Input on 300 yard groups

[Brush4646]

I've recently worked up a load for my 300 Weatherby and need some input on the recent data I have recorded.. I am not expecting benchrest results, but I am always looking to improve my results. So any input is highly appreciated. This rifle is a long range hunting rifle and I like to shoot steel plates out to 1,300-1,400 yards. To provide as much detail as possible-

The gun is a Terramark, that has been fully epoxy bedded ( action, recoil lug, +2" of the barrel) . I torqued the action screws down to factory specs (55in/lbs), Trigger pull is a nice 2.5lbs (its a hunting gun). I have a Ken Farrel 20 MOA base that's bedded, with night force steel rings. Everything seems tight in those regards, but I do have the factory Weatherby freebore.

The brass is 3x fired norma brass. I deprime, tumble, uniform & clean primer pockets, neck size -0.002" (bushing die), body size and bump the shoulder back 0.002", I weigh my brass and all of my brass weight is within 1/2%. I do weigh my bullets and I have a bunch of 215.2gr bullets. When I seat my bullets I use Redding dry lube to lubricate the inside of the neck. I do use a Hornady concentricity tool to make the loaded ammo as concentric as possible. Note* I allow the brass to reach 2.820" before I trim. All of my dies are Redding dies.

I recently worked up a load and settled on a terrific combo. I kept my seating depth at max length 3.724" (I seat bullets off the ogive. The node is around 1.25 gr wide and I settled on 88.4gr of N570 pushing a Berger 215 @ 3026. I use Federal 215 primers. With this combination My ES is 11 and SD is 4.5. I shot a .349" 3-shot group @ 100 yards with this.

My shooting setup is a Bald Eagle adjustable front rest with a heavy front bag and a heavy "rabbit ear" rear bag. I use the free recoil method while shooting.

Over the weekend I began to test seating depths. With that being said I shot 5 shot groups of various seating depths at 300 yards. My best seating depths are as follows.

I let the barrel cool ~3 minutes between shots and use a chamber cooler.
I let the barrel cool ~15 minutes between groups and use a chamber cooler.

Base to Ogive - 2.915"
88.4 gr N570
AVG Velocity 3021
ES 11
SD 4.5
Shot 1 - Low , slight right
Shot 2 - Lower right of inner ring
Shot 3 - Lower left of inner ring
Shot 4 - Left of center
Shot 5 - High, slight right of center
Group - 2.615" (I did not count the cold bore shot. It was a carbon free barrel. I do not remove copper until accuracy falls off).

View attachment 138360


Base to Ogive - 2.870"
88.4 gr N570
AVG Velocity 3017
ES 22
SD 8.2
Shot 1 - Right high
Shot 2 - Middle high
Shot 3 - Right high
Shot 4 - Middle high
Shot 5 - Flyer
Group - 1.913" (I did not count the flyer. It was my fault I rushed the shot and moved the rear bag).
*Note, prior to this group I did adjust my elevation by 0.5moa up and 0.25 moa left*

View attachment 138361

I really like how group #2 shot, but I cannot explain the spacing between them. Would increasing or decreasing neck tension improve my groups?

I've recently worked up a load for my 300 Weatherby and need some input on the recent data I have recorded.. I am not expecting benchrest results, but I am always looking to improve my results. So any input is highly appreciated. This rifle is a long range hunting rifle and I like to shoot steel plates out to 1,300-1,400 yards. To provide as much detail as possible-

The gun is a Terramark, that has been fully epoxy bedded ( action, recoil lug, +2" of the barrel) . I torqued the action screws down to factory specs (55in/lbs), Trigger pull is a nice 2.5lbs (its a hunting gun). I have a Ken Farrel 20 MOA base that's bedded, with night force steel rings. Everything seems tight in those regards, but I do have the factory Weatherby freebore.

The brass is 3x fired norma brass. I deprime, tumble, uniform & clean primer pockets, neck size -0.002" (bushing die), body size and bump the shoulder back 0.002", I weigh my brass and all of my brass weight is within 1/2%. I do weigh my bullets and I have a bunch of 215.2gr bullets. When I seat my bullets I use Redding dry lube to lubricate the inside of the neck. I do use a Hornady concentricity tool to make the loaded ammo as concentric as possible. Note* I allow the brass to reach 2.820" before I trim. All of my dies are Redding dies.

