The Firing Line Forums - View Single Post - How to shoot measurable groups with handgun

Snobal · December 16, 2009, 09:24 AM

Our handgun ranges have benches and most folks sit and use sandbags for a rest to test their loads.

My preference is a "rabbit-eared" sandbag rest. Mine cost fifty cents at the thrift store for a pair of little kid's jeans. Cut off most of the legs, sewed up the ends, stuffed zip-lock backs with sand and then inserted them into the legs and butt area. Sewed up the belt area and use them with the legs pointing up.

I rest the handgun frame in the crotch of the upside-down jeans. This gives both vertical and horizontal stability. I hold the gun with both hands and rest my hands (and sometimes my arms) on sandbags.

I shoot at a measured 25 yards to test accuracy for target shooting --- if the load is for hunting, I start at 25 yards and go out to 100 yards.

For a target load, I am satisfied if the load groups under 2" at 25 yards --- but I am not talking about a single 6-shot group --- but rather an 18- or 24-shot group.

I believe that an occasional group of less than 1" does not mean the load shoots less than 1". For example, on 11/23/09 I was experimenting with a new load and shot four, six-shot groups --- each group was shot on a new target. Afterwards, I picked one of the targets to be the "master," and carefully placed each of the other three targets, one at a time, on the master, then drew in the bullet holes so that all 24 shots were seen on the master target.

The four, individual 6-shot groups for that load measured 1.72", 1.42", 1.04", and .662" --- all within my "standard" of less than 2", but more importantly to me is that the aggregate --- when overlaid --- went into less than 2".

A chronograph used to measure shot-to-shot velocity variations will really save time and money. While a load with small variations does not always group the best, small velocity variations indicates good potential for a load.

Muzzle blast will eventually eat through the legs of a rabbit-eared rest made from jeans, so you may want to patch them or add some leather to the "blast" areas.

Now the bad news....

Just because you find a load that groups great one day, does not mean that same load will group well with a drastic temperature change.

In the 1970's, the "rage" was Bluedot powder. It worked great for my .41 Mag loads when the temperature was in the 70's --- but when I tried it in sub-freezing temperatures (getting ready for a handgun deer hunt), the velocity variations went crazy and the load did not group well.

I eventually figured out that my velocity variations with H-4227 powder did not change much from "cool" to below freezing temperatures and that became my power-of-choice for hunting (but H-4227 does not do as well on a hot day --- H110 and 296 seem to be the most stable).

There ain't no end to this mess once you start....

Good Luck!

JMHO - YRMV

December 16, 2009, 09:24 AM	#7
Snobal Senior Member Join Date: January 4, 2009 Location: Arizona Wilderness Posts: 121	Our handgun ranges have benches and most folks sit and use sandbags for a rest to test their loads. My preference is a "rabbit-eared" sandbag rest. Mine cost fifty cents at the thrift store for a pair of little kid's jeans. Cut off most of the legs, sewed up the ends, stuffed zip-lock backs with sand and then inserted them into the legs and butt area. Sewed up the belt area and use them with the legs pointing up. I rest the handgun frame in the crotch of the upside-down jeans. This gives both vertical and horizontal stability. I hold the gun with both hands and rest my hands (and sometimes my arms) on sandbags. I shoot at a measured 25 yards to test accuracy for target shooting --- if the load is for hunting, I start at 25 yards and go out to 100 yards. For a target load, I am satisfied if the load groups under 2" at 25 yards --- but I am not talking about a single 6-shot group --- but rather an 18- or 24-shot group. I believe that an occasional group of less than 1" does not mean the load shoots less than 1". For example, on 11/23/09 I was experimenting with a new load and shot four, six-shot groups --- each group was shot on a new target. Afterwards, I picked one of the targets to be the "master," and carefully placed each of the other three targets, one at a time, on the master, then drew in the bullet holes so that all 24 shots were seen on the master target. The four, individual 6-shot groups for that load measured 1.72", 1.42", 1.04", and .662" --- all within my "standard" of less than 2", but more importantly to me is that the aggregate --- when overlaid --- went into less than 2". A chronograph used to measure shot-to-shot velocity variations will really save time and money. While a load with small variations does not always group the best, small velocity variations indicates good potential for a load. Muzzle blast will eventually eat through the legs of a rabbit-eared rest made from jeans, so you may want to patch them or add some leather to the "blast" areas. Now the bad news.... Just because you find a load that groups great one day, does not mean that same load will group well with a drastic temperature change. In the 1970's, the "rage" was Bluedot powder. It worked great for my .41 Mag loads when the temperature was in the 70's --- but when I tried it in sub-freezing temperatures (getting ready for a handgun deer hunt), the velocity variations went crazy and the load did not group well. I eventually figured out that my velocity variations with H-4227 powder did not change much from "cool" to below freezing temperatures and that became my power-of-choice for hunting (but H-4227 does not do as well on a hot day --- H110 and 296 seem to be the most stable). There ain't no end to this mess once you start.... Good Luck! JMHO - YRMV Last edited by Snobal; December 16, 2009 at 09:39 AM.