Strange group???

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dave
7mm08 Rem
Posts: 985
Joined: Mon Jul 10, 2006 1:30 pm

Re: Strange group???

Post by dave »

Ordered the following,

EGW rail
Bushnell AR 223 3-12x40
Rifle basix trigger

Once its all together will shoot some more groups hopefully with better results!
RDavies
.257 Roberts
Posts: 785
Joined: Sun May 25, 2008 9:43 pm
Favourite Cartridge: 7 SAUM
Location: Singleton, Hunter Valley, NSW

Re: Strange group???

Post by RDavies »

If you check the barrel twist the way BradY mentioned and find the barrel twist is lower than expected, see if you can get the velocity up higher (safely) with the 2208 powder. The extra velocity (and hence spin rate) might help it stabilize slightly better. If accuracy is better on a hot day (with less dense air), then it is likely the twist rate could be marginal. Otherwise, try a very different seating depth with the same bullets. If neither works, the barrel just might not like em.
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aaronraad
.17 HMR
Posts: 203
Joined: Sat Dec 24, 2011 11:19 am
Favourite Cartridge: Solid head brass :)
Location: Qld
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Re: Strange group???

Post by aaronraad »

dave wrote: Well just to get my eye in and get a few more cases i put down a group of 5 at 100m. Well i was pretty happy with the cheap federal stuff as it put 5 shots into an inch and a half considering the wind was painful and the scope aint all that great. Soooo after that i let the barrel cool a little and loaded up my new batch.

Well i fired 2 lots of 4 and as the heat haze was picking up i couldnt precisely place where the shots had gone. So off to the target i went and bugger me ive never had a worst set of groups ever, kind of reminded me of a shotgun!

Dave
Don't forget to rule out the change in the conditions on the day before looking at the equipment. Going from shooting in wind to a mirage boil can make a significant change, if you factor in that the Nikko 8x56 comes with a factory set parallax from memory (100m, 150m)? The focal diopter also needs to be set correctly. I understand factory set parallax focus can be adjusted but that is another topic altogether.

I'd suggest also that the Barnes 69gr MB might be a little over-spun at ranges less than 300y/m with a 1:9". The recommended twist is 1:10" and this might have been rounded down from anywhere under other common factory barrel twist at the time 1:12"? Barnes would struggle to advertise the optimum stability of the 69gr at 1:11.2" for example. :?:

At 300m the Barnes might have dampened and your sight picture may have cleared up depending where your target was set-up. Just something else to consider with what the others have suggested.
dave
7mm08 Rem
Posts: 985
Joined: Mon Jul 10, 2006 1:30 pm

Re: Strange group???

Post by dave »

Just an update, 69s didnt get any better cheap american eagle 50gr Hps went into 2" for 5 shot group and got 50gr VMAXS into an 1" and half for 5 shots, pretty happy with minimal load work.....may hang onto the savage but very tempted to off load it, i have some glass i need to pay for to go on a 6/284 soooon :twisted:
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