30 cal PB boolits at longer ranges?

[RU shooter]

I know the bigger bore crowd does this all the time with success but what about us 30 cal shooters? I am trying to get away from the use of gas checks as vel. is not important to me just the accuracy aspect of it. Now I am talking about shooting 200 yds with a PB boolit , I have done this already with some success with a 160 gr group buy plinker TL boolit and had enough elev. on my rear sight in the 1400 fps or less range so I know it can be done sucessfully and accurately(as to my accuracy standards anyways) . I also know that a boolit has to deal with the turbulence as it goes back below the sound barrier which is prob. around the 125-150 yd range??(just a guess there)
Question is this, would a certain style/type /weight of boolit be better at accuracy at longer ranges at plain base speeds? For instance would a spitzer nose be better than a round or flat nose or heavier (say 200+gr.) be better than a lighter shorter boolit? So far my uneducated theory (thinking out loud here) would be a lighter shorter boolit is being stabilized waaaay more than needs to be in that 1:10 twist and thus would deal with the sonic transition better than say a 210 gr. Yes the lighter boolit would be affected by wind drift more but reading the wind is half the fun is a HP match anyways. So what say you all ?

Thanks ,Tim

[Bob Krack]

Question is this, would a certain style/type /weight of boolit be better at accuracy at longer ranges at plain base speeds? For instance would a spitzer nose be better than a round or flat nose or heavier (say 200+gr.) be better than a lighter shorter boolit? So far my uneducated theory (thinking out loud here) would be a lighter shorter boolit is being stabilized waaaay more than needs to be in that 1:10 twist and thus would deal with the sonic transition better than say a 210 gr.
Thanks ,Tim

I wonder too (or is that "wander")!

I'ma thinkin that heavier would be better in this type of application? Also, the shape of the boolit would have drastic effects of the aerodynamics.

Ya could also go heavy enough that 200 or more yards were effectively covered by a subsonic projectile, ala "wisper 300" by D.J. Jones?

Opinions?

Vic

[felix]

Just make sure you stay above or below 1100 by a full 100 fps throughout the 200 yards. ... felix

[RU shooter]

Just make sure you stay above or below 1100 by a full 100 fps throughout the 200 yards. ... felix Thanks Felix I know thats the Ideal way of doing it but two problems arise #1 is I am already at 700 yd sight setting on the rear sight (800 is maxed out) front sight is already the shorter 03 blade so I cant really take it that much slower,#2 is the load I am shooting now is in the 1350-1400 fps range so I cant push up the vel. hardly any more to stay sonic out to 200 without doing bad things to the boolit base and then accuracy will suffer.

Anyone have one of those computer programs that will show at what speed I need to get at the muzzle to keep sonic at 200 with a 200 gr RN boolit?

Tim

[Tom Myers]

Anyone have one of those computer programs that will show at what speed I need to get at the muzzle to keep sonic at 200 with a 200 gr RN boolit?

Tim[/quote]

Tim using Lyman's published BCs and velocity ranges for their 31114 bullet, Starting out at 1450 fps will just keep the velocity above the 1120 fps speed of sound at 200 yards.

I know that is not a round nose bullet, but the BC should be about the same or just a little lower. So, if you keep velocities in the 1500 fps range, you should be good to go.

Hope this helps.
Tom Myers
Precision Ballistics and Records (http://www.tmtpages.com)


http://i164.photobucket.com/albums/u35/dutchtom/30Cal.jpg

[HORNET]

FWIW, the old-time shuetzen boys used to compete at 300 yards with 38-55's and .32-40's. Plain-based boolits with a moderate meplat. They usually used the heaviest boolit they could get to be barely stable at the desired range. Some have reported good results using the RCBS 30-180-SP recut to plain-based out of a 10" twist.

[TAWILDCATT]

I use a lyman 311291 with 13 gr red dot at 1680 in 30/06.the man that gave me that said it was excelent at 200.few speak abou the 13 gr red dot load only those who know about it.I am going to be loading a Modern Bond pb 180 gr this summer
The lyman was set for 300 yrd to go on at 100.try the 13 gr red dot at hundred.I also uuse it in all my military loads 8mm lebel/8mm mauser/7.7 jap./303.:coffee:
[smilie=1: :Fire:

[leftiye]

RU, Try taking a look at the paper patched boolits. No lube grooves, round nose, but with an ogive. Better still, pointed like a Postell design. Much better wind bucking capabiities. Paper would extend your accurate velocity capability upwards some too. Flatter shooting (could probly reach 300 yds and still be above the sound barrier (WAG), and with those sights). Use slow powder, card wads, or maybe COW to keep base cool, and stop gas cutting. Paper patch protects the base too.

[RU shooter]

Thanks Tom for the ballistics print out ,thats just what I was after,Now I know what my starting point should be as far as MV.

Hornet, What type of vel. were the shuetzen shooters trying for for with the 32-40 ctg.?

TAWILDCATT, Ive used that same load with success at 200 but with GC 185 gr boolits and does shoot well but with a PB boolit it may be a little too much heat. My first attempt at this was 10 grs of RD with a 160 PB and it did hold the 10 ring for my last 5 rds after I found my zero, I was gettting just a faint grey streak in the barrel ,boolit lubed with LLA. I need to keep any leading even minor to a minimum as I'll be shooting a 58 rd match and the last 20 are the most important so If accuracy goes south after 15 rds I'm Doomed!

LEFTIYE,Thanks for the new to me Ideas, I really didnt think about those other options as I never really had needed for them. BTW I thought card wads were mainly for straight walled ctg.'s can you use them for bottlenecked rds too? How do you keep them on the boolit base? I think I'm also gonna experiment with some dacron fluff and see how well that protects the base, I'll do a search on the COW filler also

Thanks All for the help and ideas keep it coming !!!!!!

Tim *anyone have any extra HBC mold *

[runfiverun]

look at what some of the b/p guys are using p.p. and postell designs
with p.p. 2000 fps is easy, cheaper than g/c.
most of the bp guys shoot at 2-3 hundred but they have raised rear sights so ya gotta cheat a bit with velocity to equalize things some, cause of the weight.

[45 2.1]

As long as the alloy is correct for the pressure involved, you can shoot it pretty fast, as long as you protect the base from the powder gases. Ground shotshell buffer will do that along with some other things. Please note that useing case fillers will reduce the powder space and change the loading data down in charge to be safe. Medium to slow burning powders work better for this.

[HORNET]

Tim, Most of the shuetzen rounds had muzzle velocities around 1450 fps or maybe a little less. Of course, at the time they were using mostly black powder loads with a few duplexed loads near the end of the era. The boys in the ASSRA run in the same velocity range but usually with smaller cases and higher pressures. Still lots of drop and wind drift.