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David R
10-19-2006, 09:07 PM
I was thinking instead of duplexing (pain in the butt) I could take a few cases, enlarge the flash hole and see if it makes the same effect as a duplex load.

I am using a 308 with a 311644 (190 gr) and 46 grains of WC860.

Now I am getting velocity in the mid 1700s. I don't want to go over 2000, because my guns seem to have a self imposed limit. Accuracy goes away over that.

Also, 46 grains of powder, 190 grain boolit @ 1700 fps = Plenty of kick for me.

I don't want to re invent the wheel. I do have a crony and mebee the time.

Right now all I load for the 308 is this load. Its accurate as can be, but the barrel needs to be cleaned often. Last time I cleaned it, it had ben many hundreds of rounds and I couldn't push a dry patch through the barrel. Too much fouling in front of the chamber. It also cruds up the ejector and action.

Thoughts?

David

Ricochet
10-19-2006, 10:00 PM
I seriously doubt enlarging the flash hole will make any noticeable difference in pressure, velocity, or completeness of powder burning.

Feel free to test it and prove me right or wrong. They're your cases.

Bass Ackward
10-20-2006, 07:05 AM
Where I find that it makes the most differences is with stick powders. That is because the increased flame can move farther up the powder column because of the air space in between the kernals. And this will raise pressures considerably.

But for high density balls where the powder fills the case and will stop the progress of the flame because of the increased density, then all you seem to see is better ignition. Then there is the danger that more powder can get down into the hole and actually clog up the flame. So it still might be advisable to duplex as this would prevent this if you kept it under slight compression.

Char-Gar
10-20-2006, 09:22 AM
David.. Go ahead and try it and let us know what you find out. My own (very limited) exerience with enlarged flash holes is I have seen no difference how how things work. There are some reasons to enlarge flash holes in some instances, but I don't think giving a hotter ignition is one of them.

However, I can be wrong, so try it and let us know.

9.3X62AL
10-20-2006, 10:24 AM
David--

No 308/WC-860 experience at all, and a little with #311291 and WC-860 in 30-06. I used WLR non-mag primers, and didn't get a whole lotta trash in the bore, and yielded 2100-2150 FPS extreme spread. Not real accurate (probably due to velocity threshold issues like yours), but consistent velocity-wise.

Have you tried a hotter primer, e.g. Federal 215's? It's not all beer and pretzels, the 215's opened up groups in my Ruger Swede 6.5 with the 215's and a full case of WC-860, gave the same velocity as WLR's (2475-2500 FPS) with Nosler 140 Partitions. Winchester primers supposedly have an aluminum oxide fuel element that is included to enhance performance with ball powders--those (WLR's) might be another route to try.

Larry Gibson
10-20-2006, 01:50 PM
I agree with Back Assward especially with the medium/slow burning powders. Enlarged flash holes are also of good benifit to smaller charges of fast powders especially in large cases. They get the flame out to where the powder is quicker and give better ignition uniformity and less case sensitivity. I stear clear of them with ball powders as Bass says.

Larry Gibson

WBH
10-20-2006, 07:34 PM
The only time I have enlarged the flash-holes is when I shoot my 7.62x39 in sub-sonic with 6.2 gr of RedDot under a 175+ grain bullet seated backwards. Devastating out to 200 yards.

David R
10-20-2006, 09:36 PM
Thanks for the comments. I see your point Bass, I didn't think of that. I posted here before I tried it to see if it was a good idea, or had already been done. I might try it with 5 cases just to answer my curiosity.

I load on a Dillion, and duplexing would be a big slow me down. My loads now will shoot about an inch at 100 and one hole at 50 yards. This is accaptable to me. I will try some magnum primers. My 311284 weighs 218 grains, but doesn't shoot as well as the 190 grain 311644.

Al,
I had the same exp with my '06 and a full case of 860. Too much for me or my rifle. Accuracy was poor, Kick was Big. I was getting around 2200 fps. My enfield likes 13.5 of red dot. So do I.

9.3X62AL
10-20-2006, 10:51 PM
There seems to be/have been a "sweet spot" with a couple 30-06's of mine around 1800 FPS, and if I stray past 2000 FPS things go sour with #311291. The 6.5 x 55 and its fast twist in milsurps (1-8") is a known threshold of about 1600 FPS before things fly apart, maybe the 1-10" with the shorter #311291's in 30-06 (and some 308's) gets squirrelly due to rotation speeds too. I have run this same boolit in the 30-30 well past 1900 FPS in their 1-12" twist, and things stayed pretty consistent accuracy-wise. We're only talking a 3-rifle sample in 30-06 and 2 in 30-30, but there it is. Lotsa variables I could try--alloy, lube, yadda yadda--but I'm happy with the work the rifles do within their limitations. I don't hunt large game with either caliber and castings, so there's not much vigor for me in chasing down higher velocities in these calibers.