Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 9, 2010 19:38:47 GMT -5
some interesting discussions from the brainier gents around here but one thing I might add is the 45 dd pacnor barrel on my gun is not nearly as hard on sabots as the factory barrel, matter of fact I cant say that I have had a blown sabot with my max load so far ( 63 grns 4198/ light blue harv/200 sst or 195 barnes). in the summer I can shoot three shots as fast as i can load without problems, maybe just dumb luck. Im sure a 26 twist will be fine and I will also be looking foreward to some range results.....Bill
|
|
|
Post by ET on Jan 9, 2010 19:51:03 GMT -5
Squirrelhawker This might be of interest to you. kwk.us/twist.htmlThe calculator does work when you type in required info. Ed
|
|
|
Post by sw on Jan 9, 2010 20:39:37 GMT -5
:)Vince, I have 1 40 cal and 3 45 cals: all Pacnors. The 40 cal is 16 twist and the 45s are all 22 twist. The 45s are 448,450,and 4535 land-to-land. In the beginning RB and I discussed the problem of the 45 PacNor having too fast of a twist to be able to shoot the 2600'/sec we hoped to get to shoot. We initially shot 53g H-4198 and IMR-4198 with 300g bullets and 55g with 275g bullets both sabotless and 58g with 200SSTs . The 200s were going appx 2500+ '/sec and we were surprised that sabots were doing ok. There were about 5 initial 45 shooters at this time - DaveD was one I'm quite sure. I didn't do well at all: others did. Then we found that PacNor had a few barrels not at 450 but at 4535 and were too loose. Then the PacNors seemed to be about 448 and 4485 and they were outstanding saboted and good with re-sized 450 and 452 bullets. The 22 twist did great even at 2700+ with light blue Harvesters. I've shot to a little over 3000 with no sabot problems with my 448 and 450 45s. I routinely shoot my 40 at 2930'/sec with EWCs and Chucks recommended duplex load of VV-110/Varget(I can't take credit for this super duplex). It always shoots the same. My experience, though limited to 10-12 barrels/twists and 1000's of precision hand loads, including slow and fast twist 6PPCs, 22-250 AK IMP, 223, is that fast twists tend to be more accurate thru a wide velocity variance. They are load forgiving. 26 twist should still do very well(it is not slow for 45 cal but much faster will work). I expect all loads over 2400'/sec will do great. I have a 50 cal SMI 36 twist. It shoots great fast. It will not stabilize a 285g Barnes Spitfire but will stabilize a slightly shorter 290g Barnes. The Sav 50 cal will stabilize both. The previous concern over sabot inability to be shot fast thru a fast twist has been put to rest. 20 twist vs 22 twist - just opinion on my part. Likely a 20 twist can't do anything that a 22 twist hasn't already done. I like fast twists. All 22 CF with 7 twist? Might be a good idea. As I stated, my next 223 barrel will be at least 8 twist. What very little deer hunting I do with a CF, and not in years, is done with the 223 and a 60g Partition, and rarely a 53g Barnes. For long range hunting,I use the 22-250AK with 75 A-Max, 80 Sierra, or 80 Starkee. I understand concern about using long range tgt bullets on game(Sierra Match King and A-Max) , but their terminal performance is "text book". Anyway, enough rambling.
|
|
|
Post by smokeless77 on Jan 10, 2010 21:22:30 GMT -5
I had a chance to shoot the 1 in 20" krieger today all with the 195 barnes with the light blue harvester. The 5 shots of 62 grains H-4198 was a 2-3" group. The 5 shots with 12/48-n110-2015 this load was very accurate .5 group hardly no recoil. Do not no the fps, have no crony. Plenty more shooting to do to get it figured out.
