Post by Richard on Feb 7, 2018 17:10:13 GMT -5
LRMP vs. LRP
It seems that in all discussions involving rifle primers, we use Large Rifle Magnum Primers; myself also; so, I thought I would try some “non” magnum primers side by side and see what, if any difference there was? My normal magnum primers are CCI and Federal as both seem to give the same velocity when shot side by side. So right now, I have been using up some Federal LRMP’s. Other than what I have noted here, everything else is Federals.
To foul the barrel I started off with a 10/66 duplex of N-110 and H-4198 behind a 230 gr. Hornady H.A.P. which produced an average of 3215 fps with a 6 fps ES and a decent .577” clover leaf group.
Note: I forgot to reset my scope to last weeks zero and had left it with 1 ½ MOA so the first four groups are somewhat higher than normal.
The second group was the start of my test with the bullet of choice being the 300 gr. XTP and 78 gr. of H-4198 (I wanted to use a straight charge so there was no influence with the booster) along with my standard Fed. LRMP. The velocity averaged 2995 fps with a nice 8 fps ES and a .354” group.
Group #3 used a CCI 200 LRP and gave me 2977 fps with a 13 fps ES and a .854” group (mistake on my sheet-but not in photo)
#4 group used a CCI BR LRP and averaged 2971 fps with a 7 fps ES and a .535” group.
For group #5 I shot the same load but made a scope adjustment. Here I shot five shots since #3 was exceptionally high?----------These are all measured loads? As can be seen, shots 4 and 5 came back to were they should. So the average without #3 was 2994 (previously in group #2 it was 2993) with an ES of 12. Shot #3 also went left of the group leaving the best four shot in .701”
Conclusion: With this very limited testing, the standard primers worked well but produced about 20 fps LESS velocity. The ES’s and accuracy were fairly close. I would give the edge to the LRMP’s and will continue to use only them. I am sure that on another day with a different load and/or bullet, the results might be somewhat different? I also think that with a bushing type ignition system that the results might be more pronounced than with direct ignition.
For group #6, I switched to the 300 Fury star tip and a 10/75—N110/2015 (my old lot) where the velocity was 2953 but the ES was a terrible 60 fps. Still the five shot group was .634” Go figure?
In group #7 I used the same ratio of 10/75 but plugged in N-130 for the main charge. This gave me 2996 fps with a 27 fps ES. Here again, I had one shot (#4) that was much higher. So looking at shots 1,2 3 and 5, the ES was only 9 fps. All five shots in 1.534” with the best 3 in .476” And, that higher velocity shot grouped in that sub half inch cluster? Go figure?
In Group #8 I again used the 300 Fury but from a batch sized some time ago and were either on the tight side to begin with or some spring back occurred. I noticed they were going down a little tighter. As I was getting near to finishing up, I declined to get the sizing die set up. The load was one that normally shoots well: 9/68—N110/H4198, The first shot was way low (could have been the change over from the N-130) and made the average of 4 shots 2964 with an ES of 74. Without that low shot the ES would have been 21 fps. Still the group strung vertically at 2.3” These bullets just need to be a much looser fit.
For my final group which I shot at 300 yards, I used the 300 Fury with 78 gr. of H-4198. The shots all went down with two hands and some weight. The fifth shot was a hammer down at 3055 fps. The other four averaged 3020 with an ES of 22 fps. I still managed 3 (in a row) at 2.1” with all five in 4.1”. Most of which was a windage problem as was evidence by Bill’s 200 yard wind flag.
It seems that in all discussions involving rifle primers, we use Large Rifle Magnum Primers; myself also; so, I thought I would try some “non” magnum primers side by side and see what, if any difference there was? My normal magnum primers are CCI and Federal as both seem to give the same velocity when shot side by side. So right now, I have been using up some Federal LRMP’s. Other than what I have noted here, everything else is Federals.
To foul the barrel I started off with a 10/66 duplex of N-110 and H-4198 behind a 230 gr. Hornady H.A.P. which produced an average of 3215 fps with a 6 fps ES and a decent .577” clover leaf group.
Note: I forgot to reset my scope to last weeks zero and had left it with 1 ½ MOA so the first four groups are somewhat higher than normal.
The second group was the start of my test with the bullet of choice being the 300 gr. XTP and 78 gr. of H-4198 (I wanted to use a straight charge so there was no influence with the booster) along with my standard Fed. LRMP. The velocity averaged 2995 fps with a nice 8 fps ES and a .354” group.
Group #3 used a CCI 200 LRP and gave me 2977 fps with a 13 fps ES and a .854” group (mistake on my sheet-but not in photo)
#4 group used a CCI BR LRP and averaged 2971 fps with a 7 fps ES and a .535” group.
For group #5 I shot the same load but made a scope adjustment. Here I shot five shots since #3 was exceptionally high?----------These are all measured loads? As can be seen, shots 4 and 5 came back to were they should. So the average without #3 was 2994 (previously in group #2 it was 2993) with an ES of 12. Shot #3 also went left of the group leaving the best four shot in .701”
Conclusion: With this very limited testing, the standard primers worked well but produced about 20 fps LESS velocity. The ES’s and accuracy were fairly close. I would give the edge to the LRMP’s and will continue to use only them. I am sure that on another day with a different load and/or bullet, the results might be somewhat different? I also think that with a bushing type ignition system that the results might be more pronounced than with direct ignition.
For group #6, I switched to the 300 Fury star tip and a 10/75—N110/2015 (my old lot) where the velocity was 2953 but the ES was a terrible 60 fps. Still the five shot group was .634” Go figure?
In group #7 I used the same ratio of 10/75 but plugged in N-130 for the main charge. This gave me 2996 fps with a 27 fps ES. Here again, I had one shot (#4) that was much higher. So looking at shots 1,2 3 and 5, the ES was only 9 fps. All five shots in 1.534” with the best 3 in .476” And, that higher velocity shot grouped in that sub half inch cluster? Go figure?
In Group #8 I again used the 300 Fury but from a batch sized some time ago and were either on the tight side to begin with or some spring back occurred. I noticed they were going down a little tighter. As I was getting near to finishing up, I declined to get the sizing die set up. The load was one that normally shoots well: 9/68—N110/H4198, The first shot was way low (could have been the change over from the N-130) and made the average of 4 shots 2964 with an ES of 74. Without that low shot the ES would have been 21 fps. Still the group strung vertically at 2.3” These bullets just need to be a much looser fit.
For my final group which I shot at 300 yards, I used the 300 Fury with 78 gr. of H-4198. The shots all went down with two hands and some weight. The fifth shot was a hammer down at 3055 fps. The other four averaged 3020 with an ES of 22 fps. I still managed 3 (in a row) at 2.1” with all five in 4.1”. Most of which was a windage problem as was evidence by Bill’s 200 yard wind flag.