I recently worked up a load and settled on a terrific combo. I kept my seating depth at max length 3.724" (I seat bullets off the ogive. The node is around 1.25 gr wide and I settled on 88.4gr of N570 pushing a Berger 215 @ 3026. I use Federal 215 primers. With this combination My ES is 11 and SD is 4.5. I shot a .349" 3-shot group @ 100 yards with this.

My shooting setup is a Bald Eagle adjustable front rest with a heavy front bag and a heavy "rabbit ear" rear bag. I use the free recoil method while shooting.

Over the weekend I began to test seating depths. With that being said I shot 5 shot groups of various seating depths at 300 yards. My best seating depths are as follows.

I let the barrel cool ~3 minutes between shots and use a chamber cooler.
I let the barrel cool ~15 minutes between groups and use a chamber cooler.

Base to Ogive - 2.915"
88.4 gr N570
AVG Velocity 3021
ES 11
SD 4.5
Shot 1 - Low , slight right
Shot 2 - Lower right of inner ring
Shot 3 - Lower left of inner ring
Shot 4 - Left of center
Shot 5 - High, slight right of center
Group - 2.615" (I did not count the cold bore shot. It was a carbon free barrel. I do not remove copper until accuracy falls off).

View attachment 138360


Base to Ogive - 2.870"
88.4 gr N570
AVG Velocity 3017
ES 22
SD 8.2
Shot 1 - Right high
Shot 2 - Middle high
Shot 3 - Right high
Shot 4 - Middle high
Shot 5 - Flyer
Group - 1.913" (I did not count the flyer. It was my fault I rushed the shot and moved the rear bag).
*Note, prior to this group I did adjust my elevation by 0.5moa up and 0.25 moa left*

View attachment 138361

I really like how group #2 shot, but I cannot explain the spacing between them. Would increasing or decreasing neck tension improve my groups?

 

[Tangent]

My 2 cents:

• Like others have mentioned, I would stop 'testing' on a freshly cleaned barrel.
• I don't discount 'cold bore/cold shooter' rounds.
• I also wouldn't try to "free recoil" - employ the fundamentals.
• 5 shot groups are not statistically significant and shouldn't be used to calculate mean, SD, or ES. To me, statistical descriptions are great to evaluate hit probabilities, but you need much more data for any meaningful evaluation.

Smacking steel at 1,400 is a blast! Since you aren't looking for benchrest accuracy, if you're getting ~1 MOA results at 300 yards, I would move on and spend your time getting better at calling wind. Wind kicks my a-- far more often than anything else at distance. Good luck!

 

[Ronald W Schaefer]

I use a lead sled on my big bores when Im working up loads/gathering data...it helps take "me" out of the equation. As Tangent says (and my buddy "Foot" who is a professor of statistics) 5 shots are not a statistically significant sample size, with that said, it's what most of us do. So just out of curiosity, tangent, what is a Sig sample size for this type effort?

 

[Saracen]

I've recently worked up a load for my 300 Weatherby and need some input on the recent data I have recorded.. I am not expecting benchrest results, but I am always looking to improve my results. So any input is highly appreciated. This rifle is a long range hunting rifle and I like to shoot steel plates out to 1,300-1,400 yards. To provide as much detail as possible-

The gun is a Terramark, that has been fully epoxy bedded ( action, recoil lug, +2" of the barrel) . I torqued the action screws down to factory specs (55in/lbs), Trigger pull is a nice 2.5lbs (its a hunting gun). I have a Ken Farrel 20 MOA base that's bedded, with night force steel rings. Everything seems tight in those regards, but I do have the factory Weatherby freebore.

The brass is 3x fired norma brass. I deprime, tumble, uniform & clean primer pockets, neck size -0.002" (bushing die), body size and bump the shoulder back 0.002", I weigh my brass and all of my brass weight is within 1/2%. I do weigh my bullets and I have a bunch of 215.2gr bullets. When I seat my bullets I use Redding dry lube to lubricate the inside of the neck. I do use a Hornady concentricity tool to make the loaded ammo as concentric as possible. Note* I allow the brass to reach 2.820" before I trim. All of my dies are Redding dies.

I recently worked up a load and settled on a terrific combo. I kept my seating depth at max length 3.724" (I seat bullets off the ogive. The node is around 1.25 gr wide and I settled on 88.4gr of N570 pushing a Berger 215 @ 3026. I use Federal 215 primers. With this combination My ES is 11 and SD is 4.5. I shot a .349" 3-shot group @ 100 yards with this.

