6.5x55mm 120gr Prohunter OAL

Milligan

Well-Known Member
Hi,

What OAL are people loading their 6.5x55mm and Sierra 120gr Prohunter to?
Reason for asking is if it goes to SAAMI spec 3.150 there is very little in the case.
2.990 seems to be getting nearer where it should be in terms of neck/bullet contact.

Not looking for a debate about leade or jump or touching lands or any other academic stuff. ;)

Thanks,

Will
 
The Nosler manual suggests 2.975 inches for a 120 gr Spitzer bullet. You're the man on the spot, seat your bullets deep enough to be securely held in the case neck and then work your load up.

Merry Christmas.

JCS
 
Sierra says 3.000 hope this helps Glynne
Hi,

What OAL are people loading their 6.5x55mm and Sierra 120gr Prohunter to?
Reason for asking is if it goes to SAAMI spec 3.150 there is very little in the case.
2.990 seems to be getting nearer where it should be in terms of neck/bullet contact.

Not looking for a debate about leade or jump or touching lands or any other academic stuff. ;)

Thanks,

Will
 
Hi,

What OAL are people loading their 6.5x55mm and Sierra 120gr Prohunter to?
Reason for asking is if it goes to SAAMI spec 3.150 there is very little in the case.
2.990 seems to be getting nearer where it should be in terms of neck/bullet contact.

Not looking for a debate about leade or jump or touching lands or any other academic stuff. ;)

Thanks,

Will

That SAAMI specification is generic .... for the 140gr (maybe even the 160gr military RN) in the long throat of the 6.5 SE.

Whatever OAL is used with the Sierra 120gr flat-base won't meet it. Mine is 78.3/3.070" in CNSZD Lapua cases which is bare-minimum grip I can get away with.
 
In a case like this, the rule of thumb is to seat the bullet at least a half-calibre deep in the neck, ie a bit over a tenth of an inch for a 6.5 / 264. In practice, for a sporting round being used in magazine operation, a full calibre or so, provides more security / robustness and still usually works well - a quarter inch or thereabouts here. The ProHunter is a tangent ogive model and these Sierras happily take silly amounts of jump to the rifling lands, so don't worry about 'jumping bullets too much'. This can see pressures and hence MVs reduced considerably though, and on chronographing actual results in such loads, it's not uncommon to find they're well down on what the reloading manual or powder manufacturer's data says you ought to be getting.

In single-shot match use where the ammo is kept protected from rough handling in MTM boxes before loading, I've seated bullets so shallow that they're barely gripped by the case-neck and found that precision can be superb. A good example was 6mm 55gn Ballistic Tips and Nosler CTs in a 6mm BR Norma match rifle with a well worn and eroded out throat.
 
When in this situation I seat the base of the bullet to the base of the neck. Optimizes neck tension and utilizes those expensive die you used to size the case oh! so perfectly. Hasn't failed to produce good results from the start.~Muir
 
Thanks, Laurie and Muir are where my loads are at the moment at what should be a moderate charge.
Will take my hand press, load some longer and see what happens.
I'm using N150 and the max varies between manuals by a few grains...
 
It does, but you gotta start somewhere.
I'm wary of approaching top end of published charges off the bat when loading what is allegedly short.
I agree whole heartedly. I'm just saying that it's easy to have your loads reach maximum well before the listed "max" charge weight is used. ~Muir
 
I am using the 120gr Pro Hunters with 47.3 gr of N160 through my R93. My COL is presently at 2.842" which is around 180 thou back. I was up to 100 rounds ago about 220 thou back but this barrel has had a few thousand rounds though it and I was starting to see accuracy dipping so came 40 thou closer which (for the time being) has put accuracy back on track.

Peter
 
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