.303 downloads keyholing

[EGGY]

Favourite load in all my Enfields for indoor shooting @ 25 yards is 110g soupcan boolit sized to .315 over 5g of Bullseye with Federal large rifle primer, never had any problems with this load . However Iv just added a No 5 Jungle Carbine to the collection and is keyholing 2 out or 10 shots ????. Should I try increasing the charge ? if so what do you advise. The range limit is 1700 fps and 480 ft lb, current load is chronoed at 1200 fps and 280 ft lb .... thanks

[Tatume]

Have you looked inside the flash hider to check the condition of the crown?

[dromia]

Have you slugged the barrel on the No5?

Tumbling is usually a sign of poor boolit fit or perhaps a crown/muzzle issue as Tatume has suggested.

I suspect that all the rounds are wobbly and it you look you will see oval holes as well.

Are you putting a gas check on the soupcan?

[Muskyhunter1]

I second the slugging of your barrel. I am thinking with the low powered load, your bullet base is likely not going to expand (obturate) from the pressure. Groove fit is critical. Good luck and keep us posted.