Question about barrel length in 7 mag.
 

I have a 21 inch barrel on an Encore in 7 mag in order to have a short tree stand gun. Knowing there is a loss in velocity in the shorter barrel but will that effect the accuracy? It is a bull barrel. But groups are 2" at 100 yards with Hornady SST 162 Grain. Have sub MOA groups with same ammo with other 7 mag rifles. Is 21" not enough time for rifling to stablize the bullet? Or is the powder burning out the end of the barrel having an effect on the bullet? What would be the best way to improve the accuracy? Would shooting a lighter load help?

RE: Question about barrel length in 7 mag.
 

Barrel length really doesn't have any effect on accuracy according to the custom barrel folks. Actually a shorter barrel should have less whip and thus have the potential for better accuracy. I've never tested the theory personally. As per rifle accuracy, that barrel might not like that bullet. Mt Browning Medallion does not like the 162 SST but shoots almost every other bullet sub-moa. If your handloading try Alliant RL-22 powder. It shoots well in most 7 mags I've seen.

RE: Question about barrel length in 7 mag.
 

Each rifle has it's own preference for loads and just because a load shoots well in one rifle,it doesn't mean it will be accurate in all rifles.Try other loads.

RE: Question about barrel length in 7 mag.
 

Sounds like your rifle doesn't like that bullet, or that weight of bullet. The bullet might be heavier than what your rifle likes. Try a 140 grain bullet and/or try a different bullet. With a barrel as short as yours the velocity is probably in the range of a 7mm-08 or a touch faster, so you may consider a 140 grain Nosler Ballistic Tip. They are well renouned for their accuracy, and should work well at the velocities your gun likely produces.

Good luck.

Mike

RE: Question about barrel length in 7 mag.
 

encore barrels need a little more detail in correct head space measurements to shoot to there fullest potential. you need to know barrel to frame gap and resize your cases so they protrude .001 less than that distance. you can measure barrel to frame gap with feeler gauges. case protrusion can be measured with a depth mike or by sizing cases till a piece of aluminum foil slips out between the case head and cylinder face on a closed chamber.
a loose barrel hinge pin that allows wiggle when your action is open also can effect group size as well. good luck in your quest for accuracy.