8mmFan
07-08-2019, 10:48 PM
Today we completed a penetration test on dry pine boards that were sandwiched one behind the other and held together with workshop clamps. The shots were fired at appx. 10 yards.
The 8mm LEE 170g RN was fired from a 8x57 Yugo Mauser with a 23.5” barrel. The 7mm LEE 130g Soupcan was fired from a Ruger 7x57 with (I believe) a 22” barrel. All bullets were water quenched.
8 shots were fired. ALL cartridges — 7x57 and 8x57 — consisted of 2.5g of Bullseye and a cci primer. “Cat Sneeze” - type loads.
There were 6 shots fired with the 8x57, half with copper gas checks, half with aluminum.
There were only 2 shots fired with the 7x57, both with copper gas checks. We stopped at two, because they completely penetrated all the boards and can’t immediately be recovered so we didn’t waste any more cartridges.
There was appx. 4.5” of board-thickness in total, consisting of six .75” thick boards clamped together as described above. As I said, the range was approximately 10 yards.
Of the six 8x57 loads fired, the deepest penetration was exactly 3”, measured from the front of the first board to where the bullet tip penetrated the deepest. The shallowest was 2.75”. There was NO bullet deformation on any of the bullets except one, which took on a “bulbous” shape from the bullet tip to about 1/3 back. ALL COPPER GAS CHECKS STAYED ON THE BULLET; ALL ALUMINUM GAS CHECKS CAME OFF ALONG THE TRAIL OF THE BULLET. All gas checks showed rifling consistent with that of the bullet.
The 7x57 bullets were fired next. The first COMPLETELY penetrated all six boards and went out the back, landing in the very wet earth somewhere in back of the target. The second bullet also completely penetrated the target, landed in the earth, and burrowed a hole in the wet dirt for AT LEAST 11 inches. We stopped digging for it and will look for it later this week with a metal detector.
My conclusions for my own personal use:
A) The LEE 7mm 130g Soupcan obviously out-penetrates the LEE 8mm 170g RN using identical 2.5g charges of Bullseye.
B) I was VERY surprised by the power and penetration of the Soupcan. This is the first time I have ever cast or fired it. I can make no observation as to accuracy as the range was too short.
C) I was also surprised at the hardness of the 8mm bullets. Only 1 of 6 showed any deformation whatsoever other than rifling.
D) I have always suspected that copper gas checks stay on better than aluminum due to the loose fit of aluminum experienced during the sizing process. This test seems to confirm that, at least for this individual 8mm bullet. I didn’t recover the 7mm bullets that both had copper gas checks but I think I’ll be able to, using a metal detector, and then we’ll see how those checks held.
E) All but one shot was fired by my 10-year old son. He absolutely enjoyed the experience. The only point here is that, although these shots fired exhibited decent penetration on pine boards, albeit at a very short distance, the recoil is quite pleasant.
F) At this point, I will be really hard-pressed to use these bullets for deer hunting. Even if I can get good accuracy and speed witht them, say 2000+ fps, I’d have a real fear of them just “pencilling through” a deer and not expanding. Although they’d probably be just fine for breaking a shoulder or a spine, I usually like to be able to shoot for the heart-lung area on deer, and I’d be afraid of these bullets not expanding with that type of shot.
All of the above is shared simply for the edification and use of anyone who might find it useful.
8mmFan
The 8mm LEE 170g RN was fired from a 8x57 Yugo Mauser with a 23.5” barrel. The 7mm LEE 130g Soupcan was fired from a Ruger 7x57 with (I believe) a 22” barrel. All bullets were water quenched.
8 shots were fired. ALL cartridges — 7x57 and 8x57 — consisted of 2.5g of Bullseye and a cci primer. “Cat Sneeze” - type loads.
There were 6 shots fired with the 8x57, half with copper gas checks, half with aluminum.
There were only 2 shots fired with the 7x57, both with copper gas checks. We stopped at two, because they completely penetrated all the boards and can’t immediately be recovered so we didn’t waste any more cartridges.
There was appx. 4.5” of board-thickness in total, consisting of six .75” thick boards clamped together as described above. As I said, the range was approximately 10 yards.
Of the six 8x57 loads fired, the deepest penetration was exactly 3”, measured from the front of the first board to where the bullet tip penetrated the deepest. The shallowest was 2.75”. There was NO bullet deformation on any of the bullets except one, which took on a “bulbous” shape from the bullet tip to about 1/3 back. ALL COPPER GAS CHECKS STAYED ON THE BULLET; ALL ALUMINUM GAS CHECKS CAME OFF ALONG THE TRAIL OF THE BULLET. All gas checks showed rifling consistent with that of the bullet.
The 7x57 bullets were fired next. The first COMPLETELY penetrated all six boards and went out the back, landing in the very wet earth somewhere in back of the target. The second bullet also completely penetrated the target, landed in the earth, and burrowed a hole in the wet dirt for AT LEAST 11 inches. We stopped digging for it and will look for it later this week with a metal detector.
My conclusions for my own personal use:
A) The LEE 7mm 130g Soupcan obviously out-penetrates the LEE 8mm 170g RN using identical 2.5g charges of Bullseye.
B) I was VERY surprised by the power and penetration of the Soupcan. This is the first time I have ever cast or fired it. I can make no observation as to accuracy as the range was too short.
C) I was also surprised at the hardness of the 8mm bullets. Only 1 of 6 showed any deformation whatsoever other than rifling.
D) I have always suspected that copper gas checks stay on better than aluminum due to the loose fit of aluminum experienced during the sizing process. This test seems to confirm that, at least for this individual 8mm bullet. I didn’t recover the 7mm bullets that both had copper gas checks but I think I’ll be able to, using a metal detector, and then we’ll see how those checks held.
E) All but one shot was fired by my 10-year old son. He absolutely enjoyed the experience. The only point here is that, although these shots fired exhibited decent penetration on pine boards, albeit at a very short distance, the recoil is quite pleasant.
F) At this point, I will be really hard-pressed to use these bullets for deer hunting. Even if I can get good accuracy and speed witht them, say 2000+ fps, I’d have a real fear of them just “pencilling through” a deer and not expanding. Although they’d probably be just fine for breaking a shoulder or a spine, I usually like to be able to shoot for the heart-lung area on deer, and I’d be afraid of these bullets not expanding with that type of shot.
All of the above is shared simply for the edification and use of anyone who might find it useful.
8mmFan