Home Forums Reloading Varmint Rifles Primer Selection and Effecting groups

If I get a chance I will post the targets, if that is important.

Today I got a chance to get to the range and check out a load that has been shooting exceedingly well in all of my 22.250s

The loads have been using anywhere from 40 grain to 55 grain bullets and Benchmark powder. I have been using the starting load data from Hodgdon, and that seemed to have been the secret.

Stiffer charges, were not as accurate until you get to max load and then that varied depending on bullet weight.

Today I went out and tried it out in my last 22.250 to test them on. a Model 70 with a 28 inch Pac Nor barrel on it.
the bullet choice was a 52 grains Speer HP, and excellent varmint bullet.

With all of these loads, I have been using CCI and Federal Large rifle primers..10 rounds had the CCIs... the other 10 rounds had some Winchester Large Rifle, because I am running low on CCI primers, and they have not been on store shelves locally..

As expected with the CCI primers, the 52 grain HP Speer and a charge of 32.5 grains of Benchmark, I ended up with 2 Five shots groups that were basically a 25 to 26 caliber hole...this at a 100 yds, with the Leupold 6.5 x 20 set on 16 power...

This is exactly the accuracy these starting loads of Benchmark have been giving me, in the other rifles ( using CCI and FEderal primers).

Same load now but with Winchester primers. We go from one hole groups to 3 to 4 inch groups, with 5 shots! Needless to say, what a big difference primers can make..

this probably represents the more radical extreme I have seen, but a tack driver load becomes virtually useless when going to Winchester primers..

it doesn't mean that Win Primers are bad, it just shows that they don't work well with this load/powder combo..

but with the current primer shortages and lack of availability, I am sure glad I didn't load up a couple hundred rounds of this, and had to change primers at the 12th hour, just due to lack of availability....

The difference tho, rendered the load useless beyond about 50 to 60 yds on prairie dogs and especially sage rats sized targets..... and that distance, I might as well just use the bolt action 22 Rimfire..

Just another example of at times, just a change of primer can make a big difference, either good or bad...

i use cci bench rest primers when ever i can.50grn v-max in my savage mod 12 22-250.

This is one of the many reasons I favor the Optimal Charge Weight concept of load development and selection. Primer differences can still impact on-target results, but a genuine OCW load would be hard-pressed to go from brilliant to truly useless based on a primer brand change. ...unless you have a super-finicky rifle that's the real issue here?