My shooting setup is a Bald Eagle adjustable front rest with a heavy front bag and a heavy "rabbit ear" rear bag. I use the free recoil method while shooting.

Over the weekend I began to test seating depths. With that being said I shot 5 shot groups of various seating depths at 300 yards. My best seating depths are as follows.

I let the barrel cool ~3 minutes between shots and use a chamber cooler.
I let the barrel cool ~15 minutes between groups and use a chamber cooler.

Base to Ogive - 2.915"
88.4 gr N570
AVG Velocity 3021
ES 11
SD 4.5
Shot 1 - Low , slight right
Shot 2 - Lower right of inner ring
Shot 3 - Lower left of inner ring
Shot 4 - Left of center
Shot 5 - High, slight right of center
Group - 2.615" (I did not count the cold bore shot. It was a carbon free barrel. I do not remove copper until accuracy falls off).

View attachment 138360


Base to Ogive - 2.870"
88.4 gr N570
AVG Velocity 3017
ES 22
SD 8.2
Shot 1 - Right high
Shot 2 - Middle high
Shot 3 - Right high
Shot 4 - Middle high
Shot 5 - Flyer
Group - 1.913" (I did not count the flyer. It was my fault I rushed the shot and moved the rear bag).
*Note, prior to this group I did adjust my elevation by 0.5moa up and 0.25 moa left*

View attachment 138361

I really like how group #2 shot, but I cannot explain the spacing between them. Would increasing or decreasing neck tension improve my groups?

Shoot only groups with no interim scope adjustments.
If you don't anneal your brass, you should.

 

[Tangent]

I use a lead sled on my big bores when Im working up loads/gathering data...it helps take "me" out of the equation. As Tangent says (and my buddy "Foot" who is a professor of statistics) 5 shots are not a statistically significant sample size, with that said, it's what most of us do. So just out of curiosity, tangent, what is a Sig sample size for this type effort?

All depends on how anal you want to be

I tend to tell guys to familiarize themselves with the concepts of Confidence Interval and Confidence Level. There are on-line calculators for these two concepts, but the kicker is you typically need a solid SD and mean (which you won't have from 5 shots). Personally, I wouldn't run any calc's until I have ~40 - 50 rounds...but more is better.

If you want to only shoot a 5-shot group, I would use the median instead of the average, and completely ignore SD & ES 'reporting'.

To me, there is a direct analogy between group sizes and statistical measures. 3 shots groups will always be better than a 5 shot, and 5 shot better than 10 shot, etc. Pictures of 3 shot groups are only really good for posting pictures on-line. Similarly, 5 or 10 data points are only good for 'reporting' small SD or ES on the internet.

I'm not saying this to disparage anyone. I'm just saying that using bad numbers will cause you to chase errors in the wrong places down the line. For example, if you think you have a 0.25 MOA gun because of one 3-shot group, you may look in all the wrong places once you start seeing 0.75 or 1.0 MOA groups....maybe you just have a 1 MOA gun and don't know it.

 

[Nagy Rezk]

Hi I am a new member and here is some important information
To shoot this combo I built a custom rifle
Defiance deviant XM with hinged plate
Bartlein barrel 26/10 twist
GRS laminated stock
Built by Gordy Gritters
Custom sizing die using same tool specs which used to chamber
Tight throat so I have to turn necks
The XM action is long enough to let you seat the Bullet in the lands
So everything has been built for this configuration
I will receive this bad boy in three weeks and happy to post results
I have the honor to be a member

 

[BLC3128]

Your techniques and process seem solid. FYI, I have a great load for my .300 WM: 180 gr Barnes TTSX, 79 gr IMR 4831, Fed 215 primer, Weatherby Brass, Max COAL. 3208 fps with a 26" BBL. I been there and back again and always return to that load. How did you break in your barrel? I started using the break-in regimen from Fierce Rifles and had good luck with it. Fierce firearms guys recommend:
Your break in will require shooting one box (20 rounds) of ammo

1. Shoot one round and then clean
   Do this for the first five rounds.
2. Shoot five rounds and then clean
   Do this for the next fifteen rounds.
3. Shoot a fouler round and then a three shot group for accuracy.

