I rebarreled my model 10 to a McGowen 6.5 CM they had in stock last year and by measuring my Berger 140 I have overall length from boltface to tip of bullet is 2.940 OAL. the longest I can run my OAL in my gun and function though the mag is 2.870, so I am sitting .070 off the lands. My question is will it ever shoot well with this much freebore?
TIA Kevin
Quote:
Originally Posted by Kev1Doggy
Just for the heck of it sometime measure the freebore using GMM and I think you will be surprized how huge it is. I shoot a ton of 6.5 in different rifles and it appears to be one of the most forgiving on BTO of any of my rifles.
I am beginning to think the bullet jump doesn't make as much difference as what I have been led to believe. I experimented a little yesterday with a bullet .016" off the lands and .035" off. The .035" actually shot slightly better but it could have been me. I am not perfect. The .035" was slightly over .5 MOA and the .016" was slightly less than .7 MOA. I think it depends on the bullet some.
Only one way to find out.
Thats exactly correct, so long as it shoots well who cares.Quote:
Originally Posted by Balvar24
Look at how much freebore Weatherby's have and they're done that way on purpose. Most of the time they seem to shoot pretty well. As the others said, there's only one way to find out and I'm not so sure it hasn't been over-hyped as well.
Your title should read .070 bullet jump. Your freebore is probably closer to .200" than .070. I bet it shoots great with that jump, ounce you get the powder charge figured out.
Shoot Barnes out of it. They need a good jump to shoot well.
Or Sierra Match Kings. The Bergers I use in my .308 are sensitive to jump, ie, they don't like much at all.
Sent from my SM-P580 using Tapatalk
Anytime I do a barrel job I do a chamber cast first. You would be
surprised how sloppy some throats are. A good long, tight throat
can be very accurate jumping from a short magazine.
Do the Sierras work better with more jump? I know you like the 77 grain SMK. How far off the lands do you have them. I believe you also have used the 69 grain Sierra MK. What about that one? I have a 223 Axis also.Quote:
Originally Posted by charlie b
In your situation, I think I'd seat the bullet so the heel is just above the neck/shoulder (to avoid donuts) and work forward towards mag length max dimensions. Then take the best of that study and work the charge. In the unlikely event that fails to produce excellent results, I'd switch to a bullet with a more forward ogive.
The 77 and 69 SMK's are both at least .020, probably closer to .030.
Sent from my SM-P580 using Tapatalk
Each barrel is different. I shoot the Berger 140 VLD-H bullets out of my 6.5 Creedmoor .010" off the lands. Shooting the same bullet out of my 6.5-06 and loading out to magazine length, the bullet is seated .140" off the lands.
Both gun's will shoot groups well under 1/2 moa when I do my part.
I setup a series of 4 , 3 shot groups. The first was .070 the second was .090 the third was .110 fourth was .130. the groups in .110 were improving and the .130 was better yet. So I did 4 .120 and 4 .140 jumps. The .140 is my new load it shoots a lot better. I reseated all of my already loaded and will start trying different powder chgs.
Good Lord, when I saw that I first thought it was MOA instead of bullet jump. I am trying to get better but I would never get that good.