Flyers in .303

[milrifle]

I was going to try to work up a load in my No. 4 Mk 1 with my new NOE 316299 and IMR 4198. I first did a ladder test and found 25.0, 25.5, 26.0, 26.5, and 27.0 gr loads all 'noded' very close together. So, I loaded up 10 rounds at 26.0. Seven of them went into a nice little group not much larger than 1". One was about 1-1/2" to the right of this group and I may well have pulled that shot. However, two of them, were 2-1/2" higher than the group and maybe 2" apart from each other. I KNOW I didn't do that!

I read up on "Lube purge flyers", but I'm not sure that's what was happening. I was using a fairly soft home made lube called Simple Green or Simple Lube from a recipe I found on this sight. It was rather warm yesterday. In the 90's. Maybe, but I'm not sure.

Another theory is that I had two rounds that were a tad harder to chamber than the others. The bullets are sized .314 and are seated out where the first driving band is just being engraved by the start of the lands in the throat. But like I said, on two rounds, I could feel the camming action of the bolt seemed like it was meeting a slight resistance as I closed it. I'm wondering if those two rounds may have had too much land engagement and allowed higher pressure to build, resulting in higher velocity and higher point of impact. Hindsight is 20/20. I wish that I had been taking notes and shooting over the chrony, and looking at each round rather than just going downrange after firing the 10, but I didn't. I'm definitely going to pursue this load some more, though, as I was very pleased with the grouping of the 7 rounds. Especially given it is just a beat up old milsurp with iron sights. Factory ammo sure don't group like that in this rifle.

So, do you guys think my theory is valid, or do you think something else is going on?

[curator]

So, do you guys think my theory is valid, or do you think something else is going on?

Fliers can have many causes. Voids in the boolit--did you weigh-sort them? Lube-purging--sometimes enough is too much. The smallest lube-star is usually best. Powder position? Gas check coming off? Boolit sized off center? Base-first sizing can produce out-of-round boolits. Case neck out of round or too thick/thin? Many bench rest shooters eliminate cases that produce fliers. Cheek placement on the stock, forearm placement on the rest, shoulder pressure on the butt plate, as well as all sorts of operator error. 2 1/2 inch groups with a No.4Mk1 rifle are fantastic using the issue sights. A Parker Hale 5C can tighten them up a bit, but not much.

[nekshot]

many a time I loaded a boolit I did not like and low and behold it left the groub, almost every time. It goes to show how precise we must be if we want consistancy.

[longbow]

I can't say I had fliers but accuracy was not very good with anything but light loads until I oven heat treated.

This applied to both boolits from a home made mould and NOE 316299 with gas check. Both sized to 0.315" to suit my throats (multiple .303") and 0.314" grooves.

Recovered boolits were showing signs of skidding with attendant gas cutting when I used ACWW or range scrap. Since I had slugged the bore and was sizing to 0.315" to suit the throat and 0.314" groove I knew fit good.

Oven heat treating solved the skidding and accuracy improved.

I also took to loading with COW filler and have had very good results since. I find I can shoot loads using ACWW or range scrap that are giving good accuracy now that were not without filler if not heat treated. One day I will do a side by side velocity and accuracy comparison between air cooled alloy/filler vs. oven heat treated with no filler.

Anyway, the point is a harder boolit may help so try water dropping or oven heat treating to see if it improves accuracy for you. Water dropping is easy and oven heat treating in bulk is not difficult.

Longbow

[Scharfschuetze]

I'm wondering if those two rounds may have had too much land engagement and allowed higher pressure to build, resulting in higher velocity and higher point of impact.

Lee Enfields have a reputation of shooting higher velocity rounds lower in the group than slower rounds, at least with jacketed bullets. I've read that this made for some accurate shooting at ranges of 800 yards and further as the trajectories of the various velocity rounds in a string tended to come together and thus make for a smaller group than at closer ranges where the highest and lowest velocity rounds would produce vertical stringing opposite of what we expect with most rifles.

Sounds like you've found a good load though and one we can take note of.

:) As Forest Gump would have said: "Flyers happen." :)

[milrifle]

These were water dropped. I do have some air cooled, but they are only a couple of days old. I am going to try them later on.

[Scharfschuetze]

Last week I had a similar issue with an 1891 Mauser and it was from the first shot through a clean barrel. That's been a common reason for flyers for me over the years. Usually I'm smart enough to fire some fouling shots first, but as you can see, I overlooked that simple solution. I don't know if you plotted your shots or not, but perhaps the flyers from your No 4 were from a clean barrel at the start of your test.

I hadn't pasted over the group from last week so it was easy to get a shot of it. It'll get pasted and shot at again later today.

[PAT303]

My No.4 did the same thing with the same powder but with NOE 316365,lower charges grouped together then spread at 25-26-27grns but came back together at 28grns,my rifle gave a hard bolt lift at 28 so that ended that. Pat