Thanks Richard & sabotless guestion

[wako]

Just wanted to thank Richard for all he has done for me.He set up a 45 PN for me and has been most helpful with any subsequent questions or problems. I have several of his tested loads shooting great out of this rifle. He is,among many others, a real asset to this board. Repeatable accuracy is the main reason I went with the 45PN(after two 50 cal barrels).Happy I did too. Here's the question: I have intentionally left loads for extended periods of time to see any change from poi. As someone else posted...always high by 2-3 inches.It was mentioned it might be due to the sabot contracting or shrinking. Has anyone experienced this with a sabotless load? I 've got the itch to get set up and try the sabotless thing. Or has anyone found a load (sabot) that repeats after left loaded for a few days? I haven't tried them all. So many combos. Thanks everyone! JAT

[smokeless77]

wako, Are you saying in your test with the 45 cal. you were 2-3" high also?
What bullet did you use in the test?

John

[wako]

Jon, At a range session(45 cal PN)I'd pick a load that was grouping very well and use the same loading regimen and leave it in the rifle. Always the 200 SST BH. I tried a couple single loads 4198 and a hot duplex load. The duplex load surprised me most as it was a very tight grouping at the range. But this load had been left in rifle for a week....then printed nearly 3" high. But if the sabot is the culprit for whatever reason (shrinking-blowby?) I'd like to see if the same happens with sabotless loads. Confidence in repeatable accuracy is what we all want. And maybe I'm just curious to play around with sabotless loads...just for fun. Do need a SS press and dies though so still thinkin about it. Thanks JAT

[12ptdroptine]

could sabot expansion into the rifleing be giving it a tighter seal? or sabot expansion or contraction of somekind be the culprit? IE: the change from ambient temps from inside to outside and back and forth over time help to promote the sabot to "comform" more to its surroundings? Was the velocity on that first in line with the others of that same day? Drop

[Richard]

James........Thank you! By the way, I had a nice long conversation with Dennis at "Harrell's Precision" the other day when I was ordering some muzzle brakes. He mentioned a "guy" buying a powder measure and something about duplex loads ;D ;D.......I said: "yup, I know that guy!" ;D
Don't know what the deal is with those high shots? I have never left my ML loaded from session to session.
Let me ask you this? What did the load chronograph when you were shooting it prior to leaving it "loaded?". Then, what velocity did the "pre-loaded" round clock that went high? To be 3" higher than before, the load would probably have to be a couple of hundred fps faster to give that much rise?
Richard

[screwbolts]

I think Richards question of speed has a lot of merit but I believe that the high shot may be from a lower speed more than higher speed. The high shot could be because there is more barrel time with the lower speed and this can allow for more barrel rise before the projectile clears the barrel.

Screwbolts

[dave d.]

:)I just shot a load from my .45 that had been loaded for 6 weeks with zero poi change. The load was 54grs of 4198 and a 195bx.now what I did for a test was I knew I was going to the range so I made up 2 fresh charges to shoot along with the loaded rd and a chrony . First shot registered 2432,2nd- 2443,3rd shot 2430 and it went into a nice little 1" group. This was just my experience.

[fishhawk]

Screwbolts, I've seen exactly what your talking about. It shows up for me most on handguns with different speeds. My 460S&W shoots 6" higher at only 25yds shooting 45 long colt that is about half the speed of 460.

[Richard]

Screw bolts.........I have seen this situation occur mostly with heavy bullets........like the 300 grainers in my .50. Generally speaking with the lighter faster bullets I get more of an increase in elevation with increased speed. Lower speed print lower? I can't explain it because I was also of the impression that the slow moving bullet remained in the barre longer while it was rising and subsequently printed high. Definitely as Fishawk mentioned in hand guns?
If I am sighted in dead on with a load producing 2700 fps (say, a 200 gr. XTP) And I switch to load generating 2900 fps? It will always be higher, noticeably so!
I think the answer lies in the velocity. Maybe Wako was not using his chronograph?
The chronograph along with the Pressure Trace provides a lot of answers. Once you see a pattern, it is possible to work with just the chronograph. But in my opinion, going to the range without a chronograph is like taking a bath without water ;D. IF you are going to do any serious testing? To say.........just sight in your rifle with a KNOWN load? No!

And, I still have not figured out why I had those odd shots way out of the group on targets one and two with the single N-110 load??? Yet, no problem with the duplex's?
Richard

[wako]

Thanks for the insight and relaying your different experiences. I'm especially curious about your load of 54 grs 4198 Dave. I'm gonna try that very load and see what happens after a few days of time....and a loaded gun. And Richard you flushed me out. I didn't chrono those loads but hereafter I will, to get a better idea of what's happening. One more little questiion: concerning sabotless, how many thousands can you go down in one step in the resizing process? I see the general rule is to size down to .448 and Knurl up to +- 450. Is one die all you need to go down to .448 from .452? And how does that swinglock die size in such tiny increments? This board has saved me so much frustration,time and $$$. Thanks guys. JAT

[Dave W]

One die manufacturer recommends steps of no more than .004. One die will take a .452 down to 448.

[Richard]

James.........The first die I bought from Lee was the .448" one. With no problem, it takes a .452 down to .4484" Not quite .448"!
Somewhere on the forum is a discussion about Tom Post's (Swinglock) die. Those that have them say they are very good. I have to assume that it is some type of collet die. I have still gotten my best results by sizing with the .448 die and then knurling up to slightly over .451". Those little nubbies will then compress as you seat the bullet.
Richard