New 6.5x55

[rwh38238]

Just got my 6.5x55 back with a new barrel. I was looking at the throat with the borscope and notice some freebore. Is this normal with 6.5x55 reamers. It is not a match or custom reamer. The gunsmith said it was a no-turn but tight chamber. I was wanting to shoot some 140 Bergers in the lands but its impossible with that freebore. Isn't it? I think there is some real potential at 1000yds with this cartridge.
139 scenar, 46 gr h4350, lapua case, CCI br primer with a 28in. barrel= 2850 fps

 

[1000yardstare]

My 6.5x55 Tikka T3 stainless/synthetic has a ton of freebore. Seems to be the norm to allow seating the long 160 gr RN bullets with their bases above the shoulder.

This means coyote bullets such as the Sierra 100 gr HP cannot be seated anywhere near the rifling and still be in the case neck. I seat them for adequate neck retention (3/16). They shoot sub-moa despite the large jump to the rifling.

 

[kemen4]

I was reading an article on throat dimensions by Chris Bekker ...
He lists the CIP measurement for freebore + throat in the '55 as '16.2mm which probably relates to the original deseign criterisa'.
Yet I suspect there is plenty of variation by gunsmith and reamer. .
My Swede was cut with a "match reamer" for the Lapua s and they seat comfortably at the lands. At the same time a 125 Partition flush at the base of the neck is just under 20 thou jump but another 120 grainer gets a buspass and either touches the neck or the lands - but not both and still shoots as accurately as the others.
I guess its a try and see what (bullets shape) works....?

 

[rwh38238]

yeh thats what Im thinking. So far it has shot the Scenars good with the jump. It of course wasn't very impressive with the VLD type bullet but maybe some more testing. Next question. What bushing size is everyone using for good neck tension? I ordered a fl bushing die for it with several bushing in case I decide to neck turn.

 

[2506]

Many people are finding that the Berger VLD will shoot great if you back it waaay off the lands. I think it is on the longrangerifle.com that the people from Berger have a test they did and what the suggest to do in your case. I think it was loading them 30 to 40 thousands off the lands. I would do a ladder test with seating depths of 5 thousands shorter with each group. You will most likely find a node where they will shoot. One other thing, you did not mention the twist you have in your barrel. If it is a 9 or slower twist it may not shoot those long 140 gr bullets. Yes the standard reamer is made with a loooog throat to handle the 160 gr RN bullets. I too have a 29" barrel 6.5X55 Swede but it is a sported 96 Mauser. I average the same 2850 fps with 45 grs AA4350 and 140 Sierra or Hornady bullets. This is also an under 46,000 C.U.P load that is safe for the 96 Mauser action.

 

[rwh38238]

Thanks Im going to try the long jump. The twist is 1:8 so i think it will work. Im pondering building the cartridge on on a savage target action with a 30in brux and a different reamer. I think this will make it hard to beat. I still have a ton of testing to do. Thanks for the info and Ill keep it coming.