CYanchycki
Club Coordinator
6BR, 95gr SMK and 10 twist...New results
I thought I would share something with you long range fellows. Please chime in and give me your thoughts on what has happened.
Here is the story...............
Cabin fever is setting in here in Manitoba. Can't get out of town to chase coyotes till Thur and Fri so..................
Yesterday I decided to pull out my Rem 700 6BR with a 10 twist and fire a few reloads down range. It had not been fired since August 30 when it was fired at 1000 yards.
The load at that time was 30.8 grs of H4895 and a 95 gr Sierra Match King coming out of the 26.5" barrel at around 3100 + or -. It was jammed 10 thou into the lands. The temp that day was not known as I did not mark it down.
I would assume that it must have been in the low 20's celcius that day.
I know there was not a lot of wind when I fired my best group of the day. The 95 gr SMK had no problem stabilizing out to 1000 yards. My best target was 4 out of 5 shots into a group just under 6". I was tickled as hell for only my second time shooting at that distance.
The holes in the target at that distance were perfect little round 6mm holes. No sign of any keyholing.
No flags were used except for one at the target. I shoot from the highest hill on my parents farm across the tame grass to the third hill. It is ranged in 2 steps at 1017 yards.
The rest of the story.
Yesterday Dec. 29 I loaded up JUST 7 rounds to confirm the load was still pretty good despite the more than 40-50 deg temp swing.
Set a target out at 100 yards and proceeded to shoot the 7 rounds and not hit the paper. I adjusted the scope thinking I had not rezeroed after shooting at 1000 yards but could not confirm as I only had 7 rounds. Yah I know, dumb thing but the range is only about 8 minutes from my house.
The only thing that I had done since it was last shot was strip the barreled action out of the stock and give it a thorough wipe of oil to prevent rust and reassemble. It went into the locker until just yesterday.
When I got home I checked to make sure nothing was loose. All seemed 100%. I decided to clean the bore thoroughly and make more reloads to check the gun at 25 yards today to figure out the problem.
Made 16 rounds of the exact same load as yesterday. The only difference was going up to 31.0 grs from 30.8 which had been used in August.
At 31grs out of the Rem 700 in August bolt lift was getting pretty firm and I had even pierced a CCI Magnum primer. First time ever. The firing pin had not been bushed and I was not to worried about it being bushed.
Back to this AM.
I headed to the range, stapled a target at 25 yards, set up on the rest and fired. There was no hole in the paper. Totally baffled I was. Since I played with the turrets yesterday trying to find paper I figured it must be low so I aimed at the top of the target and fired again. Finally, a hole but about 5" low. I adjusted the Leupold VX3 8.5-25X50mm and fired again. That was better, but something was wrong. The hole looked mighty big for a 6mm hole at 25 yards. I proceeded to the target only to find that the 95gr SMK's were no longer stabilizing they were keyholing. Went back fired once more and another keyhole. Now I was starting to think, why? Packed up and headed for home.
I began to draw some conclusions and some of which I was pretty sure of the answers.
I thought I would share what I figure is the culprit. What could be a good or what one thinks is a good load one day and the next not worth sh++.
This is where I want you guys to chime in, OKAY.
In reality when I built my 10 twist it was built around shooting the 95gr Berger. This was re an article I read from another site. I chose the 10 twist and the 95gr Berger because according to the article on the other forum, on paper, the 95 gr Berger gave BETTER downrange ballistics than the 107 SMK's. In theory if you punch in numbers to many of the programs available it comes out that the 95gr Berger is better downrange than the 107 SMK.
I did not know if I would ever shoot at 1000 so I was not concerned whether or not I could shoot to that distance. I decided to try and see if I could do it one day.
The 95gr Bergers proved to stabilize out of my 10 twist so I was happy but I thought I would try the then new 95gr SMK. They appeared to work and work well out to 1000 in August.
In theory the 10 twist should be marginal for stabilization of the 95gr Berger or SMK but they appear to have worked for me until the last couple of days. What happened?
The only logical explanation I can find or think of is the lack of muzzle velocity required to stabilize the 95gr SMK out of the 10 twist barrel. It was the velocity that helped stabilize those bullets and not the twist alone. The twist is marginal for the SMK. The bullets needed that velocity to stabilize them which in Aug was around 3100 fps in say a +20deg celcius day. Today it was more than 40 degrees colder and I was trying to shoot the same load with just .02 grs more powder. It is not enough extra powder to make up the lack in velocity to stabilize the bullets.
Make sense? I think that is the explanation.
Tommorrow I will load up the same 31 grs but this time with the 95 gr Berger bullets which have approximately 55 thou shorter bearing surface than the 95gr SMK's and see whether or not they stabilize at 25 yards and then 100 yards.
I have not played with the Bergers and H4895 as of yet but I will give it a shot tommorrow and see what comes of it.
I will not pull the current loads but will put them away until it warms up in the summer and try them again to see what happens at that time. I would like to think they will be okay?????????????????
I will take my chronograph and fire a round over it with the 95GR SMK's and see what they are coming out of the muzzle at. I would think there will be a substantial loss of velocity. I may try and bring the velocity up to make up the difference and see what happens as long as the pressure signs stay within limits.
Any thoughts from the PRO's out there?????????????????? Make sense?