Forgot, It was 100 yds.
|
|
|
Post by sw on Jan 10, 2010 22:24:00 GMT -5
I had a chance to shoot the 1 in 20" krieger today all with the 195 barnes with the light blue harvester. The 5 shots with 12/48-n110-2015 this load was very accurate .5 group hardly no recoil. Do not no the fps, have no crony. The velocity is likely in the 2690-2730'/sec range. FYI, 10/54 VV-110/2015 gets 2754-2777 in 50ish temp range. This is 25" 22 twist PacNor.
|
|
|
Post by Dave W on Jan 10, 2010 22:38:35 GMT -5
I had a chance to shoot the 1 in 20" krieger today all with the 195 barnes with the light blue harvester. The 5 shots of 62 grains H-4198 was a 2-3" group. The 5 shots with 12/48-n110-2015 this load was very accurate .5 group hardly no recoil. Do not no the fps, have no crony. Plenty more shooting to do to get it figured out. Forgot, It was 100 yds. I have shot the 12/48 a good bit out of my 20 twist Shilen, avg velocity 2690 or 2695 fps at 35*. It lost approx. 200fps once the temps dropped into the teens though.
|
|
|
Post by smokeless77 on Jan 10, 2010 22:53:09 GMT -5
It was 25* today, And forgot to add that it has a 28" barrel if that makes any big difference in velocity.
Thanks guys, John
|
|
|
Post by Dave W on Jan 10, 2010 22:58:18 GMT -5
It was 25* today, And forgot to add that it has a 28" barrel if that makes any big difference in velocity. Thanks guys, John 24.625" of usable barrel for my gun.
|
|
|
Post by squirrelhawker on Jan 12, 2010 3:47:34 GMT -5
:)Vince I can show you a group in 89 degree weather with 5 minute wait's between shot's @300yrds the measures 1.3 . I don't see the need to rush things when I'm at the range but I also don't believe 5 minutes between shots is a long time to wait either. How much you are going to gain on 4" of twist I don't know but I'm glad you did purchased a 26 because I'm looking forward to your results. DW Like I said...I know you guys...quite a few of you, get good/great results with the faster twists. To me...it was worth paying the extra money for them to make another button to do the 26" twist. I KNOW it will stabilize the bullet/s I will shoot and the least amount of rotational force on the plastic sabot is what I wanted. I needed to try it! Now..others can also get that twist from pac-nor. I bit the bullet. When you have to start using cooling rods and waiting between shots and swabbing between shots or you MAY blow the sabot..it tells me that you are right AT the limits of that sabot. Maybe this twist will alleviate some of that?May be a little more forgiving? There were problems with some of the Knight & TC fast twist 45's. When they slowed it down...complaints went away. www.prbullet.com/s45.htm I realize..like Edge said, those oem barrels quality doesnt compare to these pac-nors....but logic tells me when you push things farther...like we have done with these & smokeless velocities..you will reach its limits. Perhaps slowing the twist a bit will improve a few aspects. I may shoot this gun and find that it has the same characteristics as your 22". (And..like you say..aint all bad!!) Also..it will be interesting to see if the velocity can be cranked up a little more with the slower twist ?? I hope to find out. I promise to be honest with my results. Also...I will be trying out the MMP tan sabots in my testing along with the harvester smooth and the harv. CR. I know the MMP blows when I tried it in my TC and H&R 45 barrels.(45-70 conversions.) I dont mean to imply that this is the only way to go..or necessarily THE answer to the best twist. (for saboted) I am anxious for the weather to warm..that, I am sure of.
|
|
|
Post by squirrelhawker on Jan 12, 2010 4:55:32 GMT -5
DW Here is some interesting info. See link below. (I know you are a man of science ) We are talking about jacketed bullets here but the concepts are the same. As far as our delicate plastic sabots...it is relative info..IMO. accurateshooter.wordpress.com/2008/06/03/calculating-bullet-rpm-spin-rates-and-stability/ For what it is worth. i did some calculations using the formula from the above link. lets say you are shooting a 200 SST @ 3000 fps. out of your 22" twist. 3000 x .5454 x 60= 98172 RPM now my 26" twist 3000 X .4615 X 60= 83070 RPM According to this.. even at 3500 fps....with the 26" twist 3500 X .4615 X 60 = 96915.....I'm still under your RPM. You wondered how much diff. the 4" of twist mattered. In real life..it might not matter..ha ha. There are benchresters out there who feel that they only want to stabilize the bullet minimally to keep unnecessary forces off the projectile. (Read the info in the above link) and they are dealing with tougher copper jackets...not the frail sabots we are talking about. For what it is worth.
