not resting on the rubber coated V. I also adjust the sled so it's holding the rifle on target and I'm putting very little input on the rifle and just making a good trigger pull. I have shot many sub .5moa groups with mine. But once I have my load I don't shoot from it again, just field positions.

 

[snox801]

The engineer in me can't get my head around this. Since the action moves less and more slowly in the sled, acceleration and deceleration of the scope would seem to be less. What am I missing?

Look up some videos of the flex of the barrel when shot. That movement also goes through the action some. With it being able to move backwards freely it lesson some of the force.