The Accurate Reloading Forums
CHRONO RESULTS....UN - PUZZLING.....!!!! 308 & 30/06
18 October 2011, 02:16
Sargeny1CHRONO RESULTS....UN - PUZZLING.....!!!! 308 & 30/06
Hi All...at my club range today to re-shoot that 45gr. load from last week that gave those puzzling results.....
Rifle - 308W... Ed Brown Marine Sniper...built in 2000....24" KREIGER BBL....Jewell Trigger set at 40oz.....Swarovski 4 x 16
Temp 58deg....Sunny....
Lapua Cases 2nd Loading CCI BR2 NOSLER 165gr. Partition
2.810" OAL
5 SHOT GROUP
45gr. VARGET
#1 - 2755fps
#2 - 2723fps
#3 - 2745fps
#4 - 2696fps
#5 - 2750fps
AVG - 2734fps
ES - 59fps
SD - 22fps
LOAD #2 - Same as above except 45.5gr VARGET..
#1 2767fps
#2 2768fps
#3 2760fps
#4 2745fps
#5 2748fps
AVG 2758fps
ES 23fps
SD 9FPS
The interesting thing about 45.5gr load was that it placed 3 shots into ONE hole at 100yds....I was NOT shooting for groups but was trying to place the bullets thru the same spot over the chrono - (RCBS Chrono)...
46gr is MAX in Nosler #6 manual...will try that next...no pressure signs at 45.5gr...Velocity is in the ballpark re the Nosler #6 Manual....
NEXT was 30/06...Rifle is Winchester Pre 64 #65xxx...24" bbl...Bausch & Lomb 3 x9
Load is: Lapus Cases 2nd Loading CCI BR2 Nosler 165gr. Partition 3.310" OAL
57.5gr. Hodgdon 4350 MAX. LOAD in Nosler #6 Manual
5 shot group
#1 2829fps
#2 2870fps
#3 2888fps
#4 2859fps
#5 2856fps
AVG 2860fps
ES 59 fps
SD 19fps
These 5 shots grouped into .75" at 100yds....Once again, I was NOT shooting for accuracy...just trying to place the bullets over the same spot in the chrono...no pressure sings and plenty of recoil and blast...57.5gr of H4350 fills these Lapua cases to the base of the neck...
OK...I am of the opinion that I am getting all the velocity these two weapons can deliver...which is not too shabby either...now the hard part is which one do I use on opening day of deer & bear season here in NY on Nov 19th...????? AHHHHH...life's difficult decisions......
What say ye learned gentlemen....????
Pete
18 October 2011, 02:44
<Andrew cempa>Okay, what is puzzling you about the results?
Looks well within reason to me.
22 or 9 or 19 Sd is pretty good-you did not say how you measured powder, so if dropped, then I think they look like my 308 and 30/06 match loads, if trickled up using a digital scale, then still pretty solid.
How far from the lands in the target/"sniper" gun? I find lower SDs with my 308 match gun at about 40 thousandths off with Nosler 155s and 168s for short lines comapred to max OA length for a magazine (the gun is on a long action, so mag length is no concern to me), 20 off with 178 AMaxs for longer.
Best;
18 October 2011, 03:03
RaySenderoIf the 308s were shot in that order, Could be the 308 barrel is losing some velocity with each suscessive shot?
________
Ray
18 October 2011, 06:44
bartschequote:
Originally posted by Sargeny1:
...now the hard part is which one do I use on opening day of deer & bear season here in NY on Nov 19th...????? AHHHHH...life's difficult decisions......
What say ye learned gentlemen....????
Pete

Do you really think it matters??

roger
Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..
18 October 2011, 07:49
Larry GibsonSargeny1
Your velocities are where they should be. However, while 5 shot groups are "standard" in gun rags they are not industry standard. Ten shot test strings are SAAMI standards to get a high "confidence" level in the load. A 5 shot string does not have enough sample shots to give that "confidence" level. I suggest you switch to 10 shot strings or at a minimum 7- 8 shots, especially if you chronograph has shorter than 4' screen spacing. With a ten shot test string both of those loads may very well have bee much closer in actual ES/SD.
Also don't be surprised if the next test strings of the same load give somewhat different results in the average velocity, ES and SD. A 10 shot test string will get you closer to reality for the load tested.
BTW; in choosing between the two for hunting if on a stand and long shots were possible I would take the marine sniper .308W. If stalking or still hunting I would take the '06 as it is more portable and quicker to use in those scenario's. However, regardless of which you choose just make sure you take the rifle ammo for the chosen rifle

Larry Gibson
18 October 2011, 21:06
Donald NelsonDeer won't know the difference.
Molon Labe
New account for Jacobite
24 October 2011, 12:28
WstrnhuntrUse the load that YOU most comfortable and confident in.. They are right, the deer aint gonna care..
AK-47
The only Communist Idea that Liberals don't like.
27 October 2011, 21:22
Greg KStand hunting or woods walking? Which rifle is lighter? Which one "fits" best.
Anything from .243 up will kill NY whitetails. I'd pick based how the rifle handles.
27 October 2011, 21:39
carpetman1"Deer won't know the difference". That use to be true. Deer now surf the internet and read sites such as this and are fully informed. Neither of those two guns are a magnum so neither will work. These educated deer insist you use a magnum. Anything less is an insult. The picture on the ammo box is even more important. If you buy a box of ammo that has an eight pointer on it and you see a big ten pointer--you are out of luck. But then again a .223 works fine on uneducated deer.
27 October 2011, 21:47
carpetman1Sargeny1--You left out an important detail. Is that B&L scope an older Rochester NY made or is it a later one made some foreign country? If NY made you can trust it, they were very good optics.
28 October 2011, 03:22
AtkinsonSargeny,
You have a real problem there, I have no idea how your gonna solve it...Might try a shrink!

I solved that problem years ago..My .308 is a Savage 99 and I use it for hunting horseback as its flat and easy on the leg...If Im walking or using 200 gr. bullets then the 06 is my choice or the 300 H&H, now there is a real problem, the 06 or the 300, oh my!!!

Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120
rayatkinsonhunting@gmail.com
29 October 2011, 06:58
Lost OkiEasy choice....rebore the 06 to 35 whelen and leave the 308 home.