|
|
|
Post by squirrelhawker on Jan 12, 2010 5:08:37 GMT -5
:)Vince, I have 1 40 cal and 3 45 cals: all Pacnors. The 40 cal is 16 twist and the 45s are all 22 twist. The 45s are 448,450,and 4535 land-to-land. In the beginning RB and I discussed the problem of the 45 PacNor having too fast of a twist to be able to shoot the 2600'/sec we hoped to get to shoot. We initially shot 53g H-4198 and IMR-4198 with 300g bullets and 55g with 275g bullets both sabotless and 58g with 200SSTs . The 200s were going appx 2500+ '/sec and we were surprised that sabots were doing ok. There were about 5 initial 45 shooters at this time - DaveD was one I'm quite sure. I didn't do well at all: others did. Then we found that PacNor had a few barrels not at 450 but at 4535 and were too loose. Then the PacNors seemed to be about 448 and 4485 and they were outstanding saboted and good with re-sized 450 and 452 bullets. The 22 twist did great even at 2700+ with light blue Harvesters. I've shot to a little over 3000 with no sabot problems with my 448 and 450 45s. I routinely shoot my 40 at 2930'/sec with EWCs and Chucks recommended duplex load of VV-110/Varget(I can't take credit for this super duplex). It always shoots the same. My experience, though limited to 10-12 barrels/twists and 1000's of precision hand loads, including slow and fast twist 6PPCs, 22-250 AK IMP, 223, is that fast twists tend to be more accurate thru a wide velocity variance. They are load forgiving. 26 twist should still do very well(it is not slow for 45 cal but much faster will work). I expect all loads over 2400'/sec will do great. I have a 50 cal SMI 36 twist. It shoots great fast. It will not stabilize a 285g Barnes Spitfire but will stabilize a slightly shorter 290g Barnes. The Sav 50 cal will stabilize both. The previous concern over sabot inability to be shot fast thru a fast twist has been put to rest. 20 twist vs 22 twist - just opinion on my part. Likely a 20 twist can't do anything that a 22 twist hasn't already done. I like fast twists. All 22 CF with 7 twist? Might be a good idea. As I stated, my next 223 barrel will be at least 8 twist. What very little deer hunting I do with a CF, and not in years, is done with the 223 and a 60g Partition, and rarely a 53g Barnes. For long range hunting,I use the 22-250AK with 75 A-Max, 80 Sierra, or 80 Starkee. I understand concern about using long range tgt bullets on game(Sierra Match King and A-Max) , but their terminal performance is "text book". Anyway, enough rambling. Sw thanks for taking the time to write. Lot of good info there. Like you said...I am sure my twist will work for me. I have been a reloader for years but have not shot at a competitive level. When one does some research...benchresters def. have their own opinions on twists. There are some .224" people that ..if shooting very fast 4100+ lets say..want a 1 in 15" or even 16". just enough to stabilize their bullet. They dont want to subject the bullet to the forces of the faster twist. Then..others like you said...seem to shoot everything thru a fast twist. I guess whatever you can make work. PS- I am definitely not any authority on this stuff...but i spend too much time pondering it & sometimes go with hunches.
|
|
|
Post by squirrelhawker on Jan 12, 2010 5:20:31 GMT -5
Squirrelhawker This might be of interest to you. kwk.us/twist.htmlThe calculator does work when you type in required info. Ed yeah...I have seen that formula. Thanks. According to this..I can stabilize the 200SST at 2300fps with the 26". At 3000....around 30" or 32" might work? NAW!!!
|
|