I was shooting my newest Mosin 91/30 yesterday. The ammo I was using was from J&G in 148 grain and heavy ball, yellow tip. The 148 grain shot tight groups at 50 yds and cycled perfectly. The heavy ball, yellow tip shot open groups and the bolt would tighten up during extraction in the last 25-30 % of the cycle. Why was I having a tougher time opening the bolt on the heavy ball, had to bang the bolt with the palm of my hand to open it? Dwayne
sticky bolt is not uncommon in these 50-100yr old rifles. part of the problem can be dirty bolt componants, cosmoline in the receiver, ammo that isnt exactly perfect, moving componants not lubed...
It would also be a good idea to have the headspace checked as well, if you haven't already. For safety's sake.
Also, it depends on how much Quality Control was implemented in the manufacturing process of the ammo.... Some of those rounds may have bloated rims which will affect your head spacing considerably. Also, if you have a digital scale, weigh a few rounds and see how much difference you have between 1 round and another. You may have significant irregularities in just the loads themselves. If one round weighs more than 1 or 2 grains than another, that round may be charged with more powder which will affect your accuracy... Just my $0.02...
typically ive had no issues however with the Bulgarian stuff from the '50s... in fact i have about 600 rounds of it.
Could be a couple things causing the issue, but I had similar results a few years back with the Chezch 147gr light ball and some surplus Russian heavy loads. The light ball cycled fine but the surplus loads would stick about 50% of the time. Upon closer inspection I saw the tell tell signs of high pressure in the surplus rounds and that was most likely the cause of the hard extraction. rimfirehunter
Look at the primers, do they look very flat and with a very shallow dent? Thats a common sign of overloaded rounds. The pressure will actually flatten the primer out to a degree. I have seen overpressure rounds actually partially erase the headstamp (forgot what thats called).
