carl gustaf developing a bad smoking habit

[motard]

I reload my CG with Vihtavuory N160, and commercial brass I have fired on same rifle (mostly S&B). Primers are CCI Large Rifle and as for bulletts selection I have tried Hornady Amax 140 gr, Lapua scenar HPBT 139 gr, and Sellier Bellot Fmj 140 gr. I have tested varied loaded from 44,2 min to 44,6 max, factory crimped and not, and varied the coal from 7,60 min to 79,50 max (depending on bulletts: S&B FMJ are way shorter than the other two) but the cases are always smocked since the rim. This DOES NOT happen when I am firing the factory loaded S&B or Fl Fiocchi, whilst it happened somethimes (but rarely) with Nato surpluss and Prvi Partizan. Looking close at the primers they appers reasonably flattened but with no sign a huge over pressure infact the collet mouth dilatation is not great (I can slide in a new bullet in butforcing it). So I know I can rise the charge to 45,0 gr but I don't will to go over the maximum load wich should be (as per VV manual n 9,44,6 gr) considering the age of the rifle (1943 built).
To be honest I know I should have checked my rifle chamber depth too and I have jet prepared myself a chamber shooted brass tapped with the wheird theard of the Hornad Coal Gauge. But haven't still takend the measure.
As a marginal note, with the Amax (the loghest bewten the 3 bullets I have) if diply seated (11mm) and whell crimped (LeeFC die) the smoke is barely noticeable.

[RBHarter]

I think annealing the cases will help. While I haven't had this with rifle cases except once ,it happens often with a 45 Colts, 38 Special and even 357.

Each time the brass is worked it gets a little harder and more resistant to working, both sizing down and expanding to release the bullets. Depending on the brass loads etc annealing should be done about every 5 to 7 cycles . I do have brass I have to do at 3 cycles in a 280 AI but I go 10 in several 30-06'.

[motard]

Thanks RBharter, I had listed anealing in my to do agenda, but beeing the brasse only one time fired did'not thought it was important. I Insteda, per your's suggestion, I'll gave try on a few round before next shooting day and will report here.

[62chevy]

I was having problems with some once fired .308 LC brass and annealing fixed the problem for me.

[motard]

Today at the range tested some AMAX and some S&B balls both with 44,9 grain of VVn160 (a little over the maximum but still in the safe zone). No smoke with Amax, smocked S&B. Cause this ball (S&B) is way shorter than all the other it means that the seating deep and the crimp had cured the problem raisi the internal pressure enaught to seal the brass and the chamber. Later I will post effective difference, in mm and convert to inch just in case anyone is interested

[motard]

Upon revising closely the last shoots at the range I discovered some sign of overpressure with my last loads: AMAX bullett 44,9 grain of VVn160 primer CCI LR, coal 78,50. Mouth dilatation is perfectly achieved, as wrote in prvious post (so not smocked brass), but primer is too flattened else if pin dent appears about normal. So I will test 2 grain less charge (44,7) an 1 mm more coal 79,50, either crimp or not: hope this will fix.
meanwhile I have checked the chamber (I tested rifling when bought the rifle and theu where a tad under 55mm). Chamber lenght is 82,74 mm (3.262 inch) and mesauring at the ogive with Hornady LNL gause it traslate in 68,96 mm (2.716 inch). I would relly appreciate any suggestion