Originally published at Notes from the bunker…. You can comment here or there.
Non variable background:
Rifle: CZ 550
Caliber: .308
Barrel: 26″ heavy
Optics: Leupold Varix-II 3×9
Stock:H-S Precision Kevlar, barrel floated
Rings: Steel CZ
Todays variables:
Temp: 58 degrees
Weather: overcast, some wind
Distance: 100 yards, shooting seated from bench using ammo box as rest
Load data:
Cases: Rem. once fired, fireformed and neck sized, trimmed to 2.010″
Bullet 1) 30 rounds using Speer 165 gr. BT SP
Bullet 2) 10 rounds using Nosler Ballistic Tip 165 gr.
Powder: 41.5 gr. IMR 4895 run through a Redding BR3 measure
Primer: CCI LR
OAL: 2.807″ with Speer, 2.812″ with Nosler
I measure from the two most distant holes in the paper, inside edge of one to outside edge of the other (which averages to a center-to-center measurement) in fractions. For figuring mathematical averages Im converting them to decimal.
| Group # | Four shots | Three shots (omit flyer) |
Comment |
| 1 | 1.875″ | 0.75″ | |
| 2 | 1.25″ | 0.50″ | |
| 3 | 2.25″ | 1.25″ | Horizontal stringing |
| 4 | 1.125″ | 0.50″ | |
| 5 | 2.25″ | 0.938″ | |
| 6 | 1.75″ | 1.625″ | Nosler load |
| 7 | 1.75″ | 0.50″ | Nosler load |
| 8 | 1.25″ | 0.75″ | |
| 9 | 1.75″ | 1.50″ | Horizontal stringing |
And, just for fun:
Average 4-shot group using Speer: 1.37″
Average 3-shot group using Speer: 0.884″
Average 4-shot group using Nosler: 1.75″
Average 3-shot group using Nosler: 1.0625″
Yes, hardly scientific since the sample groups were different in size, I know….
Some of the horizontal stringing, esp. group #3, came when I shifted my grip and rest.
If youre doing the math, that leaves four rounds unaccounted for. I took two Noslers and two Speers and shot them at the steel tanks at 300 yards. Missed the first two until I recalled that I needed to holdover about a foot..at that point they rang quite nicely.
Im annoyed at the flyers. I thought they were from being the first rounds off the magazine but that wasnt it. Im betting the problem is me. Im going to order upo someLapua brass, some Fed BR primers and some Sierra MK's and see where it goes from there. I also want to try some Varget and and some BLC-2. I think this rifle has good potential, it just needs to be played with. At this point it has about 140 rounds through it. Also need to go through it an make sure all the screws are tight….that horizontal stringing pisses me off.
