It's a familiar story.
I've also been saying this for ages now.
Years ago I used to use AA Field ( JSB ). They just shot very well in all of my rifles. That was a few years ago now ( prob 10 ish ).
More recently I struggled to find a batch/die of AA or JSB that would group as well. I also noticed that the poor ones seemed to be the ones with the more 'filled' in insides. I would go to the local shops and have them open up tins so I could see if the profiles were more 'hollow' and deeper like the ones I used to use.
I got so fed up with JSB stuff that I switched to Crosman Prems for my 77s. Paul James suggested this but said he selected his Prems by size.
So I started doing that. Not a massive improvement to be honest.
I never measured or bothered too much chrono testing with the old AA. Never needed to.
The later JSB stuff ... the heads were no where near what it said on the tins ( we all know that now ). The variation in head size was quite large ... 0.06mm spread over a smallish sample. I could never get them to give a tighter spread than 20 - 25fps on the chrono.
As I said ... the USA Prems not much better ... head sizes from 4.46 to 4.52. If I just used the ones from 4.50 - 4.52 they grouped very well.
Over the chrono the 4.50 to 4.52 ones gave a spread of 14fps ... so better than the JSB ( but I was just using the selected ones ).
I was given a tin of old Webley Mozzies.
Head sizes were 70% 4.46 and 30% 4.48 ... so pretty good. Tin said 4.52.
Chrono ( 10x ) 803 - 809fps. So just a 6fps spread. All the pellets looked in good condition.
I tried some H&N German pellets
H N Barracuda Match ( tin said 4.51 ). These are like Magnums and are heavy at 10.6gr.
I got bored of measuring head sizes as they were all 4.50mm. I couldn't find a damaged one.
Chrono ... the 1st pellet went through at 689fps ( may have been due to it being the first as I didn't clean the barrel ). The next 9 went through at either 693 or 694. So just 5fps spread including that first one. If you ignore that first one then 9 went through with just 1fps spread.
H N FTT ( tin said 4.52 ).
I got bored measuring these as well because they were all at 4.48mm. Again, couldn't find a damaged one.
I sadly didn't chrono these.
I did further 10x chrono testing and got very similar results. Maybe not enough to be totally conclusive but painted a picture.
I know vernier measurements of head sizes and chrono readings doesn't mean they will group well ...
... but the German pellets were far more consistent than the JSB and the Crosman ones ( head size ).
I've said it before but JSB must be pi55ing themselves that we are all spending a fortune buying loads of these pellets so we can try and find a decent batch/die.
I've been saying for ages that I'm not convinced there are batches/dies that suit certain barrels ... more like good batches/dies and sh1te ones. We are just doing their quality control for them and paying 10 quid a tin, in some cases, for the pleasure of finding their sh1te.
Last edited by skires; 7th July 2015 at 07:06 AM.