A bit late getting the info out but, here's what I've got to offer .
I cut my chamber with a .100 freebore .297 neck on a Proof 1/8 twist . Finished length is 26 inches .
I ordered 400 rounds of this ammunition (primarily for the brass) . First thing I noticed is the 142 SMK was seated pretty deep into the case - Sitting .075 off the lands . The loaded round will actually fit inside a MAGPUL . 308 magazine at this seating depth . Brass is solid , my understanding is its coming from Norma but I have no confirmation. I shoot Norma in 6XC and I can say its consistent with the hardness of the 6xc brass and the primer pockets are tight after several firings with Remington 9 1/2 which typically runs a bit on the small side..
The ammunition is loaded with powder coming from BOFORS according to other sources I've seen on the internet, but that's hearsay . What I can tell you is I've pulled nearly 200 rounds apart and randomly weighed the charges ..also weighing charges of an entire box of 20 rounds . Charge weights are an astonishingly consistent 63.5 grains on all cases from that box and those randomly weighed in others within the case. One thing of note here. This stuff has been sitting around for a while . There is a cold weld between the bullet and the brass on most of what I've pulled and the bottom 2/3 of the powder column is coagulated which is consistent with what I've seen in other factory ammunition I've pulled apart as well as my own handloads after sitting for several months. Cold weld takes longer depending on neck tension .
The chronograph (oehler 35) velocity of the ammunition as it came to me on the barrel previously noted was a 5 shot 3186 FPS Avg. with an SD -14 at 100 degrees . The group printed at 300 meters was a vertical 2.5 inches sub MOA total.
I then proceeded to pull the 142 and adjust seating depth to .015 off the lands . Fired another group at 300 meters over the Oehler. The result was 3159 FPS Avg SD-15 1.6 inches tall at 70 degrees. This particular load was subsequently put on a 12 inch by 12 inch plate at 1492 yards 3 out of the 4 shots fired . One round was over the target at 1 O'clock my guess was approximately 6 inches off the plate .
I have since used the powder that was pulled from the cases in both once fired prime brass with a Unis Genex primer (actually quite a good primer but very tight going in to pocket) and the virgin brass with factory primer (unknown) . Adjusted charge weights of 61.5 , 62 and 62.5 grains were put into the once fired case with a 140 ELD loaded .025 into the lands . Four shot groups were fired at 300 meters over the oehler at 90-92 degrees.
61.5 gr - 3154 Avg SD -7 produced a big flyer at 10 O'clock a minute and 1/2 out . Others were .75 inches tall.
62 gr. - 3180 Avg. SD-9 produced at .556 inch tall group .893 inches wide . Quartering headwind 8-12 MPH .
62.5 - gr. - 3192 Avg . SD-2 produced a group of 2.5 inches overall . Pressure note on two of four rounds with ejector footprint noticeable.
The 62 grains of BOFORS was used with the 140 ELD .025 into lands with 1x fired brass and UNIS primer on 12 in diameter circle plate at distances of 1000- 1400 yards in 50 yard increments with excellent elevation at the velocity of 3180 fps all the way back . No shots were missed due to elevation but wind only.
Note - Virgin brass with factory primer and 140 ELD seated .025 in yielded a velocity of 3141 fps. Lower velocities were noted with my 30 inch Krieger 7.5 twist using Reloder 23 with 150 SMK and virgin brass /factory primer as well.
30 inch kreiger data below.
54.5 gr reloder 23 with once fired UG primer 3070 fps
54.5 gr. reloder 23 with virgin brass and factory primer was 3034 fps.
I do not believe the variable of the factory primer versus the UG primer is producing the significant difference in velocity, although there is likely some , but rather the difference coming from the brass being formed and the slick surface of the virgin brass .. that's conjecture. Nonetheless, I was surprised to see that big of variation . I've seen this in virgin vs. formed brass in other calibers (though not as significant) ....headspace of both virgin brass and 1x fired is both .001- .0025 .
I have data with 140 ELD, 142 SMK and 150 SMK bullets in both the 26 inch Proof ,as well as the 30 inch Krieger using Reloder 16, Reloder 19, Reloder 23 and H4831SC . I would pass on if interested .
My overall impression of the PRIME Factory ammunition is favorable but I would not take it into competition, as is , beyond 300 yards. (mid to long range high-power). I would personally limit my engagement distances in the field on deer size game to 500 yards if were using it for that purpose. I cant tell you how this would perform in a SAAMI chamber with generous free bore if that applies to you . Bigger targets ( something around 2MOA ) at longer ranges in my barrel with this ammunition will do quite well but I have yet to put it on a decimal target at 600-1000 yards.
Phil Hayes