NOTE: Allow barrel to cool before shooting each series of break-in rounds to avoid unnecessary throat erosion. Do not shoot your rifle in succession until the barrel is too hot to touch with a bare hand. This can burn the throat out of your match grade chamber.

When cleaning we recommend the following items

• Use a quality one-piece cleaning rod.
• Use high quality patches.
• Use a bore guide.

Clean from chamber end only.

Clean powder residue from bore using a high quality barrel cleaning solvent.

Follow with a copper remover like Barnes CR-10 Copper to remove copper fouling. Follow the instructions on the bottle.

Finish with a patch lightly coated with gun oil. Your rifle is ready to shoot.
Remember to clean your rifle after 20-30 rounds.

This process can be done even though you have already been shooting the rifle. I did this with all three Fierce rifles we've had and two Weatherby factory rifles, it helped.

I broke the barrel in according to weatherby recommendations. Shoot /clean/copper remove for the first 10 shots. Shoot/clean/copper remove for 5 groups of 3. Shoot /clean/copper remove for groups of 5. It was a 40 round break in over the course of two days. The barrel cleans very easy and hardly picks up copper . Anymore I clean the carbon after 30 -40 Shots and only Remove copper when accuracy falls offs.

 

[BLC3128]

You're under MOA @ 300 yards with a cannon. You're not trying to achieve bench rest results. Honestly, what more would you prefer to see? I'm not trying to be negative here. I'm paying you a compliment. I think you might have achieved the performance level your rig can achieve. Just my opinion.

Thank you! I'm always trying to improve. That's my nature. Even if I can tighten my groups up by 0.1 moa, I consider that a win.

 

[BLC3128]

My 2 cents:

• Like others have mentioned, I would stop 'testing' on a freshly cleaned barrel.
• I don't discount 'cold bore/cold shooter' rounds.
• I also wouldn't try to "free recoil" - employ the fundamentals.
• 5 shot groups are not statistically significant and shouldn't be used to calculate mean, SD, or ES. To me, statistical descriptions are great to evaluate hit probabilities, but you need much more data for any meaningful evaluation.

Smacking steel at 1,400 is a blast! Since you aren't looking for benchrest accuracy, if you're getting ~1 MOA results at 300 yards, I would move on and spend your time getting better at calling wind. Wind kicks my a-- far more often than anything else at distance. Good luck!

I agree about reading the wind. It's a job in itself to become consistent with. The current charge now of 88.4gr has been tested at various seating depths and over the course of ~35 Shots is maintaining a avg velocity of ~3026 with a SD ~8.6..

 

[BLC3128]

Would increasing neck tension effect accuracy? (ex. I use a
.333 bushing now, so using a .332 bushing to increase tension)

I know I may be opening up a can of worms, but I'd like to hear input.

Thanks.

 

[Danny Butler]

After your rifle bbl is broke in properly I stop using Barnes CR10. I do believe in cleaning with a good solvent after 20 to 30 rds. Working up your groups at 300 yards for shooting at distance is way more productive than 100 yard load development.. that's some info that has proved to be true for me after some old school shooters explained to me when I was struggling..

 

[BLC3128]

After your rifle bbl is broke in properly I stop using Barnes CR10. I do believe in cleaning with a good solvent after 20 to 30 rds. Working up your groups at 300 yards for shooting at distance is way more productive than 100 yard load development.. that's some info that has proved to be true for me after some old school shooters explained to me when I was struggling..

I'm a fan of KG products. I have been using their line of cleaning products for years with great results!

 

[DavidleeCole]

Can I suggest that try either a 3 or 5 shot group with ammo that has not been straightened in the Hornady tool. I may well be wrong but I can't see how straightening a round by holding the bullet tip at one end and the base of the case at the other and pushing on the neck doesn't in some way distort the brass in the neck.

Good point I have the same tool and seams to be hard to get the best results from it

 

[DavidleeCole]

I love your post I have an customized .300 Whby mag and loaded up Berger 185's with 82.7gr H1000 and have had good results. I have a questions why does do you use and where did you get them? And I would agree with Sam Pace or magnum rifles will shoot 1 MOA and under but it's a hard row to hoe trying to get them under 1 MOA at all ranges but it can be done just have patience. I personally have been trying to load up some 210 Nos Accbound LR but I am stuck on what powder to use. Would love any suggestions. I go to around 70 to 100 rounds before cleaning I find the copper fouling equilibrium is great up to this point. And at this point I still don't clean the bore heavily.