Originally Posted by 358WCF
Originally Posted by B52RadarNav
On RL-15 had a recommendation of 38.5 gr up to 40gr … seems I’d get signs of pressure around that 40gr and too high?


Every rifle is different. Start lower & work up in 1/2 gr. increments. Also seating depth can make a big difference in group size. I settled on RL15 too after having pressure excursions with H380 & 2700 on hot summer days, so 86ed their further use. Too lazy to dig out the old notes but I stopped a touch below book max with both H4895 & RL15 because the groups were so small & started growing with more powder. RL15 got a bit more fps than H4895, both shot tiny groups. I had a lot of Hornady 50gr SXs that shot very well & was able to get them close to 3900fps without them coming apart in flight. Speer 52 & Hornady 53 match bullets shot well too but didn't have the same 'splodey effect as the SXs out at 450+ yds. Norma brass couldn't be beat at the time & may still be top of the food chain if you can find some. As always my stuff is/was different than your stuff so YMMV.

Also, my Swifts were all 14 twist which limited pointy bullet selection to 55gr & under. Not that that's a bad thing... Unsure what twist yours has.


IIRC all remmy 220 Swift had 14 twist. Also if you can find 60-63 grain bullets less than .75 in length they should stabilize. As far as hot days getting pressure with 380 and 2700 I just backed off .5-1 grain if it was going to be over 85.



Swifty