25 Round groups as Proof

Joined
Dec 29, 2015
Messages
382
I'll be a brief as possible, but...


Facts:
Sig Cross 6.5 Creedmoor (started as 308, shot the barrel out), MDT Grnd-Pod bipod, Vortex PST G2 3-15x44, Warne Hyperlite rings
Starline brass
140 ELD-M
CCI Primers
Brass was once fired, annealed, full length sized with no expander ball, 0.263 expander mandrel for neck size
CBTO 2.214 and 2.220
25 round groups with each as well as 2 different muzzle brakes

Obviously seeing some of the posts here, reading a lot on other reloading forums and long range forums the waters/science of reloading can get muddy.

I began reloading for my newly barreled Cross with a factory new take off barrel sold by Straight Jacket Armory. I did the install and torqued at 50 lb/ft.

My initial reloads were not very promising as they ALL shot at about 1.5 inches at 100 yards. This would have been shots 31-75 through this rifle.

Shots 1-30 were with 130 ELD-M and most of them shot MOA or better. Back to the 140s...

I decided that I would run at 42 grains of H4350 since it was the most consistent SD/ES of everything I tried. I then decided to do a seating depth test. All my measurements were measure CBTO.

I tested the following and results are followed with avg, ES then SD.
2.245 2615 50 26
2.242 2614 77. 42
2.239. 2610. 19. 10
2.234. 2588. 16. 9
2.229. 2593. 16. 8
2.226. 2613. 47 26
2.223. 2606. 16 8
2.220. 2593. 19. 9
2.217. 2603. 38 19
2.214. 2600. 26 14

the 2.214 shot a 5 shot group at 0.271"
1000006678.jpg

The 2.220 shot a 5 shot group at 0.57"
1000006679.jpg

Even though these did not represent the absolute best of SD/ES I figured I would give them a try.

After the initial firing of reloads I accumulated the means to anneal as well as an expander mandrel so I added those steps to my process. In other words, I changed stuff. I cannot be certain how much this changed the outcome of future testing but annealing and using an expander mandrel are steps that were going to be included no matter what.

After the controversial Hornady Podcast about your groups being too small: YT Video and hearing @Form on the Exo Mountain Gear Podcast talking about Cone of fire and essentially proofing/proving your accuracy, I figured I needed to do just that. This would allow me to find the balance of deficiencies between myself and my rifle, or just reaffirm that maybe I just need to be better.

I fired 25 shots of each CBTO group of cartridges and through 2 different muzzle brakes (testing for change of impact and recoil impulse). All groups were dialed high to keep the aim point clean.

Group 1: 2.214 with VG6 Gamma 7.62 Brake resulted in a 2.2" group
20241224_211254.jpg
20241224_211322.jpg

Group 2: 2.220 with VG6 Gamma 7.62 Brake resulted in a 1.5" group
20241224_211313.jpg

Group 3: 2.214 with PRI/MSTN Brake resulted in a 2.1" group
20241224_211304.jpg20241224_211331.jpg

Group 4: 2.220 with PRN/MSTN Brake resulted in a 1.45" group (Alibi: I was sandwiched between a guy shooting a 300 RUM and a 7 Rem Mag Braked during this grouping, I still accept the outcome)
20241224_211336.jpg


My rhythm was load 5, take well aimed shots, not timed, reload and do it again until all 25 shots had been fired. The barrel was HOT at the end. I am sure if I waited a minute or two between each 5 shot strings my results would have been better. However, I want to know what my rifle is capable of. I think this shows that.

While some may argue that their if their rifle made a similar 0.271" group they have an MOA all day long gun, I would disagree with facts. My rifle is a 1.4-1.5 moa all day long gun and i am thrilled with that. I have the truth with data to back it.

My next steps will be to do similar testing off of a tripod, hiking sticks with Wiser Precision Quick-Stix, and a RoadRunner Rifle Rest to mimic field conditions since I rarely rely on range positions to ensure I can hunt effectively.

The end...for now.
 

RDF1

FNG
Joined
Dec 2, 2024
Messages
23
Very nice example.

