Hello Joe! There are some benefits to having 5R rifling, however, I believe they more pertain to certain cartridges shooting L-O-N-G for caliber bullets. I think this also pertains to L-O-N-G shot strings during competitive matches. Four (4) groove conventional rifling has sharp edges and each land is directly opposite of another land. Five R rifling has an alternate land and across from it a groove, with "rounded edges" on the lands. The 4 groove opposing lands will exert more pressure on the bullets and the sharp edges can cut into the jacket rather than "denting" it like 5R does. I believe that those two concepts reduces friction considerably, thus minimizing possible blow-ups. Additionally, I have seen certain cartridges using long-for-caliber bullets cause bullet problems in flight. The 6 Creedmore, 6 x 47 Lapua, 6 Competiton-Match etc..etc.and the like can push 115 DTACs or 110SMKs well past 3100f.p.s. with either H4350 or RL-16. Shooting long shot strings during competition, with 4 groove conventional rifling can cause bullet failure. I have not seen that activity with 5R rifling. Having said all that Joe, unless you ARE shooting long bullets, with a super fast i.e.7 twist, in a competitive match with 20-25 shots in less than 30 minutes, I doubt you would need nor see the difference between the two styles>>>but I have shot long bullets in those cartridges and the 150SMKs in the 6.5 x 284 and had bullet failure during competition!I have used both 4 and 5 grove barrels. I can't see any difference on the target, so I won't pay more for a 5R.
Some have told me that 5R barrels are easier to clean, but after going through ten barrels, I can say that is not true. One 260 barrel that was particularly difficult to clean the copper was a 5R. I check my rifles with a borescope after I clean it.
Joe
I believe that Larry dispenses very good advice! Look at his track record>>>very difficult to debate against super success!Ben,
I agree with you on the L-O-N-G bullets. 5R may help and will not hurt those shooting the long bullets. But on advice of Larry B. I gave up on the Berger 195 EOL and never looked back.
Joe