Patiently await your thoughts.
Calvin
I thought I would share something with you long range fellows. Please chime in and give me your thoughts on what has happened.
Here is the story...............
Cabin fever is setting in here in Manitoba. Can't get out of town to chase coyotes till Thur and Fri so..................
Yesterday I decided to pull out my Rem 700 6BR with a 10 twist and fire a few reloads down range. It had not been fired since August 30 when it was fired at 1000 yards.
The load at that time was 30.8 grs of H4895 and a 95 gr Sierra Match King coming out of the 26.5" barrel at around 3100 + or -. It was jammed 10 thou into the lands. The temp that day was not known as I did not mark it down.
I would assume that it must have been in the low 20's celcius that day.
I know there was not a lot of wind when I fired my best group of the day. The 95 gr SMK had no problem stabilizing out to 1000 yards. My best target was 4 out of 5 shots into a group just under 6". I was tickled as hell for only my second time shooting at that distance.
The holes in the target at that distance were perfect little round 6mm holes. No sign of any keyholing.
No flags were used except for one at the target. I shoot from the highest hill on my parents farm across the tame grass to the third hill. It is ranged in 2 steps at 1017 yards.
The rest of the story.
Yesterday Dec. 29 I loaded up JUST 7 rounds to confirm the load was still pretty good despite the more than 40-50 deg temp swing.
Set a target out at 100 yards and proceeded to shoot the 7 rounds and not hit the paper. I adjusted the scope thinking I had not rezeroed after shooting at 1000 yards but could not confirm as I only had 7 rounds. Yah I know, dumb thing but the range is only about 8 minutes from my house.
The only thing that I had done since it was last shot was strip the barreled action out of the stock and give it a thorough wipe of oil to prevent rust and reassemble. It went into the locker until just yesterday.
When I got home I checked to make sure nothing was loose. All seemed 100%. I decided to clean the bore thoroughly and make more reloads to check the gun at 25 yards today to figure out the problem.
Made 16 rounds of the exact same load as yesterday. The only difference was going up to 31.0 grs from 30.8 which had been used in August.
At 31grs out of the Rem 700 in August bolt lift was getting pretty firm and I had even pierced a CCI Magnum primer. First time ever. The firing pin had not been bushed and I was not to worried about it being bushed.
Back to this AM.
I headed to the range, stapled a target at 25 yards, set up on the rest and fired. There was no hole in the paper. Totally baffled I was. Since I played with the turrets yesterday trying to find paper I figured it must be low so I aimed at the top of the target and fired again. Finally, a hole but about 5" low. I adjusted the Leupold VX3 8.5-25X50mm and fired again. That was better, but something was wrong. The hole looked mighty big for a 6mm hole at 25 yards. I proceeded to the target only to find that the 95gr SMK's were no longer stabilizing they were keyholing. Went back fired once more and another keyhole. Now I was starting to think, why? Packed up and headed for home.
I began to draw some conclusions and some of which I was pretty sure of the answers.
I thought I would share what I figure is the culprit. What could be a good or what one thinks is a good load one day and the next not worth sh++.
This is where I want you guys to chime in, OKAY.
In reality when I built my 10 twist it was built around shooting the 95gr Berger. This was re an article I read from another site. I chose the 10 twist and the 95gr Berger because according to the article on the other forum, on paper, the 95 gr Berger gave BETTER downrange ballistics than the 107 SMK's. In theory if you punch in numbers to many of the programs available it comes out that the 95gr Berger is better downrange than the 107 SMK.
I did not know if I would ever shoot at 1000 so I was not concerned whether or not I could shoot to that distance. I decided to try and see if I could do it one day.
The 95gr Bergers proved to stabilize out of my 10 twist so I was happy but I thought I would try the then new 95gr SMK. They appeared to work and work well out to 1000 in August.
In theory the 10 twist should be marginal for stabilization of the 95gr Berger or SMK but they appear to have worked for me until the last couple of days. What happened?
The only logical explanation I can find or think of is the lack of muzzle velocity required to stabilize the 95gr SMK out of the 10 twist barrel. It was the velocity that helped stabilize those bullets and not the twist alone. The twist is marginal for the SMK. The bullets needed that velocity to stabilize them which in Aug was around 3100 fps in say a +20deg celcius day. Today it was more than 40 degrees colder and I was trying to shoot the same load with just .02 grs more powder. It is not enough extra powder to make up the lack in velocity to stabilize the bullets.
Make sense? I think that is the explanation.
Tommorrow I will load up the same 31 grs but this time with the 95 gr Berger bullets which have approximately 55 thou shorter bearing surface than the 95gr SMK's and see whether or not they stabilize at 25 yards and then 100 yards.
I have not played with the Bergers and H4895 as of yet but I will give it a shot tommorrow and see what comes of it.
I will not pull the current loads but will put them away until it warms up in the summer and try them again to see what happens at that time. I would like to think they will be okay?????????????????
I will take my chronograph and fire a round over it with the 95GR SMK's and see what they are coming out of the muzzle at. I would think there will be a substantial loss of velocity. I may try and bring the velocity up to make up the difference and see what happens as long as the pressure signs stay within limits.
Any thoughts from the PRO's out there?????????????????? Make sense?
Patiently await your thoughts.
Calvin
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