What i started doing is setup my rifle and shoot it only once a day at 100 yards. Every day about noon id go out and only fire one round and over 10 days average them together or see if there was a pattern.
I used the Larue targets that have 2 aiming spots with 1/2" grids. Had 5 of those targets setup and it was interesting for sure.
 

KyleR1985

WKR
Joined
Jul 28, 2019
Messages
650
I'll be a brief as possible, but...


Facts:
Sig Cross 6.5 Creedmoor (started as 308, shot the barrel out), MDT Grnd-Pod bipod, Vortex PST G2 3-15x44, Warne Hyperlite rings
Starline brass
140 ELD-M
CCI Primers
Brass was once fired, annealed, full length sized with no expander ball, 0.263 expander mandrel for neck size
CBTO 2.214 and 2.220
25 round groups with each as well as 2 different muzzle brakes

Obviously seeing some of the posts here, reading a lot on other reloading forums and long range forums the waters/science of reloading can get muddy.

I began reloading for my newly barreled Cross with a factory new take off barrel sold by Straight Jacket Armory. I did the install and torqued at 50 lb/ft.

My initial reloads were not very promising as they ALL shot at about 1.5 inches at 100 yards. This would have been shots 31-75 through this rifle.

Shots 1-30 were with 130 ELD-M and most of them shot MOA or better. Back to the 140s...

I decided that I would run at 42 grains of H4350 since it was the most consistent SD/ES of everything I tried. I then decided to do a seating depth test. All my measurements were measure CBTO.

I tested the following and results are followed with avg, ES then SD.
2.245 2615 50 26
2.242 2614 77. 42
2.239. 2610. 19. 10
2.234. 2588. 16. 9
2.229. 2593. 16. 8
2.226. 2613. 47 26
2.223. 2606. 16 8
2.220. 2593. 19. 9
2.217. 2603. 38 19
2.214. 2600. 26 14

the 2.214 shot a 5 shot group at 0.271"
View attachment 811224

The 2.220 shot a 5 shot group at 0.57"
View attachment 811225

Even though these did not represent the absolute best of SD/ES I figured I would give them a try.

After the initial firing of reloads I accumulated the means to anneal as well as an expander mandrel so I added those steps to my process. In other words, I changed stuff. I cannot be certain how much this changed the outcome of future testing but annealing and using an expander mandrel are steps that were going to be included no matter what.

After the controversial Hornady Podcast about your groups being too small: YT Video and hearing @Form on the Exo Mountain Gear Podcast talking about Cone of fire and essentially proofing/proving your accuracy, I figured I needed to do just that. This would allow me to find the balance of deficiencies between myself and my rifle, or just reaffirm that maybe I just need to be better.

I fired 25 shots of each CBTO group of cartridges and through 2 different muzzle brakes (testing for change of impact and recoil impulse). All groups were dialed high to keep the aim point clean.

Group 1: 2.214 with VG6 Gamma 7.62 Brake resulted in a 2.2" group
View attachment 811226
View attachment 811227

Group 2: 2.220 with VG6 Gamma 7.62 Brake resulted in a 1.5" group
View attachment 811228

Group 3: 2.214 with PRI/MSTN Brake resulted in a 2.1" group
View attachment 811229View attachment 811230

Group 4: 2.220 with PRN/MSTN Brake resulted in a 1.45" group (Alibi: I was sandwiched between a guy shooting a 300 RUM and a 7 Rem Mag Braked during this grouping, I still accept the outcome)
View attachment 811231


My rhythm was load 5, take well aimed shots, not timed, reload and do it again until all 25 shots had been fired. The barrel was HOT at the end. I am sure if I waited a minute or two between each 5 shot strings my results would have been better. However, I want to know what my rifle is capable of. I think this shows that.

While some may argue that their if their rifle made a similar 0.271" group they have an MOA all day long gun, I would disagree with facts. My rifle is a 1.4-1.5 moa all day long gun and i am thrilled with that. I have the truth with data to back it.

My next steps will be to do similar testing off of a tripod, hiking sticks with Wiser Precision Quick-Stix, and a RoadRunner Rifle Rest to mimic field conditions since I rarely rely on range positions to ensure I can hunt effectively.

The end...for now.

I got excited for a minute thinking you shot all 10 CBTO lengths for 25 rounds haha!


Good info thanks for sharing
 
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