Help with 300 ultra groups....

[IdahoRedneck]

When I develop a long range load I will start at a distance where I plan most of shots will take place so typically my ladder will start at 500 yards with a blank piece of paper appx. 3 ft long with bull in the middle ( 1k target at army surplus works great). After deciding on my start and appx max load I will load 1 round in .3-.5 increments (depending on what I'm shooting) to my max. I dope my scope so I will hit low on the paper while holding on bull so as the charge increases the pattern will climb. Document after every shot on the target and inspect brass for excessive pressure. After all shots are fired the target will show a node with the least amount of vertical variance. Once the node is noted, it will be between .9 and 1.5 grain spread (depending on what increment I loaded) lets say the node is 92.3-93.2. Now I know that even if my powder thrower throws a little light or heavy my point of impact is going to stay relatively the same. Now I will load 3 shot loads 92.2, 92.4, 92.6, 92.8, 93.0, 93.2 and go shoot at 700 round robin style documenting each shot and find the load with the least amount of vertical variance. This will be my new best friend for this rifle. I don't worry to much about horizontal because as you know by the time you start and finish the wind here will change alot. This is what has worked for me and several rifles, maybe it will help you in your quest to 1k, maybe you already know. Figured if I didn't share then it may be new info left not shared.

I have read about the ladder test and even have one loaded up to go shoot. I have never shot one though
When you guys say cool between shots do you mean excactly that.... Let the barrel get completly cold again..... I am usually careful not to let it get to hot but ive never waited long enough between shots for it to get cold again... How long do you guys wait between each shot when developing your long range loads...
Ill try the round robin method aswell.....

 

[Mikiedem]

Since I develop for a hunting rifle, I do all development for cold bore first shots. For us in Idaho I find first thing in the morning usually has less wind and the colder ambient temp helps cool the barrel between shots at the longer ranges. So if I had to put a time on it I would say 10 minutes between each single shot.

 

[IdahoRedneck]

Since I develop for a hunting rifle, I do all development for cold bore first shots. For us in Idaho I find first thing in the morning usually has less wind and the colder ambient temp helps cool the barrel between shots at the longer ranges. So if I had to put a time on it I would say 10 minutes between each single shot.

10-4 thanks again, pm sent

 

[Time Killer]

My bro n law is running this load with good results in his 300.
93 grains Retumbo, Fed 215m, 210 VLD, Rem Brass. Seat to 3.632.
Not sure if that helps, but there you go.

 

[royinidaho]

IRN,

You seem to be burnin' up a bunch of barrel life with this quest. Been there done that. Not good.

I'm down here in Blackfoot, and Mikiedem is is up in Rigby.

I'll throw my hat in the ring for some collaboration. I have an up to 300 yard range in my back yard. And a handy LR drop chart development spot up in Wolverine.

Plus I hunt Unit 69.

Am at your service should you desire.

Regards

Roy

 

[IdahoRedneck]

Thanks Roy, that is generous of ya.... I have thought about barrel life.....was told when I bought the barrel there werent 200 rounds down it, plus the 100 or so I put down it not sure how long that leaves me...... On the up side this is a huntin rifle so when load development gets done hopefully ill still have a few years left on it. Ill be headin up to 69 in november with the rest of the mad house lookin for a cow....... Ill pm ya later on. Dan

 

[Mikiedem]

Roy's a good man, if it was me I would take him up on the offer.

 

[IdahoRedneck]

We'll do. Good luck on your hunt mike.

 

[cohunter1]

My shooting partner and I have been tweaking factory senderos for several years now, and are still learning. But one of the most crucial must do's is torque your action bedding screws to match your load. We have wrangled some unbelieveable accuracy by doing this. Just a thought




Aim small Hit small

 

[Mikiedem]

Got him, high shoulder shot at 715 yards!

 

[royinidaho]

Good job!!!!

 

[Mikiedem]

Thanks Roy!

 

[IdahoRedneck]

Congrats Mike..Nice little buck ya got there made pretty short work of that hunt haha...took your advice and had a nice chat w Roy today and got somethin put together in the near future. Thanks again roy its much appreciatedand was nice talkin with ya. Thanks again to all for their ideas and opinions. Dan

 

[Rustystud]

I rebarreled a customers 300 RUM with a 26" #4 Rock Creek Sporter, 1:10, 5R, with a Harrel's Muzzle brake. The rounds are being loaded with 180 Nosler Balistic Tips or 180 Swift Scirocco II. The throat has been opened to 3.315" Thus giving the bullets a .200" jump. I shot 5 shot groups with Reloader 22, H-1000, Retumbo, H-4831SC, IMR 7828. The brass was Remington, Primers were Federal 215 GMM. I full length sized, trimmed, chamfered, anealed, and cleaned primer pockets, between reloadings. My loads with H-4831SC were sub .5moa. and the loads with Retumbo were sub 1. moa. I shot velocities between 3,150 and 3,300fps. Quite a round. I shot over 100 rounds today.

One thing I noticed with the H-4831SC was I shoot 78.5grains with 180 Scirocco in my 300 Win Mag to get 3,1150 fps. With the 300RUM I was shooting 86. grains to get basically the same velocity.

With the 300 RUM it will be nice to be able to shoot 150 grain bullets at 3,400- 3500 fps.
Nat Lambeth