A buddy of mine just purchased a new Savage 110BA in 300WM, and experienced a problem I hadn't thought possible with a belted magnum and lived! Also, we DID take precautions in developing this load. We started with his new out of the box, cleaned, Savage, at the range and worked up increasing loads, (yes, we reloaded at the range). We stepped up charges of H1000 from 74 to 77gr, with Fed 215M primers, with sorted and prep'd RWS cases, 210gr Berger VLDs all seated 0.010 off the lands. We checked for signs of over pressure and chronographed each shot. All sizing was performed with a 300WM Lee collet die. We found the 76gr had a nice 2860fps velocity with no signs of over pressure, although none of the loads were over pressure. We then loaded up multiple rounds at 0.010 into the lands, 0.010, 0.030, 0.050, 0.070, 0.090, and 0.110 off the lands to find the "sweet" spot for the VLDs. The 0.010 into and 0.010 off the lands seemed to be the best (although neither was any better than 1.0 MOA). We then attempted the ladder test with all rounds loaded at 0.004 off the lands (this has historically been my magic jump), with 75.2, 75.6, 76.0, 76.4, 76.8gr to see if we could find a sweet spot. The 76.4 seemed the most likely, although it still didn't group any better then 0.75MOA. So now we are out of time, and there is a Long Range Precision Rifle match the following week. We are not super excited about any of the loads. The 76.4 seemed the best, but had a Standard Deviation of 30fps...which is huge for the effort we put into hand weighing each charge to 0.05gr. The Lee Collet die that we were using squeezes the case neck against a mandrel. As a result the brass is forever attempting to rebound outward away from the bullet. I hypothesized that inconsistent neck tension caused the large velocity Standard Deviations we observed. I lent my buddy my Redding 300WM neck only die which utilizes a button to expand the neck outward. The brass would forever rebound in toward the bullet, and he should experience the single digit velocity Standard Deviations that I enjoy. Time for the match. Actually 1 hr prior to the match. We zero his gun at 100yrds, and determine the scope setting for 600yrds. We will then use a computer to predict the scope MOA setting for each of the match distances. Not ideal, but good enough for the time we have. Well, we are shocked that his groups at 600yrd are AWESOME! They are 2" at 600yrds! or .3 MOA! His gun has no problem cycling the rounds. The SD is 8fps... although I am later informed the velocities average 3020fps! (for a 210gr bullet)
Anyway, he does very well for the first quarter of the match, and then his gun jams with a primer that has fallen out of the primer pocket and wedges the next round. We decide that it is best to stop shooting. Anyway, this story is getting long...I have NEVER heard of a belted magnum that pushed a primer out. All of his cases showed significant signs of over pressure with cratered primers, the extractor pin embossed into the base of the case, and very flattened primers. This is with the exact same cases, powder, charge, primer, bullet, and seating depth that shot 160fps slower the week before. The only difference was the neck-only sizing die that squeezed in...vs..drawing an expander ball out. Anyway, my buddy is starting back at square one with with his health, and a new Redding die. Also, if someone could walk me through the steps that allow a new bolt action rifle with a belted magnum to push a primer out, I'd greatly appreciate it.
Thanks
DaveS
Anyway, he does very well for the first quarter of the match, and then his gun jams with a primer that has fallen out of the primer pocket and wedges the next round. We decide that it is best to stop shooting. Anyway, this story is getting long...I have NEVER heard of a belted magnum that pushed a primer out. All of his cases showed significant signs of over pressure with cratered primers, the extractor pin embossed into the base of the case, and very flattened primers. This is with the exact same cases, powder, charge, primer, bullet, and seating depth that shot 160fps slower the week before. The only difference was the neck-only sizing die that squeezed in...vs..drawing an expander ball out. Anyway, my buddy is starting back at square one with with his health, and a new Redding die. Also, if someone could walk me through the steps that allow a new bolt action rifle with a belted magnum to push a primer out, I'd greatly appreciate it.
Thanks
DaveS
